father_jack
Member
- Joined
- 26 Jan 2010
- Messages
- 1,076
6A11 Robeston to Theale tank train broke 2 rails near Llanharan yesterday, recessed in Bristol East Depot for inspection...........
6A11 Robeston to Theale tank train broke 2 rails near Llanharan yesterday, recessed in Bristol East Depot for inspection...........
At around 02:10 hrs on Saturday 6 March 2021, train reporting number 6A11, the 21:25 hrs freight service from Robeston (Milford Haven) to Theale, caused damage to the track that it travelled over on the part of its journey between Pencoed and Llanharan, including two broken rails. The train, which did not derail, stopped beyond Cardiff Central station following a call from the signaller to the driver informing them of a possible problem with the train. The driver was instructed to continue over the wheel impact load detection system at Marshfield, to try and confirm suspicions that wheel flats had caused the track damage. The detection system did not highlight any problem with the train, which was then allowed to continue on its journey. The train was finally stopped in the Horfield Junction area, near Bristol, after a report of it making unusual noises was made by staff at the maintenance depot at Stoke Gifford.
The train consisted of a locomotive and 23 tank wagons loaded with petroleum products. Examination of the train found that part of the brake rigging on the leading bogie of the eleventh wagon had become detached, and that the trailing pair of wheels on that bogie had suffered significant damage (wheel flats). Some of the components of the braking system were missing altogether. Upon inspection, several other wagons in the train also showed evidence of wheel tread damage, possibly consistent with their wheels having stopped rotating at times during the journey.
The RAIB’s preliminary examination has concluded that the brakes of all the wagons in the train were almost certainly properly released when the train left Robeston. It appears that some sets of wheels ceased to rotate at some point during the journey, leading to the development of the wheel flats, and began to turn again, possibly after the train had come to a stop at Margam for a change of driver. The impacts from the rotating, damaged, wheels, particularly those on the eleventh wagon, gave rise to the broken rails, and may also have caused the damage to the brake rigging on that wagon.
Our investigation will aim to establish the sequence of events and determine why the wheels behaved in this way, and why the braking components failed. It will examine how the developing incident was handled by the Network Rail operating staff along the route, and consider any underlying management factors. Our investigation will also explore any similarities to the events leading to the derailment at Morlais Junction in August 2020, which is the subject of an on-going RAIB investigation, and to the track damage incident between Ferryside and Llangennech in 2017, which is described in RAIB report 17/2018.
Sorry for my naivety, would this have been a similar type of train between the same locations as the one that derailed at Llangennech last August? That too has been linked to flat spots and an issue with the braking system.
The loco that hauled 6A11 would appear to be 60015. It would also appear that since the same train was involved in the Morlais Jn derailment last August, its departure time from Robeston has changed from 21.52 to 21.25.
Sorry for my naivety, would this have been a similar type of train between the same locations as the one that derailed at Llangennech last August? That too has been linked to flat spots and an issue with the braking system.
Two similar incidents in a relatively small space of time would (at least in my mind) indicate more than bad luck, even if the root causes of such a situation turn out to be different.
It's three similar incidents:- Carmarthen Jcn - Llangyfelach Tunnel, 21-10-17, Llangennech 26-8-20, and Pencoed - Llanharan 6-3-21. (edited for typo correction)
I think that people who live near the line where a regular service passes are valuable sources of information. What sort of sounds are you hearing? Evidence of flats on the wheels? What is the rail type near you? Is it jointed or smooth rail?Yes 3 similar incidents now. How old are these wagons? They seem to have been around for ages. I know it's more about maintenance than age though. They pass about 15 metres from my house and each wagon makes a different sound. Some rattle more than others. How often are they inspected I wonder?
The track here is CWR, straight, and 75mph limit, although the oilers pass up to about 60mph. Each wagon seems to sound different - mainly rattles and bangs, but I'm no expert on wagons so perhaps this is normal anyway. Each wagon is in a different livery and there are a number of designs from what I can see. They are mostly quite dirty, but that's not necessarily equivalent to poor maintenance. Sometimes some wagons do sound like they have wheel flats, but as the trains are noisy anyway, its hard to be sure. I guess the signalman here keeps an eye on them!I think that people who live near the line where a regular service passes are valuable sources of information. What sort of sounds are you hearing? Evidence of flats on the wheels? What is the rail type near you? Is it jointed or smooth rail?
So much so that it took me a minute or two to realise where all the old posts had gone! (Thought it was an update to the previous thread)Sorry for my naivety, would this have been a similar type of train between the same locations as the one that derailed at Llangennech last August?
I'd guess that it doesn't take very long for newness to be overtaken by inadequate maintenance as far as safety is concerned.I understand that the previous two incidents were caused by faults from wagons that were built as recently as 2005