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128 SMOKERINGS
News,views andcomment on theworld of modelengineering
SteveGoodbody writes with talesofthe trials andtribulationsofa modelengineer’s life
161 ATWINTANDEMCOMPOUND STEAMENGINE
Graeme Quayle presents an interesting design fora compound windingengine.
165 HARRISTWEED
RogerBackhouse discovershow an iconic fabric is produced
168 INNOVATIONSINTHE LAST 100 PUBLISHED MODEL ENGINEER ARTICLES
Luker reflects on hiscontributions to Model Engineer
172 CLUB NEWS
GeoffTheasby compilesthe latest from modelengineering clubsaroundthe world.
175 CLUB DIARY Future Events.
E CO VER
Leufortin –a ⅞thG scaleinternal combustion locomotive by IanBayliss(photo by IanBayliss)
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IMLEC
MARTIN EVANS Editor
TheInternational Miniature Locomotive Efficiency Competitionisnow only a week away anditpromises to be amemorable event. So,ifyou aredoing nothingonthe weekend of July 19th Isuggest that youmight head over to Southport. As well as thecompetition itself, therewillbetrade stands andseveral craftstalls.The 16mm andgauge 1tracks will be availabletovisitors, as will thelargergauge tracks during theevenings. Saturday eveningwillfeature livemusic andfood will be available. Campingfor tents, caravans andcampervanswillalsobe available.
DIANE CARNEY Assistant Editor
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
So this is notjustany IMLEC, this is aSouthport IMLECwithaddedattractions andactivities. More informationisavailable at theSouthport club’s website: southportmodelengineering. club
CurlyBowl
If youare interested in,or own, an LBSC locomotive, youmay be interested in this year’s LBSC Memorial Bowl Rally (a.k.a.the ‘Curly Bowl’), to be held at theCheltenham SMEonSeptember 1st. This year’s eventmarks 100years sincethe ‘Battleofthe Boilers’ contestbetween Curly’s Ayesha andthe Greenly/Bassett-Lowke Challenger at the1924Model Engineer Exhibition.Ifyou have alocomotivebuilt to oneof LBSC’s designspleasebring it alongand turn theevent into amajor gathering. Giventhe significanceofthe occasion, it wouldbegood to achievea gatheringofasmanyofLBSC’s ownlocomotives as possible. So,ifyou owna ‘Curly’ locomotive,pleasedoconsider bringing it alongtoCheltenham
on September1st,asyou will be especially welcome! More informationabout theCheltenhamclubmay be foundatwww.cheltsme.org uk andany enquiriesshouldbe directed to csme@cheltsme. org.uk
Sharing
John Wing’s letterabout exhibiting (Postbag,page 155) prompted me to wonder what motivatesustooccupy ourselveswithcreating miniatureengines.Ofcourse, ourprimary motivation is for ourown satisfaction –the senseofachievement in finally completing theproject and creating (wehope) athing of beauty.The journeyitself, of course is also arelaxationand therapeuticinitself, even if,as so oftenhappens,the journey is nevercompleted
Surely,though, agreat part of thesatisfactionwegainfrom ourhobby must foundinthe extent to whichweshare it with others with thesameinterests Joininga club enablesus to shareour experience with others andgainfurther knowledgeand inspirationfrom seeing what ourfellowclub membersare doingand how they tackle particular issues or overcome certainproblems. Taking amodel to ashow allows us to shareour work more widely andgainuseful feedback,helping us perhaps to do even betternexttime! Entering acompetition offers thechancetogaina tangible reward forour work
If youhavea modelthen, complete or not, whynot take it alongtothe CurlyBowlorthe Midlands show andlet others seewhatyou have been doing. If youhavea completedmodel, enteritintoa competition andlet it be measured againstothers’ efforts. More importantly(from my point
of view,sitting in this editor’s chair) writeabout what you have done so that others can shareinthe journeyyou have undertaken.I shallalwaysbe pleasedtopublish your story.
Reader’s 100th
We at ModelEngineer would liketocongratulateone of theYeovilclub’sfounding members, knownsimplyas ‘JP’,onhis onehundredth birthday.Whenhewas younger he wasa gunsmith andmade airrifles whichsoldinAmerica He startedmodel engineering when he first sawasa boy someonemachining metalon alathe.ThisinterestleadJP to making hisown modelof theTichwhich wasrun on the newtrack he helped to plan andbuild in Yeovil Somerset He is still an active member of Yeovil club.Justthink of thehistory andinventions JP haswitnessedinhis life. Thepicture showsJPwith hiscardfromthe king,ata smallbirthdaycelebration held recently at theclubhouse Happy birthday,JP!
Cock-upCorner
Well –thisisbecominga regularfeature!Inissue4645 (June14) Iconfidentlyasserted that BanburyisnearLeeds. Of course it isn’t– my mind hadwanderedwhile Iwas writingthatand Iwas thinking of anotherplace.Whatwith Llanelli andBanbury,itseems that geographyisnot my strong point.
SouthportMEC
Cheltenham SME
The Le ufo rt in Pr ojec t uf o
IanBayliss presents an internal combustion G-scale locomotive.
Dedications
To my long sufferingwifefor hersupport over many years. To allthe people at theRoyal WolverhamptonNHS Trust whohavekeptmewellenough to complete this projectand achieveanambitionplusmuch more.A debt of gratitudeis owed to youall.
