S-Stock Trains (1)

MQT on 2011-02-23
Session date: 
February 23, 2011
Question By: 
Caroline Pidgeon
Liberal Democrats
Asked Of: 
The Mayor


How many incidents of S Stock Traction Shoe loss have there been since the trains have been introduced? How much have these incidents cost, why were the S Stock trains fitted with light weight alloy shoes when the A60 has more substantial traction current shoes and is this a case of cutting corners? What is being done to prevent this from happening again?


Answer for S-Stock Trains (1)

Answer for S-Stock Trains (1)

Answered By: 
The Mayor

Traction shoes are designed to come off if they strike anything unexpected, to prevent more significant damage to trains. This is the same for both A and S stock trains.

S stock manufacturer Bombardier has identified that the original shoe design needed some adjustment in this respect, and has modified them accordingly. Since this modification two shoes have been lost, and Bombardier is testing these to double check that they were legitimate losses, and not due to any stress fracture within the shoe itself.

Lost shoes are being replaced at Bombardier's expense, pending formal acceptance of the shoe design being fit for purpose. It should be noted that the shoes fitted to the S Stock (including the original design) were of the normal cast iron material and not of a lightweight alloy type as suggested.