The Bulletin – April 1969

Quarterly Journal of The Association for Petroleum Acts Administration

THE ASSOCIATION FOR PETROLEUM ACTS ADMINISTRATION

Chairman: C. T. PEACOCK Vice-Chairman: B. W. C. THACKER

E. V. BEEBY J. BEER J. BIRKS J. W. FRID H. GRIFFITHS D. HALL G. H. HARVEY J. W. HEWISON

Rugby R.D.C. 2071

Worcester City 23156

Chesterfield B. 2825

Cambridge City 58977 Walsall C.B. 25661

Newcastle-under-Lyme B. 60161 Dudley C.B. 55433

Council: Havant and Waterloo U.D.C. 6311 Officers:

Hon. Secretary/Treasurer:

B. HODGSON K. C. HUGHES R. HUNTINGTON T.KERR H. R. MELLOR C. R. PESKETT R. E. J. RODEN J. SHORT

Wigton R.D.C. 2133-5 Stafford B. 3507

Thornbury R.D.C. 2258

Glanford Brigg R.D.C. 2041 Blackpool C.B. 23848

Godalming B. 191-2 Birmingham City 021-23<6 9944 Paisley Burgh 5400

Hon. Editor: L. A. CAVE

R. P. HOLDAWAY

Liaison Officer: G.N.DEAN

Branch Secretaries: ANGLIAN J. W. FRID, CUMBRIA B. HODGSON, EAST MIDLAND J. BIRKS, NORTHERN B. W. C. THACKER, NoRTH WESTERN H. R. MELLOR, ScorrisH J. SHORT, SouTH EASTERN C. R. PESKETT, SouTH EAST MIDLAND R. E. DUST, WESSEX AND SOUTH WALES R. HUNTINGTON, WEST MIDLAND G. H. HARVEY, YORKSHIRE C. T. PEACOCK,

Hon. Electrical Adviser: J. A. SHARP.

Hon. Legal Adviser: P. D. WADSWORTH,

Subscription:

talking point

Post office petrol installations

A Bill currently in committee stage in the House of Commons is expected to change the status of the Post Office from that of a Government Department, to a Public Corporation which will not enjoy Crown exemption.

As a consequence of this changeover which is to take place later this year, petrol installations operated by the Post Office will be bound by the provisions of the Petroleum (Consolidation) Act, 1928.

In some areas staff of the General Post Office Telecommunications Branch have anticipated this event and circulated local authorities seeking advice and guidance regarding existing installations. It is important to all concerned that full co-operation is readily given to the G.P.0. in order that any work necessary to bring an installation up to standard is carried out prior to vesting day. Secretary/Treasurer:

notes and news

New Members

Abingdon RDC Berks. H

Ashbourne RDC Derby s

Belper UDC Derby H

Border RDC Cumberland H

Bury CBC Lanes. F

Caister RDC Lines. s

Chesham UDC Bucks. s

Clitheroe MBC Lanes. s

Clowne RDC Derby S&H

Colwyn Bay MBC Denbigh s

Dronfield UDC Derby H

Eastwood UDC Notts. H

Gainsborough RDC Lines. S&H

Glamorgan cc F

Greenock Burgh Renfrew WM

Halifax CBC Yorks. F

Ilkeston MBC Derby H

Keswick UDC Cumberland S&H

Kirkby-in-Ashfield UDC Notts. H

Letchworth UDC Herts. H

Lakes UDC Westmorland HM

Mangotsfield UDC Glos. s

Mansfield Woodhouse UDC Notts. H

Maryport UDC Cumberland s

Newport CBC Monmouth F

Northallerton UDC Yorks s

San down-Shanklin UDC Isle of Wight H Worsley UDC Lanes. H

Officer

Mr. E. L. F. Welch St. Albans City Herts. WM

Associate Members

Mr.

Mr. G. W. Graham, Construction and Maintenance Supervisor, Shell & B.P. Scotland Ltd.,

Littleborough U.D.C., Clerk of the Council,

States of Jersey Fire Service, Chief Fire Officer, Mr. L. G. Stephen, Architect,

Mr. R. Thompson, Supervisor (Engineer),

Corrections

Mr. R. Gething, Harlow U. D.C., not R. Gethin.

Delete Mr. R. Kirkham (Officer Member) and substitute Congleton R.D.C., Cheshire.

Whitley Bay M.B.C., not U.D.C.

Resignation

Mr. R. Chaplin, G.L.C.

Appointments

Mr. R. N. Allman, Deputy Engineer and Surveyor, Doncaster R.D.C., has been promoted Engineer and Surveyor.

!'Ar. H. Appleyard, Deputy Engineer and Surveyor, Wigton R.D.C. , has been promoted Engineer and Surveyor.

Mr. G. H. Barrett, Chief Building Surveyor, Birmingham, has been appointed to the reconstituted Building Regulations Advisory Committee.

A. Leese, Chief Fire Officer, Coventry, has been appomted Consultant Fire Officer to the Birmingham Region.al Hospital Board. Coventry Public Protection Committee to the appointment, thought to be the first of its kmd. The Hospital Board is overhauling fire. precautions throughout the region in the light of a serious fire at Shelton Mental Hospital last year.

Mr. H. R. Tarrant, Deputy Chief Inspector of Weights and Measures, Bournemouth, has been promoted Chief Inspector.

Mr. N. P. Youldon, Deputy Engineer and Surveyor, Farnham U.D.C. has been promoted Engineer and Surveyor.

Retirements

Mr. J. R. Beasley, Chief Inspector of Weights and Measures, Bournemouth, after 43 years' service with the Council.

Mr. W. T. Gilby, Chief Fire Officer, Wakefield, after 35 years in the Fire Service.

Mr. G. Poole, Engineer and Surveyor, Farnham U . D.C.

Mr. W. E. Rudgley, Engineer and Surveyor, Portsladeby-Sea U .D .C., after 34 years' service with the Council.

Mr. T. Anderson, Equipment Maintenance Supervisor, Shell & B.P. Scotland Ltd. ,

Mr. J. D. D. Bates, Commercial Broker and Manufacturer's Agent, Beck & Co. (Meters) Ltd., Manufacturing Engineers,

Mr. W. W. J Cable, Equipment Maintenance Supervisor , Shell & B.P. Scotland Ltd.,

Cambridgeshire and Isle of Ely C.C., Chief Fire Officer, Co unty Fire Brigade Headquarters,

Cumber land County Fire Brigade, Chief Fire Officer,

Mr. A Diggle , Service Engineer, Pump Maintenance Ltd .,

Mr. J . Dougla s, Co nst ructi o n and Maintenance Supervi so r , Shell & B.P. Scotland Ltd.,

Mr . D. S. Eccles , Cons ultant Engineer,

A. R. Evans, Sales Development Advisor, ShellMex & B.P. Ltd.,

Mr. W. H. D. Summers, Engineer and Surveyor, Wigton R.D.C.

Mr. A. J. Williams, Engineer and Surveyor, Doncaster R.D.C., after 40 years' service with the Council.

We wish these gentlemen a long and enjoyable retirement.

Congratulations

Mr. F. Taylor, Chief Fire Officer, Liverpool, has been .;:i.warded the C.B.E. and Mr. W. T. Gilby, Chief Fire ·Officer, Wakefield, the M.B.E. in the New Year's Honours List.

Obituary

It is with regret that we report the death at the age of 69 years of Mr. Ernest Vaughan, formerly Chief Public Health Inspector and Petroleum Officer of the Solihull C.B.C.

Always keenly interested in Petroleum Administration, Mr. Vaughan was a founder member of the West Midlands Petroleum Acts Administration Group-later to become the Association-and served for a time as a member of the Council. On his retirement he was elected a life member.

Certificates for safe electrical equipment

The Ministry of Technology's testing a:nd certification service for electrical equipment likely to ·be exposed to flammable atmospheres became operational on 6th January, 1969.

This new service, to provide certificates of assurance for equipment to be used in places, other than mines, where flammable atmospheres constitute a hazard, was announced in June, 1967, after the Minister had accepted a proposal from the Confederation of British Industry which led to the formation of the British Approvals Service for Electrical Equipment in Flammable Atmospheres (BASEEFA).

Submissions for new designs of flameproof equipment will be considered from January and submissions for new designs of intrinsically safe equipment will be considered from a date to be announced early in the new year. Certification of other classes of equipment will be undertaken as soon as the necessary certification standards have been approved.

Fa?ilities for te.sting and certification will be built up as qmckly as possible to meet the need of electrical manufacturers for a national service to cover a wide variety of industrial products and instruments.

A programme of research and development on some of the technical problems concerning electrical apparatus in flammable atmospheres has also been arranged by BASEEFA.

Flex Colour Code for the Home

Regulations for the colour coding of electrical flexes are to be introduced by the Home Office on the lst July.

The regulations, making Britain part of a new international code, will mean changes in the colour of flexes in domestic electrical appliances. In future, the "live" wire will be brown (previously red), the "earth" green and yellow (it was green, or green and yellow), and the neutral blue (it had been black).

Nairobi Garage Fire

A £3 OOO Mercedes Benz car was completely destroyed by fire 'at a Nairobi petrol station. Chief. Fire G. M. Muchiri reports that when the fire brigade the car, four petrol pumps, a sun canopy and the entire forecourt were well alight.

But firemen prevented the blaze from reaching nearby underground tanks 7,00.0 gallons of petroleum spirit, motor vehicles m sery1ce pits and a smgle-storey building. They used one lme of foal!1 fr?m a No. 5 mechanical foam generator and a coolmg Jet from two pumps supplied by hydrants.

An attendant said afterwards that a motorist dr<;>ve away while the nozzle was either still in the tank or restmg on the bumper. The hose was torn off and a back-fire or sparks set the petrol alight.

Coventry Fire Brigade-Applicator for use at Spillages

Sub Officer G. T. Butler and Leading Fireman J. Taylor of the City of Coventry have produced a applicator using an 011 sbck dispersmg agent to deal w1 oil spillages.

As more use is made of oil and the of vehicles on the road increases so the likelihood of spillage The main hazards of these spillages are those of fire possibly life, especially where pers<;>ns are trappe m vehicles involved in accidents. Oil trails are road! and motorways increasing the hazard of sk1ddmg to d very high Other hazards include to roa surfaces; smell, and contamination of drams and sew.ers.

During the past year, spillage on the road caused by accidents involving vehicles have lead to the Brigade s attendance at over fifty incidents.

Many Authorities rely on the clearance of ?ils petrols by an application of sand. or by washmg water. These methods are not efficient and many o t e hazards mentioned remain.

Coventry Fire Brigade experimented with various which break down the oils and remove all .1ances designed for the application of hql;ltd were found to be subject to attack by 1.t and to give satisfactory service. Using these ".Vere manually operated, was a slow and 1t o v1ofs that mechanical means must be devised to mcrease t 1e and area of application.

The applicator produced by the Officers is adapted from a two-gallon fire extinguisher and has proved a complete success.

A fifty per cent solution of an oil slick dispersing agent and water is expelled from the applicator by a pressure-fed supply of water from a hose reel. The area of spillage broken up by the fully charged IS approximately 360 square feet in than rm!1utes. For thick oils and deep spillage, this area 1s obv10usly reduced.

With a supply of dispersi.ng agent avapa?le, t.ime taken to re-charge the apph?ator a!l mc1dent 1s over two minutes. The apphcator 1s simple but efficient in operation and was produced at very httle cost to the Brigade.

MODEL CODE

I am in absolute agreement with the views of Mr. Andrews given at the Scottish Branch Meeting during the discussion on the Home Office Model Code, when he stated that it was obligatory for petroleum officers to follow the pro- visions set out in the Petroleum Spirit (Motor Vehicles, etc.) Regulations, 1929.

With this in mind, I would submit that condition 24 (page 22) of the code is contrary to the requirement of the above mentioned regulations in allowing for vessels up to five gallon capacity to be filled from a measuring pump, as it is clearly laid down in the 1929 Regulations that such vessels shall not exceed two gallons capacity.

Swansea F. w. BROWN

A.D.R.