Acknowledgements
Before starting Iwould liketo expressmyappreciation to all of thepeopleand businesses whohavehelpedinthisproject, mostly quiteunknowingly Some of them must think‘Oh no,not that eccentricoddball again?’. Ihavenocommercial links to anyofthemother than as acustomer. Some areour betterknown model engineeringsuppliers,others aresuppliers to widerindustry andmoreinother areas of supplytoour miniature worlds.Ofperhaps special note,exceptional help has come from alocal modelshop specialisinginthe radiocontrol modelcar andaeroworld, Wheelspin Models.A local fastenerscompany,Johnand PamofFasteners (Midlands) Limited, Technobots Limited, Metals4U,MSC Supplies, BearingBoysinNorwich,Arc Euro Trade, Chronos, Tracy Tools, Warco, Andrew Mustun of Ribbonsoft GMBH (QCAD) AndtoJohn, aclose friend and16mmgardenrailway enthusiast whotells his16mm colleagueshetalks with the ‘Mad Professor’
Aims
Ihavenowishtogivea blow by blow accountofhow to
build this locomotive unless asked, buthopefully provide theinspiration andinformation as to howI have done things Highlight some of thepitfalls anddisasters (and successes?) Ihavehad.And most of all pass on thegood positive benefitsthatthishobby can bringeveninthe darkestof timesonthe most difficult of pathsand thesatisfactionthat even alittlesuccess brings
Pre-amble
Iamsurethatthe sharpeyed readership will have understood thenameof this project, being‘nitro-fuel’ backwards. Andthatisabout theessenceofthismodel.Itis hopedatthe time of starting this articlethatitwill be oneof twotocompletethe locomotive roster formylittlerailway whichisthe Dirranbandi and Toowoomba LightRailway (hereinafter DTLR). Therailway motto is AudaxetSceler, roughlytranslating as Bold and Speedy.Something narrow gaugerailwaysdefinitely arenot.Fatewas smiling benevolently when thename wasrandomlychosenfrom blindfoldedpinsina map. Whilstthere is contention amongstthe seriousacademic scholars,the most likely meaningofthe railway’s name is foundfromthe obscure Yuwaalaraay Australian Aboriginal dialect(dhurran-galhairycaterpillars andbaanda-y moveinsinglefile). o we have ‘Hairy Caterpillars Move in Single File to TheSwamp’. Not abad name foranimpecunious narrowgauge railway methinks his is a ths scale garden
railway.For thosenot au fait with this scale, it is aniche area within thealready niche area of garden railways. The mainstream scales arereally G-Scale(1:22.5)representing metregauge (originally) continentalrailways, running on gauge1 (45mm) trackof robust construction (code332 rail) andgenerally of track poweredelectricpropulsion, or 16mm narrowgauge (1:19) running on both ‘0’gauge (32mm) andgauge 1(45mm) track. 16mm narrowgauge tendstobelivesteam,battery electric anda littleIC(internal combustion). Thereare of course theGauge 1groupings running exceptionalmodels of standard gaugeprototypes, usually livesteam propulsion (1:32and 1:29 seeminglythe prevalentscales).These all used to be real fungroupings that came to be servedwell by thekit andready-to-run marketsand some pretty famous names- sadlyattimes to thedetriment andderisory side-liningofthe scratch buildingfraternity. ths evolvedsomeyears agoand Ibelieve itsrootslay in NorthAmerica wheresome enthusiastswishedtobuild and runlarge ‘Maine Two-Footers’ andbuild largemodelsofvery smallprototypes. Theidea came here to theUKand when Ifirstbecameinvolvedand passionateabout this scale, therewas basically nothing in theready-to-runmarket andpreciouslittlebythe way of kits,althoughenthusiasts were starting andrunning businessestoprovide some parts.
My inspirationcamefrom averyamusing scratch-built exhibitata garden railway show,seen forthe first time andI wassold. Or lost as some garden railway hobby colleaguesinthe mainstream were wont to putitwhenacting politely.
Youbuckled down,designed it andmadeitbyscratch buildingin ths. It wasnot theretobuy
This gave greatscope forthe freelance designs. Butare they ‘freelance’, Iwould ask? Just aboutanythingyou candream up (thathas some credibility, even some that hasnot!) has aprototype in theindustrial, colonial,agricultural, estate, civilengineeringnarrowgauge railway areas, bespokeoften to do a ob andtomeet s ecific traffic re uirements. owe have ascale whichinprinciple is 40% larger volumetrically than themorecommon16mm scalei.e. thsofaninch (22.225mm) represents 1foot or 1:13.7 in termsofscale.We runon45mmgauge trackto represent2 foot narrow gauge generally and‘0’ gauge(32mm) to represent18inchgauge railways.
This scaletherefore is actually larger than the generally accepted ‘model engineering’ gauges of two andhalfinchand threeand a half inch representing standard gaugeprototypes. Anditisnot farshort of fiveinchgauge (1:11.3)
Ipersonally do notknow of anyparticipant that runs on electric trackpower.Live steam, batteryelectric, internal combustion (bya smallnumber of enthusiastsinthisscale and 16mm) arethe orderofthe day.
So we have ascale which hasenormousdepth,from theadditional size providing scopefor thosethatwishto embody high levels of detail in theirmodels, to providinga robust tracksystem(s) andto thosemodelsofa more rugged nature,all of whichhavea real presence in the12inchto thefoot environmentwhere we allrun ourtrains. Andlike so many of theother scales, manufacturershaveentered
the‘ready-to-run’market. We do nowhavea rangeofkit suppliers as well.
Nowtothe projectitself.
Thebackground
Firstlylet us notbefooledby thephotographheading this article(photo1). It turned out initially to be adisasterorat leastpartially so butitdoes give an idea of what is to come Aftera couple of days of bitter disappointment, logicset in, analysis anddiagnosis were undertaken,witha redesign andmanufacture of offending bits.Ithas been along, twisted andconvolutedhistory
It wasfirstconceived approximately16years ago as a‘revenge’ project, my object beingtoproduce adirty, smokey,oily,smelly,noisy, ugly,cantankerous(nottoo cantankerous,I hadtorun the thing) andmostofall annoying to others,locomotive. Allthe very wrongreasons to design/ make anything.All duetosome prevailingpoliticsacrossa wide spectrum in what should be apleasurable hobby.My thoughts,atthattime, turned to theinternalcombustion enginesfavouredbyradio controlcar andmodel aircraft enthusiasts. Memories came to mind of ‘diesel’ (compression ignition)motorsof50years ago beingprettyobnoxious forms of life, Iseem to remember, he says,ruefullyrubbing what were once sore fingers Variouscircumstances intervened andverylittleof much import wasdone. I bought asecondhandengine (a Kyosho GS11 2.5cc approximatelyglowplugengine with pullstart) forjusta few pounds at atoyfair,thinkingI will do that up (photo2).
Therehad been thoughts of I.C./Electricusing aDCmotor as agenerator butI threwthat away in favour of amechanical design.Morepressingreal lifematters forced theputting asideofthe projectand Iam nowgladtheyintervenedin many ways
Isincerely hope what follows will providesomecomfort, help andinspiration to others whomay be lookinginto
Thefrsttragicattempt…
theinfamousglass darkly Somethinggood andpositive will come from this so Iask for your indulgence to bear with me fora littlewhile longer RogerBackhouse recently wrotea finearticle alluding to similarissues
Retirement came andnow wasthe time to really getstuck into my railway -nothoughts of Leufortin again. Butthe hand of cardsdealt wasnot oneto wagerupon.
