Class 142 Bodyshells

[61653 HTAFC]

That's actually not much damage for a head on collision, although, given the location, I imagine it will have been a low-speed collision.

It doesn't look like much at first glance, but note the location of the crew door and of the steps which should be aligned with said door. You may also note that the bodyshell is tilted slightly nose-up. The bodyshell appears to have become detached from the underframe and has slid backwards, much like the 142 at Winsford, albeit to a lesser degree.

 

[MG11]

It doesn't look like much at first glance, but note the location of the crew door and of the steps which should be aligned with said door. You may also note that the bodyshell is tilted slightly nose-up. The bodyshell appears to have become detached from the underframe and has slid backwards, much like the 142 at Winsford, albeit to a lesser degree.

Yes it does, but if you also look at the picture of the Winsford crash posted earlier, the Class 86 also appears to have become detached from the underframe, so perhaps this is a problem that's not unique to the Pacers?

 

[sprinterguy]

Yes it does, but if you also look at the picture of the Winsford crash posted earlier, the Class 86 also appears to have become detached from the underframe, so perhaps this is a problem that's not unique to the Pacers?

It was a class 87, and it didn't become detached from its underframe, it was lifted off its leading bogie.

 

[Wilts Wanderer]

The 156 had a bit more damage than that. There was talk of having to write off a vehicle. If you look at pictures of the 156, the body was distorted back to the second window.

I've seen a picture of the 156 having basically a new cab fitted. In the event it wasn't written off, presumably the difference being the monocoque body/frame assembly wasn't broken or bent?

 

[sprinterguy]

In the event it wasn't written off, presumably the difference being the monocoque body/frame assembly wasn't broken or bent?

Indeed: The 156s have been involved in some quite violent, and in one instance fatal, collisions, yet a single vehicle has yet to be written off or withdrawn.

 

[Peter Mugridge]

It doesn't look like much at first glance, but note the location of the crew door and of the steps which should be aligned with said door. You may also note that the bodyshell is tilted slightly nose-up. The bodyshell appears to have become detached from the underframe and has slid backwards, much like the 142 at Winsford, albeit to a lesser degree.

As originally designed, the Pacer bodies were held on by four bolts, one at each order, which were designed to shear off on impact in order to reduce the crushing damage to the bodyshell. It follows that in this instance and at Winsford the bolts performed exactly as they were designed to do.

Given that the bodyshells are now much more firmly fixed to the underframes, it would be interesting to see what would happen to the bodyshell these days should one suffer a heavy impact. Look at the pictures of Winsford, then imagine what would have happened to the bodyshell had it not detached from the underframe; it would not be just the end that got crumpled - the locomotive would very likely have been half way along the inside of the carriage.

 

[edwin_m]

That's actually not much damage for a head on collision, although, given the location, I imagine it will have been a low-speed collision.

It looks very much as if the underframe is bent downwards, which would be a major repair and presumably not economic. Ironically the body has probably survived better!

 

[507 001]

As originally designed, the Pacer bodies were held on by four bolts, one at each order, which were designed to shear off on impact in order to reduce the crushing damage to the bodyshell. It follows that in this instance and at Winsford the bolts performed exactly as they were designed to do.

Given that the bodyshells are now much more firmly fixed to the underframes, it would be interesting to see what would happen to the bodyshell these days should one suffer a heavy impact. Look at the pictures of Winsford, then imagine what would have happened to the bodyshell had it not detached from the underframe; it would not be just the end that got crumpled - the locomotive would very likely have been half way along the inside of the carriage.

Well, considering they’re all being withdrawn in a year or two, maybe we could arrange a repeat of the ‘nuclear flask test’.....

 

[Peter Mugridge]

Well, considering they’re all being withdrawn in a year or two, maybe we could arrange a repeat of the ‘nuclear flask test’.....

That could be quite interesting actually....

 

[dubscottie]

Well, considering they’re all being withdrawn in a year or two, maybe we could arrange a repeat of the ‘nuclear flask test’.....

They should do it with a member of the "star" family. 170/357 etc.

They are bolted together. I remember there was talk of a crash test after Ladbroke Grove but it never happened.

