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368 SMOKERINGS
News,views andcomment on theworld of modelengineering
369 PARKLANDSRAILWAY HEMSBY –END OF THELINE
Brian Bakerlaments thelossofa well-loved 7¼ inch railway on theEastAnglian coast.
375 THESTATIONARY STEAMENGINE
RonFitzgerald tells thestory of the developmentofthe stationary steamengine.
380 ATANDEMCOMPOUND MILL ENGINE
DavidThomasrevisitsArnoldThrop’s design of aCorlissmill engine
385 BOOK REVIEW
RogerBackhouse readsGeorgeHodgkinson's book on thelaunching of ships.
386 WE VISITTHE SWANSEA MODELENGINEERS
John Arrowsmith continueshis tour of SouthWales.
391 POSTBAG
Readers’ letters
393 ABRSTANDARDCLASS 4 TENDER ENGINE
Doug Hewson leadsusthrough the construction of theBRStandardMogul
397 BUTTERSIDE DOWN
SteveGoodbody writes with talesofthe trials andtribulations of amodel engineer’s life.
402 DRIVINGTROLLEY FORA BATTERYLOCOMOTIVE
Mike Joseph buildsa braked driving trolleyfor Zahia
404 ENHANCED BY VEHICLES
Ashley Best adds alittlevariety to his1/16th scale tram display
407 LITTLELEC2024
LesBrimson andOwenChapman report from this year’s littlelocomotiveefficiency competition.
Jack Potterfromthe NorfolkRailway Society bids afarewelltoParklands behind his M.J. EngineeringBagnall (photo BrianBaker).
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Maidstone’s95th
On Saturday 17th August Ispent apleasantday at theMaidstone club trackinMoteParkatan Open Daytocelebrate the club’s 95th anniversary. Many otherclubs visited andthe trackwas declared outofbounds to Maidstoneclub members’ locomotivesso only guests couldrun.The Open Daywas very well attended andthe clubhouse wasfulltooverflowingfor thecutting of theclub’s95th birthday cake
MARTIN EVANS Editor
DIANE CARNEY Assistant Editor
Theclubstarted as aMeccano andmodel railway club and then developedintoa model engineeringsociety.The current trackinMoteParkhas alongsteadyclimb up to the topcurve,aroundwhich the climbcontinues before running back down to thestation This canpresent abit of a challengeatfirst. Thetrack can accommodate 3½ and5 inch gaugelocomotives
Congratulationstothe Maidstoneclubonreaching this milestone! Ishall look forwardtothe 100th anniversary‘if we’respared’ as averyelderly friend of mine used to say. However, Ishall of course hope to have the opportunitytovisit Mote Park againbeforethatimportant eventcomes around
Mar tin Evans can be contacted on the mobile number or email belowand would be delighted to receive your contributions, in the form of items of correspondence, comment or ar ticles. 07710-192953 MEeditor@mortons.co.uk
Racestothe North PatrickHendraislookingfor material on thefamous‘Races to theNorth’and is particularly interested in photographs of models of some of the locomotivesinvolved. Of specialinterestare:
GNR:
StirlingSingle
Caledonian:
Lambie or Drummond 4-4-0
NER:
4-4-0Class Jand 4-2-2Class F
LNWR:
Lady of theLake2-2-2 and Jumbo(Precedent) 2-4-0–preferably Hardwicke Pre-grouping liverieswould,of course,bepreferred! If anyone hasmodelsoflate 19th centurybogie andsixwheeler coachestheywould also be of interest. Ishall be pleasedtopasson anyoffers to Patrick.
CallingHarlington
Noel Shelleyhas been trying to contactthe Harlington Locomotive Societybut so farwithout success. Could someonefromthe club please drop hima line? Hisemail addressisnoelshelley@ hotmail.co.uk
Cock-upCorner
Welcometoour regularfeature! In RonFitzgerald’sarticle on George Forrester in M.E.4749 (August23rd) theillustration on page 344shows thewrong locomotive.The correct illustration is givenhere. If you hadalready spottedthatthen full marks– very impressive!
