Collision and derailment near Salisbury (Fisherton Tunnel) 31/10/21

[physics34]

Being a driver myself and suffering a slide of over a mile long i get a little sense of what the driver went through.

I keep thinking about had there been a fire(god forbid) in the tunnel and with the driver being trapped..it couldve been hellish.

 

[AdamWW]

once the emergency brake is applied and it‘s evident you’re going to be involved in a collision there’s nothing more you can do. I’ve always been told if you find yourself in that position and you have time, then get into the coach and sit, if possible, your own safety is paramount and no, you wouldn’t be disciplined for leaving the controls.

I would imagine that, given the choice, a rear facing seat would in general be best.

 

[swt_passenger]

Maybe I'm getting muddled up but my recollection is that SWR have modified 158's with the leading vestibule out of use for passengers. I assume that's to ensure a quick exit for the driver if required, though maybe there's some other reason I've missed. (It's not very convenient from a passenger point of view).

It’s basically to allow the driver space to get in and out of the train to trackside safely without having to worry about passengers. SWR 158/159 operate on a multi-track DC electrified railway and isolating the leading vestibule was done when new, as it was on the 442 for the same purpose.

 

[jfowkes]

Imagine you are a passenger on a 158/9 and you see the driver exit the cab (which is into the vestibule) whilst the train is moving and walk into the passenger cabin!

What is the driver then supposed to do which won't instill instant panic in dozens of people in a confined space?

I think by the time the brake has been applied, the driver has realised there is going to be a collision and has exited the cab, there probably isn't going to be much time left for panicking, for the few passengers that actually notice the driver and understand what's happening.

 

[norbitonflyer]

In general, if I saw someone in uniform walk from the front cab into the saloon I'd assume there had been more than one person in there.

If I was on a train where the braking had clearly gone into emergency I might come to a different conclusion but I don't think I'd criticise the driver for doing so.

I'm sure I've seen notices on internal cab doors saying to keep them clear for emergency use, and I'm sure I've read accident reports where drivers have done just that. If I saw someone casually walking out of the cab I too would assume someone else was driving. But if they were exiting it in a hurry, (and probably telling the passengers to get back, or to brace themselves) I might reach a different conclusion.

 

[DelW]

Imagine you are a passenger on a 158/9 and you see the driver exit the cab (which is into the vestibule) whilst the train is moving and walk into the passenger cabin!

What is the driver then supposed to do which won't instill instant panic in dozens of people in a confined space?

In that situation, and *if* that was what the driver chose to do, I'd suggest as calm as possible (in the circumstances) announcement, "ladies and gentlemen, we're about to experience a very sudden stop, please brace yourselves against the seat in front".

 

[LAX54]

In a full wheel slide where everything is locked up, nothing. The emergency brake could increase it to 500 bar but it still wouldn't make a difference.

Having spoken to many drivers, when filling out the forms needed after such an event as sliding, I always came away with the impression that it is like an F1 car on the gravel or grass having spun off, they say the Driver is just a passenger at that point, nothing he can do will alter what will happen.

In that situation, and *if* that was what the driver chose to do, I'd suggest as calm as possible (in the circumstances) announcement, "ladies and gentlemen, we're about to experience a very sudden stop, please brace yourselves against the seat in front".

Depends how many 'seconds' you have !

 

[ExRes]

I'm sure I've seen notices on internal cab doors saying to keep them clear for emergency use,

In my experience of driving 170s those notices were, unfortunately, regularly ignored by passengers, bicycles, luggage, portable pet carriers were often placed against the door

 

[alxndr]

I'm sure I've seen notices on internal cab doors saying to keep them clear for emergency use, and I'm sure I've read accident reports where drivers have done just that. If I saw someone casually walking out of the cab I too would assume someone else was driving. But if they were exiting it in a hurry, (and probably telling the passengers to get back, or to brace themselves) I might reach a different conclusion.

The derailment at Kemble in 2007 was one such incident where the driver saw an imminent potential for derailment and ran for safety while alerting passengers. There's no comment how the passengers reacted to this though.

Para 32 - The driver immediately applied the emergency brake, looked out of the right hand side cab window and decided to escape from the cab into the saloon. As he moved to the back of the leading vehicle he shouted a warning to the four passengers in that vehicle who also ran to the back of the vehicle.

