Whatever must IKB be thinking ?!

I have just read the press reports which are vague and sensational. There appear to be two separate failures, one of the suspension and the other of the "chassis". I am sure that we will not be told more. It is odd that the worst failures are on GWR, some of the track originally built by IKB.

If I was cynical I would suggest that unreliable, uncomfotable trains would be a good method to get passengers off our overcrowded railway. It makes more sense than building HS2 to free up space for freight.

I could go on but this is far too complex a subject and I am sure the Moderators will step in sometime. Was Robert Stephenson a greater engineer than IKB?

JA

E s Cox wrote many years ago that hardening equipment for railway service was not easy. He was writing about diesel engines at the time, but it took time to get the English Electric engines that became widely used up to a reliable condition. The Brush Sulzers had to be derated after crank case cracking occurred.

This latest problem appears to be cracking of aluminium by prolonged minor vibration. Aluminium and its alloys are susceptible to this problem. Steel components can be stressed, but as long as the stress is below a limit their life can be long or very long. Aluminium has no such lower limit, even minor stressing leads to failure in the long term.

Mike Potts

Al 2024 has a very high cyclic fatigue strength, but is very expensive compared to a lot of other alloys. I was told with Al made parts, it's not if it will fail, it is when will it fail. It is why aircraft need a lot of inspections. In NZ was a company making Al freight truck trailers , but had a lot of issues with cracking of the main chasis frames. It was from loads that were just centre placed like they did with the steel frame trucks. There are many stories about equipment being damaged by the vibration of the track joins on the cargo being freighted by trains over long distances. The best part is that the cracks have been detected long before any catastrophic failure.

Picture here [also available at other places] : **LINK**

https://www.devonlive.com/news/devon-news/pictures-show-cracks-stopped-gwrs-5390963

MichaelG.

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This is offered only as a ‘find’ ... I am not qualified to comment ...

Please note the date of the first post:

**LINK**

https://www.railforums.co.uk/threads/gwr-withdraw-some-800s-due-to-cracks-in-yaw-damper-bolsters.216705/

MichaelG.

As per JA's suggestion to make trains more uncomfortable to reduce 'overcrowding , I can reliably say this has been done with new Spanish stock to replace the old 'Pacers'.