Fast forwardto2018/2019 andtwo housemoves later, twoworkshops laterand two incomplete railwayslater the very worstcircumstances conspiredtogetherafter the previous interruptions that were beyond ourcontrol
In an effort to speed up when thetimecametoplay trains,despite beinganavid believerinscratch buildingand promotinggood basicskills, Iswallowedmypride andI have built up asmall collection of eightdedicated livesteam ths scalelocomotives professionally,commercially built from threeseparate reputablemanufacturers.I was notabletorun thesewithin thewarrantyperiod. Iam pretty able butnot onesingle
locomotive hasworkedin anything likea satisfactory way ‘straightfromthe box’.The only onewhich hasa semblanceof workingisthe only onewhich waspurchased second hand as a‘do-upjob’. They allhavea lengthyworksheet of differing faults to be rectified.And they have languished in adisplay cabinetbasically unused almost sincepurchase. Disappointmentand disillusion wasbeginning to creep in.Sobattery electric for ever.Isthatall Icould manage? Really?Itwas up to me to design andproduce themotive powerfor my railway Following on alltoo quickly came March2020. The pandemic struck!Atthe same time Iwas informed that the worstmalignant relation of the BigMrC hadcometovisit my oldand tatteredouter fabric
The frst secondhand engine themodel wasbased upon
Despitethe best attentions of theladysurgeon’s eviction tools, skilfully wielded, he returned multiple timesto thesamesiteorimmediately adjacent to it.Despite the‘take no prisoners’ approach of my lady surgeonthe bigblowcame late in 2021whenI wastold he hadtaken up permanent residenceinternally. He must really likethe site.Hewas immune to physical eviction by that time butmaybe tightly controllable, at leastfor awhile as conventional treatments areineffective, furthersurgery beingtoo dangerous. Iasked fortruth andwas givenmy tickingDoomsday ClockinJuly 2022 andthe time it wasset to.Thatisthe waythe numbers crunch,havingdetermined, with diagnosticsover6 months,the usually unpredictabletrajectory my unwanted visitorwas likely to follow.I assume theclock is wrong! Andlivelifealso pursuing this hobby on that assumption
Compoundingthis unfortunateset of circumstanceswas that I couldnot work on therailway itself as significant civil engineeringworks alongwith theaccompanying painfully slow legalproceedings hadto be undertaken to ourproperty alonga lengthyboundary. A thirdofthe trackhad to be liftedinthe smallarea(10 metres x5 metres)I useand forsafetyreasons Iwas kept outofthe workshop fortoo many months
Astrategytodealwith thesituation hadbedrawn together that enabledthe ability to cope with it
Butall wasnot lost!I will admitthatI have unashamedly minedmyhobby fora very precious resource, knowninthishousehold as ‘UNOBTAINIUM’i.e.the ability, theresilienceand internal personal resourcestocope. TheDTLRinall itsvariety provides averyrichseam. At thefirst andemic restrictions andthatfirstblow, I wasasked by themedicswhat Iwas goingtodowithmyself. Iansweredsimplywith“Ihave an allabsorbing hobby”.
Thoughts turned to Leufortin againbut in amuchmellowed waythanoriginally conceived. Somethingthatwas going to stretchall my skills both practicaland academic,shall we say. Somethingthatwould stretchand fully utilisemy workshop facilities. Something that wouldforce thegathering of newinformation and thelearningofnew skills Somethingtobecontent in my owncompany.Reclusive comeseasyanyway.
An obviousway forward wastoresurrect the Leufortin project. It wasunusual with relatively fewparticipants. Thedrawing numbering system Ihad devisedduring my professional engineering design days hadalready been broughtintouse again. Ihave used,inearnest,someofthe most sophisticatedcomputer aideddesign3Dmodelling systemsavailableina previous life. They arenot needed.I had used Draftsight hobby-wise, a lotuntil it no longer wasfree andbecamequite expensive. HoweverI hadbeenusing, on andoff, anicelittle2D CADpackage calledQCAD. It hasa totally free version butI paya nominalsum each year forall theupdates.I get 50 downloadsa year.I even runanold laptop (nolonger supported by Windows) with LINUX(UBUNTU distribution) in theworkshopfor reference to drawings with QCAD andit is very acceptable.Itactually nowgoeslikegreased lightning compared to howitwas in its heyday
Next came aseriesof questionsofmyself. Could Ireally design agearbox of spur gears, with forwardand reversetohandlesuchhigh RPM? CouldI actually make it?Did Ihaveenoughpractical skills?Did Ihavethe workshop resourcestoactuallybring this projecttofruition? DidI even by this stagehavethe personal, mental andphysicalresources to seeitthrough?I decidedthat with apositiveapproach, afew minoradditions, some handson practice,designing to utilise very basicengineering practice andprocesses, YESitwas
achievable andin-house. Ihad my pointoffocus Nowthe ethos. Ilikelots of things that areutilitarian butdoa jobwell. Ihaveoften been accusedinthe past of ‘Victorian Engineering’ Most of theirstuff worked andstill does.Whenitdidn’t, persistencewas thename of thegametoget it right. What came to mind wasthe ATCO lawn mowerofthe past.Pleasedonot askwhy -evenI do notknow. Iam sure many will remember the school groundsman,the local cricketclubgroundsman, thegardeners in public parks maintainingtenniscourtsand sports pitchesall beingtowed alongbythe machineonwhat looked likeanold tractorseat mountedona stalkwithtwo wheels his fittedmyagenda very well indeed.Thiswas a machinedesignedtodoa job anddoitwell- nothingfancy, no fashionable, chic,trendy curves andbodiesand perhaps in themodernvernacular‘Let it allhangout,Baby!’. Iknew that themostproblematic thingfor me in theend would be bodywork.Thisethos minimisesthatproblem.Even though thescale is quitelarge, volumetric spacewould always be at apremium unless the runtimewas to be cutdownto between 5and 10 minutesonly. Andrun rather more quickly than it should.
Impatience cutinagain andI purchaseda nitrofuelledradio controlledcar 1/10th scale with a4.6cc glow plug engine (rated up to 30,000r.p.m.!).
