Jump to content

25 miles Carstairs to Edinburgh with no brakes?


Recommended Posts

On 12/08/2019 at 13:28, The Stationmaster said:

The Rule Book requires a Running Brake Test to be carried out -

 

2093590429_runningbraketest.jpg.2cc6350973c6a3e13dd10f5290891cab.jpg

Hi Mike.

Would this be why I have seen FCC and later Thameslink drivers accelerating rapidly and then braking (quite sharply in some cases) before taking power again when leaving Brighton station? It was only ever them and not Southern or Connex drivers before them so must have been a FCC company procedure that got carried over, but at least they were doing it.

Link to post
Share on other sites

Interesting report. I would have lost my wager that the continuity test hadn’t been done, but in mitigation it probably ought to be done when all other activities have been completed. 
 

I wonder if the conclusions will result in a change to the TSI to require sensible brake isolation cocks to be used. 

Link to post
Share on other sites
Posted (edited)

I remember in another thread about the new sleepers, @The Stationmaster commenting on the position/design of the brake IC .

The general conclusion of the report and paragraph 68 in particular being pretty much what he thought at the time

(Oops! It was on p.1 of this thread)

Edited by keefer
  • Agree 1
Link to post
Share on other sites

Hi everyone,

 

The way the BBC reported this yesterday initially made it appear to a repeat of the incident, prompting a "oh no, not again .... " response..  Thankfully it was simply reporting the release of the RAIB report.

 

Regards,

 

Alex.

Link to post
Share on other sites
1 hour ago, david.hill64 said:

Interesting report. I would have lost my wager that the continuity test hadn’t been done, but in mitigation it probably ought to be done when all other activities have been completed. 
 

I wonder if the conclusions will result in a change to the TSI to require sensible brake isolation cocks to be used. 

 

It seems to have fallen between two stalls. If the Mk5s were conventional loco hauled coaches with buffers and so on then sensible brake isolation cocks are specified and required. But auto couplers don’t require them as it assumed the isolation cock will be somewhere else, not trackside. Indeed that was the initial design of the Mk5s. They were later moved to trackside, but the design wasn’t changed, and as it uses auto couplers no one picked up on the requirement for sensible isolation cocks. 

CAF and Caledonian sleeper are changing them though. They’re mounting the isolation cocks the other way up so you have to push the handle up (rather than down) to isolate the brakes so accidental knocks or the handle not being fully latched will lead to it failing open with the brakes on. Seems obvious with hindsight. 

  • Like 2
Link to post
Share on other sites
5 hours ago, nightstar.train said:

 

It seems to have fallen between two stalls. If the Mk5s were conventional loco hauled coaches with buffers and so on then sensible brake isolation cocks are specified and required. But auto couplers don’t require them as it assumed the isolation cock will be somewhere else, not trackside. Indeed that was the initial design of the Mk5s. They were later moved to trackside, but the design wasn’t changed, and as it uses auto couplers no one picked up on the requirement for sensible isolation cocks. 

CAF and Caledonian sleeper are changing them though. They’re mounting the isolation cocks the other way up so you have to push the handle up (rather than down) to isolate the brakes so accidental knocks or the handle not being fully latched will lead to it failing open with the brakes on. Seems obvious with hindsight. 

 

Surely even the original cocks are self venting,  I'm sure both the cock on the loco and train were closed.

I just don't see any advantage in the way these couple to the loco especially when transpenine mk5s have conventional draw gear. But there again I struggle to find anything advantageous with the modern railway 

Link to post
Share on other sites

What I found interesting in the review was the fact that Mk5 coach air brakes are so well sealed that the coaches maintained full pressure throughout the journey whereas the locomotive did vent but the locomotive was able to achieve full pressure again because it could recharge faster than the air was being lost.

 

image.png.931f89f5d2ff830c2fe9302d1aae5d4f.png

image.png.b8be1d4dee0f485d597d3765c7c2ee03.png

image.png.b87fca625041a7998f1e238946a1eb9d.png

Perhaps carriages should have an element of bleed built in otherwise there is a risk that a train could actually have the brakes left off and simply roll away.  You shouldn't rely on age and less than ideal maintenance of a system to introduce leaks as a mitigation.

  • Like 1
  • Agree 1
Link to post
Share on other sites
Posted (edited)
9 hours ago, david.hill64 said:

Interesting report. I would have lost my wager that the continuity test hadn’t been done, but in mitigation it probably ought to be done when all other activities have been completed. 

I'd be very surprised if anyone in this day and age of data recorders would not do a brake test, it would be a foolish thing to be caught doing. It's a fundamental part of the train prep and I don't know anyone I work with who would even consider not doing a brake test.

I agree the brake test should be the last thing in the preparation of a train, and am glad to read that Caledonian Sleeper have revised procedures to make it so.