It were better had my letter on A.D.R. in the January, 1969, edition (Vol. 8, No. 1) of the Bulletin not been written. The opinion expressed in it is wholly incorrect.

The maximum exemption quantity for petroleum mixture in the Petroleum Spirit (Conveyance by Road) Regulations 1957 remains the same as for petroleum spirit, namely, 50 gallons in one barrel. The same exemption limit applies to petroleum :rrllxture under the Inflammable Substances (Conveyance by Road) (Labelling) Regulations 1968.

The Petroleum Spirit (Conveyance by Road) Regulations 1958 do no more than increase the permissible size of a container, not being the carrying tank of a tank wagon or tank trailer , from 50 gallons to 90 gallons if the contents are petroleum mixture containing not more than 75 % of petroleum; they do not alter the exemption provisions of the 19 57 Regulations.

I must apologise for any embarrassment that my error has caused to your readers.

Greater London Council W. C. R. DALE

DRILLING FOR LOST PETROL

Reading the alarming report "Drilling for lost petrol" (120,000 gallons of it !) in the last issue of the Bulletin must have set many petroleum officers wondering how so much petrol came to find its way out of the storage depots concerned. In particular, was there any catchment area below the tanks ?

Having had experience of one distributor's thinking on this question in recent years, I am wondering if the "experts" managed to convince the local petroleum officer that an impervious catchment area below the tanks was unnecessary and possibly dangerous. The argument, as far as I recall it, was connected with a possible build up of water, or foam, in the bunded areas below the tanks in the event of a fire, leading to a flood of burning petrol should an affected tank burst.

Could we have something from the erudite and entertaining "OTTO" on this bunding business sometime, please ?

Eastbourne

M. STEVENSON

Saharan Adventure

Invitation

Total Oil Great Britain Ltd. is the British subsidiary of Compagnie Francaise des Petroles (CFP). It was through Total that CFP extended an invitation to two members of the Association to join a party of eight on a visit to the Saharan oil wells of Algeria.

Journey

The expedition to the Sahara began with the member s of the party assembling in the Departure Hall of London' s Heathrow Airport. From there the flight by Boeing 727 to Orly Airport on the outskirts of Paris took only fifty minutes .

After an evening in Paris, the party was joined early the next morning by two ladies from CFP who were to act, most efficiently, as manageress and courier.

The Caravelle from Paris to Hassi Messaoud success fully pliyed leap frog over France , the Mediterranean and Algeria, landing at Marseilles and Constantine on the way. In each case the time spent at an airport exceeded the time spent in flight.

Hassi Messaoud

As the plane began its descent toward s Hassi Messaoud it became possible to see pipelines strung out across the desert. Small pipes from individual production wells merged and later joined larger pipes on the way to the production unit. The untidy stringing of the pipelines marred the effect of the precise geometrical spacing of the production wells.

In Arabic "Hassi" means "well" and "Messaoud" means "lucky" . The lucky well referred to is, in fact, a water well, dried up through disuse. There is now plenty of water through other sources.

Hassi Messaoud scarcely merits the name " town". ln a country such as the U .K. it would be marked only on the largest scale map. The residential area is on the eastern side of the town and here live a few married oilmen with their wives and families. To the west is a factory estate where the plant and paraphernalia necessary for oil drilling operations are stored.

As is customary, the airport is some way from the town. Its single airstrip is bumpy and is used by only a few aircraft each The few single buildings are nondescnpt. The Customs and imrrugration officials occupying the buildings are probably not overworked despite their meticulous attention to detail.

Maison Verte

The final part of the journey to the base ca mp wa s accomplished in a Minibus over metalled roads of sur prising quality.

The difference between the arid desert and the fertile base camp is startling. The camp is well named "Maison Verte". Eight years ago it was as stark as around it but now it runs with water. The ava1lab1hty of water means that lawns, trees and flowers grow in cultured

The creation of this new oasis is changing the climate Wisps of cloud can ?ccasionally be seen above where previously existed only the empty blue s Y· 1 e flaring of huge quantities gas near the camp may a so have assisted in the format10n of cloud.

Birds migrating north and south across th_e have discovered Maison Verte and now break their JOUrndy a few days at the camp. A few appear to have ma e e camp their permanent home.

Every possible taste in sport is catered for the oldest-women are not normally to be fou.n.. m t e P . . of sporting and other fac1hties are camp. rov1s10n . t me the necessary to avoid tedium but th!s no overco tensions that can arise from daily seemg onl) the Id faces Thus visitors to the camp are we come an pa;ty arrives each month, except inhJuly/nd it is too hot, and in December w en eser wm can create sandstorms.

. " ,,

Each a rt eats successive meal s m a different Il'l;e ss ln this :ay :very resident engineer has of talkin to someone new. Thi s is a particu ar y we ' g .t ·r the party speaks Engli sh because English ?pportum Yt.a1l langu age in the oil industry which all the is an essen 1 engineers learn.

. · d . ' d 1 1 ·

On arrival the party was installed m m iv1 ua rnt s " b ,d ' 1'ngenieur" as they are called. Each hut or ea mes · t ·1 t d . b d s ittincr room with en s uite 01 e a n compnses a e 0 · d' · · , d heating I a refrigerator and air con it10rung a n s huts are placed in two rows an arcade canes fixed to scaffoldmg The extend on three sides of a triangle and s ut t th1 t l nds and a formal garden. Bougamv1llea 1s ornamen a po " d " d b · t · (i to re tch the roof of the area e on o ne s1 e emg tra1::ie an '1.n11er sc reen between the hut s and th e so a s o 101m · . Th ' ·

d The Outer screen consists of palm trees. is is gar en. d · · t tl f the fas hionable part of the ca'.11P 1t 1s n o ore · · that 1·t 1's called " Sememe ' after the fashionable surpnsmg ' di stri ct of Pari s.

Two Arab workers outs id e their qu a rter s

Exploration

A few hours after their arrival, the party was given a talk by Mr. Drouhin , the Director of the camp. He told how oil had been found in the desert.

Until oil was discovered in the Sahara, France had traditionally been a nation short of oil production wells. Theoretically, the prospects of finding oil in the Sahara desert were good but the difficulties to be overcome could only be described as formidable. The conditions under which geologists and prospectors would need to live were appalling. If the stakes were high, so were the risks.

To undertake the actual exploration and development of the Sahara oilfields CFP formed a company, Comp agnie Francais des Petroles Algerie (CFPA), in which it held 85 % of the capital. CFPA agreed to carry on the work in association with another company, the Societe Nationale de Recherche et d'Exploration en Algerie (SN REPAL). The exploration concession areas were divided equally between CFPA and SN REPAL and in every way co-operation was the keynote.

Prospecting began in 1953. Thereafter four long wearisome years passed during which vital information accumulated but no oil. Only a few weeks of the original five year exploration licence remained and spirits were low. There was talk of abandoning a "wild cat" at Hassi Messaoud because a hard layer of rock was encountered at about 9,000 feet. However, work continued and at 11,000 feet oil was struck. The actual strike was made close to the boundary separating CFPA's concession from SN REPAL's in the latter's territory.

Water is, of course, vital to an oil production unit and this had first been struck at a depth of some 1,500 feet. This water, however, contained so much salt that effectively it was useless.

At around 9 OOO feet, there was more water which was both fresh and high pressure, not unlike _ the wells beneath London. Maison Verte owes its existence to this water as much as to the oil.

The field is not yet in full production. Currently, production wells are spaced about 4-5 apart. The final arrangement will be to have a spacmg of about 2.5 kilometres.

lt is the intention that the oi l field should be run ultimately wholly by Algerian personnel a_nd progress to this end has been made. There 1s a difficulty, in that Algerian engineers once tra!ned , tend to migrate to the fertile coastal s trip of Algena where hfe ca n be more pleasant and where many lucrative posts await them.

Production

'!'he next morning the party went to view the l?roduction to which all pipeline s from CFPA's port10n of the field lead. The purpo se of the unit is to remove gas and sa lt from the crude before its onward transmission. The process is continuous and only a few above ground " bu.ffer" tanks have been erected to provide some storage aga m st unfore seen eventualities. These tanks are of the typica l fixed roof freely ventilating type in conventional bunds. Fixe d foam inlet s to them are provided for firefighting purposes.

Gas is allowed to flash off from the crude in separators at decreasing pressures. First separation releasing the C 1 and C 2 range of hydrocarbons is at a pressure of about 350 p.s.i.g.; second separation at about 100 p.s.i.g. releases the C 3 range, and final separation occurs at atmospheric pressure to release the C 4 hydrocarbons. As a final precaution to remove the last traces of gas the crude is heated and passed into a stabilization tower (i.e. a simple fractionating column); here gas passes over the top and oil comes from the bottom. Prior to entering the stabi lization unit the crude has passed through an electrostatic desalting unit to reduce its sa lt content and thus on le aving the stabilization tower the crude is ready to start its long journey to the coast.

By separating gas in three stages some of the n a tural pressurization of the crude is retained and a considerab le saving in energy is effected.

Formerly all gas whic h was not used for heating or s imilar purpo ses in the unit was flared off but a further use for some of it has now been found. Part of the waste gas is now press urized to about 5,600 p.s.i.g in ma ss ive three stage compres sors. The gas is then injected into the oil bearing layer via typical well holes, working in reverse. The pressurized gas "squeezes" oil out of the oil be a ring

Crude oil is heated in the furn ace (left) before entering the stab ilization tower (right)

sandstone with the result that the oil recovery rate has been improved from 8 % to 20 %-a substantial achievement for a waste by-product.

The pumping station uses gas from the oil field to drive four large three-phase alternators. The electricity generated provides power not only for the station's pumps but for the whole of Hassi Messaoud and district. Thus the engineer in charge needs to be competent not only in hydraulics but in electrotechnics and mechanical engineering as well.

Drilling

It w.as left to the next morning to make what was perhaps the most interesting visit of all, to a drilling rig. A drilling bit had been replaced and the party arrived just in time to see the last sections of the drilling string being fixed in position before drilling commenced. The great speed at which the drill pipes are joined and lowered depends wholly on team work and the understanding which exists between the men on the derrick floor, the man high above on the top of the derrick and the man controlling the pulley and power drive.

The massi_ve third stage compressors raise the gas to a pressure of 5,600 p.s.1.g

Re-claiming the desert

On leaving the producti.on unit <;me encounters a huge lake where water with oil from the plant collects. The lake is arranged very much like the first of a petroleum interceptor to trap the oil which is burnt off from the top periodically.

clean water flows along a pipe into another depress10n to form a fresh water lake. Around the perimeter of the lake, planting of trees has started. It was alleged that fro15 .had already been seen in the water but the party s opm10n was that this was typical French humour and had some connection with an upturned boat in the lake.

Pumping

Ii:i the afternoon the party was shown over the pumping stat10n. at Haoud el Hamra, which is owned and operated by Soc1ete Petroliere de Gerance (SOPEG). Both CFPA and SN REPAL send oil to this station for pumping the coast. at Bougie some 400 miles away. On its the 011 has to pass over mountains more than 3,000 feet high. Once over the mountains it falls by gravity to the seaport.

The facilities at the pumping station are practically ml; .only sufficien.t "buffer" tanks are provided to possible emergencies. The tanks are similar to those mstalled at the production unit.

Two pumping stations are required to speed the 011 on its way. However, although these stations are manned both are controlled and monitored remotely from th.e pumping station at Haoud el Hamra. A soph1sticat.ed system of alarms is provided ; an alarm even sounds m room if someone happens to enter one of the mtermediate pumping stations.

There is no effective way in which the control room can r.ecognise other than a major leak in a pipeline. The pipeare patrolle.d and leaks are detected visually. It was said Bed?ums have been known to drill a pipeline for oil-m fairness, they have not the equipment to go deeper.

When all the drill pipes had been joined and lowered the "belly" was attached and all was ready for drilling operations to begin again. The weight to bear on the bit and the speed of rotation is determmed by the nature of the layer through which a bit is drilling.

