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612 SMOKERINGS
News,views andcomment on theworld of modelengineering
616 BUTTERSIDE DOWN
SteveGoodbody writes with talesofthe trials andtribulationsofa modelengineer’s life.
619 ABRSTANDARDCLASS 4 TENDER ENGINE
Doug Hewson leadsusthrough the construction of theBRStandardMogul
623 THESTATIONARY STEAMENGINE
RonFitzgerald tells thestory of the developmentofthe stationary steamengine.
627 KINEMATICS
Rhys Owen looksatthe relationships between distance,time, velocity andacceleration
630 THESHEER BEAUTY OF VINTAGEMODEL TRAINS
Henk-Jan de Ruiter looksbackfondlyatthe days of thetin-platetrain set.
634 WE VISITTHE VALE OF AYLESBURYMODEL ENGINEERINGSOCIETY
John Arrowsmith takesa trip to Quainton Road,inthe depths of Buckinghamshire.
640 ALED MODELOFA LOCOMOTIVE KEROSENE HEADLIGHT
Douglas Pitney discoversthata LED‘tealight’ fits thebill perfectly.
643 BOILER INSPECTOR’S SEMINAR
BobHayter reportsfromthe Echills Wood Railway
644 BOOK REVIEW
RogerBackhouse readsPeter Tuffrey’s book on theShropshireand Montgomery LightRailway
645 POSTBAG
Readers’ letters
648 ATANDEMCOMPOUND MILL ENGINE
DavidThomasrevisitsArnoldThrop’s design of aCorlissmill engine
653 AGWR PANNIER TANK IN 3½ INCH GAUGE
Gerald Martyn buildsa 1366 Classlocomotive from worksdrawings.
656 ANOTHERSTEAM PLANT
IanBeilbyreckons that twosteam plants are betterthanone
661 UNSEIZINGA BEAM ENGINE
MitchBarnesrestoresa nicely made but neglectedbeamenginetoworking order.
Amodel of a1962 Raleigh TrentTourist bicyclemadetoa scaleofroughly 1:5byBill Godrey of Brighstone,IsleofWight (photo: MandyMeadows).
This issuewas publishedonNovember1,2024. Thenextwill be on sale on November 15,2024.
IMLEC2025
MARTIN EVANS Editor
Anotefor your diaries. IMLEC2025will be held at theFareham andDistrict SMEoverthe weekendof the20th, 21st and22nd June 2025. Thefull contactand webdetails will be publishedin theJanuary editionof ModelEngineer.Inthe meantime youcan start practising!
ExtraCurriculars
of nerveconduction) and Martin Ryle (aperturesynthesis in radioastronomy).
Thecomputerwas constructedofthermionic valves (transistors were not availablethen),ofwhich there were about3,000 dissipating 11kW.The machinefilledabout 14019inchchassisina dozen racksand occupied an entire room.Itwas capableofabout 600instructionsper second andthe storecontained 512 18 bitwords
DIANE CARNEY Assistant Editor
Have youeverwonderedwhat your hard-working editor does with thevastexpanse of free time that comeswithhis job? Amongstthe many activities that occupy hisidlehours is workingonthe EDSACReplica ProjectatBletchley Park (photos1 and2). Theoriginal Electronic DelayStorage AutomaticCalculator(EDSAC) wasbuilt at Cambridge University between1947 and 1949 andcameabout when the director of theMathematical Laboratory,Maurice Wilkes, attended aconferenceonearly computersinthe USA. Inspired to producehis ownimproved machine, he sketched outthe design on hisvoyageback across theAtlantic.
Many computer designs, at thetime, claimedtobefirst butthe truthisthattheywere allthe first to displaycertain features.EDSAC claims to be theworld’s first practical electronic stored program computer.Oncecompleted, it became thebasis of the university’s computingservice, thefirstinthe country. In that role,its computingpower was instrumental in helpingtowin threeNobel prizes –for John Kendrewand MaxPerutz (structure of haemoglobin), Andrew Huxley (mechanisms
From analysingproteinsto counting buns –the EDSAC design wasthe basisofthe first commercialcomputer in thecountry,the Leo1, commissioned by J. Lyonsand Co.and used forpayroll and stockcontrol
TheEDSAC ReplicaProject aims to rebuild EDSACinits original form andismannedby a(mostly)agedteamofretired electronicsengineers, one or twoofwhom(incredibly) hadactually used theoriginal machineasstudents. The projectisrun by Andrew Herbert, formerly director of MicrosoftResearchin Cambridge, andhimself a former studentofMaurice Wilkes
TheEDSAC replicashares alarge room with theHarwell WITCH, theworld’s oldest original workingcomputer, at theNationalMuseum of ComputingatBletchley Park.Thisisnextdoor to the codebreaking museum anda visittobothmakes agrand day out. Seewww.tnmoc.org
Sinister
Ihappenedtovisit St Paul’s Cathedrala fewdaysago and descendedtothe crypttovisit theloo (asyou do). Down there, Icameacrossthissign
(photo 3).Unisex(err- good), Accessible(very good), Left handed (what??).Since when hasbeing left-handedbeen ahandicapinthe contextof personal hygiene? Howdoesa left-handedpersoncopeifno left-handedloo is available? Answersona postcard please (writtenleft-handedly,of course).
Cockup Corner
We suffereda little photographic mix-up in our articleonthe GWRpannier tank in issueM.E.4753(October 4th).Photographs 4and 5 arethe wrongway round. I regret this wasnot spotted at theproof readingstage Congratulationstoanyonewho didspotit!
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
National Museum of Computing Youreditorwrestleswiththe machine.
Relieffor theleft-handed
Bikes.
Whether you’ve been searching for the perfect gift forfriends andfamily, or you’re just wanting to tre yourself–look no further!
Pa rt 23 :T he Wo nder so f Te chnology -P ar t2
Detai ls Mat te r
Steve Goodbody takesa
random walk through modelengineering.