Speed up thework, gutthe thingout,chuck allthe wanted bits into alocomotivechassis, getrunning.Not in keepingwith theintention andwhenI looked at it,itwas toonicea model to stripand vandalise. In fact beautifully engineered Just as an aside, forthose that mightnot understand, ‘nitro’isnot nitro-glycerin,itisa volatile fuel forsmall glow plug enginesthatisblended from nitromethane (I wasadvised to use20% as anovice), methanol andoil. Theoil used to be castor oilbut Ithink there is some syntheticlubricant
blendedwithit. Iamnot an expert
So curbingthatimpatience Iwentbacktothe proper reasoningfor building Leufortin
Theworkshop
Thereisabsolutelynothing sophisticatedabout my workshop.Ithas facilities forbasic processes. Idonot useDRO’s as such,purelythe digitaltachometers that came with themachinesand the down feed of themill quills
Theshopitselfisa heavy duty shed more akin to a sectionalwoodenbuilding, nominally 12 feet by 10 feet (4 metres by 3metres).The heavydutyframework allowed us to insulate with Corotex/ Kingspan andinternally clad with ply. Ifound asupplierin Powiswho supplies‘seconds’ in 8foot by 4footaluminium foil clad rigidinsulationsheets at very advantageous prices andwill deliver it.There was basically minimaldamageto anyofthe sheets, just some discolouration in places.Worth everybit of finance andeffort at thetime(autumn 2018). Addguttering anditprovides additional waterfor my wife’s vegetablegardening from the waterbutt.
Theaforementionedhouse movesand retirement meant that Ihad sold my industrial sizedequipment alongwith allthe larger tooling. As I had lannedfor,finally,this railway to be my enjoyment in retirement Ihad decided that allmachineshad to be handleable by us (atthe time) andbench top. Ihad previously mercilesslywornout amini lathecommercially butwas notdispleasedwithit. Buying partswould have meantmore moneythanbuyinga new one. AConquestminilathe wasboughtwhich wasa big mista e. efinitelysuffering from theFridayafternoon car syndrome of ageneration ago. My tribulations with this machinehavebeen well discussedinother arenas Persistenceinthe endhas givena very tractablemachine whichnormallyhas an ER32
Lathemandrel back stopstoHaroldHallbasic design colletchuc fitted. It fully earnsits keep nowwithall the modifications andu gradesI went throughwithbothminilathes.Due to this problem Ihad purchaseda Warco WM180 lathe. Very impressed, it arrivedcleaned andoiled. Allitneeded wasa wipe down, re oil anditran to s ecification themomentitwas mounted on thebench.The lathes each have acomplementof chucks includingfour-jaw self centring andanER32as stated.Conquest80mmbased, WM180 100mmbased
Themill is aconventional WM14, againWarco.As with thelathe it worked immediatelyand is adream to use. It hasonlyrequired onerealinterventionand that wasa bearingadjustment aftera number of hoursof use. Ialready owneda 12 inch (300mm) 3-in-1 sheet metalmachine.I hadto replacethe drill press. The newone sufferedconstant looseningofthe single pulley grub screwdrivenintothe keyway of aChinese single phasemotor shaft. Ibit the bulletand convertedittoa fully variablespeed machine with athree phasemotor and
inverter.I made useofproper ‘TaperLok’ pulleyshence giving theopportunityfor sensible belt sizes, theoriginalChinese setupfallingbetween all thestandardbeltsizes,even with themotor adjustments. Ihavea micromill drill which originally wasusedtodrill home brewed PCBs formanual speed controllersonbattery locomotives. This nowsports an X-Ytable as well.
Themillhas twocollet chucks,one acheaper item with colletsfor endmills and slot drills plus also an ER32 colletchuck andstandarddrill chucks.Anaddedextra just for additional visibilityand access wasanER16colletchuck with twosizes of collet forcutting thesmall keywaysinshafting. Having hadtoget ridofmy no. fly ress(indeterminate age) underthreatasI had damagedmywife’sfoot dropping thething ashort way when thecrane bent during amove, Iboughta little1 ton arborpress whichalsohas proven itsworth as we will see later. Ihavesilversoldering facilitiesand a6 inch grinder. HoweverI foundthatlifeis very much easier if thetime is takentoenhance some of
They area mixtureofhis twodesigns with acoupleof ideasofmyown,thusturning my basicgrinder into afairly passabletool andcuttergrinder forHSS tooling. They do need my electronic protractor (usually nicknamedWIXEY) andmanualbevel protractor to setup. TheWM180 lathe hada carriagestopmadefor it,whilstthe Conquest Mini lathehad afour-wayadjustable carriagestopmadetothe same design of thefive way one(butsmaller) made forthe Colchester Bantam Ihad Amostusefuladdition to the workshop machineequipment wasagain aHaroldHalltype mandrelbackstop, made firstly forthe 1 . he mandrelbores forbothlathes ares ecifiedasnominally the 3 4 6 5
same diameter.Theyare far enough different to ensure that Ihad to make anotherone for theConquestmachine.Still they work andhaverepaidthe effort handsomely (photo4).
Tucked away underthe grinderisa horizontal bandsaw whichisa real labour saver. Anotheritemworthyof mentionisthatI hadsalvaged thetailstock from theaforesaid worn outminilathe.I had alreadyconverted it to lever operationand camlockso thecareful manufactureof an adaptorfroma chunkof steel barI hadallowsmeto usea 5/16 inch Alfred Herbert Coventry dieheadthatI bought reconditionedyears agofor use on thecapstan attachment of theBantam. Itsnow ajoy of course to make notably10BA andM2threads plus asmall number of others that Ihave diesetsfor
theseitems of plant. Iran into troublewithturnedfinishes whichatthe time seemed insurmountable.Havingspoken with akindred spirit whoisa contributorto ModelEngineer Istoppedproject work and made twogrindingrests (one left hand andone righthand) with acoupleofaccessories usingthe principles that Harold Hall hadlaiddowninhis books (photo3).
Perhapssomething simple butworthyofnotefor those whoseworkshoptimemay be limited by health factorsisthat having made thedecisionto have benchtop machineryand actually having used it fora littlewhile Ireduced this down to desktopheight. Ibought threeofthose bolt less racking type bits of kitand cutthe legs down.Beaware -don’t usethe rackingitems,alwaysspecify theworkbench items. They aremadefromheavier gauge steel.I was/am unable to stand forlengthy periodsnow so Ialsoboughta comfortable ‘operator’s’ chair. Iwanted castorsnot slides as are mandatoryonthe tallerchairs. Iagreed adisclaimerwiththe manufacturer as it fell outside thenormalH &S approved products.Justhow useful thesearrangements have proved to be is demonstrated by beingabletostart say 9.30am andwithonlymorning teabreak plus lunchfor 45 minutesorsoand finally finishing on thegooddays 3.30pm to 4.30pm
Ihaveprovidedtwo general pictures of my workshop to show just howbasic it really is (photo5 and photo6).
