Brakevalveclosedon runawaysleepertrain
AN RAIBinvestigationinto a CaledonianSleeper'Lowlander' sleeperservicethat failedto stopat EdinburghWaverleyon August1 lastyearhasdetermined the brakepipe isolatingcock betweenthe locomotiveandthe leadingcoachwasclosed.
Theinvestigationsaysthe cock becameclosedduringcoupling operationswhen the Edinburgh train wassplit from the Glasgow portion at Carstairstation.
Thishappenedafterthe mandatedbrakecontinuitytest had beencompleted.
Aftercompletingthe brake continuitytest,the drivernoticed the shunterhadonly connected one ETScable,but on attempting to do so,the shunterhaddifficulty andwasassistedon the trackby the driver.
Onceconnectedt,he train departedandthe driver undertooka runningbraketest within five minutesof leaving, which slowedthe train.
Sixminuteslater,afterpassing Cobbinshawsummit,the train reached87mphat which point the driverthen madethe first of manyshortservicebrake applicationsto controlthe train's speedon the down hill gradient towardsWaverleyJ.ustafter Curriehillstation,the pantograph unintentionallydroppedand it isverylikelythe rheostaticbrake stoppedworkingatthis point, leavingthe driverwith friction brakeson the loco,No.92020.
Whythe pandroppedisnot stated.
Asthe train nearedSlateford station,the driverrealisedthe train brakeswerenot performing asexpecteda, nd beforethe train approachedHaymarkeEt ast Junctionthe driveroperatedthe emergencybrakeplunger.
Thishad no immediateeffect, andwith the train still travellingat 41 mph,it enteredthe 20mph speedrestrictionat PrincesStreet Gardensa, t which point the driver madean emergencycallto the signallingcentreadvisingof brake problems,requestinga clearroad throughWaverley.
Thetrain manageralsorealised therewasa problemwhenthe train passedthrough platform 11andoperatedthe passenger alarmbutton,which haltedthe train,with the locoandsome carriagesin CaltonSouthtunnel.
It wasquicklyidentifiedthe cockwasclosedand permission waseventuallygivenfor the train to reverseinto the platform.
Theisolationcockwasknocked closedduringthe connectingof the jumper cable,but happening postbraketestwith the brakes chargedto five bar.
Thedriveralsofailedto sound the train in distresswarning, RAIBsayinghad he doneso it is possiblethe train managerwould haveheardit andeithercalled the driveror usedthe passenger alarmbutton earlier.
Investigatorsalsosaidhadthe routenot beenclearit ispossible a collisionbetweenpassenger trainsat significantspeedcould haveoccurred.
RAIBhasnow mandatedthe brakecontinuitytest isonly carriedout afterall coupling activitiesareconcluded.It also recommendsa reviewof the designof the isolatingcock becauseof its vulnerabilityto undetectedor inadvertent operationor beingknockedby foreignobjects.
CaledonianSleeperand GB Railfreighthavealsoreviewed and amendedsomeof its procedures.