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

[Ianno87]

There is a major flow that relies on a connection between the GWR train and the SWR train. There are far more passengers from Southampton/Portsmouth/South Coast to the WofE line towards Exeter than from the WofE to the Bristol line. The Bristol line generally relies on Westbury for its London connection.

Also, in real world timetabling, the paths of these trains are dictated by what happens at Waterloo, Woking, Axminster, Southampton, Bristol etc, so are presented into Salisbury at times that suit the wider network; it "gets what it's given".

 

[Crossover]

Being the first unit behind a RHTT isn’t a pleasant experience either.

If I may ask, why so? Rails too clean, or sometimes made worse if all the mess hasn't been cleared fully?

 

[Graham H]

Just wondering what the situation with the Laverstock loop is. Might seem churlish to ask given the bigger picture but this must be impacting freight that usually heads that way from/to Southampton. I take it the track is fine but presumably signalling is affected by any damage caused. There is, as someone else mentioned way back, a steam special scheduled on Saturday and the tour website put up a message pretty soon after the initial RAIB report appeared that they "are closely following the progress of repairs to the track near Salisbury following the incident at the weekend. We do not anticipate that this will affect the tour and will be in touch with all those booked should there be an issue" which seems at odds with the National Rail expectation of disruption until at least Monday. I assume the tour group is talking to Network Rail rather than the Daily Mail so perhaps something will be able to run through the loop sooner than the main station ?

 

[43096]

I'm also hopeful that the leading set will make a comeback!

158762 (the lead set) should be moving back to SPM, possibly under its own power, in the next day or two according to posts elsewhere.

 

[Dan G]

Not really sure the RAIB statement (which was not a "preliminary report"; we'll get the proper Interim Report in a few days) was all that helpful.

As has been stated, the wheelslide won't even have been a wheelslide; the WSP prevents that. What did happen was insufficient retardation -- but that's only part of the accident sequence, NOT "the cause".

Why couldn't the SWR train stop before the signal, and certainly before the overlap?

• Did the 159's sand hoppers have sand in them? The 375 at Stonegate had empty hoppers
• Was the adhesion forecast correct? If so, was it correctly acted upon?
• What effect did the lack of RHTT runs have? (This does seem extraordinary, given the weather)
• Did the driver apply braking appropriate for the conditions?
• Was the SWR train travelling at a appropriate speed before braking?

There will be other questions I haven't thought of, for sure. RAIB is going to have a lot to look at...

Edit: When writing the above I assumed the WSP was working correctly. We don't know that... Lots to look at.

 

[LOL The Irony]

Reminder that there is a spare Express Sprinter bodyshell lying around that could be used should either unit be written off.

 

[JN114]

I find it ridiculous that drivers are given no warning that they are going to be following the RHTT on their diagrams . Control will have this information, so there's no excuse.

I had this on Saturday and the adhesion was awful.

The RHTT timetable is far too dynamic, it wouldn’t be possible to put onto the diagrams as TOC traincrew diagrams are written long before the RHTT timetable is finalised.

So it would have to be done on the day - and dozens of different trains could follow one RHTT, you’d have to identify each one, identify who is driving, get messages to them. And then undo and redo that if it runs early, or late. All while monitoring/managing the train service (which is typically more involved in RHTT season).

I can’t envisage having the time or capacity to do this as a controller - I’m only one person, looking after every train on 250+ route miles.

 

[Towers]

Reminder that there is a spare Express Sprinter bodyshell lying around that could be used should either unit be written off.

Wasn't that used to repair the 158 that was struck by a runaway 47(?) in the early 90s?

 

[Steddenm]

RAIB have issued an update:

At around 18:45 hrs on 31 October 2021, train reporting number 1L53, the 17:20 hrs South Western Railway passenger service from London Waterloo to Honiton, collided with the side of train 1F30, the 17:08 hrs Great Western Railway passenger service from Portsmouth Harbour to Bristol Temple Meads. The collision took place at Salisbury Tunnel Junction, which is on the immediate approach to Fisherton Tunnel, near Salisbury in Wiltshire.

Aerial view of Salisbury Tunnel Junction

This junction allows the Up and Down Dean lines which lead to and from Eastleigh to merge with the Up and Down Main lines which lead to and from Basingstoke. At the time of the accident train 1F30 was using the junction to join the Down Main line from the Down Dean line, while train 1L53 was approaching the junction on the Down Main line from the direction of Basingstoke.