Report 07/2008: Derailment at Kemble

Derailment of a train at Kemble, Gloucestershire, 15 January 2007.

www.gov.uk

 

[Steddenm]

Update from GWR:



(For those using a screen reader it says: Joint statement from GWR, SWR and Network Rail Western: Investigators have now handed back the accident site and we will begin the process of removing the trains, assessing the damage and planning repairs. While it is too early to determine how long the works will take, we can confirm that the railway around Salisbiry will be closed until at least Monday 15 November.

 

[Right Away]

It provides additional braking force. A full service application will give 3-3.5 bar of brake force and an emergency application will give 4-4.5 bar of brake force.

I don’t know how much of a difference it would make in a slide like that but you’re instructed to use the emergency brake whenever it becomes apparent you’re unlikely to stop at the intended place using normal braking procedure. If the driver didn’t use the emergency brake and subsequently collided with another train he probably wouldn’t drive again.

On 158/159 units, an emergency brake application provides the same brake force as a full service step 3 brake application. The reason the emergency position is provided is because it is fail safe. The Westcode electro-pneumatic system uses 3 wires which are energised in different sequences according to the position selected on the brake controller. The emergency position de-energises and earths all of the wires ensuring a brake application is guaranteed and immune from any stray feeds to the wires in the event of a failure of the system.

If the emergency brake is causing the wheels to lock, staying at his post trying to adjust the strength of the brake application (cadence braking, I think it's called in road transport) to control the slide might be worth a try. He may also have been sounding the horn to try to warn passengers in the other train that he was bearing down on them.

On 158/159 units, the Westcode system means that once the emergency position has been selected on the brake controller, moving the brake controller to another position will have no affect until the train has come almost to a stand as the control wires have been de-energised and earthed.

Edit: The excellent post from Llama below this one provides much more technical detail.

 

[Llama]

If the emergency brake is causing the wheels to lock, staying at his post trying to adjust the strength of the brake application (cadence braking, I think it's called in road transport) to control the slide might be worth a try. He may also have been sounding the horn to try to warn passengers in the other train that he was bearing down on them.

I am no fan of Richard Branson, but I thought he was unfairly criticised for commending the driver at Grayrigg (2007) for "staying at the controls" during the derailment. Whilst undoubtedly a "passenger" once the train was off the rails, his prompt action after the derailment, despite serious injury, was a factor in getting the rescue operation under way quickly. (Despite the high speed - about 95mph - no-one was fatally injured in the crash, but one passenger suffered a heart attack and died later in hospital)

Absolutely not, in no circumstances should we attempt to release the brake in an emergency. For a start such an attempt would be ineffective, once an emergency brake application is initiated on these type of units that emergency brake application cannot be released until the low speed relay operates (nominally 3mph, usually more like 5).

It is also very unlikely that all wheels were locked, the WSP system will most likely have been functioning correctly throughout the train and applying sand to the railhead, that system would have been compromised if what I describe in the paragraph above wasn't the case and the driver had actually been able to try to regain wheel rotation - he would have had to fully release the brake. Don't forget this is not a road vehicle. As an experienced driver I know just how long it takes to regain wheel rotation after a wheel lock-up, you are talking maybe more than ten seconds, it can be a surprisingly long time before the wheelsets can regain enough kinetic energy from a very slippery railhead. It also depends on which wheelsets are locked up - on a 15x unit the wheelsets on #1 end bogie are effectively free-rolling, on #2 end bogie both wheelsets are mechanically locked together by the cardan shafts that form the drive train from the transmission. And don't forget this is academic as it's unlikely the train was completely sliding. Each wheelset on #1 bogie has its own WSP blowdown valve which can partially release the brake when wheel slow-up is detected, on #2 bogie there is just one WSP blowdown valve for both wheelsets because they are mechanically locked together. Sand is applied on both sides from the sand delivery pipe on the leading vehicle which is before #2 bogie as is the norm on most DMUs. The WSP system operates totally independently on each vehicle so even if there was a fault on one vehicle there were still two other vehicles it should function on. Sand is only ever deployed from the leading vehicle however, because if all vehicles deployed sand it would bring the risk of the rear-most vehicles standing on so much sand they would be at risk of failing to operate track circuits and therefore wrong-side track circuit failures.