Nostalgia
During thesummerI enjoyed averypleasantday outonthe NorthYorks MoorsRailway We took atripfromPickering to Goathlandand back again, with avisit to theexcellent tea shop at Goathlandaswellas aridebehinda BlackFive. All very nostalgic– liketakinga daytripinthe TARDIS,steam driven of course.Evenmore than thetrain,orthe teashop, what really took me back wasa littlesignonthe village green,redolentofa gentler age. It reminded me of L.P. Hartley’sline: ‘The past is a foreigncountry:theydothings differently there’.I wondered if Icould perhapsdowithmore foreignholidaysinfuture.
MaidstoneMES
Maidstone’s95thbirthdaycake.
Your editor is allowedthe privilege of cutting thecake(photoRichard Linkins)
TheArtizan’s plateshowing oneofthe twoGJR locomotivesbuilt at thecompany’s Edge Hill workshops.
Pa rk land sR ai lw ay rkl and He msb y– End of the Line
All good th ings must Al lg ood co me to an en d
BrianBaker marksthe endofan erafor arailway on the Norfolkcoast
Itseemsa long time ago when firstventure intoa arklan s ailwa eek so e ti e in the i s an still have thevi eo a e that a ulle roun this attractive inch gaugetrack in thevillage of e s in orfolk. That a was ulle a essie an tank loco otive esigne en wannan riven or an tkins. a l he no longer has theloco otive ut he is still a regularvisitor latel withhis fine arshi . first wrotea out therailwa in ModelEngineer with an articlein anuar vol. issue entitle The ecret ailwa .
Therailwa was uilt in stages thelate on itheri ge as aho onthe e ge of lan he urchase to evelo intohis lue i an oli a usiness in theearl s. havehear it suggeste that thefiel was wherethe shunting horsefor e s tationwas gra e when it was artofthe i lan reat orthern ailwa fro reat ar outh each stationto talha then an otherstationsin orfolk ulti atel connectingwiththe eter orough an eicester. hat is in no ou tisthatthe ranthrough thefiel an that e s station was
a out ar ssouth of it ew hotogra hs of thestation e ist ut this one photo1 showsthe stationinthe earl stages of e olition. on s usinessventure ros ere an so he egan hisrailwa cul inating in the s ste we have to a . ast forwar a few ears an the railwa wasnow a ou letrack continuous circuita out th of a ile in length. arious i rove ents were a e inclu inga tunnel two ri ges an a long via uct e tensive si ingsan storagean a threeroa stea ing a .The last igi rove ent wasin earl to whenall
7¼ Society
John Ward foundthisphotograph of Hemsby station, whichwas locatedwhere thecemeteryand
are. Photographsofthe stationare rare
Notoften seen in redlivery, this Holmside Bess enjoyedthe week with ownerD.Smith
DavidMawdsleytries outfor size aDeans 0-6-0Goods2562. TheWeek is agoodopportunitytosampleother locomotives.
When notmanagingthe yard “inyour owntime, driver”orgivingrides in his Model‘T’ Ford,Nigel Surman runs his Hunslet.
thewoo enslee erswere re lace with lasticones see o el ngineer issues an PlasticMagic . ignallingu gra es an i rove ents have continue u to thestart of this ear s eek an the attache iagra (fg 1 shows thelatests ste . e starte e s eek in thelate san egan inviting hisfrien s in the auge ociet to oin hi for aweek which hascontinue interru te onl covi to the current a . n ee fora ti e thereweretwo eeks one in earl a when the righouse lu atten e . ften uring 2 5 6 3 4
Mick Jonesenjoyinga tour of passenger duty with hisGWR 0-6-0 Collett Goods. He also broughthis Schoolsclass loco No. 901 Winchester
Eric Upchurch’s Petclass Creweworks shunting locomotive frstran at Parklandsa fewyears agoand is still aregular visitor
Karl Oliver is oneofour home grownyounger memberswho proudlydisplayed the ListerD engine he hadjustfnished restoring, complete with newtrolley.
We triedhardtoget a‘groupphoto’but some were always missing.Tough enough jobgetting them alltosmile!
