Water­loo sug­gests lessons of Clapham crash be­ing for­got­ten, fears RAIB

Rail (UK) - - News -

The lessons of 1988’s fa­tal ac­ci­dent at Clapham may be fad­ing from the rail in­dus­try’s col­lec­tive mem­ory, warns the Rail Ac­ci­dent In­ves­ti­ga­tion Branch (RAIB) in its re­port into Au­gust 2017’s de­rail­ment of a pas­sen­ger train at Water­loo.

The train de­railed on points that were in nei­ther one po­si­tion nor the other, af­ter a sig­nal tester added ex­tra wires to in­ter­lock­ing in Water­loo re­lay room but failed to re­move them once test­ing was com­plete and the rail­way re­opened. In ad­di­tion, plans to clamp and lock the points in the cor­rect po­si­tion were not im­ple­mented.

RAIB calls on Net­work Rail to im­prove the knowl­edge and at­ti­tudes needed for sig­nal de­sign­ers, in­stall­ers and testers to de­liver work safely. In ad­di­tion, it calls on con­trac­tors OSL Rail and Mott MacDon­ald to de­velop and mon­i­tor the non-tech­ni­cal skills of staff work­ing for them.

The ac­ci­dent took place on Au­gust 15, dur­ing a ma­jor block­ade at Water­loo that closed Plat­forms 1-10 while work to lengthen Plat­forms 1-4 took place. This work meant that the sta­tion’s sig­nal in­ter­lock­ing had to be changed. Mott MacDon­ald de­signed the changes, and OSL Rail checked them and de­signed and checked a ‘test desk’ to be in­stalled in Water­loo re­lay room. This test desk could be con­nected to the sig­nalling to make it eas­ier to test in ad­vance of phys­i­cal equip­ment be­ing in­stalled on the track.

How­ever, RAIB found that poor com­mu­ni­ca­tion meant that the test desk was not kept up-to-date to re­flect changes to the in­ter­lock­ing. This meant that when testers came to check the points on which the train later de­railed, the test desk would not work prop­erly with­out ex­tra wires be­ing added to the in­ter­lock­ing’s elec­tric cir­cuits. When added, these wires fooled the in­ter­lock­ing into think­ing all three sets of blades in Points 1524 were in the cor­rect po­si­tion when only one set ac­tu­ally was (be­cause they were in­side the block­ade and had been clamped shut).

As a re­sult, sig­nallers could set a route from Plat­form 11 and clear the sig­nal at the plat­form end for the 0540 to Guild­ford. When it left, the train’s driver no­ticed the points in the wrong po­si­tion. He braked, but could not pre­vent his train de­rail­ing and strik­ing the side of an en­gi­neer­ing train placed to pro­tect the posses­sion from such in­cur­sions.

Clapham’s ac­ci­dent in 1988 was caused by sig­nal tech­ni­cians not prop­erly dis­con­nect­ing wires, with the re­sult that a sig­nal that should have been red cleared to al­low a train past (see pages 48-53).

A sub­se­quent in­quiry se­verely crit­i­cised Bri­tish Rail, and led to rad­i­cal changes in the way sig­nalling is de­signed, in­stalled and tested with each stage be­ing done in­de­pen­dently of the oth­ers.

It is the loss of knowl­edge of why these changes were made that con­cerns RAIB. It said in its Water­loo re­port: “The ma­jor changes to sig­nalling de­sign, in­stal­la­tion and test­ing pro­cesses trig­gered by the Clapham ac­ci­dent re­main to­day, but RAIB is con­cerned that the need for rig­or­ous ap­pli­ca­tion is be­ing for­got­ten as peo­ple with per­sonal knowl­edge of this tragedy re­tire or move away from front line jobs.

“This deep-seated, tacit knowl­edge is part of the cor­po­rate mem­ory vi­tal to achieve safety. Loss of this type of knowl­edge as pre­vi­ous gen­er­a­tions leave the in­dus­try is a risk which must be ad­dressed by or­gan­i­sa­tions com­mit­ted to achiev­ing high lev­els of safety,” it said. ■ See Haigh, pages 54-55.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.