To be continued.
Upgraded basic6 inch benchgrinder to enable basictool and cuttersharpening.
Lookingsouth into theworkshopfromthe doorway.
Lookingnorth towardsthe workshop doorway.
We Vi sit the Bedfor d Mod el Engineer ing Society y
John Arrowsmith visits awell establishedand active club.
Myvisit to theBedford ModelEngineering Societycoincided with the50thAnniversaryofthe 7¼ Inch GaugeSociety so there were lots of activities goingon at thesametime. TheSociety itself wasformedin1948as an amalgamation of various othergroupsinthe area,to promotemodel engineering andits many variants.Like many modelengineering clubs, therehavebeen some upsand downsduringthislonghistory
My host andinformant was Alan Gilderslevewho joined the club in 1989 andhas been on thecommitteecontinuously ever since, so he hasmuch experience of theclubbehind him. Alan informed me that 1989 wasthe year theclub nearly packed up becausethey hadnocandidatesfromthe then memberswho wouldbe chairman.Havingjustjoined theclubAlanvolunteered becausehewantedtobepart of amodel engineeringclub. He hada long tenure as chairman whichsaw theclubbegin to flourishand really establish itself in this area
hefirsttrac theclub hadwas at thevillage of Wilhamsted whichwas changedtoWilstead by the
local authoritybyrequest from residents. This trackwas locatedabout amile away from wheretheyare now. It wasina field behind a ub calledThe Rose andherethey establisheda very nice raised track, brick-built clubhouse andall thenecessary fittings fora miniaturerailway.Itwas asuccessful site that worked well with localpeople, butthen theinevitablehappened; the pubwas sold andtheywere askedtomoveand to take theirentiretrack with them Thebrick-built clubhouse, however, wastobeleftinplace alongwitha couple of other buildings
Anotherlocal enterprisethe ummerfields ruit arm -was approached andthey subsequently allowedthe club to establisha ground leveltrack alongsideone of thefarmroads leadingtothe strawberry pickingarea. This wasthe startofthe presentday ummerfields ailway which continuedinthisway until, sadly, theeconomicscene changed, ending theviabilityof thefruit farm andsoitclosed down
This time,however,the club wasallowedtostayastheir agreementwas with Whitbread Estatesand hadresultedinthe developmentofthe railway to thecondition it is in today. Thetrack plan of today resemblesa hockey stickwith thelonguphillclimb from HayesEnd to HammerHill (photo1). TheHayes Endarea of theclubsiteiswhere allthe main facilitiesare located. A splendid wooden clubhouse hasample spacefor their meetings andgeneral club events andhas ausefulkitchen area whichiswellappointed (photo2). Outsideisa paved patioareawitha brickbuilt BBQand this is combined with
Theoverall site layout. Inside thewellappointedclubhouse
apleasantgrass picnic area (photo3)providing agood spacefor otherattractions or displays if theclubwishesto entertainvisitors.
Behind theclubhouse is theclubboundarywhich,as youapproachthe railway,has anotherspace behind it,parallel to theroaduptoHammerHill,
andinwhich theclubhas very cleverly positioned anumber of steel containers.These have been used as astorage facility forsomeoftheir rollingstock andlocomotives (photo4) together with afine wor sho Thestorage containerhas a substantialtraverser in front, connected to aspurlineonto
asidingatthe platform end anddirecttothe main line (photo5). As Imentioned,the main stationatHayes End is awell-built four platform structurewithanoverall roof providingplentyofcover from both rain andshine (photo6). As this is also theterminus stationonthe line, thereisa
largeturntable facilitatingboth access from thesteamingbays andenginerun-roundsduring busy periods(photos 7 and 8). Unloadingvisitingengines is accomplishedbyusing the largehydraulic lifting platform adjacent to thesteaming bays.Another locomotive storageshedisalongside the 3 4 5 6 7 8
fne clubhouseand groundsatHayes nd.
Thestation approach with thelineintothe storageshed.
The tation uildingatHayes nd.
pproachingthe main stationatHayes nd.
ell laid outstorage shed
n impressi e relayboard in thesignal bo .
carparkand steaming bays. Thereissomecomplicated track-work on theapproach to thestation from Hammer Hill andtocontrol allthis, with the requisitesignals,isthe station signal box. Thebox hasa good allround view of workings and hasa fully operationallever frameand circuits with afull trackdiagram andcircuit board fittedoverthe leverframe.A neat andveryprofessional lookingcontrol unit completes theoperational needsofthe railway at this end(photos 9, 10 and 11).
Thejourney from HayesEnd stationtoHammerHill Junction stationis, Iwould estimate, about¼ mile with quitea steep inclinesuchthata fully laden four coachtrain with a7¼inch gaugeLNERB1onthe front needsa ‘banker’ to assist it As in full size practice,this engine assiststothe topand then just lets thepassenger
traincarry on before backing down to HayesEnd station. or assengersthisisan interestingaspecttotheir trip
Anotherfine ieceof engineeringforms part of the tracklayoutonthissection;a splendid girder bridge spans awideditch.Built by students at theBedford Training Group, this andthe adjacent smaller masonrybridge, together with asmallergirderbridge on thereturnline, makesan impressive site on therailway (photo12).
Alongthissection of track is asmall additional station, BadgersHolt, whichprovides an additional lineside feature that canalsobeusedasa passing loop forthe main line. Thelinealsohas anumberof signal gantries that controlthe movement of trains up and down thecircuit.
At theHammerHill endof therailway is acompletely different layout with the ground levelbeing laid in three different oval circuits,each accessiblefromone another by usingdriveroperated pneumaticpoints. Thesafety protocol here is ‘GiveWay’to thetrain on your left.Thiswas
theonlyrequirement forthe AGMtoagree to allowmore trains to operateatthe same time,otherwise themanual switches arealsosignal controlled. This giveseach driver theopportunitytokeep goinground thesecircuitsfor as long as they want.Onone side of theouter loop there is amagnificent anoramic view outoverthe GreatOuse Valleywhich is in itself a greatadditionalfeature for passengers(photo13). Inside thesegroundlevel trackloopsisa largearea whichhas an elevated track
for2½, 3½ and5 inch gauge tracks.A substantially built track, it features anti tipping rails on thewhole circuit. Thetrack system hasa good steaming bayareaand turntableallowing access to all thesteamingbaysand it has itsown stationplatformand watertower.A liftupsection of trackgives maintenance access between thecurvesof theraisedtrack.Atpresent it is beingextendedwithanother loop across themiddleofthe site (photo14). It also shares themainstation (photo15) whichhas twoplatforms
Thetrack diagramboard in thesignalbo . othmainlines with theirarrangementofbridges
The splendid view over theGreat Ouse Valleywiththe outer loop in theforegroundThe raised tracke tension underconstruction.