SincelastyearGeorgeWitheridgehas acquired this fneHolmsideand beinga bit quietbecause of therain, is sneaking outontothe trackfor aquick run. Normally during theweek he,likeall Parklandsmembers,isinvolvedwithrunning therailway andassistingvisitors.
John Dalton is aregular visitortoParklands andfor thepastfew yearshehas broughthis steamroller, butthisyearhis Britannia70025 WesternStar.
theweek therewereworking afternoonswhenever one woul worktogethertoi rove on srailwa a l in on asse awa an the railwa now owne the itheri ge a il was left to thesu ort grou arklan s ailwa ociet too erate onthe sa e asisas on ha no charge forri es lue i an visitors
an ersonalvisitorswelco e articularl ociet e ers. n ee therailwa washostfor twosociet
s over the ears utnow sa l itistoclose at theen of this ear as thefa il have regretfull eci e toclose the usiness.
ver ear a ailwa eek is hel on theweek inclu ing thelate a ank holi a
an canre e ervisitors atten ing acke Tues a evening inner ances oote an suite inthe ighwa an otelwithover iners s len i ti esthese were.This ear is the thsuchevent t was e ora le ecauseit raine regularl an wasver col ut orei ortantl how uchvisitorsen o e this last ever week ever wherewas s ilingani ate eo leclearl
having agreat ti e. eha visiting loco otivesofvarious t esan will o estto show as an as ossi lein the hotogra hs
So,theythink it’s allover? o this th eekwas the last eventat arklan s well not uite ecause in or erto cele rate arklan s ailwa we were aske the auge ociet to utona
Anotherday,somerainand thepit is full again.
Charlie Riches from NorwichClub, drivingPeteKing’s(standing on theleft) 0-6-0 Romulus Sophie B,a regularvisitor to therailway.
Rick Upchurch brings his Pearl regularlytothe railway anddespite thedamp conditionswill tackle thebanks with acoach full of visitors.A rare sight, John Painterdriving hisown GWR42XXclass 2-8-2class 4203, since he usually generously enjoys watching otherpeopleonthe regulator. On freight duty today.
AndyPotterbrought this fne6 inch scale‘LittleSamson’ Showmans engine which ranquietly allday,justticking over sweetly.
John Painter(in theorangejacket) hashappy memories of workingwithcraneslike this in hisearly days with BritishRailways.
Dayisa chance forustoshowoff what
busy. Here in thecalmbeforethe stormPeteKingwaits
ini gathering forthree a s at theen of une anevent organise the ociet for e erstovisit therailwa for thelastti e. Theseevents in ifferent artsofthe countr allow e ers to eet an runtheir loco otivesatti es when the ociet s event ight e alittletoo farawa oroccurring at an inconvenient ate. ou canfin ore infor ationa out ini gatherings an the ociet generall fro itswe site www.sevenan a uarter org. e organise it ust likea ini eek with aconrolls an cakefro the Café de Parklands ver uch in evi ence. o e loco otivesatten e so e for ustthe a an the event was eclare the ociet as the estatten e et.
candoand
gain the hotogra hs show s iling eo leen o ing the selves in it ust esai uch etterweather than the week
It is now!
o that wasthe last event organise at arklan s well not uite. thas een our custo fora while nowto invite e ersofother o el engineeringclu s o el railwa clu s the orfolk ailwa ociet an ourfrien s an fa il to our nvitation a where it is theintention that we runas an ofour trains as we can together with afew guestloco otives so that theguestscan en o ri es chatting loa s of cake fro the Café de Parklands an en o the ha at os here of arklan s. uite ifferent fro
Back fora second visitthisyear, Lisa Chiver from Maidstoneispassenger so that Sue Parham canhavea fewlapsonClass 08 833 ‘Liverpool Street Pilot’.
TimColes from Cambridge, newlyappointed 7¼ Magazine editor took time to join us with hisLMS ‘Jinty’47406 andisthatanS&D wagonheisridingon?