Continuedfromp.599
M.E.4754 October18
InPart1,the author expoundedhis view that, while thebenefits o a technology areoften arguable anddi ficultto uanti ye en in hindsight, theresults of ourmodel engineering activities representa clearly beneficialand complementary technology to theirprototypes because, thanks to their more manageable size and accessibility, they areoften betterabletodemonstrate the workings of theirfull-size brethren;especially if the latterare confined, coldly and inanimately, to amuseum.
Phew,whata mouthful
Thedrama of big
Having plantedthe small is beautiful banner upon ButtersideDown’sgrassy plain, in theinterestofbalance andcounterpointit’stimeto contradict myself entirely and thosewho recall my earlier medicalself-diagnosiswith respecttotechnologyare likely shakingtheir headsinpityand Ithank them fortheir concern. Yousee, whileitisindeed “… hard to beat thesensory appeal andmajesty of afull-size engine thundering alongthe main line… , to shamelessly uote
myself from Part 1, Ican think of oneexample which, in my opinion, does indeed sitabove that loftytechnological treat. Letmeexplain It’s 11:50amon12April, 1 1 I’minmyfirstyearat theCrowborough Beacon secondaryschool in East Sussexand thebellhas just rung to mark theend of the mornin ’sfinallessonand the startofour one-hour lunch break. tu fin books, pens andruler roughlyintomybag,I rapidlyheadfor theclassroom door;not exactlyrunning (I don’twanttobeadmonished by theteacher,for that would causea delay),but certainly at abrisker-than-normal pace Once in thecorridorI do break into arun,boundingdown thestairsthree at atimeand, fi eminutes later, burstinto anotherclassroom alreadyhalf full of teachers andstudents. Theroom is darkened because thecurtainsare drawnand a bulkytelevisionprojector sits at thefront in thecentre, itsotherworldlyred,green andblue lenses focusedonthe large screen above.
“Has it started?”I call frantically to afriend, still unable to seethe projected
imagefor theheads of the people in front, andthankfully he shakes hisown head as I work my wayaroundtothe far side of theroom fora clearer view.A teachercalls fororder andwedutifully sitdownonthe provided chairs as more people arrive.Weshush them as they enter.
Theviewonthe screen sinceI arrivedhas remained largelyunchanged,but then,a fewseconds afterour hightechnology digitalwatches register midday, alarge plumeofsmoke appears, spaceshuttle Columbia risesfromlaunchpad 39-A atop ada lin ballo fire andthe first mission o the SpaceTransportationSystem program- STS-1- begins. I, twelve yearsold and mesmerised by this historic spectacle, watchinawe as the boosterrockets detach and fall symmetrically away from themaintank, silently vowing to witnessa shuttlelaunch myself,one day.
Setting ourwatches forwardnearlythirtyyears to 4:53 pm on theafternoon of 24 February 2011, having boardedano ficial bus rom rlandoatfi e o’clockthat morningwithmyfour-yearolddaughter, we,and several thousand otherticket-holding spectators whohad arrivedon similarbuses,cheer in unison as spaceshuttle Discovery repeatsthe same feat as her sadlydepartedsister, from the same launchpad, on STS-133: thespace shuttleprogram’s penultimatejourney and Discovery’s final mission. nd letmetellyou,despite being
Takenwitha long lens from our viewpointseveral milesdistant,Space Shuttle Discovery departsonSTS-133, herfnalmission
asteam enthusiast,and with neithera shadow of doubt nora pang of guilt,evena well-foundsteam locomotive rushingthrough theBritish countrysidecannotbeatthe trulyjaw-dropping sensation when,twenty-eightseconds afterits main enginesignited, andwiththe rocket already in theair,thatwallofnoise finally hits us rom across the six-mile gaptoKennedy Space Centre’s viewingareaand our bodies begintoshake from theinsideout as thedistant fireballascends.Then, ust two minuteslater,atanaltitude of roughlytwenty-sixmiles, we watchspellbound as the boosterrockets againdetach andthe glow of thethree main enginesslowlydisappearsinto space.
It is withoutdoubt themost spectacularthing Ihaveever seen or heard, andI urge you alltowitness aFlorida rocket launch if youpossiblycan:I promiseyou won’tregretit (photo122).
With thescene thus set, let us return to earthand continue whereweleftoff from Part 1.
Four factorsfor success
In my experience,all model engineerslovetopondera good mechanism, whetheritbe aclock,a tram,a locomotive or awater mill (all of whichhave appeared in ourmagazinein recent times, incidentally)and especially if it’s historically si nificant andwellpresented It’s true,isn’t it?And knowing this to be thecase, anddespite my personal disappointment in many technologicalmuseums, Ican saywithout reservation that themuseums at the Kennedy SpaceCentrein
Thebusinessend of a Saturn V frststagebooster, superbly manufactured yetwithanexpectedlifespanof less than threeminutes andwith eachengine– thelargest liquidfuelledrocketengineeverproduced - generating thesamethrustasthe latter-dayshuttle’s threemainengines combined.
Floridaare simply extraordinary -byfar thebestI have ever seen on anysubject,anywhere in theworld –and despite severalvisitstodateI would return time andtimeagain if I couldbecause thereisalways more to take in
Now, to be fair,Kennedy’s museumsdocover apopular subject– spacetravelis belovedbymany– butthenso areBritain’s railwaysand you know my feelings aboutone railway museum in particular whichshouldbegreat and yetmissesthe mark by a mile (see ButtersideDown Part 10 – Privilege andJoy -if youwishtorefer). So,what makesKennedy’s museums so special? Well, in my view it’s
thecurator’s carefulattention to four critical factorswhich, Ibelieve,represent thekey to thesuccessful presentation of atechnological subjecttothe public
Firstly, of course,there’s theengagingnatureofthe technology itself –inthis case auni uecombination of mechanical,electrical, electronic,chemical, structural andsoftwareengineering, the dramatic result of whichis, even when viewed on adim projectorina darkened room in an East Sussexsecondary school,spectacular.While it helpsthatthe underlying engineeringisinteresting,the importance of theengineering is notoverlooked by the museum,itishighlighted and well explained, andthatmakes abig difference.
