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

[MadCommuter]

The GWR shown is the rear unit of the 2 units.
159’s can’t be 4 cars. All 159s are 3 car.

Which suggests the two 158s have been split at a point in time between the train approaching the tunnel and the photograph taken.

 

[theking]

If people think that the FGW driver is in error for not carrying out protection, well imagine if he or she had done so.

The protection issue has been latched on because its in the rulebook, in these days of gsmr it's a last resort.

Where was the rec call to the signaller.

Why didn't the signaller stop all trains.

If no rec call was made why?.

If the gsmr was out why was it out?

These are the questions that will need to be answered.

 

[swt_passenger]

Looking at the photos, the impression I got is that the GWR hit the SWR.

Yet the view from the other end - of the front of the SWR unit - suggests the exact opposite…

 

[geoffk]

It's a pretty awful area for Rail replacement transport in general but Gillingham is the best for that very reason. I was unfortunate enough to be on a cancelled Exeter Waterloo service two weeks ago but for weather rather than this tragic incident.

Two RRBs at St. David's this afternoon but none shown on RTT.

 

[backontrack]

Also BBC with a much clearer photo this morning of how the two trains have ended up where they have.

Salisbury train crash: Driver suffers 'life-changing injuries'

Passengers describe being thrown from their seats when two trains collided in Salisbury, Wiltshire.

www.bbc.co.uk

My word! How on Earth did the passengers in the middle coach of the SW Turbo escape catastrophic injury?

 

[Dave W]

In this example with these specific two trains which would have been given priority at the junction normally? The GWR service is booked first but was running 20 minutes late so clearly had missed it's path. The SWR service was 6 minutes late but with a 5 minute stop at Salisbury (according to RTT) in could have got back much closer to time. My instinct says that if I were the signaller I would give priority to SWR given the long single track sections it had ahead of it towards Honiton.

Afaik it's a 5 car unit, and that 1L53 hit 1F30 from the rear.

The image in the above quoted post [reattached here for ease of viewing] shows that 1F30's headcode has stepped forward to the next berth, whilst 1L53 is in the previous berth. Usually - although not always - railway accident reports point at this as a giveaway to which train has passed a signal at danger (if a train passes a signal at danger, the headcode doesn't step forward)

I don't know whether that's the case here, of course.

 

[FOCTOC]

My word! How on Earth did the passengers in the middle coach of the SW Turbo escape catastrophic injury?

Because it wasn't a catastrophic accident. Fortunately.

 

[Bacon_BMW]

My word! How on Earth did the passengers in the middle coach of the SW Turbo escape catastrophic injury?

Luck.

 

[Llama]

If a train passes through a set of points set against it what kind of noise would you hear from inside the train? I’ve always assumed that the blades would shift with the weight of the train, but would it be a bit of a rough experience?

Not much I would imagine from a set of points like that. A bit of a clunk at most that might not be noticed by most passengers.

HPSS points run through in the trailing direction might be a different matter, although the points in this incident aren't HPSS.

 

[chiltern trev]

Re going to Fratton for fuel - is it possible to bring a fuel tanker (road or rail) to a more suitable location and have a temporary fuel pump etc.?

 

[43096]

Looking at the photos, the impression I got is that the GWR hit the SWR.

I have no idea how you reach that conclusion. Looking at the photos everyone else has reached the opposite conclusion.

 

[LOL The Irony]

From the BTP statement:

I would expect an official BTP statement to be very precise in its wording and there a clear implication in it that the GWR train hit the SWR train - and not the other way around which so far most people seem to have been suggesting. (Note: if you aren’t certain which train hit which, the correct wording would be ‘… a Great Western Railway service from Southampton to Cardiff and a South Western Railway service from London to Honiton collided…’)

I have a feeling that these conflicting reports are both correct and it isn't a black and white one hit the other.

 

[Miken]

BBC News now reporting that one of the train drivers received "life changing injuries" - my heart goes out to that individual and his family and colleagues...

Salisbury train crash: Driver suffers 'life-changing injuries'

Passengers describe being thrown from their seats when two trains collided in Salisbury, Wiltshire.

www.bbc.co.uk

 

[Crossover]

In this example with these specific two trains which would have been given priority at the junction normally? The GWR service is booked first but was running 20 minutes late so clearly had missed it's path. The SWR service was 6 minutes late but with a 5 minute stop at Salisbury (according to RTT) in could have got back much closer to time. My instinct says that if I were the signaller I would give priority to SWR given the long single track sections it had ahead of it towards Honiton.

To disclaim again, as a layperson, my understanding is that generally it is preferable to keep things in booked order. As mentioned upthread, there was also 1F27 to consider as well

 

[MarkyT]

Do we know if there is point to point locking between points 105 and 106?

Sorry, don't know. Standard double junction flank protection controls in the route and signal layers will be present no doubt. At some date, I think designers were instructed to stop putting direct point-to-point locking in relay and processor interlockings. Back in mechanical days, it was standard as it simplified the locking significantly.

Questions (I not looking for answers, just things to think about, the kinds of questions that the investigators will be asking, so please don’t speculate here):

What was the reason that caused the driver of GWR train 1F30 to stop their train where they did? Did it actually hit something? Was there a problem with the points fittings (point number 106) ? Or was there a problem with the train? If this train did hit something or if there was a problem with 106 points, did this train derail?

Certainly an odd place to stop voluntarily, so suggests some problem forced a halt.

Why did the TD not step the ‘head code’ forward for 1L53 when the train has clearly passed signal SY31?

Good question. Depending on the system and how its wired, that's one of the things signallers, techs, managers and investigators often look at after an incident as a quick indicator as to whether a SPAD has occurred. Some, but not all TDs require that the route is set for a track circuit triggered step to take place. There should also be comprehensive logging data available from the interlocking.