Daniel Masonbrought hisLNERMogul 4698 from Nottinghamtorun passenger service
Invitation
therailway
it is very
with Sophie B andBrian Aldridge with County of Norfolk forthe funtostart.
JackPotterwitha load of NorfolkRailway Societymembers on hisM.J EngineeringBagnall. Note theheadboard
Anumberofvisitorscameregularly from overseas andhereLuc Tennstedt is double headingwitha GWRlocomotivebehind, Ithink driven by averyyouthful JohnHancock andI thinkthatisBen Fraser immediatelybehindhim.Thislongtrain isclimbing thebankintoLaurelGreen station.
This is theman whose‘hobby’built ParklandsRailway.Don Witheridge hada fne stockoflocomotives,nearlyall standard gauge, butmanythink James, a0-4-0 Romulus, washis favourite, although some wouldargue that hisB1 Bushbuck is topofthe list. BrianReading,a keen supporter of therailway,and current president of the7¼Gauge Society, is acting as guard.
the eek we othe running thevisitorswatch an ri e. s usualthe weatherwas fine with ust thehintofa ossi le shower to ai closing on ti e an usher theinviteesho e an the lacewas crow e . This eventnor all takes laceinthe first week of orfolkschool su er
holi a san thus gives harasse u san ran as so ewhereto a use their charges an wellasen o ing the selves ell that is theen of our organise events although elieve we have an a ult art an a irth a art loo ing as well as acou leofschool
IfI hadtosum up in onepicture what ParklandsRailway is allabout Ithink this does it -Friendship, Relaxation andContentment
classvisitsin e te er Theseeventsa art wewill alwa s consi er a rivate visit an organisation or clu who wish to visitusaswecontinue running therailwa untilthe en of cto er on un a an Thurs a ornings an then arklan s ailwa will finall closean thetrack will e lifte . ME
RonManning from Chingfordpossesin Robert, hisHunslet
MalcolmWade, aNorwich member,brought hisscamp to help outand spentthe afternoon on demonstrationfreight haulage.
RonFitzgerald takesa look at thehistory and developmentofthe stationary steamengine.
Continuedfromp.263, M.E. 4749, August 9
The Stati onar y Th eS tati Steam Engin e
PART 61 –LOCUS CLASSICUS
The Greenwich explosion waswidelypublicised anditundoubtedly had atemporarily depressing effect on u lic confi encein high-pressure steam. As noted earlier, Bentham’sdecisionnot to usethe Trevithick engine that he hadpurchased forthe second of hisdredgerswas areactiontothe explosion andFarey said that demand forTrevithick’sengines never
attained thelevel of popularity that they wouldhave, hadit notoccurred. Even so,there is evidence that thepufferengine wastoo attractive as asmall powerunittoignoreand it may be that theintroductionofthe newtypeofboilerassuaged some of theconcern.Certainly, Farey’sexample of thetun type boilerseemstobeuniquein theliteratureonthe Trevithick engine andall of theexamples
knowntoday with theexception of Farey’s, have thecylindrical cast-ironboilerwithaninternal reechesflue
Thedredger engine (fg 1 ) maynot have been the earliest exampleofthe full developmentofTrevithick’s combined engine andboiler engine butthe features that it embodies were to become the hallmarks of such machines Theboilerfor thedredger
Sectionofthe dredgerenginewithdetails of thevalve chest. Thelefthandsection of thecylinder in situ in theboilerisslightly misleading as theinvertedU-shapedport appearstohavebothendscommunicating with theinteriorofthe cylinder. It is correctly shownasleading from theboilersteam spaceexteriortothe cylinderinthe right handdrawing
engine is ahorizontalcast-iron cylinder, in this case,4 feet 10 inches in diameter and8 feet long.One endplate is cast integrally with theshell whilst theother is adisc, bolted to aflange whichis artofthe shell. Thecylinderisinserted vertically into oneend of the oiler olte throughflanges to atubular mouthpiece.Seen in plan,a D-shaped projection againstthe flatsurface of the cast-inend platehouseshalf of thediameterofthe cylinder so that thecylinderproperis totally jacketed by boilerwater andsteam.The detachable end plateatthe opposite endof