Thesizeofthe hardware is also importanttoconvey, and yes, IknowI said that smallerscalemodelsoften make largescaletechnologyeasierto appreciate,but theprototype’s size is still important, no matter howbig or small, foritwas made that size fora reason Forexample,myimagination wasinsu ficient ormeto appreciate theenormityofa Saturn V rocket no matterhow many double-deckerbuses or StatuesofLiberty it was unimaginativelycomparedto. No,I only appreciatedits sheer size when Istood beneathone, looked up andgawped.
Next,there’s thesocialand political contextunderpinning
thehistory of thetime; in this case Kennedyand thecold wardriving theSpace Race in the1960s;Nixon andthe ietnamcon ict tri erin its demise andstagnationinthe 1970s.It’simportant to know why somethingwas built and theKennedy museums(sadly, unlikethe aforementioned railway museum)cover that side of things extremelywell.
Andlast, andbynomeans least, there’sthe manner in whichthe artefactsare displayedand thedepthsto whichtheyare explained, which, in thecaseofKennedy’s museums, in addition to being both visually stunning and intellectually stimulating, often allowvisitorsanunexpectedly close-up anddetailedviewof theexhibit’s innerworkings so they canexplore furtherfor themselves if theirinterestis drawn, forthe opportunityis there.
So,withthatall said,let’s look at just acoupleofthe Kennedy SpaceCentre’s superbly curatedexhibitswhich Ithink reinforcethe importance of thoughtful presentation and thefourkey factors- purpose, size,historicalcontext and function anddetail- if a technologicalmuseumisto fascinateits visitors regardless of theirage,interests andlevel o knowled e. ndfinally,I promisetoavoid that dire buzzword‘interpretation’which seemstoplaguesomany museumsthese days and which(in my view)issimply
Interactivedisplaysinfront,aninstructive modelinthe middleand theprototype behind alllayer andcombine to providea wealth of interesting, clearand informative informationtothe visiting public.Inthe author’s opinion, this is agold-standard exampleofa technologicalpresentationin thetwenty-frst century.
Amagnifcentcutaway modelofthe SaturnV launch stack, a work of artinits ownright,withthe original artefact’s second stagedominatingthe scenebeyond.
e
ficient shorthand or dumbed down to thelowestcommon denominator: don’tbother coming in if youare over eight yearsold andhaveany actual interest in or knowledgeofthe subject’.But perhapsI’m being jaded.
Thegrandestscale Let’sfaceit, museum exhibits don’tcomemuchbigger than a Saturn V rocket,built to y butultimatelyrendered redundantbythe Apollo Program’scancellation,lying on itsside, separatedintoits multiple stages andcradled by asubstantial butunobtrusive frameworkabove theheads of themuseum’svisitors. With this absolute monster towering dramatically above, theorderly masses, wandering beneaththe disassembled rocket andgawping at its size andcomplexityjust likeme(photo123)will eventually spot asuperb modelofthe beast, beautifully sectionedand supplemented by abankofcomputerised informationscreens, to aidinunderstanding the arrangement, innerdetails, function anduse of the prototypeand neatly proving my pointabout ourhobby’s uni ue technolo icalcapacity to help explaina full-size original.And while Irealise that supportingthe author’s Part 1argumentwas notthe museum’s primaryreasonfor themodel’s inclusion, it was nice of them to help me out with aperfect exampletoseal thedeal(photos 124 and 125). Now, in thepreceding paragraph, Imadea pointof
statingthatthe Saturn V stack wasseparated into itsdistinct stages,and that’s an important factor for, while Iamsure it wasmoredi ficult or the museum to accomplishthis feat,and therewas probably much soul-searching in the conservation processasa result,inmyviewitwas a brilliant andcrucial decision for, in so doing, importantand fascinatingdetails arerevealed whichwould otherwisehave been hidden from view Furthermore, hadthe rocket remained whole, itsstage-bystagefunctionalitywould be armoredi ficultto isualise andappreciate forthose less familiarwithits workings To summarise,eventhough themuseumdid nothaveto separate thestagesinorder to achieveanimpressive exhibit, in goingtothistrouble they uite literally openedupan additional levelofinterest which, let’sfaceit, should be everymuseum’sgoal.
Yetthiswas just one, albeit writ-large,example of an underlying featurewhich pervades theSpace Centre’s museumsand really sets them abovetheir peersinmyopinion: fordespite thehistorical si nificanceand priceless nature of literally everything on displaywithintheir walls,the exhibits at theKennedy Space Centre VisitorComplex areso thoughtfully andinformatively presented, so accessible andsowell-lit,thatthe interested visitorcan examine theamazingly intricateand beautifully engineered details of each exhibitwithrelativeease andtotheir heart’scontent
Thelittlethings
By wayofexample,inone of thedarkenedexhibit halls sits Apollo 14’s command module Kitty Hawk,its ablative heatshield bruisedand scarred as theresulto a fiery re entry throughearth’s atmosphere on 9February1971(photo126). Thereare some interesting displays andexplanations surrounding theexhibit,the capsule’sdoor is open and theinsideiswelllit andeasy to examinefrombehindthe viewingbarrier
On entering theroom and spying thecapsule,I,likeevery othervisitor Isaw over thenext thirty minutesorso, wandered over,peered throughthe door, wasamazedatthe lack of spaceand thedizzyingarray of instrumentssurrounding the astronauts and, feelingthatthis behind-the-scenesopportunity wassomehow special, had anotherand closer look before moving asidetoexamine the capsule’sexteriorwhile another visitorpeered throughthe door
Aftermyown inspection of theinsideofthe capsule, a family enteredthe room;the father liftedhis youngdaughter into hisarmssothatshe could take alook andshe,after a uick lanceatthe dialsand switches within,pointed at the door,exclaimed in herexcited six-year-old voice“dad, look at thedoor,it’sjustlikethe oneinthe Harry Potterbank!”, carefully examined theintricate lockingmechanism foratleast thirty seconds– alifetimefor a six-year-old –and departed to inspectthe moon-rocksample that hermotherwas peeringat nearby
Butshe wasabsolutelyright, forjustlookatthatdoor!While Iacademicallyknewthatthe capsule’sdoors hadbeen redesigned to open outwards a terthe tra ic pollo 1fire,this beautifully presentedexhibit allows theinterestedand keen-eyedvisitor to examine, in detail andclose-up, what that redesign meantinpractice (photo127). Putsimply, the ualityo en ineerin e identin that door’s lockingmechanism is e uisiteand Imustha e e amined it orfi teen minutes in total, in-between other visitors,because themoreI looked themoreI saw. And to thinkthatI wouldhave overlooked it completely were it notfor that youngchild’s keen eye! Thankyou,young lady, whoeveryou were.