 

Jo

Edited by Steadfast
  • Agree 3
Link to post
Share on other sites
1 hour ago, woodenhead said:

What I found interesting in the review was the fact that Mk5 coach air brakes are so well sealed that the coaches maintained full pressure throughout the journey whereas the locomotive did vent but the locomotive was able to achieve full pressure again because it could recharge faster than the air was being lost.

 

image.png.931f89f5d2ff830c2fe9302d1aae5d4f.png

image.png.b8be1d4dee0f485d597d3765c7c2ee03.png

image.png.b87fca625041a7998f1e238946a1eb9d.png

Perhaps carriages should have an element of bleed built in otherwise there is a risk that a train could actually have the brakes left off and simply roll away.  You shouldn't rely on age and less than ideal maintenance of a system to introduce leaks as a mitigation.

 

Am I right in thinking on mk5s the brake pipe is more of a control pipe than a pipe which actually feeds the train in large volumes on conventional stock.

If this is the case any loco with decent air capacity will overcome a closed small diameter cock.

The big question here is who the hell passed these compliant for use in this country ?

A repeat of Darlington in 77 could so easily happen with this stock

  • Agree 1
Link to post
Share on other sites

When I first saw the Mk5s appear with Dellners I was under the impression this had been done to eliminate the need for staff going down on the track during all the coupling and uncoupling moves the sleeper performs, clearly I was wrong.

 

On a DMU or EMU fitted with any kind of auto coupler does the operation of the couple or uncouple buttons in the cab not just perform the same task of mechanically opening or closing the isolating cock as appropriate? If so I'm surprised this hasn't been incorporated into the Mk5 design and could be operated from a small lockable panel in the vestibule of each coach.

 

Dale

Link to post
Share on other sites

The design intent of the MkV sleeper was to avoid the need to go on track, but that was discarded early on as impractical, The need for a high-power 1500v ETS supply killed the idea; you can't put that sort of thing through an autocoupler. The brake system is remarkably conventional - two pipe air. Hence the need for a BPIC. A DMU, on the other hand, uses an electrically controlled brake using train wires through the couplers, and an air supply which simply links the reservoirs and compressors on all the cars.

 

The roots of the MkV issue was firstly that no-one had any real familiarity with building loco-hauled coaches in the 21st century - certainly not SERCO, and certainly not CAF. That meant they depended on unthinking compliance to standards (eg the TSI) rather than stopping and thinking "this thing is not quite what the standards envisaged, so we'd better be a bit careful". Another shocker is how a very well-known and competent brake equipment supplier allowed the abortion of a BPIC to be used in such an environment without saying something to CAF along the lines of "are you sure you really want to be doing this?".  Secondly, a little internet research (eg the FOI on the franchise agreement) shows how lat the project was running, and hence everything was done in a rush. Things get missed when people are rushing.

  • Like 2
  • Agree 1
Link to post
Share on other sites
4 hours ago, russ p said:

 

Surely even the original cocks are self venting,  I'm sure both the cock on the loco and train were closed.

So you know better than the investigators who wrote the report! Perhaps you should tell them their error.

  • Like 1
Link to post
Share on other sites
8 hours ago, russ p said:

 

Am I right in thinking on mk5s the brake pipe is more of a control pipe than a pipe which actually feeds the train in large volumes on conventional stock.

If this is the case any loco with decent air capacity will overcome a closed small diameter cock.

The big question here is who the hell passed these compliant for use in this country ?

A repeat of Darlington in 77 could so easily happen with this stock

On twin pipe brake systems the brake pipe is primarily a control pipe. 
 

On single pipe systems the brake pipe also charges the reservoirs. 

  • Agree 2
Link to post
Share on other sites
10 hours ago, woodenhead said:

What I found interesting in the review was the fact that Mk5 coach air brakes are so well sealed that the coaches maintained full pressure throughout the journey whereas the locomotive did vent but the locomotive was able to achieve full pressure again because it could recharge faster than the air was being lost.

 

image.png.931f89f5d2ff830c2fe9302d1aae5d4f.png

image.png.b8be1d4dee0f485d597d3765c7c2ee03.png

image.png.b87fca625041a7998f1e238946a1eb9d.png

Perhaps carriages should have an element of bleed built in otherwise there is a risk that a train could actually have the brakes left off and simply roll away.  You shouldn't rely on age and less than ideal maintenance of a system to introduce leaks as a mitigation.

Sorry, but you will never eliminate the need for a handbrake or parking brake to prevent stock rolling away.

How long for would a 'leak proof' system be expected to last? 10 minutes, 10 hours or 10 weeks?

Link to post
Share on other sites
1 hour ago, kevinlms said:

Sorry, but you will never eliminate the need for a handbrake or parking brake to prevent stock rolling away.

How long for would a 'leak proof' system be expected to last? 10 minutes, 10 hours or 10 weeks?

In the days of vacuum brakes, use of the handbrake was mandatory for this reason: the period that the system would hold vacuum was unknown and would vary between individual vehicles.It was common for the vacuum brake to be holding many weeks after uncoupling, but you didn't know so couldn't depend on it..