theboilerisusedtosecurea sha e or reechesfire tu e cantileveredout horizontally into theboilerwater space. Oneleg of thebreechestube contains thefurnace andthe otherjoins an external iron chimneythatrises from the frontplate.Correspondingly, thefire oor whicho ens into thefurnace is adjacent to the chimney. Thefurnace side of thetubeis2 feet in diameter contractingto1 foot 2inches at thechimney end. Thetube wasalmostcertainly wrought iron.A dead weight safety valve is fitte tothe oileralthough missing is thesecondsafety
engine maybegeneralised forthe purposeofillustration buta more detailedsection is availableina drawingofa 6 hp engine prepared by Simon Goodrich whichwas to be used in theDeptfordNaval Dockyard (fg 1 ). Theboiler in this case is 4feet 3inches in internal diameter and6 feet long over externals. Theplan of theflue follows a sha e at thefurnace enditis2 feet 4 inches in diameter contracting to 20 inches at theU-bendand narrowing furtherto14inches at thechimney.Indescribing anearlyidentical boiler Farey states ( )thatthe wroughtironplatesthatmade u theflue were half an inch thickand thegrate was4 feet long,which if identically long in theDeptfordDockyardboiler wouldgivejustover9 square feet of gratearea. TheDeptford engine hada cylinderdiameter of 9inchesand astrokeof48 inches
valveina tamper-proof box andthe fusiblepluginthe lateworke ose to thefire both of whichFarey maintains, Trevithick co onl fitte afterthe explosion.
Fareyshows thecylinderin aseparatedetailand whilstit follows thedyeworksengine in itsgeneral arrangementthe valvechest is cast integrally with thecylinderbodyand thesteam path hasbeen si lifie . haust stea fro thevalve chestpassesthrough an annularfeedwaterheater before entering thechimney Thesha e of theflue that Fareydepicts in thedredger
Thereisnosurviving comprehensivelistofhighpressure enginesbuilt in accordance with Trevithick’s patent anditisnow impossible to assess thetotal number built;estimates vary between onehun re an five hun re . Nevertheless it is clearthatthe engine uickl gaine a fir hold upon theLondonmarket. In September1804,Trevithick informed Giddy that the engineer from Coalbrookdale hadjustreturnedfrom London andhad reported that twelve engineswereat work there, possiblyall built by Coalbrookdale.Amongst thesewas onesuppliedtoa gunfactory at theend of April 1803(fg 1 and ). Thecylinderhad adiameter of 11 inches with a3½feet stroke making 26 strokes perminuteata pressure of between 40 and45psi.When it wasfirstco issione it wasinuse boring four brass cannons simultaneously and also workinga clay mill at whichdutyitconsumed6½ tons of coal in 21 days working afourteen hour day. The engine hadreplaceda Boulton andWattmachine andthe proprietor of thefactory was
Afourhorse powerengineboughtbythe Navy Dockyard to scourbarrels anda set of polishing lathes.(Goodrich Collection, ScienceMuseum, London.)
abouttoorder afurther engine from Trevithick
Thegun factoryengine wasvisited by an Admiralty representative whoapparently expressedinterest. This may have ledtoTrevithickbeing invite tothe iralt ffice wherehegavefullerdetails of themachine.Heleftconvinced that:
…theyare abouttoerect severalfor theirpurposesand that no otherwill be used for government purposes
This wasinMay 1803,before theexplosion
At aboutthe same time theBoard of theWestIndia ocksor ere afloating cranepowered by oneofhis enginesthatwas to pass from ship-to-ship forthe purpose of dischargingcargoes into thewarehouses. It wasalso fitte u for firefighting a u capableoflifting 500gallons of watera minute,one hundred feet high wasattachedtothe rear of theboiler. It wasbuilt by Coalbrookdale anddelivered in September1804. Ironically,in
Fig 197
waseventually sold to powera factory.