My pointisthat, while the Apollo capsule’sinstant recognisabilityattracted even themostcasualvisitor’s attention, by choosingto presentthe exhibitwiththe door fully open andwith an arrayofexplanatory informationtoexplain the capsule’ssi nificance, each visitorwas given an unexpectedly behindthe-scenes andclose-up opportunitytoexamine some of theunderlying mechanisms andunsung technology behind themoon landings.Furthermore,during my extended sojournwith that capsuleand itsdoor,I noticedthatevery oneofthe visitors wholookedatthe exhibit, includingthatlittle girl,commented on at least onething whichcaughttheir interest,sometimes alargescalefeature butmoreoften asmaller-scaledetail- several of whichI hadalsomissed -and appeared to genuinely enjoyseekingand deciphering thenormally hiddendetails.
It was, in my view,a superbly presentedexhibit in atruly exceptionalmuseumand you canrestassuredthatplenty more awaits should youpay a visit: Ihavecovered only the merest fraction of thetreasures cleverly displayedwithin.
To be continued.
Apollo 14’scommand module Kitty Hawk,beautifully lit and cleverly displayed.
Doug Hewson describes a5 inch gaugeversion of theBRStandard2-6-0 tender engine
Continuedfromp.595
M.E.4754 October18
19
Now that we have gotthe framestretchersout of theway Ithought we mayaswellget on with the motion brackets (fg19).These areverycomplex andwill need some carefulattention IamhopingthatMikeJack in NewZealand will come up with some lost waxcasings forthese two. However, just in case theworst comestothe worst, Iamhopingthatthere will be enough dimensions etc., foryou to make adecentjob
of them as they areveryvisible items, especially theleft-hand onewhich hasthe reversing screwbuilt into it.The whole of thevalve gear dependson thesebrackets. Thereare four smallcastingswhich youwill need with your motion brackets andthese arethe ones which support theexpansion links. They should have alocation keys on thebackofthembut Iomittedthese offmy4MT as Ididn’tthink anyone would notice!Theyneed to be bushed
with bronze andthe bushes will need replacingfromtime to time
Ihaveshown thedrawing forthe motion bracketand thebracketsfor theslidebars areset at 4.57 degrees.Once againthisisa very important dimension. On topofthe motion bracketisperched the platform forthe lubricator.As youwill see, thelubricatordrive rodisshown just abovewhere it says ‘top of frameplate’but Iamnot showingany part of
thelubricatoruntil much later in theseries. Iwill have quitea lottosay aboutthe lubrication, especially as my 4MTis runnin erye ficiently. It would be very nice if youcould follow my instructions forthis. The back of themotionisshown in oneofAndrew’sphotographs (photo 31).Photograph32 is oneofmyancient photographs anditshows thekeyways across wherethe expansion links fit. lsointhe photo raph, thereare thebrake hanger brackets whichyou mayas well fit while youare down there. ote that they arefi ed to theframeswiththe 2mm or 5/64 inch oval head rivets Photograph 33 is just apicture of theright-handmotion bracketcompletelyuncluttered. My photo34 is to show you some of thedetailaroundthe expansionlinkand to draw your
attentiontothe split pins in thebolts whichsecurethe link together.I included theseon my 4MTand Ithink it looksso much betterfor it
Whilstonthe subjectofsplit pins throughsmall nuts,it makeslifesomucheasierwith a10BAnut,ifyou just drill aNo. 54 hole centrally throughone of the ats, youcan then screwa nutontothe bolt to whereyou need theholeand drill thehole throughnut andbolt, easypeasy. Agentleman once came to stay with us oneevening andhetaughtmehow to make split pins for12BAbolts.He said just to usethe wire ties whichcomewithfreezer bags He said,ifI were to scribe a deep lineacrossa bitofround bar, he couldthenlay thewire in thegrooveand scrape it down thehalfits thickness. Youcan then just wrap it round
Aviewofthe keywaysfor theexpansion links.
Expansionlinkdetails.
aNo. 60 drill,there areyour split pins.Anyway, that aside -also, on photo34are thesix oilpipes andI have included a bracketfor theseonthe rear o oneo the sand bo filler pipestoclamp them together
Photograph 35 is just ageneral view of thevalve gear centred around themotionbracket
Onething Itry to do is to always show oneofthe 76s to show theengines off.
Photograph 36 is alovely
pictureof76076 (the one before ouradopted loco)which wasphotographedatSutton OakinJune1957.Ithas the BR2A tender as it hasthe wing plates on thetender! However, Iamnot sure whereSuttonOak is as it must be ashedwhich swappednumbers in the50s.It was8Gpreviouslyand wasone of theEdgeHillgroup of loco sheds.
Generalviewofthe valvegear.
76076 seen at SuttonOak.
RonFitzgerald takesa look at thehistory and developmentofthe stationary steamengine.
Continuedfromp.521, M.E. 4753, October4
The Stati onar y Th eS tati Steam Engin e
PART 63 –BUILDERS I: COALBROOKDALE, KETLEY AND BRIDGNORTH FOUNDRY
UnlikeBoulton andWatt andMatthew Murray, RichardTrevithickdid not establishhis ownengineering workstomanufacture his patent engine.Althoughhe hadmarried Joanna Harvey, he hadnofinancialinterest in the ayle oundry, thefirst buildersofthe engine,and whilstHayle continuedto supplymachinesofthistypeto theirlocalityitisdi ficulttosee howtheycould have extended to meet aTrevithick’sambition fora nationwide market in view of theirgeographical isolation. This factor may ha e in uencedTre ithick butitisequally probable that he wastemperamentally unsuited to thelong-term commitmentinvolvedinbeing tied to asingleestablishment or even to asingleproject Instead, he begantoestablish connections with anumberof engineeringconcernsspread across thecountry whocould actasregionalmanufacturing centres.