158s (and I'm pretty sure 159s are the same although I don't sign them) don't have enhanced emergency braking, just 9%g. The difference between full service braking and emergency braking is that the 'energise to release' train wires (normally fed for the whole train by the rear-most start battery within the train formation) from train wire 4 to train wires 23 and 25 (and the negative return wire 25) are earthed out in an emergency brake application which provides a guarantee that even if some rogue false-feed could somehow be providing current to one of the 'energise to release' wires 23 or 24, it would be earthed out and therefore nullified. This earthing system proves that the braking system is activating as fully as it is possibly capable of doing.

Edit - Right Away essentially beat me to it.

 

[Saint66]

First carriage being lifted later today and will be taken away by road.

 

[E16 Cyclist]

Update from GWR:

View attachment 105169

(For those using a screen reader it says: Joint statement from GWR, SWR and Network Rail Western: Investigators have now handed back the accident site and we will begin the process of removing the trains, assessing the damage and planning repairs. While it is too early to determine how long the works will take, we can confirm that the railway around Salisbiry will be closed until at least Monday 15 November.

One thing I’m curious about is why does it now take so long to find investigate these accidents and to remove vehicles, or is it a myth that lines reopened a lot quicker in BR days?

 

[Thumper1127]

If the emergency brake is causing the wheels to lock, staying at his post trying to adjust the strength of the brake application (cadence braking, I think it's called in road transport) to control the slide might be worth a try. He may also have been sounding the horn to try to warn passengers in the other train that he was bearing down on them.

I am no fan of Richard Branson, but I thought he was unfairly criticised for commending the driver at Grayrigg (2007) for "staying at the controls" during the derailment. Whilst undoubtedly a "passenger" once the train was off the rails, his prompt action after the derailment, despite serious injury, was a factor in getting the rescue operation under way quickly. (Despite the high speed - about 95mph - no-one was fatally injured in the crash, but one passenger suffered a heart attack and died later in hospital)

IIRC the criticism was because Branson said something along the lines of the Driver staying at the controls and steering the train. It was the steering bit that was ridiculed.

 

[Stigy]

One thing I’m curious about is why does it now take so long to find investigate these accidents and to remove vehicles, or is it a myth that lines reopened a lot quicker in BR days?

Lines probably did open a lot quicker in BR days, but a lot has happened since then in terms of H&S (and rail accidents more specifically).

 

[ainsworth74]

On 158/159 units, an emergency brake application provides the same brake force as a full service step 3 brake application. The reason the emergency position is provided is because it is fail safe. The Westcode electro-pneumatic system uses 3 wires which are energised in different sequences according to the position selected on the brake controller. The emergency position de-energises and earths all of the wires ensuring a brake application is guaranteed and immune from any stray feeds to the wires in the event of a failure of the system.


On 158/159 units, the Westcode system means that once the emergency position has been selected on the brake controller, moving the brake controller to another position will have no affect until the train has come almost to a stand as the control wires have been de-energised and earthed.

Edit: The excellent post from Llama below this one provides much more technical detail.

Absolutely not, in no circumstances should we attempt to release the brake in an emergency. For a start such an attempt would be ineffective, once an emergency brake application is initiated on these type of units that emergency brake application cannot be released until the low speed relay operates (nominally 3mph, usually more like 5).

It is also very unlikely that all wheels were locked, the WSP system will most likely have been functioning correctly throughout the train and applying sand to the railhead, that system would have been compromised if what I describe in the paragraph above wasn't the case and the driver had actually been able to try to regain wheel rotation - he would have had to fully release the brake. Don't forget this is not a road vehicle. As an experienced driver I know just how long it takes to regain wheel rotation after a wheel lock-up, you are talking maybe more than ten seconds, it can be a surprisingly long time before the wheelsets can regain enough kinetic energy from a very slippery railhead. It also depends on which wheelsets are locked up - on a 15x unit the wheelsets on #1 end bogie are effectively free-rolling, on #2 end bogie both wheelsets are mechanically locked together by the cardan shafts that form the drive train from the transmission. And don't forget this is academic as it's unlikely the train was completely sliding. Each wheelset on #1 bogie has its own WSP blowdown valve which can partially release the brake when wheel slow-up is detected, on #2 bogie there is just one WSP blowdown valve for both wheelsets because they are mechanically locked together. Sand is applied on both sides from the sand delivery pipe on the leading vehicle which is before #2 bogie as is the norm on most DMUs. The WSP system operates totally independently on each vehicle so even if there was a fault on one vehicle there were still two other vehicles it should function on. Sand is only ever deployed from the leading vehicle however, because if all vehicles deployed sand it would bring the risk of the rear-most vehicles standing on so much sand they would be at risk of failing to operate track circuits and therefore wrong-side track circuit failures.