If there was no problem with GWR train 1F30 operating the track circuits (where it is in the photos I would expect it to be on at least two track circuits) the interlocking should have held signal SY31 at red. So was there a problem with the track circuits?

In the photos, points 105 look to be lying reverse, as they would have been needed for the move of 1F27 over the junction. This is the opposite way to that required for 1L53 if there is point to point locking between points 105 and 106. We don’t know which way points 106 are because we can’t see them and they may be under the GWR train. If there is point to point locking, then if points 105 are not set correctly, signal SY31 should not clear. Was there a problem here?

Even if there's no direct point-to-point locking incorporated, there will definitely be standard flank protection controls that require 105 aligned towards Andover before SY31 can clear.

Did the signaller route signal SY31? If the answer is no, then signal SY31 should not clear to a proceed aspect. Did signal SY31 stay red? Was it lit? What was the sighting like? Could approaching train drives see it clearly and at the required minimum distance?

If SY31 does not show an proceed aspect or if the signal is not illuminated , then the AWS should result in the AWS horn sounding in the leading cab of train 1L53. Was the track and lineside equipment for the AWS working? Was the train AWS equipment working?

SY31 should be fitted with TPWS equipment. The TPWS transmitter loops should be energised at all times unless the signal is showing a proceed aspect. Was the track and lineside equipment for the TPWS working? Was the train TPWS equipment working?

Definitely fitted. Can be seen on Google Earth images. Overspeed loops approx 200m from signal, with the AWS ramp nearby. Note the distance from signal to junction clearance point is approx 160m which is usually considered an acceptable overlap distance for the 50mph approach speed.

The signal, SY31 requires electricity to work, as does the TPWS. Was there a loss of power to this equipment, causing SY31 to go ‘black’ and disappear into the darkness? The signal identification plate/sign should be made of the reflective type so that it can be seen more easily in poor light conditions. Was it? Was it clean?

The AWS, thankfully, will continue to work through a signalling power failure, giving a cautionary indication and imposing a braking intervention if not acknowledged.

 

[Bertiethebobby]

Last night an older female passenger was interviewed by BBC News, she talked about leaves on the line, which seemed a bit random at the time.

On Radio 2 at lunchtime a woman said that as the rails were wet the train may have slipped off the rails.

 

[Bletchleyite]

My word! How on Earth did the passengers in the middle coach of the SW Turbo escape catastrophic injury?

Because it's fully intact, just on a 45 degree angle.

 

[bramling]

On Radio 2 at lunchtime a woman said that as the rails were wet the train may have slipped off the rails.

Ironically, it could well turn out that adhesion is the root cause. It's certainly something high on the possibility list. These things are rarely simple though, there's normally multiple factors which have come together at the wrong moment.

 

[reduke]

I would still query where the information that there were 2 158's involved has come from, or that they have split? Given the number of photos available and taken from within the tunnel, it is at least mildly surprising that no photos of this other unit have appeared.

 

[ilkestonian]

That picture paints a 1000 words.

I'm assuming you're referring to the position of the points for the line exiting the tunnel, which appear set to cross the route of the SWR service?

If this is the point you are making, then *if* the accident resulted from the SWR service hitting the side of the GWR dmu, surely it is possible that the points were disturbed by the passage of the SWR train after derailing?

Hence not possible to draw a definitive conclusion.

Apologies if I've misunderstood the point about the picture.

 

[Surreytraveller]

My word! How on Earth did the passengers in the middle coach of the SW Turbo escape catastrophic injury?

Because railway carriages are designed to protect the occupants in the event of a crash

 

[swt_passenger]

I would still query where the information that there were 2 158's involved has come from, or that they have split? Given the number of photos available and taken from within the tunnel, it is at least mildly surprising that no photos of this other unit have appeared.

Post #389 which is from a reputable source.

 

[Thumper1127]

Ironically, it could well turn out that adhesion is the root cause. It's certainly something high on the possibility list. These things are rarely simple though, there's normally multiple factors which have come together at the wrong moment.

Checking RTT, no treatment trains ran on Saturday or Sunday on the Andover route. Last one I can see is Friday. Could be wrong of course.

 

[Dan G]

So where's the other half of the GWR train? The other two 158 vehicles?

 

[Cowley]

Not much I would imagine from a set of points like that. A bit of a clunk at most that might not be noticed by most passengers.

HPSS points run through in the trailing direction might be a different matter, although the points in this incident aren't HPSS.

Thanks for that.

 

[Surreytraveller]

That picture paints a 1000 words.

Which are?

 

[Sprinter158]

What might happen to the 159 and 158 involved, will the damaged vehicles be scrapped or is there a chance ( a very tiny one seeing the photos ) they could be repaired?

 

[Ken H]

I'm due there tomorrow as part of the Structures Team investigating the part any local structures would/could of had on the incident. I'm sure the RAIB alongside the BTP will release an interim report shortly after that.

is that bridges and tunnels structures or train structures? I am guessing the former.

 

[TT-ONR-NRN]

What might happen to the 159 and 158 involved, will the damaged vehicles be scrapped or is there a chance ( a very tiny one seeing the photos ) they could be repaired?

I still wonder how the damage would have compared if the pair of 158s had been the usual Turbo.

 

[Ken H]

What might happen to the 159 and 158 involved, will the damaged vehicles be scrapped or is there a chance ( a very tiny one seeing the photos ) they could be repaired?

That will be for the insurers to decide. If the repair costs exceed the unit value, then they will write it off. The unit will become the property of the insurers. The 'railway' could buy it back from the insurers.