Grayrigg Charges

[sbt]

Why do points fall to bits, with missing or broken stretcher bars? It should be simple to model the stresses with an engineering CAD tool and then design points with the correct materials to stand up to the use. Seems very old skool thinking to rely on blokes walking the line.

Because things wear out over time? You can design something to be a tough as you can afford/like but eventually it will still wear out and need replacing and the only way to keep an eye on things is to get out there and have a look at them.

The points at Greyrigg had a design flaw and were set up wrong. This is my summary from the RAIB report.

It was found that there was insufficient clamping force to hold the 3rd tie bar in place. The design had insufficient margin, by a small amount, designed in to handle bolts that were 'stiff' to do up. That was compounded by the fact that on these points the connection lay over an identification brand on the rail, which reduced the contact area and so the clamping force.

There were also issues to do with maintenance instructions and tools that made it less likely that the bolts would be tightened to the, inadequate, design level. There were no instructions on the need to do so and the correct long torque spanner was not carried by the maintenance and patrol staff who had to use an ordinary, short, spanner.

With vibration from traffic, added to by the fact that the 'closed' switch rail wasn't tight against its stock rail, the bolts loosened and eventually came fully undone.

The points had been set up with the residual switch opening to large, basically the points did not close tightly enough. With the stretcher bar in place the right wheelsets of a passing train pushed the switch and stock rails closer together, which allowed the stretcher bar to pull the open switch rail further from its stock rail. After the bolts loosened this didn't happen and the back of some, worn, left wheelsets were hitting the 'open' switch rail. This 'hammered' the mechanism of the points, including the third stretcher bar, which was repeatedly 'crushed' between the left and right switch rails until it broke.

Without the third stretcher bar parts of the point mechanism (the Secondary Drive) that were pulling the left (open) switch rail away from its stock rail could no longer do so and the gap between it and its stock rail closed. A stray bolt between the switch and stock rails held the gap partly open but eventually one of the wheelsets on the accident train went the 'wrong way' and the derailment resulted.

The points would have failed eventually with the bolts on the third stretcher bar lost but the time taken for this to happen would have been much longer if the points had been set up correctly.

The report is worth a look, get it here:

http://www.raib.gov.uk/publications/investigation_reports/reports_2008/report202008.cfm

 

[Old Timer]

Its all rather telling that the very people who were so condemnatory about Jarvis are now deafening us with their silence when its Network Rail that is responsible.

 

[Trog]

I remember those days, and coming back on Sunday night to see which Possessions which should have finished at 1600 were still on !

It was alright for you I would still be there from Saturday night.

A bit groggy but happy over the fact that I had already earned a weeks wages and it was still only Sunday.

 

[Old Timer]

It was alright for you I would still be there from Saturday night.

A bit groggy but happy over the fact that I had already earned a weeks wages and it was still only Sunday.

And the same to look forward to the next weekend as well

 

[Hydro]

Walking the line should also help pick up on thing like the state of vegetation and infrastructure. Even if your track became maintenance free your tunnels and bridges wouldn't.

Track patrolling is a 360 degree art. It's not about spotting defects. It's about spotting a defect, and finding the underlying cause. A wet bed forming leads to drains being inspected, a slack means you're checking the embankments and even mining history of the local area. Rail foot corrosion in tunnels or bridges, let's check for cracks or leaks in the surrounding structure.

It's due to this that computerised and automated systems will never fully replace track patrolling. Supplement it, yes. Replace, no. Speaking as someone who has experience of both Basic Visual Inspection and Supervisors Visual Inspection, and of experimental/prototype automated train borne inspection systems, I can get a realistic idea of what SHOULD be aimed for.

The NMT came under a lot of flak for not picking up the problems with the S&C at Grayrigg. The fact is the NMT's video systems were NEVER able or designed to identify or pick up that type of defect in real time. The geometry measurement systems will only flag up a fault if the geometry was affected. All the PR and hype about "The NMT can do the work of 100 men" is rubbish. Always was, and always will be. Patrolmen never measured the track in real time dynamic terms. The NMT never inspected stretcher bars or fishplates. The idea of trainborne examination and visual inspection should complement each other. Not compete. I believe this should be reinforced even more thoroughly with the forthcoming advent of Plain Line Pattern Recognition inspection regimes.

 

[Old Timer]

The knack is to identify a defect before it becomes a defect !

Permanent Way men will know exactly what I mean by that contradictory remark.

 

[9K43]

I remember those days, and coming back on Sunday night to see which Possessions which should have finished at 1600 were still on !

I also remember on over-runs when there was no relief, sleeping in the brakevans of ballast trains when train working inspector, with a request to the Driver to give it a good snatch when he moved forward into the site, so that I woke up and climbed off to deal with the next one coming up behind.

Thing was we kept the job running, and the renewals got done as well, and the slack in the timetable also helped.

I have been on many of those over running jobs, one was at Hare Park Junction, when the engineer put the points in the wrong way.
Also the PW lads had an open invitation to come into the brake and get warm.This I might add was a no smoking brake van.
I have seen the back cabs of engines crammed full of the Per Way, not a problem.

 

[Old Timer]

I have been on many of those over running jobs, one was at Hare Park Junction, when the engineer put the points in the wrong way.
Also the PW lads had an open invitation to come into the brake and get warm.This I might add was a no smoking brake van.
I have seen the back cabs of engines crammed full of the Per Way, not a problem.

Ah the days when everyone pulled together to get the job done - sadly now no more, at least in the UK.

 

[Hydro]

I have seen the back cabs of engines crammed full of the Per Way, not a problem.

I was working a rail drop job one night a couple of years ago as part of a gang sent down to observe the drop and do any manual barring/adjusting if required. Job was going very well, skilled RDT crew. Only 4 of us on site, bloody freezing and starting to rain to boot and it was obvious we weren't really needed but we couldn't leave early. "Any chance of a warm in the engine, drive?" "No, sorry lads. You know how it is nowadays." "Any room in that operators cabin, mate?" "No, sorry guys, no unauthorised persons allowed on the train". Early night turn finishes were a pain, no early home for me as I got the train to and from work. Dropped at the station well before the first train and asked the sole remaining TOC rep there "Any empties going down to xxxx I could cadge a lift on mate?" "What do you think this is, the 70's?" was his reply...

Getting around the network a bit in a different role has opened my eyes to the flashes of good camraderie that still exist however. Everyone wants to get the job done, the "us and them" culture remains mainly in the management echelons. That attitude has a nasty trickle-down effect sometimes however...