The bit is lubricated by mud which is pumped under pressure down through the hollow centre of the drill pipes. The mud returns to the surface via the gap between the wall of the hole and the wall of the pipe and brings with it the debris produced by the action.of -!"-careful watch is kept on this debris. Inspect10n it md1cates the nature of the layer being drilled at any time.

Anoth e r section of drilling string is fi x ed in position

The mud pressure and consistency are arranged to prevent any water or ?il blowing to the. surface. It would be disastrous for an 011 well to blow. With the tremendous subterranean pressures, the bit and a few miles of drill pipes could be into the air. The chances of the drilling crew surv1vmg such a catastrophe would not be very great.

At the present time in Hassi Messaoud oil field it takes 45 days from start to finish to complete a well down to a depth of approximately 11,000 feet. The pipeline crew then moves into to connect the "christrnas tree" at the top of the well to a pipeline leading to the production unit.

Ouargla

In the afternoon, the party set out for a nearby oasis, so me 400 miles away. But first they had to call in at Ouargla to pick up a guide. The opportunity was taken to have a look at the eye clinic which CFP and CFPA have set up in this "town".

The Arab s suffer terribly with eye tr ou bles \: au se d by san d a nd fli es . Th e c lini c at Ouargl a d es pite ea rly s us picion has achieved such a reputation that people travel hundreds of miles across the de se rt to receive treatment a t it. Sixty men and six ty women are treated each d ay, the men being strictly segregated from the women so as not to offend against the faith of Islam.

The most noticeable feature of Ouargla was its military airport. It was said that anyone taking photographs in the town would see the inside of an Algerian prison. A similar fate was alleged to await anyone parking his car near the airport. Such restrictions in the middle of the desert may seem crazy but they reflect the constant struggle between the Eastern and Western blocs. The four MIG fighters standing on the apron of the airport bore silent witness to this.

Rats

It was dark before the cars carrying the party reached the oasis. In daylight , wild camels had been seen roaming the de se rt but now it was the turn of the nocturnal animals. In the headlights of the cars, an occasional jerboa was seen to bound across the road. These tiny rodents look like miniature kangaroos with their long hind legs and style of progression. These are the desert rats from which the Eighth Anny acquired its nickname.

Ghardaia

On awakening the next morning, one was able to see that there were five towns, each about a mile apart, in the oasis of Ghardaia. The oasis itself comprises a long sinuous valley, which might easily be adapted for use as a reservoir. The towns nestle around hillocks in the valley. At the highest point in each town is the mosque and the tower from which the muezzin summons the faithful to prayer.

The muezzin is now assisted in his task by a microphone and loud hailer and each calls on a different note. Thus a t prayer time the calls from the five towers echo around the valley as if in answer to each other.

The time at Guardaia was spent in sightseeing, admiring the d ates, vegetables, oranges and lemons grow in seemmgl y wild profusion , inspecting an ancient mosque and cemetery, looking over a Bedouin rest camp, takmg tea in the garden of a rich Arab and making a few purchases in the Arab market. Thus the day passed quickly.

The rich Arab had acquired his wealth by providing transport for CFP a nd CFPA. He had used his wealth to provide a perma nent camp where nomadic Bedouin s could rest between their so rtie s into the desert.

Repechage

1':1 the ca r the next day on the long return journey to Mai son Ve r te , the talk was of whether with the water an d energy known to be avai lable beneath it , the desert might o ne day bec ome fertile again The pe ss imist s said "No,

the soil is too salty", but the party had seen Ghardaia and the wonder of Maison Verte. In the comfortable seat of the car, the plans to make the desert bloom again were real enough.

The few remaining hours at Maison Verte passed all too quickly. A barbecue lunch in the garden a djoining t he z;go w· & by h o rs riding and a swim . Oinn 1; r was at eight and th e ae ropl a ne to Algier s was du e at 2.45 a.m. Jn the event the plane was an hour late arriving from the Congo.

Algiers

Lt was still dark when the party arrived at Algier s and it was not until later that the breathtaking beauty of this town and its surroundings could be appreciated.

A formal lunch at a seaside resort on the western fringe of Algiers was followed by a visit to the ill-fated Palais des Nations. These m ag nificent conference buildings were constructed to the design of an Egyptian architect for the meeting of African and Arabian heads of states which ne.ver started because of the Congo troubles. The cost is said to have been ten million pounds but as White Eelephants go it must have been worth every penny . Certainly the stroll down the Casbah which followed was a perfect example of "After the Lord Mayor 's Show "

The party was honoured at dinner that night with the presence of the President of CFPA and the manager in Algeria of CFP together with their wives. All the dinner guests then repaired to a night club to see Arabi a n and Spanish dancing. The respectability of the night club was assured by the presence of the British Ambassador, his wife and daughter.

Departure

same morning, after returning to the hotel from the mght club, the party assembled at Algiers airport ready to board the plane for Paris and London. incident at the airport showed that although s usbetween French and Algerian governments may exist, _ at the personal level respect and trust, if not love, remam. The party was filling in embarkation forms when two Algerians approached the French lady acting as courier to the party. Wordlessly one of them pa sse d hi s embarkation card to her. She promptly filled it in for him from his passport and the answers to a few simple questions. She did the same for his companion .

Both Algerians were illiterate and were travelling to Paris_ where, like the Irish in this country, they would provide labour for the building industry. What impressed one about the incident was the bland assumption by the Algerians that the French woman would understand their need and would help them. The Frenchwoman for her part helped them without the slightest hesitation. One had the feeling that this was as it had always been.

Farewell

The first partings came at Paris when the two Fre nch ladie s, who as managere ss and courier, had contributed so much to the success of the trip, took their le ave . The final moment for adieus arrived when the weary party di s persed at London Airport.

The Petroleum {Inflammable Liquids) Order, 1968

N. WILKINS, A.M.C.T., M.A.I., Mar.E., A.F.lnst. Pet. General Manager of C.M.W. Laboratories Ltd., Blackpool takes a look at this order at the October Meeting, of the North Western Branch

When he was first asked to talk on the nature and use of Inflammable Liquids in the 1968 Order, said Mr. Wilkins, he had readily agreed but that was before he had seen a copy of the Order ! To endeavour, in a short talk to deal with the list of over 200 Scheduled items was impossible task. He therefore proposed to suggest means by which Petr?leum might enforce the Regulations even though, m the m1tial stages, they may not know with which products they were dealing.

wanted things done properly. They did not put the1r products on the road to catch fire and to be washed down the drain by Fire Brigades. They wanted them delivered to their customers so that they would be paid for the goods and make a profit. He felt confident that Industry would be co-operative.

There was one common denominator with all the liquids and substances listed. They all had a flash-point below 73°F. But it should be noted that there were others not in the Schedule, which also had flash-points below 73°F. Perhaps these would be added to the Schedule at a later stage.

meth.od he would suggest would be to find out at which prer;iises the Scheduled products (all basic chemical raw were. manufactured in the local authority area, at which premises any of them were used and also if were used to manufacture other chemical products then have to be conveyed by road. The ramifications of manufacture of all these products was tremendou.s; .there many outlets for nearly all of them: This would have to be obtained by enqu1ry at the various premises as they were visited.

Some premises would use the common name of the product, others the alternative name and some would have trade name of their own which did not appear as such m the Schedule.

In the stages it might be worthwhile to which of the various liquids were produced and used m the greatest tonnages since the laws of chance would that the material which is handled the most was the hkehest to meet with an accident. The Board of Trade,. and pe'.haps Factory Inspectors, might be able to help with this mformation.

One item of large tonnage production used in the manufacture of other products was "Acetone" of which approxi50,000 tons were made by some five producers in this country each year.

Reading extracts from a chemical manufacturer's booklet relative to production of Acetone, Mr. Wilkins gave as some of the suggested uses: textile spmrung cellulose acetate; degreasing, degummmg; surface coatmg compositions such as varnishes lacquers, cellulose finishes and films; the compounding of printing inks; the manufacture of nitro cellulose and of

leather cloth; the purification of crude rubber; th.e e:xtr.action and purification of medicinals such as anti b10t1cs, alkaloids and drugs, and of other natural such as oils fats and waxes· the manufacture of adhesives and cements· the of explosives, cosmetics, insecticides and dyes; dyeing an.d staining; dissolving industrial gases such as acetylene. 1:h1s list could be followed, he went on to say, by a chemical intermediate list which was equally comprehensive.

The thing to do therefore would be to find which manufacturers transpose the acetone into sorr.iethmg else and send it on to a third party. Surface coatmg compositions could be taken as an example. If someone was making paints or inks or lacquers the could be contained in these products. When sendmg them on a third consumer they would therefore have to comply with the Regulations. It would not necessarily follow however, that a company that uses large quantities of acetone would have to comply when their manufactured was conveyed by road. For example, very large quant1t1es of acetone were used to manufacture penicillin but the acetone was lost in the solvent extract10n processes. As a result penicillin would not appear in the Schedule.

The problem of "mixtures" likely to be rather complex and would, in all probability, only be solved by tactful questioning of manufacturers an.d producers. auidance might be obtained from the literature published by the chemical companies who were the producers of many of the Inflammable Liquids in the Schedule. . .

Mr. Wilkins then spoke of Methylated Spmts and Methylated Spirits neither of which under those names in the Schedule because both were mixtures.

Industrial Methylated Spirits (often known as IMS) was ·i mixture of 95 % ethanol (alternative name ethyl. alcohol :_sometimes as "alcohol" and sometimes . as "spirits of wine") together with 5 % methanc;il (alternative name methyl alcohol). Its correct .labellmg therefore would be ethanol (or ethyl alcohol) mixture.

Methylated Spirits was a of0 90 %ethanol (or alternative name) with. % rr:iethanol (or its alternative name) and 0.5 % pyndme which latter was a horrible smelling and tasting compound. Its labelling would also be ethanol (or ethyl alcohol) mixture.

In concluding his talk, Mr. refen:ed to the two liquids which had m Regulations, namely ( an evil-s;mellmg compound") used principally m the rubber mdustry and acetaldehyde ("an extremely lachrymat?ry maten3;1it brings tears to your eyes") used for a vanety .of chemical applications and as a solvent. Both particularly _low flash-points and well deserved the special treatment given to them. Of all the substances listed in the Schedule those two were the ones all must hope would not be involved in an accident.

static

electricity

The danger of incendiary sparking caused by Static Electricity is now recognised by most Fire Prevention Officers, but the reasons for the accumulation of static charges, and the methods of avoiding it are not so well appreciated. In th_is _I have outline !he basic theory of static and md1cate the pnnc1ples on which prevention should be based.

Static Electricity is an electrical phenomena which must obey the usual electrical laws. Three basic laws are all we need to know in order to see how static behaves. These can be found in any elementary text book, and I will not waste too much time on them.

The first one is 'Ohms Law' which states that in any circuit the current is proportional to the applied voltage. The ratio between voltage and current is the Resistance of the circuit. Expressed as an equation this is: R is resistance in ohms

R=V/I Vis voltage in volts I is current in amps.

A quantity of electricity is expressed in Coulombs which equals current times Time (Ix t). Put another way, Q (Quantity) in Coulombs equals AmJ?S Sees. or Amps equals Q/t. This is similar to flow of where is a rate of flow, e.g. gallons per mmute. In work, current is expressed in coulombs per sec and 1s called amps.

Now let us assume that the surface of an object is positively charged. This is the a_s saying it contains more positive than negat.1ve uOits of and this surplus can be measured m coulom?s. UOit of one coulomb is too large for normal use m static,_ and the sub-unit of micro-coulomb is employed (a m1crocoulomb is one millionth of a coulomb). This charge will induce opposite charges on other objects in the vicin_ity, and there will be a voltage between the_ charged object and any other object near it. The rat10 of to voltage is known as the 'Capacity' between the two objects or surfaces. Hence our second formula:

C (Capacity) equals Q (Charge)/V (Voltage)

Units are: C-Farads, Q-Coulombs, V-Volts

The unit of one farad is too large for use in Static and the sub-unit of pico-farad is used. «?ne is one million-millionth farad). Therefore, 1f an object becomes charged, its voltage depends on the amount.of charge and its capacity. Normally we are concerned with the voltage

Contributed by C. L. DAVIDS, L.I. Fire.E.