view of itsroleasa fireengine thedockauthorities refused permission forittooperate within theirpremisesasthe Dock Actwas supposedto rohi it afire risk of thet e whichthe engine wasdeemed to represent. Theengineunit
Thei eaofa floating cranewas notabandoned butappearedinanother role as acoalwhipping cranefor dischargingcargoes from coal shipswhich arrivedinvast numbersonthe Thames in thesummermonths(fg 1 ). Theenginewas said to be built in Staffordshirealthough this couldbea mistakefor Coalbrookdale in Shropshire Itsboilerwas 2feet 6inches in ia eter an five feet long with acylinder4 inches in diameter and18inchesstroke, horizontally placed butoutside of,and above, theboiler. It was notreversible, theweightof thebasketdescendingserving to unwind thewinch barrel ( . gainthisfloating crane’scareer wasblocked but this time by vested interests, the coal whippers,who manually
discharged thecoalcargoes Ever readytocause trouble, they demonstrated againstits useand it disappeared Athird versionofthe floatingcrane arosethrough Trevithick’s ill-fatedassociation with theWestIndia Merchant, Robert Dickinson. In this case a patent wastaken out, No.3148 of July 1808, with Dickinsonas co-patentee. Thevesselwas to be capableofself-propulsion with sweep anchorssothatit couldwinch itself into heavy currentswhentowingother boats. As it wasalsoequipped forunloading cargoitwas called TheNauticalLabourer (possiblya Trevithick snub directed towardsthe coal whippers). Therewereother boating ventures.Inthe Goodrich collectionthere is adrawing of afourhorse-power engine (fg 1 )which theattached
The Goodrich drawingofa boat engine
Fig 198
Thecoalwhipping crane.
referencetable indicateswas to be mountedonthe bottom timbersofa boat (marked rr. on thedrawing).
Againthe cylinderisexternal to theboiler, mountedon brackets attached to theboiler topand slopingdownward at about15degrees to the horizontal.The piston rod drives acrossheadtowhich is pivoteda pair of connecting rods that pass back on either side of thecylinderwhere they meet overhung cranks.These cranks areateitherend of a crankshaft whichitselfhas acentral double-web crank. Labelled n. theinscription reads:
TheFlywheelshaft which is formed into acrank in the middlethatitmay be applied to thepumporany other machinery.
Thecrankshaftiscarried on acast-iron pedestal whichis independentofthe boilerand thereisa single fl wheel at one endofthe crankshaft
wasenclosedinanair-tight, iron,compartment whichanair pump pressurisedtokeep out thewater.The cranks andthe ends of thecrankshaftwere external to thebox andsealed stuffing o es.The engine wasrated at 400,000ft. lb.per minute or 12 horsepower
OutsideLondonthe Trevithick high-pressure engine wasalsoenjoyingsome success. In Cornwall, beyond theCambornedistrict, Seal Hole andBinnerDowns had enginesbeforethe patent was sealed.Twelvemonthslater Harrishad a12inchcylinder machinemadebyHayle Foundryfor Crenvermineand this wasfollowedbya 14 inch engine forDaniels’Perran Sandsmine.