  • Like 1
  • Agree 1
Link to post
Share on other sites
2 hours ago, kevinlms said:

Sorry, but you will never eliminate the need for a handbrake or parking brake to prevent stock rolling away.

How long for would a 'leak proof' system be expected to last? 10 minutes, 10 hours or 10 weeks?

Shinkanshen EMU’s don’t have a parking brake. It took a long time to persuade the Japanese to fit them to the Taiwan HSR trains. 

  • Informative/Useful 2
Link to post
Share on other sites
8 minutes ago, david.hill64 said:

Shinkanshen EMU’s don’t have a parking brake.

Really? Not even an automatic spring-applied one? That's interesting.

  • Agree 1
Link to post
Share on other sites
26 minutes ago, david.hill64 said:

Shinkanshen EMU’s don’t have a parking brake. It took a long time to persuade the Japanese to fit them to the Taiwan HSR trains. 

Realistically, neither did the Class 40s!

  • Agree 2
  • Funny 6
Link to post
Share on other sites
6 hours ago, david.hill64 said:

On twin pipe brake systems the brake pipe is primarily a control pipe. 
 

On single pipe systems the brake pipe also charges the reservoirs. 

 

I fully appreciate that,  but I've been told on this stock the brake pipe is a lot lower volume ie smaller pipe to what we are used to

Link to post
Share on other sites
7 hours ago, kevinlms said:

Sorry, but you will never eliminate the need for a handbrake or parking brake to prevent stock rolling away.

How long for would a 'leak proof' system be expected to last? 10 minutes, 10 hours or 10 weeks?

My point was that the air braking system on these coaches is too good, that a train could travel for 25 miles with no loss of pressure, it's a risk.  Older stock would bleed air because of the age of the equipment, that would mean eventually the train would have been brought to a stop by the simple action that the coaches would have lost the pressure to hold the brakes open.  This would have been a better outcome than the train reaching a junction at Haymarket, sailing through unable to stop and then approaching Edinburgh Waverley with the driver asking for a clear route through.  A small amount of constant vent that the locomotive can overcome through the air pressure it can generate would then mean only when a locomotive is attached can the train air braking open the brakes.

 

Link to post
Share on other sites
6 hours ago, St Enodoc said:

Really? Not even an automatic spring-applied one? That's interesting.

None. Wheels are chocked when stabled. 

  • Informative/Useful 1
Link to post
Share on other sites
  • RMweb Gold
8 hours ago, LMS2968 said:

Realistically, neither did the Class 40s!

Agre.  But they did, eventually, have scotches -  which were a lot more reliable than the handbrake (provided they were used ;) ).

  • Like 1
  • Agree 1
Link to post
Share on other sites
  • RMweb Gold
On 29/05/2020 at 10:34, keefer said:

I remember in another thread about the new sleepers, @The Stationmaster commenting on the position/design of the brake IC .

The general conclusion of the report and paragraph 68 in particular being pretty much what he thought at the time

(Oops! It was on p.1 of this thread)

It did strike me as a rather obvious potential for something like this should somebody have to go between for any reason after the Continuity Test had been carried out.   And when you're in between, especially if you encounter a problem, it is far too easy to concentrate on what you are trying to do with your hands and watching your head and thereby completely forget what your back end might be brushing against.

 

But in this case the use of a poor (basically unsuitable) design of isolating cock was exacerbated by a badly thought out procedure for coupling which should never, in my opinion, have been published because of the way it split up the progression of tasks in the two places at different ends of the train/set.  That really was almost as bad as the design situation in breaking down long established process although again it can be traced back to the consequences of a design decision.  All too easy to forget - assuming you ever knew - that when coupling up the very last action was to connect the vacuum pipe or (air brake) Brake Pipe and the first thing you did when going in between was to disconnect those pipes and on an airbraked train make sure the isolating cocks were open on the stock and the loco.  That way you ensured your last line of defence against train or loco moving inadvertently.

  • Agree 5
Link to post
Share on other sites
24 minutes ago, The Stationmaster said:

Agre.  But they did, eventually, have scotches -  which were a lot more reliable than the handbrake (provided they were used ;) ).

Yes, I remember them well, and all the wooden splinters when drivers forgot to remove them before moving off!

  • Like 1
  • Agree 1
Link to post
Share on other sites
7 minutes ago, The Stationmaster said:

All too easy to forget - assuming you ever knew - that when coupling up the very last action was to connect the vacuum pipe or (air brake) Brake Pipe and the first thing you did when going in between was to disconnect those pipes and on an airbraked train make sure the isolating cocks were open on the stock and the loco.  That way you ensured your last line of defence against train or loco moving inadvertently.

Absolutely. I've seen and been surprised that some crew on preserved lines threw the shackle over while both vacuum bags were still on their stoppers. Some training needed, I felt.

  • Friendly/supportive 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.