Senior Petroleum Officer Greater London Council

to earth and, therefore, the capacity to earth assumes major importance.

If such an object is charged by Q Coulombs, and its capacity to earth is C Farads, then its voltage to earth will be V volts equal to Q/C. If the resistance to earth is R ohms, then the 'leakage' current must be V/ R amps. But we have just noted that current equals rate of flow, or coulombs per sec., i.e. Q/t.

Therefore: V/R equals Q/t and V equals Q/C. Hence: Q/CR equals Q/t and Therefore: CR equals t.

CR is called the time constant of the circuit, and when C a!1d R 1;1-re expressed in farads and ohms respectively, t will be m sees. I have cheated a little in the above example, because Q and V do not remain constant during the period of discharge. The correct time of complete disc.har_ge is about three times as long as CR and is exponential m character, but the time CR does give the time for about 62 %discharge, and is an excellent indication of the relative danger of any charge persisting.

Values of capacity normally encountered in practice are of. the order of 500 pfs would be quite hi!?h. 1t 1s a matter of simple anthmetic to deduce that a capacity of 500 pfs with a leakage of as much as 200 megohms would have a time constant of only 1/10 sec. e.g. (500 pfs=500 x 10-12 , 200 megohms=200 x 106 500 x I 0-12 x 200 x 106 =5 x 10-10 x 2 x 108 =10 x 10-2 =0; sec.)

Such a value of resistance is very high but is quite to prevent any static voltage remaining on any object long enough to be a danger, and in fact it would prevent any such voltage from being developed in the first place. Such values raise the whole question of what we mean by conductors and non-conductors, many socalled non-conductors or insulators can have lower resistance values than this under certain conditions.

Conductors and Non-Conductors

Most works on static seem to infer that the effect of an electric field is different when it is applied to conductors and non-conductors. However, they never define the line of demarcation between the two. At first sight the difference is self explanatory, a conductor conducts electricity and a non-conductor docs not. But if we examine this

statement, we must arrive at the conclusion that there are no such things as non-conductors. Everything will conduct some electric current under certain conditions. For example, a vacuum passes current if the applied voltage is high enough or your television tube would not show any picture. Works of Reference list values of for all. and if a material has any resistance below 111fimty it must pass some current, however small. It must be agreed, that within the scope of normal voltages and currents, i.e. say normal mains voltages of 250, and measurable currents of a few milliamps, many materials are as good as non-conductors. This means onl)'. that they do not pass any appreciable current, or that 111 the particular situation the amount of cu:rent can be neglected. For example, if an electric fire us!ng a .of 5 amps has a leakage across the term111als. of l milliamp (one thousandth amp) it would not be noticed. The same leakage across a television tube base would ruin .the picture and probably burn out the high voltage rectifier. So we see that the effect of resistance is relative. The l _milliamp leakage on the fire would be caused by a resistance of 250 kilohms (1 kilohm is one ohms). This same resistance on the 10,000 volt telev1s1on tube would a leakage of 40 milliamps. What neglected 111 the one case, is practically a short circmt 111 the other.

. Static is by very high voltages but very little quantity of electric charge. This means that verv small of current are sufficient to dissipate the charge 111vo_lved. These two facts taken together mean high of resistance can act as a "short : Mater!als a:e classified electrically by their and dielectnc constant. The resistivity is the resistance_ across one metre cube, the absolute dielectric is purely a conversion factor to keep the units and equals approximately 9 x 10-12 , the relative dielectric constant varies from 1 (for air) to about 100. It be proved that, similarly to any capacity, all will react to an electric field in the same manner but will take to do so which is proportional to the product of resistivity, and both dielectric constants. This concept was .first i?-troduced by A. Klinkenberg and J. L. van der Mmne 111 their book "Electrostatics in the Industry", in relation to liquids they called this product the time" of the liquid, but it would_ appear .that it n:levant to solids as a guide to. their effectiveness m d1ss1pat111g any static charges. It will be that one of the terms is 9 x 10-12, and hence once aga111 the value of resistivity for a time of about l/lOth can be very high. Allowing an adequate margm and partly to give us an easy job of remembering, we can retain the figure of about 100 megohms as a safe value.

Where .liquids are one can be confused by the_ .of referring to their conductivity, instead of their (k) is merely the reciprocal of the res1st1Vlty and is expressed in Mhos. The unit of picomho used for liquids with high resistivity or As usual the prefic "pico" denotes one mtlhon m1lhoneth (l0-12). Hence a liquid with a conductivity of one picomho per metre would have a resistivity of 1012 ohms per metre. The suggested "safe" figure (108) mentioned above corresponds to a conductivity of 10,000 picomhos per metre.

Some approximate values of Resistivity and Dielectric Constant are given below: Solids Resistivity

Bakelite 109 Ebonite lQ13 Glass 1011 Rubber 1013 Shellac lQ13 Liquids Acetone 10s Benzene 101s Di-Ethyl Ether lQ13 Ethanol (Pure) 109 M.E.K. 108

Pentane 1016 2 Toluene 1014 2 Xylene 1015 2

It will be noted that the degree of variation of Resistivity is very much greater than that of the Dielectric Constant and therefore the resistivity is much more important when the Time Constant is to be considered.

Static on Solids

If two surfaces are in firm contact, there is migration of electric charge across the points of contact. This results in one surface becoming positively charged and the other negatively charged. While the two are in close contact, this charge produces only a minute voltage-probably about one millivolt. If the surfaces are now separated, the voltage between them starts to rise because the capacity between them decreases (capacity is inversely proportional to the distance between two surfaces). The whole of the surfaces cannot separate 111stantaneously and the rise in voltage will produce a current which will try to restore the unbalance of charge. The quantity of charge which will be will on the resistivity of the surface and the time of separation, because charge equals current times time (Q = Ix t) and current equals voltage divided by resistance (/ = V/ R). While the two surfaces are relatively close to each other, they constitute a capacitor which is capacity is decreasing and hence the voltage 1s 111creas111g. If the voltage rise is high enough, there may be a spark and if our two surfaces are, for example, the roller and coating surface in a coating process using highly flammable liquids, a fire may well be the result.

The amount of charge remaining on the two surfaces after complete separation depends on the time constant of the capacitor so formed and the resistance of the surfaces. If the capacity between the two surfaces is of the order of 250 picofarads, the time constant of the system will be 1/10 sec only if the resistance of the surfaces is 400 megohms. This is the surface resistance which will be affected by moisture, dirt, etc.

Thus it can be appreciated that static will develop on solids only if they have very high resistance. When surare this will be affected by outside contarn111atlon, and m particular by the Relative Humidity at the time. High Relative Humidity will cause moisture to be deposited on the surface, and this will reduce the resistance and hence the time constant.

A report on the danger of static in operating theatres suggests that when the relative humidity is above 50 %, the static danger is minimal. The following table shows the relative values of the conductivity of glass at different values of relative humidity.

Conductivity of glass referred to value at 40 %R.H. Ref. Hum, % 40 50 60 70 80

Conductivity 1 200 7,500 200,000 1,500,000

This shows a marked rise in conductivity (or decrease in resistivity) with rise in relative humidity. This due to moisture deposition on the surface and not to an mcrease in the conductivity of the air space.

The relative humidity in the open air in this country is rarely below 50 %. The records of the daily mean lowest value of relative humidity for the years 1927-58, show that on only 21 days during this period was the relative humidity below 50 %- Of days,. were m the period March to June. However, if air is heated, the relative humidity falls. As a rough gmde, between the temperatures 32°F. and 55°F., an increase in temperature of 20°F. will reduce the relative humidity from 100%.to 50 %. So it follows that in a heated. factory the relative humidity could be below 50 %, especially on a very cold day when the temperature difference inside to open air would be more than 20°F.

If the separating surfaces are part coating the static risk will depend on the res1sttv!ty ,o_f the coatmg solution. For example, 'Rubber Spreadmg is _very prone to static dangers because the comprises in a petroleum solvent, both of have high resistivity. On the other hand, a co.atmg solut10n m an alcohol solvent is less likely to give trouble because alcohols have a lower resistivity. Once the solvent has dried out, of course, it does not affect the issue.

The exact mechanism of this type of charging must be appreciated. The charge has accumulated on the surfaces and the voltage is initially the two Earthing the frame of the machme does not help this at all. However, some of the charge may leak t? the frame of the machine, and the earthmg will allo.w this to go to earth. The important thing to remember is .that earthing does not solve the problei:i, but c.ons1derable risk remains at the pomt of separat10n of surfaces.

Liquids

The generation of static in liquids is due the tion of ions. Ions are charged elements which occur m Polar liquids where oppositely charged elements are attracted to each other and combine form the .m?lecule. These Polar materials are in the mam water soluble), have high constant, and low re.s1st1Vlty. The other main category, 1.e. Non-Polar, has 10ns and is the reverse, not water miscible, low dielectric constant, high resistivity.

Jt would appear from that only. polar liquids could generate static and that this would qmckly leak away due

to the low resistance of the liquid. Unfortunately, this is not the case. Non-polar liquids frequently contain minute traces of polar impurities. These cause the generation of static.which does not leak away because the resistance of the liquid as a whole is high.

Since we are concerned with the fire risk, it might be useful to look at the main classification of solvents used in Industry.

Hydrocarbons (Toluene)

Non-polar, high Resistivity, not water miscible. High static risk, when pumped at high speed. This classification includes motor spirit, and other fuels.

Alcohols (Ethanol or 'Spirit')

Mainly polar. Low Resistivity. Partly miscible with Hydrocarbons.

Ethers (Di-ethyl-ether)

Non-polar.

Esters (Butyl acetate)

More polar than hydrocarbons but less than alcohols.

Ketones (Methyl Ethyl Ketone, Acetone)

More polar than esters but less than alcohols.

When a liquid flows along a pipe line, ions of one sign tend to be adsorbed on the pipe, while those of the other sign are carried along in the liquid. Thus the liquid has more ions of one sign and is charged electrically. The ions on the pipe will flow to earth if a suitable path is provided, if the pipe is not earthed it also will be charged. This separation of charges takes place in all cases where a liquid moves relative to a solid, an immiscible liquid or gas. Electric charging can be detected when petroleum and water are mixed (immiscible liquids), nitrogen bubbled through petroleum (gas and liquid), C0 2 jets can also be charged, leaving an opposite charge on the nozzle with disastrous results in one case. The point to remember is that the charge is in the liquid, earthing pipe lines and containers is essential but this cannot eliminate the charge. The charge will leak away to the container in a time proportional to the Relaxation Time of the liquid, and this time is mainly determined by the resistivity or conductivity of the liquid.

lf you look again at the list of Resistivities for liquids, you will note that the Petroleums have very high values of Resistivity but low values of Dielectric Constant. Other liquids with high values for Dielectric Constant have relatively low values for resistivity. Hence for the value of Relaxation Time we can assume that our liquid will have a Dielectric Constant of 2. If we express the conductivity of the liquid in picomhos, the relaxation time in seconds is given by

R.T. = 9 x D.C./k

(Relaxation Time in sees equals 9 times the relative dielectric constant divided by the conductivity in picomhos).

Thus for a liquid with a Dielectric Constant of 2 and conductivity of I/JO picomho, the relaxation time would be 180 sees or 3 mins. My arbitrary value for safe operation of JOO megohms is equal to 10,000 picomhos and hence would produce a relaxation time of 18 x J0- 4 sees. So you can see that an adequate margin of safety exists.

In their book 'Electrostatics in the Petroleum Industry' Klinkenberg and Van der Mione suggest that for most refinery operations a conductivity of 50 picomhos is sufficient, but that for high speed pumping 500 picomhos is to be preferred.

It will now be appreciated that the danger of static in liquids can be reduced by increasing the conductivity of the liquid. The Hydrocarbons have very low conductivity and are therefore prone to static troubles, but there are others which are not encountered so often (i.e. ethers), that can be equally dangerous.