HammerHill unction station.
iewinsidethe main signal bo .
tensi e collectionof and othermaga ines
anda throughlinefor non stopping trains (photo16), all connected by asubstantial metalfootbridge providing easy access to themiddleof thesite. Thereisalsoa large ground levelstorage facilityfor rollingstock andlocomotives An additional steel foot bridge here givesaccess to this area forpublic viewing(photo17). Afurther attraction at HammerHill is aGarden Railway forthe smallergauges. It toohas asimplebut effective access bridge to thecentreof thecircuit
Thethree loopsare forthe threedifferent railways. The outerloo isthe ummerfields, themiddleloops arefor the ringfield s ailway withits platform on theinnersideof ummerfields station latform -and theraisedtrack is known as the interfield iniature Railway whichhas itsown station. On public running days allthree railwaysoperate independentlywiththeir own tic et officeonthe station. Moving back to theHayes Endofthe site wheretheir fine workshop is located, three
iewing area
travel up to HammerHill where they alight from thetrain to see Santa. Each child receives a presentand then atrain returns to HayesEnd.Thisall works well andtheyare kept very busy with passengers.
steel containers have been cleverly connected together to provideanexcellent workshop area with really good lighting andwhich is e t in first class condition; the‘dirtyend’of theshopreservedfor welding andfabrication andall of the heavierjobs. They have a useful machiningsection with Bridgeport millingmachine andlarge lathecombinedwith abandsaw,drillingmachine, good sizedrollers andfolding machinetogetherwitha couple of good sizedbench grinders Some very neat storageracks andsmall drawer cabinets look aftera rangeoftoolsand fittings. In addition theclub hasa comprehensivelibrary with afullrange of bound ModelEngineer magazines (photo18).
With this comprehensive set-up,the club operates most Sundaysuntil midOctober butduringthe summerthey also operateonWednesdays. In addition to that heavy programme they also have acoupleof‘SantaSpecial’ days in December when the HammerHill stationisturned into a‘Santa’sGrotto’. On these occasions, passengersjointhe trainatHayes Endand then
Membership of theclubis around the125 mark which keepsthe club tickingover very well. They recently held aMembers’Recruitment Daywhich proved to be very rewardingwitha number of newmembers andsome family membersjoining.Those otherclubs whoare lookingto increase theirmembershipmay consider this as beingone way of promotingyourselves; at leastitisworth giving theidea some thought.
In concluding my noteson this very active society, who have areally effectiveand interestingrailway system, Ioffermysincere thanks to Alan Gildersleveand allthe othermembers Imet,for their hospitalityand information. Iho ethatthisfine club continuestoprosper andto offerthe people of thearea agood dayout in beautiful surroundings.
iewofthe HammerHill stationfromthe footbridge
Thee
Thesmall additional footbridge gi ing access to thegroundle el storageshed and
RonFitzgerald takesa look at thehistory and developmentofthe stationary steamengine.
Continuedfromp.19, M.E. 4745, June 14
The Stati onar y Th eS tati Steam Engin e
PART 59 –THE LONDON ROAD COACHAND THE THAMES DREDGERS
Despite the unpremeditated destructionofthe revithic s first ventureinto road locomotion,heremained convincedthatsteam powered transportwas viable and included amoresophisticated versionofa road locomotive with acoach built saloon intended to carry passengers as acentral featureofthe patent.Eighteen months elapsedbetween thesealingof thes ecificationand building aprototype whichisgenerally assumedtohavefollowedthe lines laid down in thepatent ( 18 ).
FrancisTrevithick’s recounting of theeventsthat leduptothe construction of this,the well-knownLondon Road Coach, is confused He seemstosuggest that immediatelyfollowing the destructionofthe pioneering Camborne machine, asecond machinewas built in Cornwall to replaceit. This he refers to as theTuckingmill locomotive, namedafter theplace where it wasfirsttested. In the spring of 1803, it is said to have journeyedthe four milesbetween Camborne andRedruth andafter this trialFrancis maintainsthatit wastaken to London whereit arrivedatthe beginning of May1803: TheTuckingmill locomotive engine hadatthattimejust arrivedinLondon. Thecylinder was5½inchesindiameterwith astrokeof2½feet.With30lbs o steamit or e tystro es
aminute ( 1 )
Although he is nots ecific, theinference is that this second Cornishlocomotive became thebasis of the London Road Coach. Theremay be adegreeof corroboration forFrancis’s accountina letterwhich RichardTrevithickwrote to Giddy in that same month. He givesthe steamcylindersize of thecoach’s engine as 5½ inches bore and2 feet 6inches stroke ( 1 ). With 30 lbs of steamthe engine made 50
strokesper minute It remainsunclear whether thefollowing entriesin Andrew Vivian’s account book whichsummarise the cost of manufacturingthe main components of the London Road Coachcan be equatedwiththe Tuckingmill locomotive or whetherthey standindependently: 1803 January- Wm Westexpenses at MessrsHarveyand Co., preparinga newcylinder. February/March -dittopreparinga boiler.
Fig 189
January1803 -AndrewVivian, -expensesinLondonand quay dues at Falmouth
July 1803- To Felton for buildingthe coach.
Total£83.5.00.
August 1803. To paid Messrs. Foxesshippers, Falmouth for carriageofenginetoLondon. £20. 14. 11.
Once againitwas William West at theHayle Foundrywho wasresponsible forbuilding themechanicalparts andthe boiler. They were assembled andtestedatHayle before beingconveyedtoFalmouth forshipping to London.William Felton,a well-knownLondon coachbuilder,was responsible forthe coachwork, reputedto have cost £207.Westwent to London to assemble the machineryatFelton’sLeather Lane works.
