Could additional Mk.4 carriages be produced?

[gordonthemoron]

a very heavy armour plated windowless tube, that's a pendolino, isn't it?

 

[starrymarkb]

a very heavy armour plated windowless tube, that's a pendolino, isn't it?

The pendo bodyshell is very light for its strength. (a lot of the weight is tilt gear etc) It uses spars along the body. The windows have to fit between the spars. Have a look at a Euro Pendo and you'll see the same thing.

I guess you could try having a structure like that in the Regioshuttles (trussing), but that does give odd shaped windows

 

[Pumbaa]

It still worries me that Mk 3s splinter as they do in accidents and yet remain in use in large numbers in this country.

The Government have the answer to that my friend - it's called IEP! And yet, still want HSTs to remain till 2035 - sorry 2020... Whoops, where did that come from?

 

[djw1981]

The IEP is overweight over engineered and unfit for purpose though.

 

[Pumbaa]

As far as I'm concerned, I think the only route the IEP should be deployed on is the fast line to the bin.

 

[starrymarkb]

But what to get instead? I know we in the far west aren't getting IEP...

 

[A60K]

Neither... They are their own bespoke design (much like the 156 is a bespoke design that happens to use some of the Mk3 parts bin)

One small point - the Class 156 is from Metro-Cammell, and I think any common parts would be shared with the Mk4 which Metro-Cammell also built - I'm guessing that's what you knew and meant to write anyway!

The raiding of the Mk3 parts bin was done for just about every other EMU or DMU built in the 1980s though, apart from those not built by BREL. Instead the first Pacers and the 155s raided the Leyland National bus parts bin.

(For our younger readers, Metro-Cammell eventually became part of GEC-Alsthom and now Alstom)



--- old post above --- --- new post below ---

The Mk 4 was a great step forward from the Mk 3. If you compare how badly the Mk 3s crumpled at Southall for instance, compared with the behaviour of the Mk 4s at Hatfield and Selby, the Mk 4 stands up remarkably well. No coach folded anywhere near that badly at Hatfield, and even the worst at Selby (the buffet) generally stayed in one piece despite the huge forces exerted on it. It still worries me that Mk 3s splinter as they do in accidents and yet remain in use in large numbers in this country.

To be honest those accidents are not comparable - impact angles, movement of the vehicles after the accident, obstacles after impact - all of these mean vastly different forces on the vehicles.

At Southall the coaches piled up behind a heavy static object with nowhere to go, with the whole train stopping instantly.

At Hatfield the rear coaches went rolling off the rails because of centrifugal force and didn't impact with anything significant apart from OLE stanchions mentioned above.

At Great Heck the DVT hit the freight engine across part of its width and was largely destroyed with the coaches following being deflected into an empty field and hitting little or nothing other than themselves.

At Grayrigg the train was derailed and then slid down a bank slowing down and hitting nothing major - the OLE mast was hit at a gentle angle compared to Hatfield and was less solid.

You can't extrapolate from these accidents that Mk3 is less safe than Mk4 - have a look at Colwich to see the exceptional strength of Mk3 stock in a high-speed head-on collision. The Mk4 stock has not been involved in such an accident yet, and hopefully it never will be.

I'm sure that all modern stock is good in accidents, with different accident circumstances having different effects in different ways. Without running a comprehensive controlled test series of crashes (such as EuroNCAP for cars) no definitive statement can be made.

 

[starrymarkb]

Nope - Having had issues with Union acceptance with the class 151 as IIRC the union refused to crew anything that wasn't built by BR (same union) - (remember that the orders were placed before Margaret Thatcher reduced the power of the unions) - Metro Cammell decided to use Mk3 parts (windows are the most obvious) so that the union couldn't do the same again to the 156

 

[yorksrob]

I guess you could try having a structure like that in the Regioshuttles (trussing), but that does give odd shaped windows

A train built with a trussed structure might look quite good - a bit like the London Gherkin on it's side

I saw some pictures of the 151's. Would have been very nice trains for short distance commuter runs if only they'd gone into production.

 

[WillPS]

Nope - Having had issues with Union acceptance with the class 151 as IIRC the union refused to crew anything that wasn't built by BR (same union) - (remember that the orders were placed before Margaret Thatcher reduced the power of the unions) - Metro Cammell decided to use Mk3 parts (windows are the most obvious) so that the union couldn't do the same again to the 156

I'd be very surprised to learn that the 155's basic body structure is not based on a Mk.3... I was under the impression that only the windows and interior lighting were Leyland National parts. Certainly if you look at the two from a footbridge it's hard to pick apart the differences.

 

[starrymarkb]

It isn't - its actually based on the 142 body

 

[Daimler]

I'd be very surprised to learn that the 155's basic body structure is not based on a Mk.3... I was under the impression that only the windows and interior lighting were Leyland National parts. Certainly if you look at the two from a footbridge it's hard to pick apart the differences.

The roof gives it away though - 156s have the 'ribbing' along the roof as does a Mk3 coach, while the 155s do not.

 

[Failed Unit]

Sorry, but I would take issue with that. The Mk4 at Hatfield showed the designs weaknesses - and the buffet car certainly didn't maintain its integrity. They are not bad designs, but they're not as good as they could be. More modern trains are better and safer due to newer standards and the lessons learned from the past.