There is an anti-static additive available which will increase the conductivity of hydrocarbons, very small quantities resulting in adequate increase of conductivity. There are usually technical difficulties in its use in process work such as colour, corrosion, etc. If this is used, it must be realised that it is still essential to earth all pipe lines and containers. The additive allows the charge to "relax" to the container or pipe line. It does not prevent the charge being produced. Hence it is even more necessary to ensure that the containers or pipe lines are earthed. If the additive has been used, and its use is to be discontinued great care must be taken during the initial period of non: use. Trace amounts of additive left in lines, valves, etc., may cause increased charging without the benefit of increased conductivity.

. If a solvent low is. mixed with one having high. c:onducttvity, the mixture will have a higher conductivity, so long as the two solvents are miscible. (Water and Petroleum do not mix, and this combination is very prone to static generation). Opinions differ as to the amount of high conductivity solvent required to increase the conductivity of a hydrocarbon to a safe level. It would however appear from experiments carried out, that about 10 % by volume is required. Paint mixing and thinning should not give rise to any risk from static once the solvents are all blended, but there is a risk during transfer of pure hydrocarbons such as Toluene and Xylene.

Sparking

!he required to produce a spark between two objects m air at normal pressures is about 30,000 volts per centimetre distance between them. This varies somewhat with the shape of the objects as the following table shows:

Sparkover 1•0/tage in Kilovolts

Spacing in Cms. I 2.5 5 lO 20

Two spheres, IOO cm diam. 77 137 266 503

Two spheres, one earthed diam 25 ems. 31 74 137 243 363

Two points 12.7 28 49.5 78 127

It will be noted that the voltage required for the two points is l.ess than half of that for the spheres, and the spheres with the smaller radius tend to have the lower voltage. The reas?n for this is that the charge density is greatest at the pomt of greatest curvature. This in turn causes the greatest electric field strength.

The spark energy required to ignite a flammable vapour is about 2/10 millijoule, which is not very much. The energy of a spark is given by ·i-QV (half times charge

times voltage). We can calculate the minimum charge on an object I millimetre from earth, which will cause ignition. If the voltage is 3,000 volts, the charge need be only 0.14 microcoulombs.

If good conductors are involved, all the charge on the conductor will join in the discharge, but ifthe object is a J;>ad conductor it will take time for all the charge on that object to flow to the point from which the spark is emanating. This time will depend on the Relaxation time, and if it is too long the energy of the spark will be reduced. Therefore it is probably true to say that sparks from bad conductors are not likely to be as dangerous as those from good conductors, but it is not wise to assume that they can never cause ignition.

Prevention

The first and most important step to take is to all good conductors. This will prevent them acqumng a voltage, and will allow any separated charges to flow to earth. The resistance to earth need not be very low, about 100 Megohms is theoretically sufficient but it is to allow a margin of safety to compensate for detenoration during use, and thus 100 Kilohms sh<"!uld not be exceeded when testing. Earthing fixed plant 1s compai:atively simple, but it is not so easy ensure that mobile equipment is always earthed when m use .

Mobile equipment includes funnels, containers, etc. These are usually earthed by using. 'croc<?dile' chps and flexible leads taken to a suitable earthmg pomt. When this system is in use, the wire have adequate mechanical strength. This 1s more 1mp<;>rtant than !I:e resistance in these cases, and by 'mechamcal strength 1s meant the capability of carrying out the tas.k thick a wire may, for example, mean that 1t flexible enough and breaks. Having installed the clil?s and earth leads it is then important to ensure the chp make good electrical contact on the eqmpment. This can be facilitated by using 'D' clamps, but on the other hand they are sometimes more prone to trouble the operator forgets to release them, the wire breaks or the equipment tips over when 1t 1s away. If .the c<?ntainer being earthed (or funnel, etc.) 1s. covered with pamt or other contamination, it may be to get contact. Even a new clip will rarely pierce.a of dned paint. If this is the case, the danger will be because there is now an earthed c?nductor near the and this is in many cases at a po.mt explosive atmosphere is likely. In short, 1f the JOb 1s not. done properly, the risk may be increased. If clips are avai.lable, it must be ensured that they are used an<;i used .m an efficient manner. A special lug could be provided, shielded to prevent contamination, use of should be avoided. It is better to use hoses fo_r chargmg funnels. The hose should have an mte.rnal bondmg wire. Ideally charging vessels should be earned out unc;ter seal. that is have pipes carried down, closed with vents to the open air. Then the atmosphere 111 the vessel would be too rich to ignite. Unfortunately, one rarelr encounters ideal conditions and one has to do the best with what can be obtained. Flexible hoses are preferable to funnels, the hoses can be allowed to dip into the receiving vessel so as nearly to touch the contents. This will minimise free fall, the hose, container, and receiving vessel should be bonded

together and earthed. Stirrers can cause static, in such cases the separation of charge takes place between stirrer and liquid. The charge on the liquid will cause an induced voltage on the container, while this and the stirrer should be earthed it is more important in this case to ensure that the stirrer is bonded to the container so that any voltage difference between the two is eliminated. Naturally, if both are suitably earthed they will have low enough resistance between them to ensure this.

Any unearthed good conductor near a charged liquid will acquire a voltage and may spark to the nearest earthed object. The use of metal dipping tapes while tanks are being filled is very dangerous and should be prohibited. Always ensure that metal floats used as contents gauges are earthed, they normally will be via the metal tape, but it is wise to make sure. Gauze filters can be overlooked; these are often used in paint factories or similar situations. They are portable and are often rested on the filling orifice of a mixing vessel. If, due to paint residues, they do not make electrical contact with the vessel, they can acquire a charge and spark over to the vessel. Lastly, remember that even with all conductors earthed, the charge will persist on the liquid for an interval of time depending on the Relaxation Time of the liquid.

The problem is more difficult when one is dealing with solids, which, because they are bad conductors, cannot be earthed. Coating or similar processes involving a belt of material passing over roller or pulley cannot be earthed. The frame of the machine can be earthed, but this is not dealing with the main risk. The danger is at the point of separation of the surfaces. A coating process can be made safer by using solvents which are more conducting; if cannot be achieved then the installation of earthed pomts near the point of separation may help. The induced voltage on the points tends to ionise the air space and allow the charge to leak away. Conducting tinsel is often used, but this could be replaced by aluminium foil cut like a

Christmas tree (most school children know how this is done). The position of the points needs careful attention because if they are too close to the danger area, they may cause the very sparks you are trying to prevent. The danger from clothing is minimal. Normally natural perspiration will reduce the resistance of any material which is being worn. If any danger is suspected, there is little that can be done except to prohibit wearing of material known to have high resistivity and low moisture absorbcnce. The removal of any such clothing in a danger area would give rise to the highest risk if any exists.

These are a few examples, the general principles are more important, reduce resistivity, earth good conductors.

The investigation of fires alleged to have been caused by static is usually guesswork. However, the least one can do is to see if the conditions were suitable. This can be done by checking the resistance to earth of all good conductors, using a megger. Check the temperature and relative humidity at the time of the fire, using tables to correct for any temperature difference between open air and inside (page 28, 'Averages of Humidity for the British Isles', H.M.S.O., 3/6d.). Check resistivity of any solvents used. Unless this is done, it cannot be said that static is the cause of any fire with any degree of certainty.

Conclusion

It is obviously impossible in one article to cover all the aspects of Static Electricity and its prevention. What I have tried to do is !O show that Static is a normal phenomena capable of bemg treated in a scientific manner and not a version of Black Magic as some would us believe.

_No doubt many other methods of obviating static risks will occur to readers; I have not mentioned the use of radio-active isotopes for ionisation for example.

In Parliament

Legislation for Dangerous Loads

Mr. Peter Archer (Lab., Rowley Regis and Tipton) asked the Home Secretary in the Commons if he would introduce legislation requiring anyone proposing to move explosive or inflammable substances by road to inform the police authorities in advance, with a view to advice on routes and the availability of safety precautions.

The Under-Secretary of State, Home Office, Mr. Merlyn Rees, replied that existing controls over the conveyance by road of explosives and inflammable substances were designed to ensure that the load was safely-packed for carriage under normal road and traffic conditions. He doubted that Mr. Archer's suggestion would be practicable, but he would arrange for it to be considered by the Standing Advisory Committee on Dangerous Substances.

Mr. Archer said there had been some disturbing near-misses. Would the Under-Secretary assure them that they would not have to wait for a major tragedy before those who undertook hazardous operations were reminded of their responsibilities.

Mr. Rees replied that there were great problems there, he discovered when he looked into the matter. He preferred to obtain advice from experts on such a question, and he would look at their advice.

Branch Reports

North Western

The Autumn Meeting of the Branch was held at the Town Hall, Manchester, on 16th October, 1968.

Present

The Branch Chairman, Mr. J. R. Roberts, Manchester, 66 Members, 2 Associate Members and 3 Visitors. 12 apologies for absence were received.

Official Welcome

An official welcome was extended by Councillor A. Williamson, M.B.E., Chairman of Manchester Licensing and Fire Brigade Committee.

Opening the meeting the Chairman expressed the appreciation of the members on the attendance of Mr. C. T. Peacock, Chairman of the Association; Mr. R. P. Holdaway, Editor of the Bulletin, and Mr. D. Hall, Chairman of the Association's Constitution and Rules Committee.

Minutes and Reports

Proceeding to business the meeting approved the circulated of the Annual General Meeting held on IOth Apnl, 1968, and a report of the Branch Executive Committee Meeting. The Branch Representative then gave a verbal report on the Association Council Meeting which he had attended the previous day. Amongst items giving rise to special interest to members was the news that there were to be two courses to be held at Attingham Park in 1969 and that at least two further courses, one to be organised by the Branches in the North and the other by the Branches in the South, were to be held in 1970. From the ensuing discussion in which both Mr. Peacock and Mr. Holdaway joined it seemed evident that the 1969 courses would be well over-subscribed.

Membership

The Secretary reported that 51 Local Authorities in the Branch area were already members of the Association and that a further 12 had notified him of their intention to join. One Associate Member was also in process of taking up membership. Membership of the Branch now totals 79 and there seemed little doubt that this figure would increase.

Branch Rules

Proposed Branch Rules, prepared and moved on behalf of the Branch Executive Committee were submitted to the meeting. Rule 4 provided that "where within the Branch area any Local or Harbour Authority, or any Petroleum Officer of such Authority, is an Ordinary Member of the Association, any other officer of such Authority employed in the administration of the Petroleum Acts shall be eligible for Ordinary membership of the Branch".

An amendment moved on behalf of the Chief Fire Officer of Wallasey sought to remove the right of the individual officer to be a member of the Branch and to substitute the local authority as the Branch member.

After discussion and vote the amendment was declared lost. The Branch Rules were then adopted to come into operation on the date they are approved by the Council of the Association.

Branch Banking Account

The Hon. Secretary and Treasurer requested and received authority to open and operate a banking account in the name of the Branch. This concluded the formal business of the meeting.

Revised Home Office Model Code

The Branch Chairman introduced a discussion on the Model Code, drawing the attention of the meeting to the principal points of variation between the old and the new Codes. Amongst questions raised and sometimes answered by both the platform and the floor were the following:

Can Stores

In view of the recommended height of 6ins. for the sill in all new can stores, what yardstick should be adopted for the licensed capacity of such stores in the future ?

Filling Stations

2.1.6(a). This form of installation did not seem very satisfactory, particularly as Figure 2 did not seem to provide any protection against subsidence and consequent fracture of the lines. Further guidance was necessary on this matter. Figures 2 and 4. In both sets of drawings the manhole walls were shown to be directly on the shell of the tank. This was most unsatisfactory. Who had prepared the drawings and were they approved by the Working Party before inclusion?

2. I.6(b). Tanks usually arrived on the site ready painted. What guarantee was there that they had been tested by the manufacturer ? The Code did not go far enough. It should have required the tanks to comply with, and be tested to, the appropriate B.S.S.

2.1.9(b). A hydrostatic pressure test was applied by sealing all holes but one, filling with water, fitting a pressure gauge on the filling pipe and applying a pressure with a pump. Not being intended as pressure vessels the pressure was specified at the low figure of 10 p.s.i.g. The advantage with the water test was that if the tank failed there would not be an explosion.

