| Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by stuving at 15:59, 28th March 2024 |     |
This was a few days ago, but the RAIB have now announced their investigation:
Investigation into the derailment of a passenger train at Grange-over-Sands, Cumbria, 22 March 2024.
Published 28 March 2024
The rear of the train following the derailment.
At around 06:05 hrs on 22 March 2024, a passenger train travelling between Preston and Barrow-on-Furness derailed after crossing over a section of unsupported track which gave way as the train passed. The track had become unsupported because a cavity had opened in the embankment on which the railway sits.
The train was travelling at 56 mph (90 km/h) when the accident occurred, with the front three carriages of the six-carriage train becoming derailed. The train struck a wall situated at the top of the embankment following the derailment. It remained upright and came to a stand with the rear of the train around 31 metres beyond the cavity.
There were four staff and four passengers on the train when the accident occurred. There were no injuries sustained by anyone onboard, although significant damage was caused to the train and to railway infrastructure.
Our investigation will seek to identify the sequence of events that led to the accident. It will also consider:
Published 28 March 2024
The rear of the train following the derailment.
At around 06:05 hrs on 22 March 2024, a passenger train travelling between Preston and Barrow-on-Furness derailed after crossing over a section of unsupported track which gave way as the train passed. The track had become unsupported because a cavity had opened in the embankment on which the railway sits.
The train was travelling at 56 mph (90 km/h) when the accident occurred, with the front three carriages of the six-carriage train becoming derailed. The train struck a wall situated at the top of the embankment following the derailment. It remained upright and came to a stand with the rear of the train around 31 metres beyond the cavity.
There were four staff and four passengers on the train when the accident occurred. There were no injuries sustained by anyone onboard, although significant damage was caused to the train and to railway infrastructure.
Our investigation will seek to identify the sequence of events that led to the accident. It will also consider:
- the condition of the railway and nearby drainage
- the planning and management of relevant railway maintenance activities
- how the railway infrastructure at this location was managed in response to local flood risks
- any underlying management factors.
Like many accidents, this one raises some questions specific to it. Some those are about where and how the railway was built, across part of Morecambe Bay (the Winster estuary), by heaping up the sand and silt from the marsh. Obviously others are about what has happened, as "management" or otherwise, since.
The picture RAIB used looks bad; this one from Phil Barrett on X shows a scarily deep hole, and may be worse:
Why was there a big void under this embankment-cum-"sea"-wall? Note that there is no obvious place for that much stuff to have come out; the seaward side is stone faced and there is a closely observed ditch to the landward. Was a void always there, perhaps due to the difficulty of building a railway across a tidal estuary?
You can see the outlet hoses of some pumps NR have been running to try (with limited success) to stop the area behind it flooding; was that in any way a cause? Is nature getting its own back, resenting the Ulverston and Lancaster Railway's interference? The course of the Winster before it was diverted away ran just under here; is that relevant?
| Re: Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by Oxonhutch at 04:40, 29th March 2024 | |
I believe it took several attempts to get this embankment built, it being washed away on more than one occasion during construction. I imagine that the fill has been washed out under the wall somewhere. Some dye testing will be very interesting.
| Re: Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by stuving at 23:55, 28th January 2025 | |
RAIB have published their report into this accident. As usual, it has loads of details about arcane topics like the history of land drainage in this part of the world. This is the summary:
At around 06:05 on 22 March 2024, a passenger train travelling at 56 mph (90 km/h) derailed on the approach to Grange-over-Sands station. The derailment occurred because a void had opened in the embankment on which the train was travelling, leading to the rails under the train losing support. The train was carrying four train crew and four passengers when it derailed. Nobody was injured, but significant damage was caused to both the train and the railway infrastructure.
RAIB’s investigation found that the void had been created because water had dislodged embankment material and carried it away. The water came from a pipe partially buried beneath the railway, which had been damaged during routine maintenance around 2 days before the derailment.
The damage to the pipe had been reported immediately to the railway control room by the maintenance staff involved. However, as a result of ineffective communications, no action was taken to stop the consequent leak. The pipe had been installed by Network Rail in 2016 as a temporary measure to assist in managing flood water in the surrounding areas, but on-call engineering staff were unaware that it was in use and carrying water at the time it was damaged.
Underlying factors to the accident were that those responsible for managing flood water at this location had not done so effectively, leading to the prolonged need to rely on temporary pumping arrangements. RAIB also identified that staffing levels at Network Rail’s Carnforth maintenance delivery unit did not provide sufficient resilience and had allowed non-compliance with the standards relating to the management of tamping to become normalised. In addition, Network Rail had allowed a temporary pumping arrangement to become permanent without applying the relevant asset management procedures.
