Letters

HOME OFFICE CiRCULAR No. 182/1971

This circular cantains infarmatian an the revacatian af :The Petraleum (Inflammable Liquids) Order 1968, The Inflammable Liquids (Canveyance by Raad) Regulations 1968, The Inflammable Substances (Conveyance by Raad) (labelling) Regulations 1968. The Order and Regulations have naw been replaced by :The Petroleum (Inflammable Liquids) Order 1971, The Inflammable Liquids (Conveyance by Raad) Regulatians 1971, The Inflammable Substances (Conveyance by Road) (labelling) Regulatians 1971.

The new Order and Regulations came into force on 1st July and contain the following amendments. (1) The Order shall apply anly when substances listed have a flash paint below 73°F (Abel clO'sed-cup test). (2) The exemption limit in RegulatiO'n 9 (b) has been increased frO'm 250 kg to 500 kg. (This applies also to labelling requirements). (3) Regulations 2 (4) nO'w allows an apen tap container as the outer container. (4) The "Inflammable" label need not be displayed on containers cantaining patable spirits.

HOME OFFiCE CIRCULAR No. 186 (1971)

This circular refers to' the above 1971 Order and Regulations and mentians that the Standing AdvisO'ry Cammittee on DangerO'us Substances is now engaged in the preparation of propasals for detailed regulatiO'ns to' cO'ntral the construction and aperation af vehicles used for the canveyance by rO'ad of inflammable liquids with a flash point below 73°F.

The Committee cO'nsiders it desirable that any such regulatiO'n shauld cO'ntain a provision similar to Regulation 7 of the Petroleum Spirit (Conveyance by Raad) Regulations 1951, which deals with parking af unattended tank vehicles only at places appraved by Petraleum Authorities.

As such parking places ·are at present limited in number, it is suggested that Petroleum licensing autharities should apprave further parking places far vehicles carrying petraleum spirit, so that these parking places will be available when the new regulatiO'ns come into operatian. It is Suggested that the Hame Office should be natified in due course of the action taken by each authority.

REPORT OF H.M. INSPECTOR OF EXPLOSIVES

The report of H.M. Inspector of Explosives for the year ending 31st September, 1970 is now available (H.M.S.O. 35p).

This report highlights the dangers of glass fibre petrol tanks fO'r motor cycles and instances three fatal accidents involv,ing motor cycles fitted with glass fibre or resin tanks which ruptured causing the rider in each case to be trapped in a pool of blazing petrol.

It has been agreed, says the report, that the Department of the Environment, which is generally responsible for regulating the construction of motor vehicles, should take over from the Home Office responsibility for regulating the construction of vehicle fuel tanks.

There is evidence to suggest that glass fibre tanks are dangerous in impact situations, the report continues. If there appears to be no Hkelihood of the forma,tion in the near future of a satisfactory performance standard with which glass fibre would be able to comply, it may be necessary for the Department of the Environment, as an interim measure to introduce a regulation to the effeffct ·that all motor cycle fuel tanks on machines manufactured and first used after a certain date be constructed of metal. This would be consistent with the current requirement of the Petroleum Spirit (Motor Vehicle etc.) Regulations, 1929.

CONSTRUCTION OF PETROLEUM ROAD TANK VEHIClESUSE OF FIBRE REINFORCED PLASTICS

During a routine examination of a road tanker which was deHvering petroleum spirit at a petrol filling station one of my Officers, authorised to carry out inspectJions under the PetroIeum (Consolidation) Act, discovered that the cab of the vehicle was cons,tructed of glass fi1bre.

Since the vehicle wa's otherwise constructed in accordance with the Regulations the matter was referred to H.M. Inspector of Explosives for his observations.

I enclose for your information a copy of the reply I received together with a copy of a Home Offi'ce memorandum (XB 519/10/2) which, t'o the best of my knowledge, has never been circulated to Licensing Authorities.

It occurred to me that other members of the Association should be made aware of the contents of this memorandum to assist them in carrying out their res'Ponsibilit-ies under the Act. Chief Fire Officer, Birkenhead. W. MIDDLETON, F.I.A.O.

Thank you for your letter of the 6th July. The tanker whi'ch you mention is known to us and is of a design approved by this Department. We do approve the use of certain types of glass reinforced plastic for the construcbion of tanker cabs. The conditions under which this is permitted are set out in the attached memorandum (our reference XB519/10/ 2) which may be of interest to you.

Perhaps this will enable you to decide whether or not the vehicle concerned has been constructed to the approved design. Do not hesitate to contact us should you require further information.

For your information, the reference under which this des'ign was approved is XB/70 532/42/1. HOME OFFICE, KEW.