2. I.15. "Compartmented tanks should not be used for storing both petroleum spirits and domestic burning oils". Would it be equally objectionable to substitute diesel oil for a domestic burning oil ?

Licence Condition No. 11. Who would constitute a "competent person" to inspect electrical installations'!

Introduction, Page 3, Para. 3. The question of the application of certain of these revised Code recommendations to existing installations would present many problems and, in the interests of uniformity, more general guidance was necessary. The Chairman of the Association reminded the meeting that the Association Technical Committee were now examining the Code in detail with the intention of submitting proposals which it was hoped

all authorities would adopt. He trusted that members would await the Council's report on this matter before advising their local authorities.

Summing up the discussion, Mr. Roberts said that it seemed clear that the last word had not yet been said on the subject of the Model Code. In time we might even have Regulations with a national application.

The Inflammable Liquids Order

The Chairman then called on Mr. N. Wilkins, who was an industrial chemist and the General Manager of C. M. W. Laboratories Ltd., Blackpool, who had kindly consented to address the meeting on the Inflammable Liquids Order. Reported on page 33.

The Inflammable Liquids Regulations

The Branch Hon. Secretary introduced a discussion on the four Statutory Instruments 1968, Nos. 570, 571, 927 and 928, outlining the new requirements and their appliin respect of the conveyance by road of carbon disulphide, petroleum spirit and mixtures of petroleum. In the course of his remarks he drew the attention of the meeting to the necessity for officers delegated to act under the Regulations to ensure that they had been appointed "duly authorised officers" by their respective local authorities.

In the short time available for discussion the function of the "suitable and efficient fire extinguisher" required to be carried was queried. Was this intended to deal with fire in the driving cab or engine or, alternatively, a fire m the load ? Since the size and type of extinguishers could only be determined when the fire hazard for which they were provided was known, the answer to this question was urgently required. Attention was drawn to the statement

Fire Circular No. 33/168 that guidance for Fire Authorities on dealing with fires or spillages involving the substances would be circulated in due course.

In answer to the question as to who would be responsible for the labelling of receptacles and containers which were on the road by Hire Firms, it was suggested that, smce the Regulations were made under Section 6 of the 1928 Act, and Section 6(2) provided that "If any contravene or attempts to contravene any regulat10n made under this section, he shall be liable, etc.", an offence _in respect of incorrect conveyance by road might comitted by several persons in the chain of responsibility from the Consignor to the driver of the vehicle.

Votes of thanks were accorded to Mr. N. Wilkins for his paper on Inflammable Liquids, to the Branch Officers for leading the discussions and to Manchester Licensing and Fire Brigade Committee for the facilities and hospitality provided.

On the conclusion of the meeting, members were entertained to tea by Manchester City Council.

South Eastern

A Meeting of the Branch was held at the Court Room, Bridge Street, Godalming, on Wednesday, 4th December, 1968.

Present

Mr. F. A. Smith in the Chair and 88 members.

11 apologies were received.

The Chairman introduced Mr. G. E. Molyneux, Divisional Manager, Southern Division, Pump Maintenance Ltd. Mr. Molyneux gave a short introductory talk to a film entitled:

SERVICE TO INDUSTRY

presented on behalf of the company. The film explained the working methods, procedures and services provided by Pump Maintenance Ltd.

In reply to questions posed by members, Mr. Molyneux stated that in addition to service and emergency calls during the normal working hours of a five day week the company dealt with emergency calls at any time of the day or night. The company could cope with calls to arrange and carry out tests of old underground petrol storage tanks. Private individuals could now obtain the services of the company without referring to an oil company as hitherto.

The Chairman expressed on behalf of all those present thanks to Mr. Molyneux, his colleagues and his company for arranging this part of the afternoon's programme.

Minutes

The Minutes of the last meeting of the Branch, held on 2nd October, 1968, at Godalming, were circulated, confirmed and signed as a correct record.

Matters Arising Association Codes and Recommendations

The Secretary reported that the revision of the Association's Codes and Recommendations were in hand and it hoped that they would be ready for publication early m the New Year.

The Chairman introduced Mr. K. Sherwood, Engineer, Petroleum Co. Ltd., to the meeting, referring to his wide and experience of the petroleum industry and his close liaison with this branch, the Association and also his instructive and informative papers regularly presented at the Association's Residential School at Attingham Park.

THE INSTALLATION OF PLASTIC UNDERGROUND STORAGE TANKS

Mr. Sherwood outlined the history and economical resulting in the manufacture, and installation (with the full co-operation of the G.L.C.) of the first fibre-glass re-inforced polyester tank in this country.

. The .fact that the tank failed in a comparatively short time did not mean that the experiment had not been a success; moreover, the whole experiment had been conducted without any risk or danger whatever to the public. It provided considerable knowledge and experience of the problems to be faced and overcome in this field.

The high cost of installing steel tanks in concrete meant that research and experiments in the manufacture of G.R.P. tanks would continue in the belief that a satisfactory method of manufacture and installation would be found which could have great economic significance.

In replying to a number of questions posed by members, Mr. Sherwood referred to the fact that the thermoplastics industry had not been able to offer tanks suitable for gasolines; specific economies might be possible by the use of G.R.P. tanks. The average life of steel tanks installed in concrete in this country was at least twenty years. It would be a fair question to ask what was the purpose of the exercise. Not unnaturally the oil company was interested greatly, if not primarily, in the economics of the installation. The tank maker was concerned to prove fibreglass tanks and sell his products. But local authorities have an interest too ! At present steel tanks are required to be installed in a specified (often varying) manner. The tanks are then licensed until they leak. How much better and safer it would be if new tanks of proven performance were permitted to be used only for the period, whether 20, 30 or more years, during which it was known with reasonable certainty that they would not leak.

The Chairman, in proposing a vote of thanks on behalf of all those present (a record number of 88), said how much all members had enjoyed and appreciated both Mr. Sherwood's talk and the following session of questions and answers.

Future Programme

The Secretary stated that he was endeavouring to arrange a visit to the West London Air Terminal and a branch meeting would be held early in the New Year with a speaker on Electrical Requirements associated with Petrol Service Installations.

West Midland

A Meeting of the Branch was held at the Council House, Halesowen, on Wednesday, l Ith December, 1968.

Present

Mr. R. E. J. Roden, Birmingham, in the Chair, and 40 Members. 10 apologies were received.

The Meeting was welcomed by His Worshipful the Mayor ofHalesowen, Alderman K. W. Johnson, J.P., who spoke of the useful work performed by the Association. The Mayor was thanked on behalf of the Branch by the Chairman.

The Mayor retired and the Meeting proceeded.

The Chairman paid a tribute to the late Mr. R. L. Bloor, Kidderminster, who had given invaluable service to the Association.

He then welcomed Mr. T. J. Metcalfe, Life Member, now retired from Warley, who replied by saying how useful the Association had been to him.

Minutes

The Minutes of the Branch Meeting held at Shrewsbury on Wednesday, l 7th January, 1968, having been previously circulated, were approved and signed as a correct record.

Arising out of the Minutes, the Secretary reported on the probable cost of a Chain of Office for the Branch Chairman. After some discussion on this item, Mr. D. Hall proposed that the Secretary refer the matter to the

National Council with a view to obtaining their views on having a Chain of Office for the National Chairman. This was seconded by Mr. R. P. Holdaway and carried.

The Secretary then introduced the question of using some of the balance of funds to provide equipment or a library for Branch use. Mr. Hall said that he was against both, but suggested sending a younger member to the Attingham school. Mr. E. V. Beeby spoke against provision of equipment. Mr. Roden suggested an illumination meter. It was decided to leave the matter until the Annual General Meeting.

Two applications for Membership of the Branch were approved.

The Business Meeting then closed at 2.30 p.m.

Electrical Provisions of the Revised Home Office Model Code

The Chairman introduced Mr. J. A. Sharp, Senior Assistant Engineer (Commercial), Midlands Electricity Board.

Mr. Sharp opened by saying that time would allow him to discuss only the provisions of Part I. The new Code was, unlike its predecessor, available to everyone and not only to Local Authorities. Interpretations could vary. The Code now defined "Danger Areas" and included distances. "Danger Areas" were defined in Divisions.

Annual Electrical inspections should be by some competent person acceptable to the Local Authorities and they put more onus on the Petroleum Officer. Suitable persons would include those set out on the Association's Recommended Electrical Report Form.

On the question of lighting levels, the standard laid down of 1 lumen per square foot for after dark deliveries was low, most stations have this, some stations have 30 to 40 l.p.s.f. "Adequate lighting" varies between persons.

The existing Association Codes were now out of date and were being revised as quickly as possible. The Basement Garages Code had not been altered.

Mr. Sharp then went systematically through the electrical requirements of the Model Code, Part I.

Pump manufacturers could be relied on to provide Group 2 FLP fittings.

For Division 2 areas it was usual for the users to define "Division 2 Areas", but in the case of petroleum installations the Home Office has now defined the areas. The pump itself and the manhole are Division l areas.

FLP Groups I, 2 and 3 fittings arc certified by the Ministry of Power.

Division 2 fittings are certified by the Factory Inspector and may be marked. If not marked as "Division 2" the manufacturer will identify such fittings. It may be preferable to put the onus on to the person who installed the fitting; ask for a letter from the manufacturer certifying that it is a Division 2 fitting.

Division 2 equipment is essentially non-sparking. A switch is not normally non-sparking and should be FLP or outside Division 2 areas, although a mercury switch is non-sparking and is suitable for Division 2 areas.

Division 2 fittings must be non-sparking in normal operation, have no excessive temperature or "hot-spot" and the enclosure should be robust and durable at all times. '

This division into types of area is good progress.

Mr. Sharp then demonstrated various types of FLP Group 2 and also Division 2 fittings (Certified by Factory Inspector).

A Division 2 fluorescent tube demonstrated was totally enclosed, did not spark, had no hot-spots (20°C), and had ends sealed with plastic; in case of failure it was better and less trouble to replace than attempt to repair.

Section 1

l.3 Electrical apparatus should be excluded from Division 0 areas or should be intrinsically safe, pressurised, etc.

l.3.1 For Division 2 areas it is permissible to use welded conduit.

l.3.5 Electrical equipment with a metal case should always be earthed. You must put faith in a competent electrician's certificate for the earth resistance.

Earth Resistance in ohms. v 0=A

l.3.7 A big change from- the old Code. Switches controlling lighting circuits should be double-poled for safe changing of lamps. Normally switches are single-pole, with N to light and L to switch. Now N and L must go to switch.

l.3.8 Portable hand lamps-no change.

Conditions of Licence

No. 10 The distance of 8 feet may be increased by the Local Authority in certain circumstances.

No. 13 Provides for Annual Inspection, etc.

Section 2

2.l.13 Within 5 feet radius of the vent discharge point in Division 1.

2.2.3 Note that lighting fittings installed within Division 2 areas up to 9 inches above ground should be of Division 1 standards. The electrical connection made by the contractor inside the pump should be Division 1 standard.

2.2.6 Large Pits-Division 2 but within 9 inches of floor must be Division 1 electrical equipment. Small Pits in maintenance bays or in Division 2 areas must be Division 1 electrical equipment.

2.3.7 Master Switch. There is a difficulty of interpretation here, with the words "inaccessible but readily visible".

2.3.8 Supply Circuits-there must be separate circuits for the lighting and the motor.

2.3.9 There must be an individual isolating switch.

2.5.1 Note one switch for isolation.

2.5.3 10 lumens per square foot is no worry on most stations. It is not necessary to economise.

2.5.4 A public address system should be installed properly-it can spark if not done correctly. See also C.P.1003 Part 3. Above 4 feet there would be not much need to worry. Below 4 feet it needs care.

2.6.2 An additional point. Emergency shut-off button for the whole lot to be made "dead". Cannot be put on again until the occupier or his agent arrives. There must not be a second re-energising button. The Master Switch is inaccessible to the public (see earlier).

