UK High Speed Rail services canacelled after cracks found in trains

[Drunkenclam]

This story has been floating around the Uk for a couple of days regarding the Hitachi 800s

 

https://www.bbc.co.uk/news/uk-57036247

 

According to a report I heard on the radio. The part with cracks is the crane lifting blocks where the body is removed from the chassis, rather than the chassis its self.

[Claude_Dreyfus]

[Welshbloke]

Yep, it's a bracket which connects the yaw damper to the bodyshell. Kind of like a shock absorber, they stop the bogies from building up a cyclical yaw which could eventually result in derailing. You can imagine the loads on it and why it would be catastrophic if one broke off at speed, even if there was no derailment there would still be a hefty lump of metal flying through the air.

 

AIUI this all comes from work BR did into raising train speeds without derailments, there were some spectacular pileups of the old 9' wheelbase 4w wagons at speed on continuously welded rail which triggered the studies. Until that point there hadn't been much research into wheel-on-rail dynamics, it would eventually feed into the HST and APT projects of the 70s and 80s as well as many others globally.