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XB 519/10/2.

Fire Protection in Petroleum Spirit Road Tankers in which the Engine is forward of the Cab The First Schedule to ,the Petroleum Spirit (Conveyance by Road) Regulations, 1957 (S.I. 1957 No. 191) Clause lee) requires that "the engine and electric batteries shall be effectively screened from the body of the vehicle by a fire resisting shield carried down to within twelve inches from the ground and upwards to, ,in the case of a vehicle other than a tank wagon, the level of the top of the cab, or, in the case of a tank wagon, to the top of the tank or, if the roof of the cab is of fire resisting construction and is without an opening, to the top of the cab."

Difficulty arose with regard to the interpretation of "fireresistant" in the context of proposals submitted to the Home Office for reinforced plastic materials for the construction of cabs. These proposals formed the subject of experimental work at the Joint Fire Research Station and subsequent discussions with industry. The experimental work was undertaken in an endeavour to arrive at an interpretation of "fire-resistant" based on a standard method of testing. It compared eX!isting approved sheet metal construction and took into account the essential requirements in relation to the hazards to be apprehended. Conclusions have been reached which enable acceptable materials to be defined in terms of a standard test. These conclusions have been extended to the body of the vehicle and its fittings which under Clause 5 of the First Schedule are also required to be "fire-resistant". 1. Cabs and forward fittings

In the ,case of cabs and forward fittings there are two essential requirements (a) the materials of construction must be of low hazard from their ignitability and tendency to spread flame and (b) the construction must be such that with a fire of the severity likely to occur forward of the fire screen the fire screen will act as an effective barrier and prevent the penetration of fire to the tank. The first requirement can be judged by subjecting the test for surfa'ce spread of flame specified in British

Standard 476: Part 1: 1953 and the acceptance level proposed is that the materials of construction throughout shall not be inferior to Class 2. The experimental work which has been carried out has provided sufficient information to indicate that compliance with the second requirement can reasonably be given by specifying a minimum standard of construction. The 'following acceptance standards ,are therefore agreed for use of reintforced plastics in the construction of cabs and fire screens for ,the petroleum spirit road tankers. The proposed reinforced plastic construction standard should apply to the whole of the cab, not simply to such parts of the rear and roof as may be designed to ,form the fire-resistant screen in accordance with the conveyance regulations. Materials

The materials used ,in the construction of the cab, fire screen, bonnet and wings shall be such that they are not inferior to Class 2, "Surfaces of low flame spread" when tested in accordance with the Surface Spread of

Flame test of British Standard 476: Part 1: 1953.

Construction

Cabs and screens of fibreglass reinforced polyester should have a thickness of not less than l inch and should be provided with adequate stiffening members.

The glass fibre should have a density of not less than 4 oz/ft2 and the resin content of the laminate should not be in excess of 60 per cent by weight. The use of materials not complying with the above should be referred to H.M. Inspector of Explosives. 2. The body of the vehicle and fittings

In the case of the body of the vehicle and fittings the only requirement is in relation to spread of flame as at 1 (a) above. The following acceptance standards are therefore agreed.

Materials (a) Wheel guards shall be constructed such that the surfaces are not ,inferior to Class 2, "Surfaces of low flame spread" when tested in accordance with the Surface Spread of Flame Test of B.S.476: Part 1: 1953,and (b) All other fittings shall not be inferior to Class 3.

CAR PARK BUILDINGS

In the Editorial of the July 1971 number of your Bulletin, you cite the suggestions made at a recent Symposium on the Fire Protection needed in Car Park buildings as an example of "the erosion of safety measures on the grounds of economy".

With the greatest respect we would be grateful if you would give us the opportunity to point out that this is not a true representation of our position.

A large programme of experimental fires carried out at this Station and which culminated in the three tests in which cars were ignited in a specially erected building, showed without any doubt at all that the risk of a spreading fire In an open-sided car park building was very small and that the fire resistance requirement for such buildings was such that unclad structural steel could be safely used without any danger of collapse. This work has since been confirmed by independent experiments involving ignited cars in Japan 'and Switzerland and is supported by the statistics of fire incidents ,in car park buildings.

We, ,as a responsible organization, would be failing in our duty if we neglected to point out that as a result of this work it had been positively shown that the fire resistance requirement for the structure of a car park building was relatively small and that to insist on a higher level was simply a waste of the taxpayers' or ratepayers' money.

This, Sir, is not the erosion of safety measures on the grounds of economy, but rather an attempt to ensure that the money available for safety measures is properly spent. F,ire Research Station. E. G. Butcher.