Train breakdown delays passengers in Leicestershire (20/02/2010)

[whole diary]

[Chris from Nailsea]

From the BBC^» (British Broadcasting Corporation - home page):

Up to 200 passengers were forced to leave a train when it broke down and started leaking fuel in Leicestershire.
Fire crews were called by police to assist in transferring the travellers onto another train, near Kibworth, on at about 1730 GMT on Saturday evening.
The 1455 GMT London St Pancras-to-Sheffield train is still blocking the line where it was forced to stop.
It was unable to reach a station so passengers were taken off onto the tracks, East Midlands Trains said.
There were no reported injuries during the incident and passengers were later able to continue their journey on a different train.
In a statement, East Midlands Trains said: "During this transfer, the safety of our passengers was our top priority, and the fire brigade assisted to ensure that all passengers were transferred safely."
Fire crews also located and dealt with the leak of oil and diesel from the train.
Emergency staff remained at the scene for nearly three hours.
Services from Nottingham and Leicester to London were diverted adding about 45 minutes onto journeys.

[devon_metro]

The media are refraining from publishing the actual truth, so I will enlighten you all.

The final drive (similar to gearbox) fell off the unit causing severe damage to a wheelset, which then resulted in a minor (yet high speed) derailment.

[Chris from Nailsea]

An update item from the BBC^» (British Broadcasting Corporation - home page) now uses the word 'derailment':

Trains disrupted after derailment in Leicestershire

Train services between the East Midlands and London continue to be disrupted after a train derailed in Leicestershire.
Up to 200 passengers were forced to leave the 1455 GMT London St Pancras to Sheffield service near Kibworth on Saturday evening.
Investigations are continuing into the cause of the incident.
East Midlands Trains (EMT^» (East Midlands Trains - about)) said a number of immediate safety checks were carried out on its Meridian fleet.
An East Midlands Trains spokesman said: "We are carrying out a full and thorough investigation into the train incident at East Langton at the weekend and are also co-operating fully with the independent work of the Rail Accident Investigation Branch. From our initial inquiries, we can confirm that two of the 56 wheels on the seven-car Meridian train became derailed. However, all carriages on the train remained on the tracks as normal and the train remained upright at all times."
The rail company said a reduced timetable will be operated to and from London while repairs are completed.
Some services between Sheffield and the East Midlands to London will be diverted adding about 50 minutes on to journeys, while some between Nottingham and Leicester to London have been cancelled.

[Chris from Nailsea]

Confirmation that the RAIB^▸ (Rail Accident Investigation Branch) is carrying out an investigation into this derailment - from the RAIB website:

The RAIB is carrying out an investigation into the high speed derailment of one pair of wheels on train 1F45, the 14:55 hrs service from St Pancras to Sheffield, at about 15:46 hrs on 20 February 2010.  The train comprised a seven-car Class 222 ^Meridian^ Diesel Electrical Multiple Unit operated by East Midlands Trains and was carrying approximately 190 passengers and a number of train crew.  On approaching the site of the derailment the train was travelling at close to 100 mph.  No other wheels derailed and the train remained upright.

No injuries were caused to the passengers or train crew although significant damage was caused to the track and signalling equipment over a distance of two miles. There were also reports that one or more road vehicles on an adjacent highway were struck and damaged by debris as the derailed train passed.

The evacuation of the passengers into another train was completed about four hours after the derailment.  The line was then closed for a period of three days to enable train recovery and repairs to the infrastructure.

The RAIB^s preliminary examination has identified that the derailment is likely to have been the result of the failure of an axle in proximity to the final drive.  The exact nature of this failure and associated factors will be the subject of detailed examination by the RAIB, with the cooperation of the operator and rolling stock maintainer, Bombardier.  Any urgent safety issues arising during this investigation will be the subject of a notification to all the industry parties affected.

To date, there is no evidence that the condition of the railway infrastructure or signalling contributed to the derailment.

The RAIB^s investigation is independent of any investigations by the safety authority.

The RAIB will publish a report, including any recommendations to improve safety, at the conclusion of its investigation. This report will be available on the RAIB website.

[Chris from Nailsea]

An update, from the RAIB^▸ (Rail Accident Investigation Branch) website:

Investigation into the derailment of a passenger train at East Langton, near Market Harborough, Leicestershire, on 20 February 2010

Updated 23 November 2010

The RAIB is carrying out an investigation into the high speed derailment of one pair of wheels on train 1F45, the 14:55 hrs service from St Pancras to Sheffield, at about 15:46 hrs on 20 February 2010.  The train comprised a seven-car Class 222 ^Meridian^ Diesel Electrical Multiple Unit operated by East Midlands Trains and was carrying approximately 190 passengers and a number of train crew.  On approaching the site of the derailment the train was travelling at close to 100 mph.  No other wheels derailed and the train remained upright.

No injuries were caused to the passengers or train crew although significant damage was caused to the track and signalling equipment over a distance of two miles.  There were also reports that one or more road vehicles on an adjacent highway were struck and damaged by debris as the derailed train passed.

The evacuation of the passengers into another train was completed about four hours after the derailment.  The line was then closed for a period of three days to enable train recovery and repairs to the infrastructure.

The RAIB^s investigation, being conducted with the assistance of industry parties involved, has found that the derailment was a result of a broken axle. To date, the investigation has found no evidence that axle fatigue initiated the failure. Currently, the focus of the investigation is on a gearbox output bearing, underneath which the axle fractured.  The inner ring of this bearing had rotated on the axle and it is thought that this slipping at the inner ring/axle interface gave rise to very high temperatures. This was sufficient to weaken the axle to the extent that it was no longer able to carry its normal loads.