RAIB’s investigation found that the void had been created because water had dislodged embankment material and carried it away. The water came from a pipe partially buried beneath the railway, which had been damaged during routine maintenance around 2 days before the derailment.
The damage to the pipe had been reported immediately to the railway control room by the maintenance staff involved. However, as a result of ineffective communications, no action was taken to stop the consequent leak. The pipe had been installed by Network Rail in 2016 as a temporary measure to assist in managing flood water in the surrounding areas, but on-call engineering staff were unaware that it was in use and carrying water at the time it was damaged.
Underlying factors to the accident were that those responsible for managing flood water at this location had not done so effectively, leading to the prolonged need to rely on temporary pumping arrangements. RAIB also identified that staffing levels at Network Rail’s Carnforth maintenance delivery unit did not provide sufficient resilience and had allowed non-compliance with the standards relating to the management of tamping to become normalised. In addition, Network Rail had allowed a temporary pumping arrangement to become permanent without applying the relevant asset management procedures.
One bit of their explanation that is hard to believe, and well outside the experience or expertise of most of us, is where the sand lost from the void went. Supposedly it went down below ground level and then inland and along the embankment westwards, through "solid" ground, and came up in the pond where water collects before (in theory) flowing away via the drain along the sea wall. That was 80 m3 of sand, in 52 hours, a distance of over 100 m! But the report claims that "the bulk of missing material from the embankment could be found in the pond".
| Re: Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by Bob_Blakey at 10:13, 29th January 2025 | |
In the last quarter of 2024 a somewhat similar explanation was provided to me by one of the engineering team working, on behalf of the Environment Agency, to install ground movement monitoring equipment along the landward side of the River Exe bund between the Turf Locks Hotel and (just north of) Powderham. Regular checks had revealed that the structure was being undermined in several places on the tidal river side but there was no evidence that the lost soil was being washed into the river itself. I do not know for sure but think that the water level of high tides can be above the landward ground level (where the Exe Estuary Trail footway/cycleway has been built).
| Re: Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by ChrisB at 10:47, 29th January 2025 | |
The RAIB video on YouTube is well worth a watch, but I can't locate it now.
| Re: Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by stuving at 10:55, 29th January 2025 | |
The RAIB video on YouTube is well worth a watch, but I can't locate it now.
https://youtu.be/v62kzDb_DW0
That video has the graphic of water flow by "soil piping", which suggests it came up some way away, i.e. in the pond. But the words in the report just say the sand was "deposited" there. So maybe it came out higher up and went into the drain at the back of the embankment, and was carried along that to the pond. Otherwise, I guess the water table is barely below ground level, so this extra water is flowing through water that's already there. And presumably already flowing, too.
| Re: Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by Oxonhutch at 11:57, 29th January 2025 | |
One bit of their explanation that is hard to believe, and well outside the experience or expertise of most of us, is where the sand lost from the void went. Supposedly it went down below ground level and then inland and along the embankment westwards, through "solid" ground, and came up in the pond where water collects before (in theory) flowing away via the drain along the sea wall. That was 80 m3 of sand, in 52 hours, a distance of over 100 m! But the report claims that "the bulk of missing material from the embankment could be found in the pond".
The report discounted the idea that sand and silt, that comprised the majority of the railway embankment, had been washed into karstic voids in the underlying limestone basement. This was identified as the reason for a collapse near to Grange's signalbox in 2019. The soil piping occurred within the embankment material and underlying salt marsh sediments and didn't enter the underlying original marine sediments. Reports of the embankment 'exploding' in the area of the train's final resting place suggest that there was a significant hydraulic head within the embankment itself sealed by the outer seawall skin. The amount of material moved by this quantity of water in the time available is quite believable and my thoughts are that the soil piping was already present prior to this breach. The tamping damage was just the final straw.
| Re: Derailment of a passenger train at Grange-over-Sands, 22/3/24 Posted by UstiImmigrunt at 08:08, 30th January 2025 | |
And it is only going to get worse...
This is being discussed with several unwanted BR dinosaurs who know a bit. Drivers, guards, signallers and controllers. The general consensus, this was a lucky escape. Drones and spreadsheets in Milton Keynes is no replacement for boots on the ground. I'd like to know why the instructor (just 5 years with a key) didn't send the trainee to try to operate a GSMR unit and make a REC whilst taking the dets and carrying out Section M. Yes, everyone is shaken up by an incident like this but emergency protection is so important to carry out.