ossi l the first Trevithick engine to work in theBristol area wasordered in early a r. la fiel a pumpingand windingengine forhis colliery.InSouth Wales,
Samuel Homfraywas the o inant influence in theiron in ustr utinco errefining hispeerwas John Morris. Morriswas buying Trevithick windingengines forhis coal minesin1803 ( )and Andrew Vivian recordsa premiumpaidfor awhimsy by Mr.Morrisunder date June 6th1803 whichwas to cost him£262. 10. 00.,suggesting alarge machine. Morris’s erstwhile partnerThomas Lockwood,who hadparted from Morrisin1803,was also a customer Furthernorth,inEngland,the taffor shirecoalfiel coul show severallarge engines by May1803, onefor Josias Spoils with a12inchcylinder (£150 premium),another forThompsonTurton, Esq., with a20inchcylinder(£315 premium) andone forLord Dudley andWard’scollieries of unknowncylindersize butattracting themassive
Twoother boating applications arerecordedby FrancisTrevithick. Onewas acanal bargewhich aletter from HomfraytoGiddy written on the2nd January1805 describesashavinga 10 inch c lin erwitha fl wheelon each side of thebarge anda crankshaft across thedeck. The fl wheelsha flat boards 2feet 2incheslong and14inchesdeep,six on each wheel likeanundershot waterwheel.The peripheral velocity of thewheelswas aboutninetyfeet perminute whichpropelledthe boat at 7 milesper hour.The bargewas intended to carry cotton to a ill in acclesfiel an ha about60to70tonsburthen It wasassembledfromparts that were alreadyavailable butwhether it ever arrivedat acclesfiel is uncertain. Theother boat is shown in aschematic sketch in Trevithick’s notebook (fg 1 ). Theenginewas housed below thedeck. It wastouse a 12½ inch cylinderapparently inserted into theboilerand worked horizontally to drivea crankaxle. Asingle, fourteen feet diameter paddlewheel Sizes andPricesofTrevithickHigh-pressure SteamEngines
premiumof£420. Much more common were engines of the3 to 10 horsepower classification at leastseven of whichwereordered between Apriland June.Atthe same time,Coalbrookdale hadsix enginesbuildingand twomore of 10 inch,completed in 1804.
Thetable showsa summary of thesizes andpricesof Trevithick high-pressure enginesbased partially on Farey’s Treatise ( 1). Farey ualifies thesefiguressa ing Thetable in this statemay be considered as afavourable representation of thehighpressure engineswhich were broughtintouse by Mr Trevithick,being rather what they were intended to be,than what they really were.The boilers were commonlyso defcient that they couldnot at theutmostsupplymoresteam than wouldimpel thepistons in themannerdesignatedinthe tableand many wouldfallshort
Includes Patent Rights &Fixingsoastoworkbut no brickwork. Source:Cols1-5 ATreatiseonthe SteamEngine, John Farey, VolII. p.38 Col. 6. SimonGoodrich.Notebooks. 16 August 1804.
of that;whereas Mr.Watt’s enginesare commonlycapable, at theirutmost, of exerting half as much powerastheyare ratedatinhorsepower: henceto have placed thehighpressure enginesinfaircompetition with Mr.Watt’sengines they must have boilersofmuchgreater powerthantheywereusually provided with Farey’sviews areusually measured andobjective but Homfray, an acuteman of business, wasunequivocal in hissupport of thehigh pressure engine:
Trevithick’s engine have been at work many months andis by farthe best we have…Any person nowwanting engines must be next kintoanidiot to erectone of Boultonand Watt’s in preference to Trevithick’s Thesediverging opinions with regard to therelative advantages of theTrevithick engine andthe Boultonand Watt engine were puttothe test somewherearound1804to 1805 when theValleyengineat Camborne wassubject to atrial measured againstthe ex-Wheal Maid Boultonand Watt steam whim which, having spent severalyears in SouthWales, returned to Dolcoath in an improved state. Trevithick was in anchester when he first heardofthe impendingcontest andwhilstdoubtless keen to seehis ideasvindicated, this engine wasnot hisfirstchoice as an exemplar of hisdesign. Whilsthehad prepared the
drawings andsentthemto Cornwall, buildingthe engine, in hisabsence,had been left to Andrew Vivian.Heexpressed hisreservationstoGiddy: Ifearthatthe engine at Dolcoath will be abad one. I neverknewanythingabout it beingbuilt untilyou wroteto me aboutthe PenberthyCrofts engine when youmentioned it Ithenrequested A. Vivian to inform me theparticulars …and Ifnd that it will notbea good job. Iwishitwerenever begun.