This issue has been notified to and within industry and mitigation measures taken.

The investigation has reached a stage where the effect of clearance between the gear-side output bearing inner ring and its associated seat on the axle, needs to be assessed by testing. It is intended that three gearboxes, with a range of such clearances, be tested on a rig in January 2011. These tests should mark the conclusion of the RAIB investigation, after which the investigation report will be published.

To date, there is no evidence that the condition of the railway infrastructure or signalling contributed to the derailment.

The RAIB^s investigation is independent of any investigations by the safety authority.

The RAIB will publish a report, including any recommendations to improve safety, at the conclusion of its investigation.  This report will be available on the RAIB website.

[Chris from Nailsea]

The RAIB^▸ (Rail Accident Investigation Branch) have published a further update on their website:

Investigation into the derailment of a passenger train at East Langton, near Market Harborough, Leicestershire, on 20 February 2010

Updated 31 May 2011

The RAIB is carrying out an investigation into the high speed derailment of one pair of wheels on train 1F45, the 14:55 hrs service from St Pancras to Sheffield, at about 15:46 hrs on 20 February 2010.  The train comprised a seven-car Class 222 ^Meridian^ Diesel Electrical Multiple Unit operated by East Midlands Trains and was carrying approximately 190 passengers and a number of train crew.  On approaching the site of the derailment the train was travelling at close to 100 mph.  No other wheels derailed and the train remained upright.

No injuries were caused to the passengers or train crew although significant damage was caused to the track and signalling equipment over a distance of two miles.  There were also reports that one or more road vehicles on an adjacent highway were struck and damaged by debris as the derailed train passed.

The evacuation of the passengers into another train was completed about four hours after the derailment.  The line was then closed for a period of three days to enable train recovery and repairs to the infrastructure.

The RAIB^s investigation, being conducted with the assistance of industry parties involved, has found that the derailment was a result of a broken axle. To date, the investigation has found no evidence that axle fatigue initiated the failure. Currently, the focus of the investigation is on a gearbox output bearing, underneath which the axle fractured.  The inner ring of this bearing had rotated on the axle and it is thought that this slipping at the inner ring/axle interface gave rise to very high temperatures. This was sufficient to weaken the axle to the extent that it was no longer able to carry its normal loads.

This issue has been notified to and within industry and mitigation measures taken.

The investigation had reached a stage where the effect of clearance between the gear-side output bearing inner ring and its associated seat on the axle, needed to be assessed by testing. Three gearboxes, with a range of such clearances, were tested on a rig in January 2011. The test results have been analysed and the gearboxes stripped down and examined.

There is no evidence that the condition of the railway infrastructure or signalling contributed to the derailment.

The RAIB^s investigation is independent of any investigations by the safety authority.

The RAIB will publish a report, including any recommendations to improve safety, at the conclusion of its investigation.  This report will be available on the RAIB website.

[6 OF 2 redundant adjunct of unimatrix 01]

is this not potentially quite worrying ?

[inspector_blakey]

I wouldn't be losing any sleep over it at the moment... Even if there is some kind of systematic design flaw (rather than a one-off manufacturing defect on the unit that was affected), you could argue that the combined 220/221/222 fleet has racked up countless millions of miles in service over the last ten years without any other occurrences so it's unlikely to be a massive problem. One worth investigating and getting to the bottom of to avoid a repeat performance, certainly, but not something that would worry me as a passenger in the slightest.

[JayMac]

The RAIB^▸ (Rail Accident Investigation Branch) have now released their full report into this incident:

Summary

On 20 February 2010, at around 15:49 hrs, a seven-car Meridian diesel multiple unit passenger train derailed by one axle of the fourth vehicle, while travelling on the Midland Main Line near East Langton. The train was travelling at a speed of 94 mph (151 km/h) when the derailment occurred, and it subsequently ran for a distance of approximately 2 miles (3.2 km) before it stopped. The train remained upright during the derailment and did not foul the adjacent line. There were no injuries among the 190 passengers and 5 crew who were on board the train, but there was damage to the track and the train, including loss of diesel fuel.

The immediate cause of the derailment was the complete fracture of the powered trailing axle of the leading bogie on the fourth vehicle. The fracture occurred underneath the gear-side output bearing of the final drive and was caused by this bearing stiffening up so that it could no longer rotate normally. When this happened the axle spun within the inner race of the bearing to which it is normally tightly fitted. The consequent generation of a large amount of frictional heat between the axle and bearing resulted in the axle being locally heated to a high temperature and weakened to the point it could no longer carry its normal loading.

Key evidence about the condition of the bearing and its fit onto the axle was destroyed in the failure, making it impossible to determine with certainty, the precise sequence of events leading to the bearing becoming stiff in rotation. The RAIB investigation has interpreted the available evidence in order to identify the most likely cause of the failure from the possible causes. The RAIB concluded that the most likely cause of the bearing failure which preceded the overheating of the axle was a loose fit between the gear-side output bearing and axle.

The RAIB has made four recommendations. Two recommendations relate to reviewing the design and overhaul procedures for final drive gearboxes on Meridians and other rolling stock. They also cover consideration of the detection of overheating output bearings in order to mitigate risk to persons resulting from a failure of the output bearings, regardless of the cause. A third recommendation relates to the oil sampling regime used for the Meridian fleet and the fourth relates to the provision of practical, simulation based alarm handling training for drivers and train crew.

Full report: http://www.raib.gov.uk/cms_resources.cfm?file=/120130_R012012_East_Langton.pdf