Like theCambornecarriage, theLondoncoach hada short life. hefirst ublic ourney involved acircuit from Felton’s factorythrough Liquorpond oad to ray s Inn oadand then via addingtontoIslington before it retunedtoLeather Lane.Other tripsfollowedin Tottenham CourtRoadand City Road when thespeed reached 9miles perhour. With John Vivian,a relation of Andrew, steeringand Trevithick urging himon, thevehicle proceeded to demolishanadjacentgarden wall with itsrailings. The ownerofthe property wasnot persuadedinfavourofsteam road locomotion
Quiteapart from this more extremetestofthe vehicle’s robustness, contemporary road surfaces calledfor more ruggedconstructionthan mightbeanticipated if the patent drawingwas followed. hechassis wasflimsy and no sus ension is shown. In thepatentdrawing thecoach body is schematically depicted withoutany indication of howitwas to be attached to thechassis. Felton probably followedthe usualpractice in hangingthe coachbody by leatherstrapsfromleaf springsattached to therigid frame, leavingthe chassis andthe machinerycompletely unsprung so that road shocks
were transmitteddirectlyto theengineand boiler.There is also no geared provision fordifferentialactionbetween thedrivenwheelswhen corneringbut thewheelscould be independentlyde-coupled from thedrive so some adroit manipulation mighthave achieved this end. Alternatively thecrudersolutionwould have been wheel slippage
Afew excursions showed signsthatthe vehiclewas shakingitselftopieces. The firebarsweredislodged with everyrun,destroyingthe fire andimpairing steaming.More seriously, theframe became badlytwisted ( 1 ). As aresultthe projectwas abandoned; themachinery wasremoved andre-used to drivea hoop iron rollingmill in SouthWales.The chassis andcoach body were sold off forwhattheywould bring. As thepartnersinthe patent had financedthe ventureentirely from theirown resourcesthe loss wasconsiderable. It was erha s fortunate that thepress seemstohave been unawareofthe exploits of theLondonRoadCarriage butatleast oneinfluential observer hadtaken detailed notice;Simon Goodrich,who wasthe engineer responsible to SirSamuelBentham, Ins ector eneral of aval Works. Goodrich made a sketch of thecylinderand boilerofthe machineand this mayhavebeen hisfirstdirect acquaintance with Trevithick’s work.Thisexperienceprobably played apartinthe events that involved Trevithick in the earliest developmentofthe steamdredger
FrancisTrevithickdevotes achapter to thedredger but againheconfuseseventsand in attempting to claimpaternal priority he fails to mentionthe fact that Trevithick’s dredger projectwas anticipatedby earlierworkundertakenby enthamhimself.In1 , Benthamhad instigated the construction of achain and bucket dredgerpowered by oneofSadler’ssteam engines. his,the first steamdredger of theladderbuckettype, wasnot
readyfor trials untilApril 1802 butits subsequent success in dredging Portsmouth harbourled him, in July 1803, to proposethata second boat should be built.Inthe following montha 14 hp Trevithick engine wasordered fordelivery to Deptford Dockyard;Andrew Vivian’s notebook underAug 6th1803 hasanentry: GeneralBertham [sic] forDeptfordDockyard, 14-horsetobeerected as per agreement……£750.
Benthamwas apparently dissuaded from usingthe Trevithick engine when the boilerofanother Trevithick engine exploded in Greenwich, killingthree andinjuringseveral more ( 1 ), an eventtobe discussedmorefully later. The second Benthamdredger was ultimately built usinganother Sadler engine.The dredging machinerywas to Goodrich’s design andwas built between 1804 and1806 by John Lloyd whohad been responsiblefor thefirstboat sengineering It wascom leted at e tford in December 1806 butdid not enterservice untilninemonths laterwhendredgingbegan at Woolwich
Theaborted plan to usea high-pressure engine in the Benthamdredger seems to have driven Trevithick to pursue theideaunder hisown initiative.Francis Trevithick’s accountofthe events that followedcites twosources. hefirstwas that of homas Bendywho,writing in 1840, relatedthathehad worked on theTrevithickboatwhich wasbuilt fora Mr.Bough ( 18). Bendysaysthat… the machinery as e in theyear 1803 andhis recollections of operatingthe dredgerrelates to work removing stoneand gravel at Blackwall. Francis expandsthisonthe basisofhis second source,Captain John Vivian,who said that he: … sawTrevithickbreakingthe rock at theEastIndia Dock entrance to theThamesat Blackwallusing awater wheel worked by thetideand also asmall high-pressure engine fordriving or turninglarge chiselsand borers andother
contrivances forbreaking andclearingawaythe rock to increase thedepth of water ( 1 )
Although Vivian does not s ecifically mentionthe dredger, FrancisTrevithick interpolates thedate1803 before thequotation and by inferenceassociates the dredgerwiththisdate.
Bendy’saccount continues by saying that in 1805 William Deverell ( )altered the machinerybut used no new materials, sim ly re fi ing the oldand repairingthe engine AccordingtoBendy thecylinder of theenginewas 14½inches in diameter andthe stroke 4 feet.Thiswould be between 12 and14horsepowerwhich is aboutthe size of theengine orderedfor Bentham’ssecond dredger. Bendycontinues, saying thecast-iron parts were made by Hazledine’s BridgenorthFoundry and broughttoWilliamRowley’s factoryinLondontobe finishedbymen from ornwall, although part of themachinery wasmadebyJackson,a Scotch millwright. Theladder bucket chainwas 28 to 30 feet long andliftedfromupto18 feet of water. Within atideof eighthours themachine was capableofraising 180tonsof stoneand gravel
In hisnotes on the developmentofthe steam dredger( 1)Professor Skempton rejectsout-of-hand theclaim that theTrevithick dredgerwas built in 1803.He writes: (d)1803: an incorrect date for steamdredgingatBlackwall. Thestatement by Francis revithic that his ather s rst steamdredger wasengaged in theremoval of BlackwallRockin 1803isnot correct …The earliest evidence fora Trevithick dredger datesfrom1806.