Afterthe initialHaylebuilt engines, Trevithick turned to theCoalbrookdale Ironworks. By this time the Dale incorporated several otheriron-making concerns includingthe Horsehay and Ketley works. Theseseparated establishments operated as specialised butinterdependent organisations, feedingeach otherwithsemi-manufactured products.Horsehaywas primarily aforge anda rolling mill producing, amongst otherproducts, wrought-iron boilerplatesand boilers
Ketley made pigironfromits furnaces which, afterprimary rolling, went to Horsehay butin addition it hada machineshop. Both Ketley andthe main works at Coalbrookdale produced engine parts. Therelationshipbetween Ketley andCoalbrookdale largelyrevolvedaroundthe family connectionbetween theReynoldsand theDarbys. TheKetleyfurnaceshad been built by AbrahamDarby II in 1755 and, when Richard Reynolds married Darby’s daughter Hannah, he acquired half theKetleystockholding andbecameresponsible for themanagementofthe site In 1789 controlpassedtohis sons Williamand Joseph, to whom he transferredhis shares
Theactiveand inventive brotherwas Williamwho, judged alongsidecontemporary ironmasters, wasamongst themosterudite,witha wide knowledgeofbothFrenchand n lishscientific literature. Thirty manuscript volumes of hisnotebookswere preserveduntil theeighteeneighties beautifully written andcontainingsuggestions, inventions anddrawings butchiefly copies from the Transactions of theRoyal Societyand other sources …(re 345). Todayonlya single sketch book is known to survive. At hishome, ‘The Tuckies’ in Broseley, Reynolds hada well-equipped laboratory whereheexercised considerable experimental skill buthis talentswerenot purely
academic.Hehad trainedat allofthe Coalbrookdale works and, afterAbraham DarbyIII died in 1789, he became the overallengineeringmanager, responsiblefor most of Coalbrookdale’s technical developments.
Reynolds waskeenly interested in thesteam engine andwas instrumental in introducingBoulton and Watt’sengines into the Coalbrookdale works, at the same time promotingHeslop andSadler’sengines.Itislikely that WilliamReynoldsformed Trevithick’s pointofcontact with Coalbrookdale particularly as Ketley wasmoreconcerned with engineeringthanthe main worksand Horsehay He wouldhavebeenincharge when thetrial engine was built in 1802 andoversaw the first commercialproductions Unfortunately, he died aged 42 in June 1803 and, although hisbrother Joseph carried on fortwo years, he hadnot the same engineeringacumen that Williampossessed.
Increasingly Joseph’s interests were diverted away from industry into bankingand a managerwas installedatthe works.
Production at Coalbrookdale does notappear to have been unduly dampened by the publicitythatthe Greenwich explosionreceived. In 1804, of thetwelveengines that theCoalbrookdale engineer reported on as beingatworkin London,the majority seem to have been built by hisemployer andanother nine were standing
Engravingthatappeared in TheEngineer,November21st1884, basedupona photograph takeninthe CreweWorks PaintShop. Thephotographisnow in the ScienceMuseum’scollection.
complete at theworks,awaiting delivery. Threeofthese were high-pressure enginesworking with acondenser as they were intended fora destination wherecoalwas scarce.The Dale wasalsoproposing to build atwo-cylinderengine. From thesetwo references it is apparent that Coalbrookdale hadassumed adegree of design independence particularly as Trevithick expresseda view that he wouldhavepreferreda single cylinderworkedexpansively rather than thetwo-cylinder engines(re 346). On theother hand he hadconfidence in Coalbrookdale’s standard of workmanship, insistingthat thefirsten ines to be sent into Cornwall by an outside builder should be by them as they wouldbewellexecuted; from Walesheconsideredthat it wouldnot be so (re 34 ). This lattercomment also indicatesthatthe un-named Welshbuilder,almostcertainly Samuel Homfray, wasnow manufacturingfor customersin addition to making theengines used within hisown worksat Penydarrenand Dowlais. Coalbrookdale wasalso buildinglargerengines Amongstthe earliest recorded, awinding engine with a26inch cylinder, wasbuilt forRowley &Emery in 1803 costing£440 with extras at £36.5.11.In1805 John Burlingham of Worcester wascharged for …a steam engine on Trevithick’s plan 18
inscylindercomplete£688.6.8 …WmHeath fora horizontal engine on Trevithick’s plan £266.0.0…
Anotherbuilder whowas subsequently to assume great importance also appearsat this time,WilliamHazledine’s Bridgnorth Foundry. When andhow Bridgnorth became involved with Trevithick’s enginesisobscure.The connectionhad possibly made been by 1803but it wasdefinitely in e istenceby September1804, when seven engineswerebeing built there (re 34 ). In discussing the twodredgers, Blazer andthe Plymouth Barge, it wasnoted that in 1806, engine partsand presumably theboilercame from Bridgnorth.Althoughnot stated,the builder must have been John Hazledineofthe Bridgnorth Foundry.
Hazledinewas amillwright whoestablished afoundry on thewestbankofthe RiverSevernnearthe bridge at Bridgnorth in 1792,eight milesdownstreamfrom Coalbrookdale (re 349). The venturefailedand wasrescued by Thomas Davies who bought thepropertyfromthe liquidators.Subsequentevents areunclear butHazledine was re-instatedasatleast partownerofthe workswhich,by 1810,had transferredsiteto Bridgnorth,Low Town,onthe opposite side of theriver.John wasjoinedbyhis brothers Robert,Thomasand Charles
aylor,the firmcontinuin tradingasJohnHazledine & Co.Daviesremaineda partner (re 35 )and onesource hashim as worksmanager (re 351). Ashare in the companywas also ownedby theManchesterironfounder AlexanderBrodie(1732-1811) Brodie wasa manofsubstance whomanufacturedironand armamentsatCalcutts and Broseley in Shropshire and wasaccusedofbeing apirate builder of theirengines by Boultonand Watt. He also had premises in CareyStreet (later famedasthe street of the Bankruptcy Court, hence… in CareyStreet…), Lincoln’sInn Fields,London, so possiblyhe wasalsoa scientificinstrument maker. Thefactthathewas financially in ol ed in the Bridgnorth Foundryimpliesthat it aspiredtobesomething of greatermomentthana locally importantmillwrighting and foundrybusiness.