2.6.3 Does this clause mean that a telephone must be installed?

2.7.3 Oil-filled radiators with FLP thermostats would be in order.

Conditions of Licence

These have been covered in previous remarks. Under No. 11 new Electrical Certificates are being drafted.

Questions . ..

R. E. J. Roden. Is the whole of the kiosk a Division 2 area and what is the position concerning electrical cash registers?

Clarification is needed with the Home Office for above 4feet. No cash register is completely non-sparking, switches can give very small sparks and under suitable conditions would spark. A telephone is sparking apparatus. The kiosk code is being revised.

G. Balshaw

(1) What is the definition of darkness?

(2) Are submersible pumps excluded from Division 0 areas?

(3) Is there a portable FLP lamp ?

(1) Probably when less than 1 lumen per square foot.

(2) Clause does not exclude submersible pumps because the Model Code states, where possible electrical equipment be excluded from Division 0 areas. Pumps could be pressurised.

(3) There is a FLP hand torch. It is stamped FLP and has a non-ferrous case and is robust. The attendant should not use an ordinary torch for night-dipping.

In reply to a question on Division 2 fluorescent fittings, Mr. Sharp said that this particular one had a plastic sheath inside and would have to go to manufacturer for repair. It could not easily be dismantled by ordinary electrician.

T. Meredith. The lighting level is too low. Can the Association approach the Home Office ?

The Home Office would probably overrule the Association.

D. Hall. Would circuit breakers be preferable to fuses?

Most use circuit breakers which give better protection. It is a question of economics.

H. H. Smith (E.C.A.). Circuit breakers are usually single pole. It would necessitate using a splitter switch. The standard circuit breaker may not be usable as an isolating switch. This was now precluded. It may need a 4 pole switch.

Mr. Smith also rasied the question of the fluorescent tubes inside the top of the pump housing which were not always Division 1 standard.

Under 2.2.4 there should be a complete break at the top of the pump between Division 1 and Division 2.

A. A. Wheatcroft. The plastic canopy had a glanded connection with normal fittings. The dial illumination shines through armour-plated glass.

E. V. Beeby raised the question of existing stations. Certificates needed every 12 months. Even a new station should not be excluded from the regular certificate.

In reply to a question as to whether a three-yearly certification would be adequate for a station unless alterations took place, Mr. Sharp said that this would depend on the fashion of code adopted. He agreed that a lot of certificates would be needed and a lot of work.

K. C. Hughes queried how to deal with existing stations, with particular reference to cash registers and the new requirement of double-pole switches.

Regard should be paid to the third paragraph of page 3 of the Revised Model Code.

W. A. Hamlett (E.C.A.). The point was made that the Midlands Electricity Board sometimes allowed an earth resistance of2 ohms on their own supply, so how could one get down to I. 7 ohms ? In some rural areas one could not get a satisfactory earth.

This l\'as a valid point and ll'ould be taken up ll'ith the Home Office. Earthing was very problematic. It ll'as menmentioned in the Code of Practice but not in the Model Code. Where the M.E.B. provides earthing facilities this would be by agreement. The point ll"as that with moving ground the sheath of a cable could break and there would be no earth protection (in certain areas).

One could provide earth-leakage circuit-breakers (currentoperated or voltage-drop) and an approach ll'ould be made to the Home Office concerning this. Earth-leakage circuitbreakers should be accepted. The Petroleum Officer must rely on the Electrician's Certificate.

L. W. Manship (E.C.A.). There were differing requirements among Local Authorities on the form of Electrical Certificate and this sometimes created difficulties in the signing.

Jn reply to the question as to whether earth wires must always be bare wire, 2.3.6, or could they be sheathed, Mr. Sharp replied that this would be looked at.

R. E. J. Roden enquired regarding car vacuum cleaners on multi-storey car parks, although this was not much of a problem with a lot of ventilation.

There are a/ll'ays sparks from the car itself----the starter, for example.

* * *

Mr. E. V. Beeby, in proposing a vote of thanks to Mr. Sharp for "helping us to see the light", spoke of the very great help he had given to the Association over the years, not only at meetings but also at Council and at the Attingham School.

This was seconded and approved in the usual manner.

After the Meeting refreshments were kindly provided by invitation of His Worshipful the Mayor of Halesowen, Alderman K. W. Johnson, J.P.

The Annual General Meeting of the West Midland Branch was held at The Town Hall, Burton-upon-Trent, on Wednesday, 26th February, 1969, at 11 a.m.

The Meeting was welcomed by the Mayoress of Burtonupon-Trent, Mrs. J. Fidler, M.A., on behalf of the Mayor, who had another engagement. She spoke of the valuable work of the Association.

Mr. R. E. J. Roden expressed the thanks of the Branch for her welcome.

The Mayoress retired and the Meeting proceeded.

Present

46 Members.

Apologies for Absence

21 apologies were received.

Minutes

The Minutes of the Branch Meeting at Halesowen on Wednesday, I Ith December, 1968, having been previously circulated, were approved and signed as a correct record.

Report of Secretary/Treasurer

The Secretary presented his an<l; Balance Sheet. This was approved. The quest10n <;>f of Office was held in abeyance pending a Council dec1s1on.

Election of Officers and Committee

The following were elected: Chairman: J. Easton, Burton-upon-Trent Vice-Chairman: T. H. Keith, Cannock U.D.C. Committee: G. Balshaw, Shrewsbury K. C. Hughes, Stafford R. E. J. Roden, Birmingham Hon. Secretary/Treasurer: G. H. Dudley (also Branch Representative) Hon. Auditor: T. J. Metcalfe

Votes of thanks to Mr. R. E. J. Roden, retiring Chairman, and to the Secretary were approved.

Petroleum School at Attingham

Mr. R. P. Holdaway, Shrewsbury, in introducing this question, and future position. Following a Council dec1s10n to mtroduce a Northern School and a Southern School (West Midlands being in the Northern Area) to be organised by the Branches in those areas, it appeared that the Northern area may be selecting some venue other than Attingham. He emphasised the good relations the Association had enjoyed with Attingham for seven years and said bookings had to be made twelve months ahead. It would be difficult to get back if once we stopped going there. Mr. Cave had, in fact, booked Attingham for one period in May, 1970, as a matter of urgency, and Mr. Holdaway suggested that the West Midland Branch hold its own School there. An Area

Meeting was being held on the 5th March, 1969, for Branch Chairmen and Secretaries to discuss the School question.

Mr. J. Beer said this was a delicate matter. There was the question of could we run three Schools as an Association, including this third School at Attingham. There would also be the attitude of the Council to consider concerning a third School. The two Area Schools would be supported by the National Association, but this third School would be entirely a Branch matter.

Mr. Holdaway said that the Report as yet was at the Education Committee level. He was satisfied that the Northern Area could fill two Schools without the support of members of the West Midland Branch.

Mr. D. Hall said that there was nothing in the Rules preventing a Branch carrying on its own activities. They should inform the Council as a matter of courtesy. A number of Midland s members bad been unable to obtain places , justifiably, in the last four year s .

Mr. T. H Keith: A lot of larger Authorities would jump at the c hance to send two or three members.

Co n s id e rable further di scu ssion took place and it was agreed that the m a tter be rai sed at the Northern Area Sc h oo l Meeting and at the National Council. A vote t a k e n at the Meeting showed that strong support could be e xp ec ted fo r a Midla nd s Sch o ol at Attingham.

Messrs. Keith and Holdaway were elected to represent the Branch at the Northern Area Meeting, the Chairman and Secretary being unable to attend.

The Meeting then adjourned for lunch.

Panel

In the afternoon a Panel was formed for answering questions on the Home Office Revised Model Code The Panel consisted of Messrs. J. Beer, H. Griffiths, D. Hall and J. A. Sharp.

Mr. Beer opened the discussion with a summary of the events to date Various points had been agreed with Committee A of the Institute of Petroleum, and it was hoped to bring out revised Association Recommendations before the Annual General Meeting. He said we could not argue with the Model Code, there was a question of Appeal to the Home Office, all we could do was fill in the gaps and explanations.

Mr. J. T. G. Craddock, Rugeley U.D.C.: ls the Association recommending concrete or vault, and who would do the certification of suitable soil conditions.

Mr . Hall: There would be Council Recommendations subject to local variations.

Mr . Beer: Fine concrete was recommended. A soil engineer or analy st would certify the condition of the soil.

Pho t ograph by courtesy of the "Burton Daily Mail"

Cathodic protection is not always possible because of adjoining pipes. Take care to isolate tanks from the electrics of the installation.

In response to a query about water-logged conditions it was considered that this was not of necessity so detrimental. Some tanks stood these conditions for thirty years. Mass concrete and "strapping" was a solution.

Mr. J. A. Sharp: In a kiosk within a Division 2 area the area above 4 feet could in favourable be regarded as a safe area. Anything in the kiosk below 4 feet should be connected directly to the electricity supply and not through a socket outlet.

Further discussion took place on safety distances for Stores, revealing some divergence of opinions. If a Local Authority differed from the Model Code it should be in a position to produce reasons on Appeal. Association Recommendations should not be accepted ad lib. They could be varied locally.

Mr. R. Churchill, Solihull, referred to an occasion when a car pulled over a pump fitted with a latched nozzle.

The electrical surge missed the contact breakers and cut-off at the M.E.B. board.

Mr. Sharp: It could be a faulty contact breaker, or an aged M.E.B. fuse, or the power load up to capacity. It was being investigated. A good contact breaker cut-off is about 10 milliseconds.

On earthing-Recommendations would include earthleakage circuit breakers.

Earth rods were not. always good. It was not permissible to connect to water pipes.

Mr. N. G. Perry, Staffs C.C. Fire Brigade, read a letter from his Chief Fire Officer raising many queries about unattended self-service filling stations.

A long and informative discussion took place with many points of view being expressed.

In the final analysis it was for each responsible Petroleum Officer to make up his mind on his recommendations to his Local Authority. Location, surroundings and facilities were all important factors.

The Meeting closed with a vote of thanks to the Panel proposed by Mr. E. V. Beeby.

After the Meeting, refreshments were served and Mr. K. C. Hughes expressed the thanks of the Branch to the Corporation of Burton-upon-Trent and to Messrs. Easton and Faulkner for their hospitality and for the refreshments both before and after the Meeting.

The meeting was opened by Mr. H. Appleyard, Engineer and Surveyor of Wigton R.D.C. He welcomed all present and thanked Mr. Peacock for braving the elements to attend. Mr. Appleyard went on to say that owing to the position of Cumberland and Westmorland it would be a good idea to form a branch of the Association in that area. To cross the Pennines to attend meetings of the Northern branch at this time of year was often impossible because of the poor road conditions. He concluded by wishing the meeting success and invited Mr. Peacock to take the chair.

Mr. Peacock kindly accepted the chair until a branch chairman could be installed.

The Chairman then stated that he was pleased to attend this meeting and that it was one of the aims of the Association to promote the formation of new branches. He felt that a close association of local authorities could bring nothing but good to the administration of the Petroleum Acts. Furthermore, he felt that before long the Minister would have to consider bringing the Petroleum Acts more into line with the Building Regulations, which are now nation-wide, with minimum requirements laid down by law and not at the discretion of the local authorities. The Ministry had gone part of the way with this in so far as the introduction of the new Model Codes were concerned. Most authorities were now becoming more aware of the dangers that could be caused by petroleum installations which do not meet the safe standards required by these Codes.

Branch Formation

At the conclusion of his remarks the Chairman called for a vote to be taken in respect of forming a Branch. It was unanimously agreed that a new branch be formed to be named Cumbria. It was further agreed that the question of boundaries be "'.ith the Council of the Association, but that m the mam the area to be covered should be Cumberland and Westmorland.

Election of Officers

Chairman: F. J. Lorrigan, Carlisle C.B.C. Vice-Chairman: R. V. Bewsher, Whitehaven M.B.C. Secretary/Treasurer: B. Hodgson, Wigton R.D.C. (also Branch Representative)

Auditor: P. Wilson, Border R.D.C.