158s (and I'm pretty sure 159s are the same although I don't sign them) don't have enhanced emergency braking, just 9%g. The difference between full service braking and emergency braking is that the 'energise to release' train wires (normally fed for the whole train by the rear-most start battery within the train formation) from train wire 4 to train wires 23 and 25 (and the negative return wire 25) are earthed out in an emergency brake application which provides a guarantee that even if some rogue false-feed could somehow be providing current to one of the 'energise to release' wires 23 or 24, it would be earthed out and therefore nullified. This earthing system proves that the braking system is activating as fully as it is possibly capable of doing.

Edit - Right Away essentially beat me to it.

Very interesting, thank you both. Glad to see I wasn't barking up completely the wrong tree but having it in some authoritative detail is very good

 

[swt_passenger]

Lines probably did open a lot quicker in BR days, but a lot has happened since then in terms of H&S (and rail accidents more specifically).

In this case NR on Twitter are also suggesting almost a full rebuild of the junction area, and they’ve also mentioned again on Twitter that they might re-rail through the tunnel at the same time, presumably if it can be done in parallel without further delay.

 

[43066]

Hope this isn't in appropriate to ask, but hypothetically, if the driver had chosen to leave the cab once he had applied the emergency brake and it was clear the train wasgoing to be involved in a collision (i.e. there was nothing futher he could do), would he have been disciplined for leaving the controls?

Absolutely not. There is actually an instruction in some driving policies that, if you’re facing an unavoidable collision with (say) a tree trunk or a vehicle, to put the brake into emergency and walk back into the passenger saloon. Clearly at that point there’s nothing more you can do!

Some Desiro family stock will actually open the cab-saloon door automatically do you depress an emergency plunger to facilitate a speedy exit!

 

[Gloster]

I would have thought that one risk for the driver if s/he decides to vacate the cab is being unable to get to a position where they can properly brace themselves. In the few seconds available the driver might open the door and find standing passengers or some luggage, be unable to even find a partition to lean against and then be thrown about when the train derails or collides with something. If the driver remains at the desk, they can at least brace themselves against that.

Somewhere on the net is a short YouTube film of a driver in Poland (?) hastily dashing out of the cab and, although it is silent, telling everybody to brace. You can also that the unit is about to hit a lorry on a crossing.

EDIT: The video is titled: Train driver rushes to warn passengers moments before crash in Poland

 

[Llama]

Some companies do indeed have such instructions in their professional driving policies, some are completely silent on the subject. Faced with a dire imminent situation with a large obstruction I know what I would prefer to do - emergency brake, horn, red button on GSMR and then hopefully consider retiring to the saloon and sitting in a rear facing seat as far down the train as possible, instructing others to do likewise if time is available.

One company in the north who is silent on the subject hasn't issued its drivers a professional driver's policy for ten years now, that was two franchises ago.

 

[norbitonflyer]

Absolutely not, in no circumstances should we attempt to release the brake in an emergency. For a start such an attempt would be ineffective, once an emergency brake application is initiated on these type of units that emergency brake application cannot be released until the low speed relay operates (nominally 3mph, usually more like 5).

It is also very unlikely that all wheels were locked, the WSP system will most likely have been functioning correctly throughout the train and applying sand to the railhead

Comments noted - there was probably nothing left for the driver to do with the brakes. Staying in his cab would however mean he could sound a warning to the occupants of the other train and/or use his radio to alert the signallers to what was about to happen.

Hats off to him and hope he has a good recovery from his injuries.

 

[Llama]

It's interesting that the hazard warning lights were switched on on the rear 158 in this incident - I'm going to assume that was switched on prior to the collision by a quick-thinking guard who wouldn't have known exactly what was happening or that the approaching 159 was unable to stop. IMO they should be given credit for their actions.

 

[swt_passenger]

It's interesting that the hazard warning lights were switched on on the rear 158 in this incident - I'm going to assume that was switched on prior to the collision by a quick-thinking guard who wouldn't have known exactly what was happening or that the approaching 159 was unable to stop. IMO they should be given credit for their actions.

There was only one incident, the collision, therefore the crew on the 158 could not have had prior knowledge.

 

[Crossover]

The passenger saloon which on trains of that vintage is not part of the crumple zone unlike the cab is!