TheonlyTrevithickhighpressure steamengineto survivetoday in substantially original conditionwas built by Hazledine& Co.Itispreserved by theScience Museum in
London butwas rescuedin 1883 from ascrap heapatthe railway goodsyardinHereford by FrancisW.Webb(re 352). Webb retrievedthe remains andsoughtout severalofthe missing partsfromthe scrap dealer before transferring theenginetothe LNWR’s Creweworks.There,a careful restorationwas carried out andthe engine continuedtobe housed in theCrewe PaintShop untilitwas transferredtothe ScienceMuseuminFebruary 1926 (fg 2 3 and 2 4). H. W. Dickinson, Keeper of Engineering, prepared a technicaldescription: Theboilershell is of castiron,56in. long,45in. diam and1 in.thick,supported on twocast-iron stools. The back endisdished, while the frontend is flangedtoallow thewrought-iron (shouldbe cast-iron?) fronttobebolted on.Tothisfront is rivetedthe return horseshoeflue, oneleg of whichis18in. inside diam andaccommodatesa grate, 5 sq.ft. in area;while theother legistapered from 12.6in. to 11.25in. inside diam.and joinsthe chimney. Thereis
TheHazledine engine currently displayedinthe ScienceMuseum.
Fig 203
Fig 204
amanhole with coveronthe boilerfront,but thewhole front canberemoved,soastogain access to theinterior. On top of theboilerisa safety valve, theareaofwhich is 3sq. in: figuresmarkedonthe lever, with theweightshown,indicate that thepressure was52lbper sq,in. Thesteam generatedis ledtoa hand adjusted throttle valvesituatedonthe valve chestofthe steamcylinder whichissunkvertically into the boilerand securedbyanupper flange.The steamisadmitted to thecylinderbya four-way cock,workedbytappetfrom thecrosshead; from thelatter twoconnectingrodsreturnto thecast-iron crankshaft below theboiler. Thecylinderis6.37 in.diam. by 30.5in. stroke.The exhauststeam passesthrough aTrevithickpipefeed-heater Theflywheel is 9ft. diam.witha balanceweightcastin.
At thepressure of 50 lb per sq.in. andsay 50 rpm, the engine woulddevelop about7.5 hp.The restored partscomprise thefiredoor andfluering; grate bars;stoolstoboiler; connecting rods;cranks; tappetgear, parts of feed waterpiping; andthe feed pump cistern. (re 353)
Thepreservationofthis engine allows twofeaturesin theconstructiontobeobserved whichmight otherwisehave remained unknown(fg 2 5). Thefirstisthe seam that occurs in theboilerbarrel towardsthe cylinderend Whilstithas notbeen possible to examinethisindetailitis assumedtobea jointwitha lead or leathergasketbetween thefacets, suggestinginternal an es bolted to ether inside theboiler. This beingthe case, thecylinderend of theboiler with itssteam cylindercasing andbracketshas been cast as aseparateunitfromthe rest of theboilershell. This is plausibleascasting this sectionintegrally wouldpose formidable foundryproblems. Thesecondfeature is less easily explained, thedishing of theright hand side of the backplate. John Liffen, retired ScienceMuseumKeeper,has suggested that when Webb came to reassemble theparts
thecrossheadwas reversed andvalve gear tappetrods were wronglyhungonthe left hand side
Themanhole covermounted on thefront-plate of theboiler carries theinscription No.14 Hazledine& Co Bridgnorth In view of thenumberofengines knowntohavepassedthrough theBridgnorthshops by 1806 No.14 must be of comparable date to these. Notablythe name givenisthatof Hazledine &Co., whichpre-dates the re titlin o the firm, Hazledine andRastrick& Co., following John Urpeth Rastrick forminga partnershipwithHazledine
It hasbeen suggested on severaloccasionsthat themissing link between Trevithick andBridgnorth wasJohnUrpethRastrick butthisproposition needsto be examined more closely. Rastrick’s laterprofessional activities warranted an extensiveobituaryinthe Minutesofthe Proceedingsof theInstitution of Mechanical Engineers (re 354)but the record of histeenageyears and hisearly twenties is only brie y dealtwith.
Born in January1780at MorpethinNorthumberland, his father,alsocalledJohn, was amillwrightwho developed thetreadmill forprisons and athreshing machinethatwas laterthe subjectofa patent dispute. John Urpeth was apprenticedtohis father at theage of 15 afterwhich he movedsouth from Morpeth: at aboutthe ageof21… to gain experience as amachinist andmillwright, particularly in theintroductionofcastironfor machinery, then almost in its infancy… (re 355).
Dickinsonand Leemaintain that hisfatherhad movedto London in 1798 wherehewas advertisinghimself from 15 CharingCross Road butthere is no mentionofan …and son… in hispublicity(re 356).
Although John Urpeth was born in Morpeth, theRastrick family hadconnections with Leedsand ancestrally with thevillage of Rastrick near Brighouse. In April1797, the Middleton Colliery bought
oak andash wood from a Mr.Rastrick’sSpringWood near Oliver’s Mill for£1200 (re 35 ). In December 1801, theMiddleton Colliery accounts (madeupannually in December forthe previous year)contain thefirstentry recordin sales of oldmetal to Humble and Rastrick’s Westgate Common Foundry. Rastrick’s partner in theWestgateFoundry was Joseph Humble,the youngest sonofRichard Humble,the managerofthe Middleton Colliery.Josephwas 34 years oldin1 . Thefirm o umble andRastrickrecursinthe Colliery recordsuntil 1805 butsubsequentlythe name is confinedto umble o Joseph Humble died suddenly in NewcastleinSeptember 1808 andin1809Crawshaw &Co.,occupied theWestgate Foundry.