Clarkhowever givesa different versionofthe story saying that Trevithick wasparty tothe contest:
Theadventurers grumbled becauseTrevithickwas so oftenaway… Glanville themine carpenter, theheadman over enginesmadea trialbetween Trevithick’s high pressure pufferand Watt’slow pressure condenser. When Trevithick heardofithebet Glanville £50 …Thenhecamedownfrom London andfound that the piston of hisenginewas half an inch smallerindiameter than thecylinder. When thenew piston wasput in shebeatthe Boultonand Watt alltonothing. …whenthe trialwas over alittle pitwas foundwithcoalburied in it that Glanville meanttouse in theWattengines
In asecondlettertoGiddy, writtenfromCamborneon February 18th 1806, Trevithick says: …onmyreturnfromtown Ialtered thepressureofthe
steamengineatthe bottomof thehill, Dolcoath…the B. &W engine hadbeatenmineby120 to 55.Since it wasaltered there have been threeother trials the result was147 to 35 in favour of thepressure of steamengine… …The steamwhimnow idle at Valley (presumablythe Boultonand Watt whim) turned thewhimone revolution to one stroke andliftedthe kibbleto same height as mine did. Their steamwas notabove 4lbs, mine wasnearer40but used a thirdofthe coals… This is what Icannotaccountfor…there is no smoke… from my fretoclog thefre sidesofthe boilerwhile thecommonboilers getsoot half an inch thickand themud falls to thebottomofthe boiler wherethe freought to actbut in thesenew boilers themud falls to thebottomwherethere is no fre.
Trevithick wasultimately vindicated.HeinformedGiddy on the21stofMarch: Trialended last Monday…The adventurersordered that the newcastingsthatweremade foranother Boultonand Watt engine to be setaside anda newengineofminetobebuilt immediately… Ihavereceived orders fornineengines in the past four weeksall forCornwall Two12inch, two16inchthree 9 inch one8 inch andone 7inch. Iexpectone will be puttowork next week at WhealAbraham forlifting water.
This WhealAbraham engine wastodemonstrate an
unanticipatedadvantage that came with unit construction When Trevithick demanded paymentfor themachine the Adventurersprevaricated. In response he descendedupon themineatnight with some menand acart; in themorning theenginehad gone
To be continued.
NEXT TIME
Thefirstrailwa loco otive
REFERENCES
Ref 327 ATreatise on the Steam Engine, Historical, Practical and Descriptive (1827), John Farey, Vol II p.29
Ref 328 Life…Vol Ip.158 Letter from TrevithicktoGiddy 30th May 1803.
Ref 329 Life…Vol Ip.325.
Ref 330 Copperopolis, Landscapes of the Early Industrial Period in Swansea, Stephen Hughes. Pub. R.C.A &H Monuments in Wales, 2000, p.144.
Ref 331 ATreatise on the Steam Engine…, John Farey, Vol II p.38
Fig 199
Engine drivinga single paddlewheel
ATan dem ATandem Compound Mill Engine
David Thomas builds
Arnold Throp’smodel of aCorlissmillengine.
Continuedfromp.312
M.E.4750 August 23
The crankshaft and fl wheel area logical laceto akea starton theengine aking these its go roun iswhatthe rest of theengineisthere to o. ith swing lathethe fl wheel wasalwa sgoing to e the ainchallengefor si e an there ust isn troo in the worksho fora igger achine lso asthis o el wasa a orchallenge to skill an e erience wasantici ating that therewoul e ti eswhen
things weren tgoing toowell having so e successfull finishe large its to look at an han lewoul e aver useful confi ence oost.
Thecrankshaft(fg co es outofthe largest iece of steel stocknee e an where in the engine an here ou nee to o as sa an not as i an u in inches of inch roun . n case there wasa shaftfro a largish gear o )thathad een in thestorage hea for
eca esan was ust theright si e . ftergetting it u to re heat in thewoo heateran leavingitovernight to cool in theashes it was ustashar as ever erha s this wasn t hotenough so car i eti s were necessar for aking an rogress. n the rocess foun so e interesting patterns( inthe etal wherethe s lines ha een an a eso ever attractive lue chi s . Thecase har ening nitri ing ust have een closeona illi etre ee . fter allthe effort the shafttook areall nicefinish fro either car i e or .
To ringthe shafttolength an set outthe a iallocations forchanges in ia eter ou nee to know thetotal length of theshaft.Thisnee sto e ore accurate than aruler i ensionan in case the inchesislongerthan iggest calli ersso aftera it of thought use the on the ill ta le 1 . The