 

[dubscottie]

Indeed: The 156s have been involved in some quite violent, and in one instance fatal, collisions, yet a single vehicle has yet to be written off or withdrawn.

Thanks to the simple design. 2x 150 vehicles went to the scrapyard and I think at the time the same was expected for the 156 vehicle. Spent long enough in Doncaster works.

 

[edwin_m]

They should do it with a member of the "star" family. 170/357 etc.

They are bolted together. I remember there was talk of a crash test after Ladbroke Grove but it never happened.

If there was a structural issue at Ladbroke Grove then it was the welding of the aluminium, which introduces a weakness. Welding was used on the 158 and the various Networkers but the "stars" used bolts instead. Hitachi use welding but it is a different technique that is stated not to weaken the metal.

In any case, the steel DVT at Great Heck didn't stand up much better than the aluminium Networker at Ladbroke Grove, in a similar type of collision. And the lack of any similar collision to the large family of Star types, some of which have now been in service for 20 years, shows how much this type of collision has been reduced by TPWS and other measures.

 

[dubscottie]

If there was a structural issue at Ladbroke Grove then it was the welding of the aluminium, which introduces a weakness. Welding was used on the 158 and the various Networkers but the "stars" used bolts instead. Hitachi use welding but it is a different technique that is stated not to weaken the metal.

In any case, the steel DVT at Great Heck didn't stand up much better than the aluminium Networker at Ladbroke Grove, in a similar type of collision. And the lack of any similar collision to the large family of Star types, some of which have now been in service for 20 years, shows how much this type of collision has been reduced by TPWS and other measures.

Ladbroke and Great Heck were 2 different accidents and the combined speeds were vastly different.

I would need to dig out the reports but it was circa 90 mph at Ladbroke and circa 140 mph at Heck.

 

[edwin_m]

Ladbroke and Great Heck were 2 different accidents and the combined speeds were vastly different.

I would need to dig out the reports but it was circa 90 mph at Ladbroke and circa 140 mph at Heck.

I agree there are differences but the lack of anything closer shows how few train-to-train collisions we have these days. So there is really no reason to worry about travelling in a particular train that might be a bit less crashworthy than another train.

 

[MG11]

I agree there are differences but the lack of anything closer shows how few train-to-train collisions we have these days. So there is really no reason to worry about travelling in a particular train that might be a bit less crashworthy than another train.

I disagree, if I ever was unfortunate enough to crash, I'd hope to be on a Meridian and not a HST. Google Image search FGW Hits Tree and you will see why!

 

[Wilts Wanderer]

I disagree, if I ever was unfortunate enough to crash, I'd hope to be on a Meridian and not a HST. Google Image search FGW Hits Tree and you will see why!

I'm guessing you normally travel in the driving cab as opposed to the passenger coaches where there were zero injuries / fatalities / grazed knees / possibly a spilt coffee...

 

[yorkie]

I disagree, if I ever was unfortunate enough to crash, I'd hope to be on a Meridian and not a HST. Google Image search FGW Hits Tree and you will see why!

I hope you don't walk, cycle, drive, or travel by bus/coach anywhere then because the risks of travelling in a HST are much reduced in comparison to those other modes.

An instruction to carry out a search doesn't count as evidence, especially when the search shows that zero passengers were injured in the incident in question.

 

[sprinterguy]

I hope you don't walk, cycle, drive, or travel by bus/coach anywhere then because the risks of travelling in a HST are much reduced in comparison to those other modes.

An instruction to carry out a search doesn't count as evidence, especially when the search shows that zero passengers were injured in the incident in question.

If you happen to drive the things day in, day out, then it's a very credible concern. Gone are the days where we necessarily, and regrettably, expect the driver to bear the brunt of any impact as a component of the crumple zone.

 

[edwin_m]

I was referring to "train to train collisions" such as Great Heck and Ladbroke Grove. The energy in these collisions is such that the vehicles involved are effectively destroyed, regardless of what type of train it is. But they are increasingly rare, with none since Great Heck. The question of obstacles on the line, including vehicles at level crossings, is different and still very much a live issue.