Diagram showing the layout of Salisbury Tunnel Junction and movement of trains (not to scale)

The impact of the collision caused the front two coaches of train 1L53 and the rear two coaches of train 1F30 to derail. Both trains continued some distance into Fisherton tunnel following the collision, before they came to a stop. Thirteen passengers and one member of railway staff required treatment in hospital as a result of the accident, which also caused significant damage to the trains and railway infrastructure involved.

RAIB’s preliminary examination has found that the movement of train 1F30 across the junction was being protected from trains approaching on the Down Main line by signal SY31, which was at danger (displaying a red aspect). Train 1L53 passed this signal, while it was at danger, by around 220 metres, immediately prior to the collision occurring.

Preliminary analysis of data downloaded from the On Train Data Recorder (OTDR) fitted to train 1L53 shows that the driver initially applied service braking to slow the train on approach to the caution signal before signal SY31. Around 12 seconds after service braking started, the driver made an emergency brake demand. As the train approached signal SY31, and with the emergency brake still being demanded by the driver, a second emergency brake demand was made by the train protection and warning system (TPWS). These emergency brake demands did not prevent the train from reaching the junction, where the collision occurred. OTDR analysis indicates that wheel slide was present both when the driver applied service braking and after emergency braking was demanded. This was almost certainly a result of low adhesion between the train’s wheels and the rails.

Our investigation will seek to identify the sequence of events which led to the accident. It will also consider:

• the level of wheel/rail adhesion present on the approach to Salisbury Tunnel junction
• the status and performance of the braking, wheel slide protection and sanding systems on train 1L53
• the behaviour of both trains during and following the collision
• South Western Railway’s policies relating to low wheel/rail adhesion
• Network Rail’s policies relating to low wheel/rail adhesion and how they managed the risk of low adhesion in this area
• the processes used to assess and control the risk of overrun at signal SY31
• any relevant underlying factors, including any actions taken in response to previous safety recommendations.

Our investigation is independent of any investigation by the railway industry, the British Transport Police or by the industry’s regulator, the Office of Rail and Road.

We will publish our findings, including any recommendations to improve safety, at the conclusion of our investigation. This report will be available on our website.

[Withdrawn] Collision between passenger trains at Salisbury Tunnel Junction

Investigation into a collision between passenger trains at Salisbury Tunnel Junction, Wiltshire, 31 October 2021

www.gov.uk

 

[Taunton]

"Driver acted impeccably, says SWR"

Salisbury train crash: Driver acted impeccably, says operator - BBC News

Well done for SWR to come out with that in public right after the RAIB makes their first statement.

Poor old chap, 75 years old. Possibly joined the railway in the last of steam days. Hope the railway looks after him well financially.

Meanwhile the RAIB can look at why, in the prevailing leaf fall conditions, NR apparently cancelled the Treatment Train on both Saturday and Sunday.

 

[theageofthetra]

The RHTT timetable is far too dynamic, it wouldn’t be possible to put onto the diagrams as TOC traincrew diagrams are written long before the RHTT timetable is finalised.

So it would have to be done on the day - and dozens of different trains could follow one RHTT, you’d have to identify each one, identify who is driving, get messages to them. And then undo and redo that if it runs early, or late. All while monitoring/managing the train service (which is typically more involved in RHTT season).

I can’t envisage having the time or capacity to do this as a controller - I’m only one person, looking after every train on 250+ route miles.

Fair point, why couldn't a berth triggered GSMR broadcast be used then?

 

[karlbbb]

Preliminary analysis of data downloaded from the On Train Data Recorder (OTDR) fitted to train 1L53 shows that the driver initially applied service braking to slow the train on approach to the caution signal before signal SY31. Around 12 seconds after service braking started, the driver made an emergency brake demand. As the train approached signal SY31, and with the emergency brake still being demanded by the driver, a second emergency brake demand was made by the train protection and warning system (TPWS). These emergency brake demands did not prevent the train from reaching the junction, where the collision occurred. OTDR analysis indicates that wheel slide was present both when the driver applied service braking and after emergency braking was demanded. This was almost certainly a result of low adhesion between the train’s wheels and the rails.

Must have been scary for the driver.

 

[guard1]

If I may ask, why so? Rails too clean, or sometimes made worse if all the mess hasn't been cleared fully?

From my own experience in the depths of leaf fall when you follow a RHTT the track isn't pristine and it has just added moisture to the track. So until the track dries I think there is still poor railhead adhesion. Additionally, the RHTT blows moisture onto the adjacent track as well as leaves so if your driving on that line the RHTT has just made the track conditions potentially worse.

