RAIB report -- derailment on switch-diamond

[martin_wynne]

The RAIB have published a report today about a derailment at Liverpool Street:

 http://www.raib.gov.uk/cms_resources.cfm?file=/141211_R272014_Liverpool_Street.pdf

It makes interesting reading with lots of diagrams and notes about the working of switch-diamond crossings.

 

The derailment was caused by gauge-spread on a sharply-curved switch-diamond.

Martin.

[TheSignalEngineer]

Reading the report, I'd say it's a miracle nothing more serious has occurred in the incident!

 

Also, our modellers practice of letting derailed trains continue to a point where re-railing occurs automagically is now fully prototypical

Had the next set of points been facing there would have been a large pile of coaches in a confined space with a loco pushing them. The results could have been catastrophic.

 

I have seen this type of re-railing occur in the past, mostly in the days of 4-wheel wagons, but was once called to inspect S&T damage where it happened to the last bogie of a passenger train travelling at about 60mph.

[The Stationmaster]

Re-railing is was not at all unusual in my experience but particularly so with short wheelbase 4-wheeled wagons and it was often easy to trace the course of such derailments (mostly in yards but I do know of at least one incident on a running line which only came to my notice when I found the marks on the sleepers several months after the derailment - there had been at least two derailments at that spot but as they were runbacks through catch points presumably the Perway hadn't worried about them?)

 

BTW I find it strange that a seemingly experienced cohort of Perway men didn't realise the need  for extra vigilance on poor geometry trackwork in a very busy location.  Switch diamonds can be a nuisance at the best of times (hence the WR taking out most of those it installed in higher speed junctions installed from the 1960s onwards plus many older examples) and where track is taking a hammering things are obviously going to be worse and need really close watching.  Sounds more to me like inexperience and inept budgetary control at a higher level restricting the experienced folk from doing what needed to be done when it needed to be done.

[Southernman46]

I suspect that these days (certainly was the case in my experience at Waterloo throat where similar circumstances existed) that even getting access to inspect adequately (that includes under traffic - which the safety people seem to have completely overlooked as a legitimate and essential activity) would need hard work and careful planning to the extent that things get missed / overlooked etc................

 

As TSM it would require a lot of effort, planning, unsocial out of hours work and yes, let's be honest, a degree of risk taking to ensure that I was able to be entirely satisfied with the state of the S&C and platform lines to ensure that there was never had a incident such as this - even missing a couple of weeks would permit things to change - a series of bullhead chairs fracturing on a sharp curve within a platform, for example - and a derailment is a derailment and a failure of the system, no matter where or what speed is occurs at.

 

Within 6 months of me moving on - 2 derailments in 8 weeks.........................I really felt for my successor having to endure such scrutiny in such a short period of time - cos everyone who has never done it seems to know better.................

 

Haven't read the report yet btw - just an opinionated ex-TSM's view..............