To be clear I'm not suggesting the driver in this incident was anything other than brave in remaining at the controls as whether or not they was anything they could do staying at controls was clearly a very brave act indeed as they must have known some seconds before the collision what was coming.

It reminds me of a post, probably on here, of a trainee asking where on the stock the crumple zone was. "About 4 feet behind my head" being the response

Maybe I'm getting muddled up but my recollection is that SWR have modified 158's with the leading vestibule out of use for passengers. I assume that's to ensure a quick exit for the driver if required, though maybe there's some other reason I've missed. (It's not very convenient from a passenger point of view).

It’s basically to allow the driver space to get in and out of the train to trackside safely without having to worry about passengers. SWR 158/159 operate on a multi-track DC electrified railway and isolating the leading vestibule was done when new, as it was on the 442 for the same purpose.

In other areas, if the driver has to leave the train, say for a signal phone, the guard has to guard the exit. Different circumstance, but on the Heysham branch in Northernland, the driver has to operate the points outside Morecambe to gain the branch line. I only did it in Pacer days, but the guard came to the front of the train to make sure passengers were away from the open doors. I imagine 156/158's are similar (if used down the branch). The SWR setup avoids this need.

Presumably, in that case, the driver would want to move the train ASAP, to avoid another train running into him

After a SPAD, the driver is moving nothing! The train should be under signal protection and I would imagine a dim view would be taken of a driver who did anything without speaking to control/the signaller first

There was only one incident, the collision, therefore the crew on the 158 could not have had prior knowledge.

There could be a possibility that the guard, if in the back cab, saw the lights of the SWR and took some action?

 

[Llama]

Yes I know there was one incident, that's why it was probably quick thinking if the guard was in the rear cab and saw the 159 approaching. Of course the hazard warning lighting might have been switched on after the collision but bearing in mind nobody really knew what was happening/had happened at the time or how the situation might unfold it was absolutely the correct action to take.

 

[swt_passenger]

Yes I know there was one incident, that's why it was probably quick thinking if the guard was in the rear cab and saw the 159 approaching. Of course the hazard warning lighting might have been switched on after the collision but bearing in mind nobody really knew what was happening/had happened at the time or how the situation might unfold it was absolutely the correct action to take.

My mistake, I thought you were considering the originally assumed situation that the GWR had already stopped.

 

[Llama]

In other areas, if the driver has to leave the train, say for a signal phone, the guard has to guard the exit.

Not necessarily - it's good practice and it might be 'managed' at certain places like using the ground frame for Morecambe though. If I get out to an SPT (a rarity these days, but very frequent a decade ago) I check the local door is free and ask people to move/keep away from the door before opening it, then obviously secure it immediately I get out. If a train was wedged it was safer to use the NRN as it was (if you were lucky enough to be able to hold a viable conversation on it). With two units the guard quite often couldn't get to the front to steward my local door anyway. If they were in the front saloon it was always appreciated when they came to the local door though, not least for safety but also so I could tell then whatever I'd been told on the SPT.

My mistake, I thought you were considering the originally assumed situation that the GWR had already stopped.

No worries, we have a much better idea what happened now compared to a few days ago. The details of exactly how and why will still take some time to extract.

One has to wonder where the 'Network Rail source' who provided some of the early dud info to the press has gone.

And of course best wishes to the train crew & speedy recovery to the driver if they happen to be reading this forum, hats off to you.

 

[Bald Rick]

One thing I’m curious about is why does it now take so long to find investigate these accidents and to remove vehicles, or is it a myth that lines reopened a lot quicker in BR days?

Investigations are much more thorough these days.

 

[fgwrich]

It's interesting that the hazard warning lights were switched on on the rear 158 in this incident - I'm going to assume that was switched on prior to the collision by a quick-thinking guard who wouldn't have known exactly what was happening or that the approaching 159 was unable to stop. IMO they should be given credit for their actions.

There was only one incident, the collision, therefore the crew on the 158 could not have had prior knowledge.

I can only guess here as I have little experience of working with the Express Sprinters, but are the Hazard Warning lights are linked to any Emergency Lighting set up on the 158 / 159s? I've noticed Emergency Lighting does seem to vary between TOCs, for example on the HST Fleets the FGW / GWR / ScotRail version will only come on when the switch is turned on, whereas the on the GNER & XC versions, they are actually switched on 24/7 as part of the normal lighting set up but are noticeable when the main lights are off.