 

[theageofthetra]

"Driver acted impeccably, says SWR"

Salisbury train crash: Driver acted impeccably, says operator - BBC News

Well done for SWR to come out with that in public right after the RAIB makes their first statement.

Poor old chap, 75 years old. Possibly joined the railway in the last of steam days. Hope the railway looks after him well financially.

Not really sure the RAIB statement (which was not a "preliminary report"; we'll get the proper Interim Report in a few days) was all that helpful.

As has been stated, the wheelslide won't even have been a wheelslide; the WSP prevents that. What did happen was insufficient retardation -- but that's only part of the accident sequence, NOT "the cause".

Why couldn't the SWR train stop before the signal, and certainly before the overlap?

• Did the 159's sand hoppers have sand in them? The 375 at Stonegate had empty hoppers
• Was the adhesion forecast correct? If so, was it correctly acted upon?
• What effect did the lack of RHTT runs have? (This does seem extraordinary, given the weather)
• Did the driver apply braking appropriate for the conditions?
• Was the SWR train travelling at a appropriate speed before braking?

There will be other questions I haven't thought of, for sure. RAIB is going to have a lot to look at...

Edit: When writing the above I assumed the WSP was working correctly. We don't know that... Lots to look at.

What I'd be interested to know is if it did have full sand hoppers were they empty by the time the incident happened?

I find it incredible that in 2021 (on the units I sign anyway ) the driver has no indication of the sander hopper level nor the maintenance team via telemetry.- all they can see is if the sander valves are opening & closing.

From my own experience in the depths of leaf fall when you follow a RHTT the track isn't pristine and it has just added moisture to the track. So until the track dries I think there is still poor railhead adhesion. Additionally, the RHTT blows moisture onto the adjacent track as well as leaves so if your driving on that line the RHTT has just made the track conditions potentially worse.

We've had a Spad recently primarily caused by spray on the adjacent track from the RHTT.

 

[backontrack]

Meanwhile the RAIB can look at why, in the prevailing leaf fall conditions, NR apparently cancelled the Treatment Train on both Saturday and Sunday.

Did they? Sigh. I was really hoping this one wasn't avoidable, but it sounds like it was, then...

 

[ScotRail158725]

Certainly losing 2 158's will have a huge effect as we're short of units as it is, again I'm speculating, but the front unit may be able to return to service as it doesn't appear from the limited pictures available that its too badly damaged, obviously though there could be some to the couplings from when the units came apart!

The front 158 is completely railed and wasn’t hit by the SWR service at all so will definitely see service again, the only damage i see is damage to the coupling if the 2 units on 1F30 were split upon contact. From ariel photos the rear coach of the GWR set doesnt look to have been hit too badly so it may well be fixed and it could be paired with the undamaged SWR coach(es) to form a full set

 

[theageofthetra]

"Driver acted impeccably, says SWR"

Salisbury train crash: Driver acted impeccably, says operator - BBC News

Well done for SWR to come out with that in public right after the RAIB makes their first statement.

Poor old chap, 75 years old. Possibly joined the railway in the last of steam days. Hope the railway looks after him well financially.

Meanwhile the RAIB can look at why, in the prevailing leaf fall conditions, NR apparently cancelled the Treatment Train on both Saturday and Sunday.

Or whether the management, control or or drivers of either TOC had any notice that the RHTT wasn't running. Given the forecast that weekend, I find all of this utterly depressing.

 

[158747]

Wasn't that used to repair the 158 that was struck by a runaway 47(?) in the early 90s?

There must have been at least two class 158 spare bodyshells built as I saw one at Crewe Works in 2005, not sure where it is now but have seen a photo of it more recently, possibly at Long Marston?

 

[Intellectual98]

RAIB have issued an update:

[Withdrawn] Collision between passenger trains at Salisbury Tunnel Junction

Investigation into a collision between passenger trains at Salisbury Tunnel Junction, Wiltshire, 31 October 2021

www.gov.uk

"Driver acted impeccably, says SWR"

Salisbury train crash: Driver acted impeccably, says operator - BBC News

Well done for SWR to come out with that in public right after the RAIB makes their first statement.

Poor old chap, 75 years old. Possibly joined the railway in the last of steam days. Hope the railway looks after him well financially.

Meanwhile the RAIB can look at why, in the prevailing leaf fall conditions, NR apparently cancelled the Treatment Train on both Saturday and Sunday.