In dismissing revithic s claims,Skemptonchooses to ignore Vivian’s andBendy’s recollections entirely andwhilst thelatter’sstatement certainly contains references that conflictwithother nownfacts it is perhapsworth examining some of theinconsistencies
Centraltodatingthe dredger
is thereference to theworkat BlackwallPoint whichAndrew Vivian maintained wastaking placeatthe entrance into the East India oc and which FrancisTrevithickdates to 1803. TheAct forthe Dock wasnot passeduntil July 1803 andaslandpurchases hadto followthe Act, it is very unlikely that anyworkhad commenced on thelockentranceasearly as that year.Itis ossiblethat confusionhas arisen with aconcurrent projectas, in thesamemonth as thedock Actwas passed, theCityof London’s Port Committeehad acquired powers to dredge the East India om any s riverside moorings.The work,carried outbymen workingfor Trinity House, beganinSeptember 1 . In August 1 ,itwas decidedtoincreasethe depth of thedredgeand,after three months delay, work re-started usingthe contractorsHughes, Bough& Mills.JohnHughes of Poplar wasinpartnership
with WilliamBough as civil engineeringcontractors.When thecontractwas signed for theworkinDecemberthe partnershiphad been joined by John Mills
Underthe same statutory powers thePortCommittee undertook to remove arock outcropfromthe bedofthe Thames at BlackwallPoint Following thefailure of underwater blasting,Jessop, theengineer,decided to use acylindrical iron cofferdam whichwould allowheavy chiselstobeusedtobreak up therockinrelativelywater free conditions.Thisworkbegan in ovember 1 4 andcontinued through1 . In January1 , JamesSpedding took over thecontractand according to Skempton he made use of poweredchisels which worked afterthe manner of conventional pile drivers butemployedsomekindof cylindermounted on afloating pontoon.Skemptonalso
notesthatin ovember1 4, RichardTrevithickasked his friend,the geologistWilliam Smithabout thenatureofthe BlackwallRock.
Theworkdredgingand blasting thematerialat theEastIndia om any s moorings andthe Blackwall PointfromSeptember 1803 untilinto1806 is notinimical with that describedinFrancis Trevithick’s Life buthis date of 1 isdifficultto ustify TheMr. Boughreferredto by Bendyisunlikelytohave been otherthanthe partner in thecontractors Hughes, Boughand Mills whodid not assume thedredgingcontract untilDecember1806. The rock breaking exercise came underSpedding,a separate contractor,but themachinery used with itspower source may well have been Trevithick’s in whichcircumstances it must have post-dated January1806.
TheTrinity HouseBallast ffice inute oo first refers
to an approach by Trevithick offering to undertakedredging forballast in January1806.On 18 February 1806 Trevithick wrotetoGiddy ( )telling himthathewas abouttoenter into acontractwiththe Trinity Boardfor lifting ballast andin Mayhesubmitted proposals forraising ballast by steam power. He wasoffereda 21 year contract to maintain asufficient de thatthe Woolwich warshipmoorings Abombship( ), the Blazer,of300 tons burden, a arently alreadyfittedwith asidemounted bucket ladder, wasplacedathis disposal by TrinityHouse.Onthishull Trevithick erectedone of his high pressure engines. The engine hadbeen fittedbyJuly andthe boat wasdredgingoff BarkingShelf in Septemberand October.
John Farey’sdrawings in Rees’ Cyclopedia show a Trevithick engineddredger ( 1 ). Thetextand the
>> rancisTre ithick sreproductionof ohn arey s dredging boat engra ingwhich frst appeared in ees Cyclopedia
plates were split between separate articles,the text for Dredging-Machine under itsown headingwhilstthe engravingofa dredging machinewas to be foundunder Hydraulics. Theplate is simply entitled Dredging Machine and in thetextthere is no mention of thename Blazer or thefact that it wasa bomb ship,the
REFERENCES
Ref 314 Life… Vol I, p. 120.
vesselissimplydescribed as thehulkofa dismasted ship.The high-pressure steam engine is separately described in the Cyclopedia underthe article SteamEngine ( 1 1). FrancisTrevithickcopiedthe engravings andbrought them together in the Life quoting verbatim from theRees article. Theengineisstated
to be sixhorse powerwhich, accordingtoFarey’s tableof engine sizes( ), would indicate acylinder8 inches by 42 inches,muchsmallerthan Bendy’sstated14½ inches in diameter fora stroke of 4 feet (a horsepower between si teen andtwenty).Itisalso underhalfthe powerwhich Benthamstipulatedinhis order
Ref 315 Life… Vol I, p. 159. Letter from Trevithick to Giddy May 2nd 1803.
Ref 316 John Vivian’s recollection Life Vol. 1p.143.
Ref317 Simon Goodrich and hiswork as an engineer.A.E.Forward. T.N.S. VolIII p. 6.
Ref 318 Life… Vol I, p. 240. Letter from T. Bendyto Francis8th November1840.
Ref 319 Life… Vol I, p. 239. StatementbyJohn Vivian in 1869, then residing in Hayle.
Ref 320 Deverell took out apatent No. 2878 September1805, for asomewhat impracticalsteam engine using twocylinders.
Ref 321 AHistory of the SteamDredger, 1797 –1830.A.W.Skempton F.R.S. T.N.S. Vol.47, 1974-6. Pp 97 et seq
Ref 322 Life… Vol II, p. 143. Letter from Trevithick toGiddy February 18th 1806.
Ref 323 Abomb ship wasa fghting vessel whose sole armament was apair of bomb throwing mortars mounted in the bows.
Ref 324 ATreatise on the Steam Engine, Historical, Practical and Descriptive (1827).John Farey. Vol. II. P. 38.
to Trevithick andVivian. In theevent,the Blazer proved to be under-powered andTrevithickofferedto build forTrinity Housea more powerful boat.Trinity declined andatthe endof January1807Trevithick negotiated to purchase Blazer from theownerswitha view to becoming an independent dredging contractor.The sale wasagreed andhefurther purchasedthe former gunbrig, the Plymouth Barge,of120 tons whichhefitted with one of his10horse powerengines Trevithick’s accountbook recordsexpensesincurredon… theballast machinefrom1805 to 1807 andconfirms that the engine partsfromBridgnorth were broughttoLondonfor erection by Cornishmen.The Plymouth Barge wasatwork in theThamesbysummer 1807. Characteristically Trevithick’s enthusiasm forthe ballast raisingventure quickly evaporated andheseemsto have sold both the Blazer and the Plymouth Barge to Hughes, Boughand Mills by theend of 1807. They used theboats to complete thedredgingof theEastIndia moorings or at BlackwellRockand possibly hiredthemtoJames Spedding In July 1 ughes, Boughand Mills replaced theTrevithickengineofthe Plymouth Barge with a16hp Murrayfour-column engine In this conditionitwas drawn anddescribed by Fareyfor the EdinburghEncyclopedia at whichtimeitwas themost powerful dredgerinexistence
To be continued.
NEXT TIME
Thefurther evolutionof Trevithick’s engine.
John Farey’sengraving of theenginefor thedredgingboat.