Thefullname… Mr. John Raistrick… (spelt indiscriminately as Rastrick andRaistrick)ismentioned specificallyontwo occasions in theaccounts butonly circumstantial evidence is at presenta ailable to confirm
that theRastrickwas John Urpeth.IfDickinson andLee are correct in moving hisfatherto London by 1798 then Rastrick senior canbediscountedand thepossibilityincreases that it wasthe son, John Urpeth
Assuming Rastrick left Leeds in 1805,thenthe commonly held view that he hadmoved to Ketley in 1801 (re 35 )orby 1802 (re 359)isquestionable. Hisobituarygives no dates merely saying that: …he remained forsometimeatthe Ketley Iron WorksinShropshire andsoon afterentered into partnershipwithMr. Hazeldine (sic)ofBridgnorth, as a mechanical engineer,taking specialchargeofthe iron foundry… Dickinsonand Lee(re 36 ) elaboratethis: …hemadethe wise decision to leavehome in ordertogainexperience; he went southand fora fewyears worked at Ketley Ironworks… at that time underthe enlightened management of William Reynolds Here Rastrick made himselffamiliarwiththe properties andmouldingofcast iron
Thecylinderend of theHazledine engine currently displayedinthe Science useum. eyond thesloping ywheel armthe ointinthe boilerbarrelisvisible The unexplaineddishing in theend platecan also be seen
Fig 205
Againthe statementis unsupported by anysource andlacks positive dates. It mayalsobepurelysurmised that Rastrick wasatKetley when WilliamReynoldswas alive, that is before June 1803. Whatever thecasemay be,whilsthewas at Ketley thereisa probability that he wouldhaveknown Trevithick FrancisTrevithickhowever felt that Trevithick didnot meet Rastrick until1808.Ina single referenceonpage87, Vol. II, he confineshimsel to the sentence: …Rastrick, whom he (Trevithick) hadknown at the Thames driftway hadbecome themanagingengineeratthe Bridgnorth Foundry… Theo ficial obituary makes no mentionofRastrick’s associationwiththe Thames Tunnelor driftway as it was underduringTrevithick’s superintendence.
Theventure wasprojected by aprivate companywhich proposed to connect the northand southsides of the Thames at Limehousebya tunnelunder theriver.The Thames ArchwayCompany obtained itsAct in July 1805 andappointed itsfirsten ineer, Robert Vazie, aCornish mining captain. Aftertwelvemonths of slow progress John Rennie andWilliamChapman were calledinasconsultants Theirrecommendations were considered unacceptable by theboard anditisthought that VaizethensoughtGiddy’s advice.Apparently,onGiddy’s recommendationTrevithick wasappointed as engineer butVaize remained with the company. By August 1807 Trevithick hadbegun to drive adrift at thebottomofthe southbankengineshaft but on January26th1808,an inrush of waterand quicksand took placethatstopped the works. Thecollapsehad caused thebed of theriver to subsideintoa depression and Trevithick proposed to recover thesituation by building two cofferdams, onearoundthe sink hole in theriver bedand anotheraroundthe engine shaft. Theexperienced northeasternminingengineers
WilliamStobart andJohn Buddlewerecalledintoassess Trevithick’s plan andwere favourably impressedbut little progress wasmadealthough some exploratoryboringand pilingcontinued to take place away rom the ooded area, on thenorth side of theriver. Vaizie left theproject at the endof1807and at some point thereafter John Rastrick was appointedResidentEngineer On the21stApril 1808,Rastrick wasinstructedbythe directors to ceaseboringonthe north side of theriver (re 361). He submittedfurther monthly reportsuptoNovember1808 (re 362)but progress had effectivelyceasedbythattime.
Thepoint at whichRastrick first became associated with Hazledine’sBridgnorthFoundry andhence with manufacturing theTrevithickenginehas neverbeen satisfactorily established. Theearliest statementtoidentifyhis presence at Bridgnorth seems to be that of RichardPreen who wasworking in thefoundry in 1809. He recalledthatthe firmwas buildin whatwere calledTrevithick’sengines At that time: …Mr. Rastrick wasconsideredthe engineer (re 363).
Nothinghas so farcome to lightwhich mightantedate Preen’s statementand the titleo the firmisin ariably Hazledine& Co., up until about1810whenitbecomes Hazledine, Rastrick &Co. By Preen’s time Bridgnorth had been supplyingTrevithick en ines or at leastfi e and possiblysix yearsand they hadbeen responsiblefor the dredgerengines.ThatRastrick wasnot connected with these vessels is suggested by a comment made laterinlife when he says that he had neverhad anything to do with boats …. Equally equivocalin dating Rastrick’s connection with Bridgnorth is hiswellknownreply during cross examinationinthe course o thefirst i erpool and Manchester Railway Bill of 1825.Hewas asked: Q. From anyexperienceyou have had… canyou speakasto
A. Aboutten or twelve yearsago Imadeone forMr. Trevithick, thepersonwho hadthe original patent formakingit; this was exhibitedinLondon; Idid not seeitmyself.
This wasanallusion to theLondondemonstration locomotive Catch-Me-Who-Can whichfinally ranin eptember 1808. Rastrick’s …ten or twelve years …would placethe event fi etose en yearsa ter it actually happened. Thewords Imadeone forMr. Trevithick have also been takenas confirmin thatthe locomoti e wasbuilt by Rastrick whilsthe wasworking from Bridgnorth butanother accountmadeby AlbinusMartincalls this into question.Martin, as aboy was givenprivilegedaccess to the enclosurewhere theengineran by: …residentengineer on the
REFERENCES
worksofthe driftway underthe Thames …WilliamRastrick… Martin confuses matters furtherbycallingthe engineer WilliamRastrickbut in this he is almost certainlymistaking thefirstnameand the esident Engineer wasundoubtedly John Urpeth Rastrick.The question remains, couldJohn Urpeth Rastrick have been both Resident Engineer to the Thames ArchwayCompany andengineer at theBridgnorth Foundrysimultaneouslyor didhejoinHazledine afterthe Thames ArchwayCompany projectwas abandoned?