Sounds like the driver did exactly as would have been expected of him; Put in the brakes, if its not stopping stick it in emergency. It must have been scary. I wish him the best and as above hope he is well looked after. I do hope this brings light to the potential severity of low adhesion

 

[skyhigh]

As has been stated, the wheelslide won't even have been a wheelslide; the WSP prevents that.

Even with WSP in full working order, there's still no guarantee that a slide can't happen. It's not a perfect system.

 

[Peter Mugridge]

From that cab video, it seems that the lineside vegetation between those two signals is largely isolated scrub and so on; the significant tree cover is only in the cutting by the junction just before the tunnel entrance - ie, after the signal where the train was due to stop. The pictures of the immediate area of the collision, together with the many comments on this thread about the need to cut down lots of trees, led me to believe that everyone making those comments knew (or at least assumed) that there was tree cover like that all the way back to where the train was due to be slowing down.

We need to also consider that there were strong winds; leaves will have blown back some considerable distance from the trees not just in the immediately preceding storm but over the days and weeks leading up to the incident. as the prevailing winds in the UK are south westerly, it is quite feasible that leaves from trees nearer the tunnel would have ended up being carried eastwards, and it doesn't take a huge volume of leaves anywhere to cause a problem because the mulch gets spread by the wheels of other trains.

 

[backontrack]

We need to also consider that there were strong winds; leaves will have blown back some considerable distance from the trees not just in the immediately preceding storm but over the days and weeks leading up to the incident. as the prevailing winds in the UK are south westerly, it is quite feasible that leaves from trees nearer the tunnel would have ended up being carried eastwards, and it doesn't take a huge volume of leaves anywhere to cause a problem because the mulch gets spread by the wheels of other trains.

Which is all the more reason to actually clear the tracks of leaves.

 

[Peter Mugridge]

Which is all the more reason to actually clear the tracks of leaves.

Agreed. The RHTT not running for two days needs to be looked at.

Also, regarding trees near the line - it should only be necessary to remove those which can fall onto the line should they blow down as a complete tree or branch. Leaves can blow in from woods some considerable distance away as well.

 

[Moonshot]

Or whether the management, control or or drivers of either TOC had any notice that the RHTT wasn't running. Given the forecast that weekend, I find all of this utterly depressing.

The non running of a RHTT is posted in the late notice case at a signing on point. It gives exact details of lines that haven't been treated..

 

[185]

Did the 159's sand hoppers have sand in them?

When both of those sets were at Northern Spirit as 158s, autumn slippage was still a big thing there too. About 20 years ago, I recall a 3-car 158... possibly this very '159' train, (on a Sunday diversion via Chat Moss) slipping almost 800m through two signals after Huyton in an emergency brake application. Came to rest short of a 142 at Whiston... scary stuff, my driver said it was a combination of a signal being put back and the sand 'button not doing anything' - possibly empty?

158s are quite light trains, and at the time Aslef kicked off asking for the sand boxes to be checked & filled twice a day during autumn.

 

[theageofthetra]

The non running of a RHTT is posted in the late notice case at a signing on point. It gives exact details of lines that haven't been treated..

Not at a weekend it won't, management will have all gone missing and no depot admin.

 

[backontrack]

Agreed. The RHTT not running for two days needs to be looked at.

Also, regarding trees near the line - it should only be necessary to remove those which can fall onto the line should they blow down as a complete tree or branch. Leaves can blow in from woods some considerable distance away as well.

And I suppose this also begs the question (to use an unsuitably corny pseudo-tabloid headline):

Are standards slipping?

 

[357]

The non running of a RHTT is posted in the late notice case at a signing on point. It gives exact details of lines that haven't been treated..

Providing the notice cases are kept up to date.

 

[Moonshot]

Not at a weekend it won't, management will have all gone missing and no depot admin.

That's complete rubbish.....it certainly appeared at my depot on Saturday morning just gone.

Providing the notice cases are kept up to date.

In any event, even if a RHTT train didn't run, drivers are under instructions to carry out regular brake tests on their journey. It's a rational thing to do in the dark as it's impossible to actually see the condition of the railhead in front of you

 

[WesternBiker]

Sounds like the driver did exactly as would have been expected of him; Put in the brakes, if its not stopping stick it in emergency. It must have been scary. I wish him the best and as above hope he is well looked after. I do hope this brings light to the potential severity of low adhesion

Absolutely agree – and it is good to see both the RAIB and SWR providing updates on the situation. One hopes the driver – reported as having 50 years’ service – makes as quick and full recovery as possible.