Shame that they don't learn from the past and make the internal enviroment for the passenger better, according the recent passenger focus survey the pendo's and voyagers are the least liked passenger trains on IC routes, saying that the 222's were top.

Back to the structure, the buffet did fail at Hatfield, but look at Great Heck the coaches all stayed in tack (except the buffet and DVT). Is the problem with the buffet rather than the mk4's in General?

 

[Royston Vasey]

Snapper, I appreciate your point and it's true no two accidents are the same; fortunately we haven't seen enough comparison between accidents of each type with each vehicle. There are some comparisons to be made between Great Heck and Grayrigg in that most coaches hit little but each other and slid down a bank with other coaches. Certainly the Pendolino coped exceptionally well at Grayrigg other than some largely cosmetic damage. Much of this will have been down to the crumple zones engineered into that design. Small windows = small price to pay for structural integrity in an accident.

As for an NCAP style test, there's no reason but money (which isn't a valid excuse) why at least scale models or portions of coaches couldn't be crash tested.

 

[route:oxford]

Why would they bother building new MkIV stock?

If it was felt necessary to strengthen the 225 sets (of which there are 31?), wouldn't it be easier to....

• Order 77 brand new 140mph capable carriages based on current "off the shelf" Turbostar or Desiro designs (obviously) built to intercity standards.
  
• Arrange and fit-out the new carriages (to include a starbucks/costa/subway/buffet) into 7x11 rakes.
  
• Test Intensively
  
• Replace existing 7x9 rakes with new 7x11 rakes.
  
• Refurbish 48 of the removed 7x9 carriages where appropriate and insert 2 into each of the remaining standard 24 sets.

This leaves 7 buffets and 8 MkIV carriages. Will leave someone else to suggest what to do with the "leftovers".

 

[jopsuk]

I think it may be possible to convert buffets into "normal" carriages? so you could get another complete rake and have four spares?

 

[Royston Vasey]

I think it may be possible to convert buffets into "normal" carriages? so you could get another complete rake and have four spares?

Didn't GNER do that at one point?

 

[Failed Unit]

Snapper, I appreciate your point and it's true no two accidents are the same; fortunately we haven't seen enough comparison between accidents of each type with each vehicle. There are some comparisons to be made between Great Heck and Grayrigg in that most coaches hit little but each other and slid down a bank with other coaches. Certainly the Pendolino coped exceptionally well at Grayrigg other than some largely cosmetic damage. Much of this will have been down to the crumple zones engineered into that design. Small windows = small price to pay for structural integrity in an accident.

As for an NCAP style test, there's no reason but money (which isn't a valid excuse) why at least scale models or portions of coaches couldn't be crash tested.

You would also hope that things have got better after 20 years, if you look at the cars 20 years ago safety has improved so much, but the fatality rate has not. People still get killed in even the 5* NCAP cars. I don't think that NCAP testing will help with trains, computer simulation is as good for what they need to know. The only way you can really compare the mk4 with a pendo in an accident as you say is to put them in exactly the same kind of accident. No manufacturer is going to do that as there are just too many permitations.

Look at some incidents over the past few year. Eurostar derails after hitting object on track stays upright no problems. Mk4 does the same thing at Heck and also would probably of stayed upright with no injuries if it hadn't hit the 66. The ICE that crashed in Germany back in the 90's (the one that destroyed the bridge) could not be tested for. In fact I doubt any train in the world would have stayed in tacked for that incident.

Thankfully railway accidents are few and far between, but if I was concerned about a coach staying in one piece in the event of an accident I wouldn't ever board a pacer, if one of them hit a lorry on a level crossing I wouldn't fancy the chances of people in the front coach surviving. Passenger comfort in cars has also improved (as well as crash safety) over the past 20 years, shame the same can't be said for trains. Why can safety improvements and comfort go hand in hand with cars, but to make a strong train we have to stare a plastic for 4.5 hours. Travelling from London - Glasgow, now national express have gone I would take the mk4 anyday, yes it may be longer, yes it may not be as safe (in some peoples eyes) but at least I will die happy.
--- old post above --- --- new post below ---

Didn't GNER do that at one point?

Yes, 2x buffets were converted into normal coaches as part of the mallard programme.

 

[starrymarkb]

The Pacers are surprisingly strong for what they are. If you look at the one rammed by an 87 at 50ish MPH it came off pretty well. It looked bad, but the passenger compartments were in one piece, the 87 destroyed the cab and door area... Pacer bodies are self supporting, they are then bolted to an underframe from a wagon, if you want proof look at a 155/153, its the same basic structure but without the underframe.

 

[Helvellyn]

Didn't GNER do that at one point?

Yes, as I posted a couple of pages back!

 

[Darandio]

The Pacers are surprisingly strong for what they are. If you look at the one rammed by an 87 at 50ish MPH it came off pretty well. It looked bad, but the passenger compartments were in one piece, the 87 destroyed the cab and door area... Pacer bodies are self supporting, they are then bolted to an underframe from a wagon, if you want proof look at a 155/153, its the same basic structure but without the underframe.

Don't agree with that assessment to be honest.

The passenger compartment was damaged approximately into the first window bay and buckled quite badly, most likely from the shockwave on the lightweight structure. Even the HSE at the time wrote

The "Pacer" train suffered severe damage, and it was fortunate there were no passengers on board.

Saying that, it is probably fortunate that they are designed the way they are because the displacement of the frame from the actual body may have had a cushioning effect thus preventing further structural damage.