Committee: W. F. Barnes, Maryport U.D.C. W. A. Clarkson, Cockermouth R.D.C. W. J. Patten, Carlisle C.B.C. J. Sewell, Carlisle C.B.C. W. R. Simpson, Cockermouth U.D.C. T. E. Thwaites, Keswick U.D.C.

Cumbria

An inaugural meeting of petroleum officers in Cumberland and Westmorland was held at the Wigton Rural District Council Offices on the 19th February, 1969.

Present

The Chairman of the Association, Mr. C. T. Peacock, together with 11 petroleum officers. Two apologies were received.

Branch Rules

Mr. Lorrigan in the Chair. lt was agreed that the Association Branch Constitution and Rules be accepted, together with minor amendments, subject to confirmation from the Council of the Association.

The meeting closed with a vote of thanks to Mr. Peacock for his attendance, to Messrs. Appleyard and Hodgson for the arrangements made and to the Wigton R.D.C. for providing accommodation.

COUNCIL AT BIRMINGHAM

Report from a meeting held on Bth .January, 1969

Present

C.T. Peacock, Esq. (Chairman), with Messrs. E.V.Beeby, J. Beer, J. Birks, J. W. Frid, H. Griffiths, G. H. Harvey, D. Hall, J. Hewison, R. P. Holdaway, K. C. Hugkhes, R. Huntington, T. Kerr, H. R. Mellor, C. R. Pes R. E. J. Roden, J. Short, B. W. C. Thacker, R. I?· i (representing S.E. Midland Branch), W. Hethermgton (Witney U.D.C.) by invitation, and the Hon. Secretary.

Minutes of Previous Meeting

These were agreed and confirmed.

REPORTS OF OFFICERS

Hon. Secretary

The Hon. Secretary submitted applications for 21 Authorities and Officers and 6 for Associate Membership. These were approved. He then reported that total membership was 616, i.e. 517 Local and Officers, 89 Associates, 10 Honorary and Life Members.

Hon. Treasurer

The Hon. Treasurer reported an income of £1,815 and an expenditure of £1,431 for the year ending 31st December, 1968, leaving a credit balance of £384. There 7 Local f\uthority, 3 Officer and 4 Associate Members m subscriptions, but these were expected to be paid within a short time.

Hon. Editor

'!he Hon. Editor in submitting his report! stated that reports from Chairmen of Committees wou!d fac1htate both Minute work and editing of the Bulletm. He reported that Mr. W. Hetherington of Witney U.D.C., was present, had kindly offered to prepare contmue a cumulative index for the Bulletin and the Chairman expressed appreciation on behalf of the Association for this kind offer.

REPORTS OF COMMITTEES

Finance and General Purposes Committee

Members had been circulated for views concerning cost ofluncheons when the Council and Committees met somewith official guests. It was proposed and seconded the cost per head should be limited to 15/- except with the express approval of the Chairman".

Resolved: That this report be adopted.

Constitution and Rules Committee

Mr D. Hall, in presenting this report, referred t? the long which had taken place to find a smtablc defimtion of Ordinary Member.

1. That the definition Ordinary Member be amended to read:

'Ordinary Member'

(i) A Local or Harbour Authority within the meaning of the Petroleum Acts shall, on payment of an Ordinary Member's subscription, be entitled to nominate one of its authorised Petroleum Officers to be its representative, and such nominated shall be an Ordinary Member of the Associat10n.

(ii) Any authorised Petroleum Officer within the meaning of the Petroleum Acts, shall on of the relevant subscription, be eligible for Ordmary Membership of the Association.

2. That paragraph (a) under the heading 'National Council' be amended so that the second sentence reads:

'The Council shall consist of the Officers of the Association, eight Ordinary Members who be elected at each Annual General Meetmg, together with a Branch Member, who shall be an Authorised Petroleum Officer, appointed by each Branch of the Association'.

3. That the proposed rules of the North Western Branch be accepted by the Council.

4. That the application form for membership be redrafted.

Resolved: That this report be adopted.

Education and Publications Committee

There had been no meeting of this Committee since the last Council Meeting and after a short discussion it was proposed and seconded that the Education and Publications Committee meet that afternoon in order to clear outstanding business, i.e. the appointment of a of the Committee, the appointment of an Admm1strative Officer to act at Attingham School, and finalising the programme in connection with the School. It was that the Committee should also discuss the quest10n of a cumulative index as proposed by Mr. Hetherington. This motion was carried.

Reference and Legal Committee

Mr. R. E. J. Roden circulated the report of this Committee. Members' queries have been answered on the following subjects:

(1) The carrying of matches and lighters in vehicles engaged upon the conveyance of Petroleum.

(2) The storage of natural gas.

(3) The licensing of fuel barge at Yacht Marina.

(4) (a) Licensing of new installation prior to completion.

(h) The application of the exemptions contained in l(l)(a) and (b) of the Petroleum (Consolidation) Act, 1928.

(c) Definition of Petroleum Mixtures.

(5) Definition of the term 'suitable and efficient fire extinguishers' referred to in Regulation 6 of the Petroleum Spirit (Conveyance by Road) Regulations, 1957.

(6) Storage of Petroleum Spirit at Motor Racing circuits.

(7) Keeping of petroleum mixtures in underground storage places.

Further letters have now been received from members and these will be answered after consultation in Committee.

It was moved and seconded that summaries of the Questions and Answers dealt with by this Committee be published as a separate supplement of the Bulletin for information to members only. The Committee was asked to draw up special rules for Yacht Marinas coming within the scope of Petroleum Regulations.

Resolved: That this Report be adopted.

Technical Committee

A verbal report on the work being undertaken by this Committee was submitted by Mr. C. R. Peskett. The Committee had not met recently but a Sub-Committee was working on revised drafts of the Association's Codes and Recommendations. Appointed representatives of the Committee had met a sub-committee of the Institute of Petroleum and two officers of the Greater London Council to discuss Codes, Recommendations and other points of mutual interest; the meeting had proved very valuable and constructive and it was proposed to convene regular meetings on these lines.

Mr. Peskett expressed the Committee's concern that the Association's revised Codes had not yet been produced and reported that he was awaiting from Association's Electrical Adviser and until this was available the preliminary work could not be completed.

Resolved: That this Report be adopted and that the Committee be asked to expedite the issue of the Codes.

ANY OTHER BUSINESS

Annual General Meeting

The Council briefly discussed a date venue f?r the Annual General Meeting of the Associat10n and 1.t was decided that the date and venue be left to the Chairman and Secretary to arrange.

Chairman's Badge of Office

It had been suggested that the Associati.on's Chairman should be presented with a and cham <;>f an? the Secretary was asked to mvestigate the design and cost for an appropriate chain and badge and report back.

Branches

Mr. B. W. C. Thacker reported that .members in the Northern Branch found the travellmg distance concerned too great, and it was therefore proposed that the

Counties of Westmorland and Cumberland form a separate Branch. The Council agreed to the formation of this new Branch and offered to send representatives to the inaugural meeting and offer the usual financial assistance.

Council and Committee Procedure

Dissatisfaction with Committee and Council procedure was again voiced by Mr. J. Beer and the Council decided to refer the whole matter to the Constitution and Rules Committee for investigation and report.

New Council Members

Messrs. K. C. Hughes and R. Huntington were invited to serve on the Education and Publications Committee.

Nomination for Chairman and Vice-Chairman

It was resolved that the Council recommend that the Chairman of the Association for the year 1969/70 should be Mr. B. W. C. Thacker, Teesside C.B., and the ViceChairman be Mr. R. E. J. Roden, City of Birmingham.

Vote of Thanks

Mr. J. Beer proposed a vote of thanks to the Birmingham City Council for the hospitality extended to the Council on the occasion of the meeting. The proposal was agreed unanimously.

through the pipeline by OTTO

HOW WILL lT BURN '!

When one reads how the heat shield of a spacecraft is burnt away at temperatures around the 3000°C. mark, one wonders whether there is any material which will not burn given an ignition source of sufficiently high temperature and duration. Certainly it means that one must apply arbitrary standards in deciding whether or not to call a particular material incombustible.

So far as building materials are concerned, these arbitrary criteria are set out in British Standard 476: 1953: Part 1: "Fire Tests on Building Materials and Structures". Not only is the size and condition of samples specified but also the test temperature and duration at 750°C. and 15 minutes respectively. On application of the test a material is considered to be combustible if (a) it flames, (b) it produces vapours which are ignited by a suitably arranged pilot flame or (c) it causes the temperatures in the test furnace to be raised 50 degrees C. or more above the 750''C. specified for the test.

Just because a material is combustible does not mean that it is automatically rejected. The British Standard sets out surface spread of flame tests which in effect enables one to grade materials according to their degree. of co!llbustibility. Thus a Class I material, i.e. a material which has a very low flame spread, could be regarded as only very slightly combustible. Similarly a Class 2 material (low flame spread) could be considered "slightly combustible", Class 3 (medium flame spread) "fairly combustible" and Class 4 (rapid flame spread) "very combustible". The surface spread of flame test is quite a severe test and for many applications materials having a Class 1 or 2 spread of flame characteristic may be regarded as bemg "reasonably incombustible", particularly if the amount of such material to be used is not great.

British Standard 476: Part 1 also sets out tests for fireresistance. The difference between the term "incombustibility" and the term "fire-resistance" is not always recognised. A material may be incombustible but only an element of structure can be fire-resisting. To be fireresisting, the element (a) must not collapse, (b) must not develop cracks, fissures or other orifices through which flame can pass and ( c) except for elements such as do<;>rs, shutters and glazing against which combustible materials are not likely to be stacked in service, must have adequate heat insulating properties. The minimum period during which a material satisfies all these requirements is indicated by its designated standard of fire-resistance (or fireendurance). Standards of fire-resistance are quoted as being ! hour, 1 hour, 2 hour, 3 hour, 4 hour or 6 hour, as appropriate.

HOW IS IT SAFE ?

Any motorist will tell you that the presence of a spar_k in a flammable concentration of petrol vapour and does not guarantee ignition. The quality of the spark is important too.

Every spark will burn some vapour but propa.gation flame throughout the whole of the mixture reqmres additional energy. There are only two sources of energy available, namely the energy of the spark itself and the energy released by the first amount of vapour burnt. Propagation occurs only when the sum of the energies from these two sources is sufficiently large.

Obviously, the amount of energy released during initial burning of the vapour depends not only on certain physical characteristics of the vapour but also on the amount of vapour burnt. In turn the amount of vapour burnt depends on the size and strength of the spark responsible for the initial burning.

This has particular application to electric sparks which may occur during either normal or abnormal operation of electrical equipment. If we group vapours according to their relevant physical characteristics we can then for each group determine the minimum energy of electric spark required for flame propagation. If, having determined this energy, we design a circuit incapable of storing or producing more than half of the required energy, then we can safely say that here we have a circuit which by its nature is inherently incapable of igniting any flammable concentration of that vapour. In other words, we have for that vapour designed a circuit which is intrinsically safe.

The rest of the world, including the U.S.A., has lagged far behind Britain in adopting the concept of intrinsic safety. However, the international seal of approval has now been set by the issue of Publication No. 79-3 of the International Electrotechnical Commission. This document sets out the internationally accepted tests for intrinsically safe apparatus and without doubt owes a not inconsiderable debt to pioneer work done in Britain.

By its very nature, intrinsically safe apparatus confers greater security than flameproof equipment. For safety, flameproof equipment relies heavily on correct installation and maintenance. On the other hand, safety is built into intrinsically safe apparatus at the design stage. This does not mean that a fool could not render the equipment unsafe if he really tried; it merely means that he would have a more difficult task than with flameproof equipment. This is recognised in the assessment that intrinsically safe apparatus is suitable for use in Division O, 1 and 2 danger areas whereas flameproof equipment can do no better than Divisions l and 2.

Intrinsically safe apparatus for use in industrial applications is now certified in this country by the British Approvals Service for Electrical Equipment in Atmospheres. BASEEFA (to use its familiar contract10n) is a department of the Ministry of Technology and has taken <;>ver the function of certifying authority from the Factories Department of the Ministry of Employment and Productivity.