To be continued.
NEXT TIME
We continue with the builders– in Manchester Liverpool andNewcastle
Ref 345 Quoted from John Randall of Madeley by H. W. Dickinson in An 18th Century Engineer’s Sketch Book.T.N.S. Vol. II, 1921-22 P. 132.
Ref 346 Letter to Giddy fromStourbridge July 5th 1804.
Ref 347 Trevithick to Giddy 23rd Sept. 1804.
Ref 348 Trevithick to Giddy fromCoalbrookdale, Sept. 23rd 1804.
Ref 349 Trevithick, Rastrick andthe HazledineFoundry, Bridgnorth S. Morley Tonkin. T. N.S. XXVI, 1947-1949
Ref 350 Trevithick, Rastrick andHazledine op. cit p. 175
Ref 351 Trevithick and Rastrick and the Single-Acting Expansive Engine.Arthur Titley T.N.S. VolVIII 1926-7. P. 49
Ref 352 Webb’s record as apreservationist is far more creditable than Churchward’s or Stanier’s,both of whom deserve to be consigned to Dante’s sixth circle of hell.
Ref 353 Reproduced in Was Hazledine’s &Co’s High-Pressure Engine and Boiler No.14Part of Trevithick’s Catch Me Who Can? John Liffen. Occasional Paper 237. Railway and Canal Historical Society, EarlyRailway Group. John’s contribution to this section has been invaluable. He has my grateful thanks.
Ref 354 M.P.I. Mech. E.,V,p.16, 1857 128-33
Ref 355 Obituary M.P.I. Mech. E.
Ref 356 The Rastricks—Civil Engineers.H.W.Dickinson and Arthur Lee. T.N.S. Vol. Iv 1923-4 P. 48 This reference is not substantiated.
Ref 359 Grace’s Guide but the date is not supported by any source
Ref 360 Op. cit. Dickinson and Lee p. 50.
Ref 361 Trevithick, Rastrick andHazledine.S.Morley Tonkin op. cit p. 175.
Ref 362 Searching for Trevithick’s London Railway of 1808.P.10. John Liffen
Ref 363 Life… VolIp.366
Kine mat ics Kinemat
Rhys Owen presents areaders’ guidetothe lawsof motion
Continuedfromp.586
M.E.4754 October18
Lasttimewetook aquick glance at thepowerfultool calleddifferentiation or thedifferentialcalculus. Now letuslook at reversingthe process.
Integration
If we know that abodyis accelerating at acertain constant rate then,aswehave seen from ourexamination of theequations of motion,we can– provided we know certain information– work out, forany giventime, thevelocityofthat body andits displacement from agiven point.
PA RT 4
Forexample,ifweknowthat abodyisaccelerating at arate of 3ms-2 then we candeduce that after5 secondsitwill have increasedits velocity by (5 x3 =) 15 ms-1
If theacceleration is not constant,but canbedefinedby asuitablefunction, then canwe determinethe body’s velocity in some way? In fact we can, effectivelybyreversing the differentiation process.
To return to theexample above, we canonlydetermine thebody’svelocityata given moment if we know what its velocity is at anothermoment.
Forexample,ifweknewthat thebodymentioned above wasalready travellingata velocity of 10 ms-1 andthen acceleratedinthe same directionat3 ms-2 for5 secondsthenwewould know that at theend of those5 secondsits newvelocitywould be (10+ 15 =) 25 ms-1
Note that,when differentiated, different functionsmay have thesame derivative.Wecan seethis by lookingatthe following examples: Figure 9 showsthe graphof abodyaccelerating from rest
Body accelerating from avelocityof2 ms-1 at time t= 0toa velocity of 10 ms-1 after 4 seconds.
at time t= 0toa velocity of 8 ms-1 after4 seconds.
Figure 10 showsthe graph of abodyaccelerating from a velocity of 2ms-1 at time t= 0 to avelocityof10ms-1 after4 seconds:
In both casesthe acceleration is 2ms-2 giving the graphofthe derivative function (i.e.the acceleration)in fg 11. Remember that 2metresper second persecondisusually written2 ms-2
We cansee that,for agiven function,the levelonthe vertical axis of that function’s derivative function corresponds to thegradient(i.e. therate of increase of thevertical componentrelativeto Theprocess of determining theareabetween thecurve of
thefunctionand thehorizontal axis is knownasintegration
Note!Whena function curve falls belowthe horizontal axis theareabetween it andthat axis is negative
∫umma =sum –a historical interlude
Differentiation andintegration aretwo aspectsofthe infinitesimal calculus and thesubject as we know it wasdeveloped more or less independentlybyIsaac Newton (1643-1727)and Gottfried Liebnitz (1646-1716). Previous pioneersincludedArchimedes, whousedinfinitesimal methodstodetermine such things as thesurface area of thesphere. Newton and Liebnitz used different
notationsand,although Newton’s system is still occasionally used,Liebnitz’s notation nowpredominates althou hinthe rarifiedworld of pure mathematicsa third notation is used). In the17th centuryacademicworkwas largelycarried outinLatin and to indicate integrationLiebnitz used thelon s rom summa, theLatin word for‘sum’ Essentially,westart offwith afunctionthatisthe derivative of thefunctionthatwewish to evaluate.For example, we couldhavethe plot of an object’s velocity.How canwe findthe displacement that hasoccurredifthisderivative function canbegiven in the form of aformula such as we have been using? Figure 12
showsanexample.The red lineinthe fi ureisa plot o the velocity of abodyagainst time Suppose we areinterestedin findin thedisplacemento the body between t= 5seconds andt =23seconds
We canget an approximate answer by dividing up the time period into small, equal, periodsand multiplyingthe time interval of each period by thevelocityatthe startof that period.Thisisshown in fg 13.Herethe area underthe curveinthe original diagram is approximated by nine rectangularstrips, theareaof each representing thevelocity at thestart of atwo-second period multipliedbythe time elapsedduringthatperiod. In this case t seconds.
