Cement train derailment in Sheffield

[corneliuslundie]

And at a different level, if most maintenance and inspection has to be done at night, how long before people start getting injunctions to prevent night work because of the noise and intrusive light? What then?

Jonathan

[Ncarter2]

On 07/10/2021 at 11:19, alastairq said:

 I think the broken screws were the result of something far more important going wrong, so to speak...the failure of NR to ensure implementation of procedures, the failure of the existing testing technology, etc etc. etc all conspiring to relegate the track maintenance down  to somebody plodding along 'kicking' the fixings. So to speak.

In other words, a Systemic failure within NR, which fed down to the staff on the ground.

I don’t think it’s as clear cut. The section of track is older track construction, timber S&C on a low speed layout. Depending on the track CAT, will depend on what BVI and SVI regime is in place. Dynamic recording of all track is what you want, but it is known and accepted that it’s not always possible, stations being a location where dynamic recording can and does suffer. There are non dynamic methods that are used, as written in the standards which NR works too. Due to the complex layout of Sheffield, they created the plan for the MPV to try and get dynamic assessment of all track, it needs to be remembered that this is not a requirement and as such is above what is needed. Indeed, the TRC Will miss sections due to trains being stabled in platforms, rather than moved into depots. 
 

I have long argued that a regular patroller is not a good thing, fresh eyes and all that. As is alluded in the report, the non regular patroller identified the shuffle, however, the supervisor followed up on this and dismissed there being an issue. I have held various track inspection competencies for the last 18 odd years, indeed, in my current role I often visit sections to review how they are performing and discharging the duties required of them. No doubt, experience was lost, and the railway suffered, but complacency breeds content, I see it all too often where the inspections identify no new faults or no actionable defects, yet I can them do a site review with the team and suddenly they start to point out all host of issues. 
 

A diligent, competent inspector will not knowingly take risk, sadly too many do and all too often it’s in plan sight.  

[Ncarter2]

On 07/10/2021 at 13:25, Bucoops said:

 

I can understand it being an accepted (if not correct) manner of checking on a track walk - but I read the first mention of a kick being by the investigators.

 

Would a tap with a hammer give any clues, similar to the old check for broken tyres? Probably wouldn't ring out even if good but it might be possible to tell. Those screws are pretty strong - do they break often?

Chances are the would be carrying a span-puller type tool, or at least they should. It’s possible you may notice a difference, but it the screws are being held firmly, without giving them a good whack, it’s negligible. The failure mode surrounding the Eastleigh derailment resulted in development of tactile testing of suspected failed housings, not all failed the tactile, and short of getting some bulky equipment to apply a significant load, how else do you test? 
I have seen shears AS screws before, but at the same time, I have seen 30year plus S screws still in the track as intended. It has to be said, there are some issues that need addressing and the local teams need to be clear on what is required of them, there is enough support out there to seek guidance from if they are not sure. 

[Ncarter2]

On 09/10/2021 at 12:09, corneliuslundie said:

Is this failure something which could be detected by any of the current inspection methods, "manual" or on-train? If not, then the components which failed need to be redesigned so that a failure can be detected. But how may of these components are in use on the railway?

And it sounds as though a night-time inspection (as per the coming regime) would make detection even less likely.

Jonathan

Dynamic data that was available didn’t give indication of significant gauge spread issues/concerns. Static measurements where consistent. Short of removing the screws or there being some other significant indicators like excessive shuffle that appears fresh, all screws leaning to the direction of spread or there being gaps under the baseplates, it’s a hidden failure that the inspection process wouldn’t have picked up on, this being reinforced by having the same individuals walk the track each week. 
There exists a differing design, for such locations, and that is the AS HT screws. There is currently a national requirement for all track sections to review S&C in the scope and identify issues not initially obvious, including replacement of the screws with the correct type if required. 
Night time inspections are not as bad as is made out. It’s like anything on the railway, reluctance to change or adapt, we have always done it that way so it’s the right way or the best way.  Example a section was struggling to complete 053 inspections during the day, train service made it near impossible, moved to nights and straight away the inspector is moaning. After the 2nd round of inspections he could not sing the praises of night inspections. He was not rushing and was able to give the inspection the time it needed. The reliability of the particular S&C increased, defects fell. Don’t get me wrong, some locations have such poor asset condition that nights is not viable, but it’s comparatively small, these sites are risk assessed and if they are not able to be done at night, they are not. There is a lot going on with the DFT to get the day time access where it is necessary.  

[Oldddudders]

6 hours ago, Ncarter2 said:

I have held various track inspection competencies for the last 18 odd years, indeed, in my current role I often visit sections to review how they are performing and discharging the duties required of them.

When I read things like that, I tend to take the contributor seriously.

 

Thanks for providing a great deal of background.