Rail Accident Investigation Branch
An empty 30 foot container was blown off an FEA(B) wagon that formed part of train 4S83 (the 23:54 hrs service from Basford Hall to Coatbridge). The train was travelling at around 75 mph (120 km/h) on the down main line in the vicinity of Scout Green, Cumbria, around 2.5 miles south of Shap Summit. The container passed over the adjacent up main line and came to rest at the bottom of the up side embankment. There was no damage to train 4S83, any other train, the overhead line equipment or the track. Trees on the embankment and a boundary wall at its foot were knocked over.
The incident took place at a time of high cross winds. Although it did not result in injuries, the potential for more serious consequences is evident.
The wagon involved was fitted with UIC spigots to retain containers on a flat wagon deck. The ability of wagons fitted with such spigots to retain containers subject to overturning forces, such as those developed in high cross winds, is dependent on compliance with the dimensional tolerances specified in standard UIC 571-4. Investigation of previous similar incidents at Hardendale and Cheddington in 2008, concluded that spigots which do not comply with UIC 571-4 are ineffective in such circumstances. The inward hinging spigots fitted to FEA(B) wagon involved in this incident did not comply with the standard.
The freight train operator was aware of this and was aiming to control the risk of containers being blown off by the following procedural means:
- if winds of over 55 mph (88 km/h) are forecast, any empty containers should be pinned down or the maximum train speed reduced to 60 mph (96 km/h); and
- if winds over 65 mph (104 km/h) are forecast, any empty containers should be removed or pinned down.
The forecast wind-speeds for Cumbria at the time were less than 55 mph (88km/h) which meant there was no procedural requirement to limit the trains speed or pin down empty containers. However, local measurements at Shap weather-station, suggest that the actual local wind-speed was around 62 mph (100 km/h).
The freight operator has since reduced the 55 mph (88km/h) wind-speed threshold to 41 mph (66 km/h) and issued a National Incident Report (NIR) to inform the rest of the railway industry. RAIB have issued Urgent Safety Advice.
RAIBs investigation will consider the sequence of events and factors that led to the incident, including actions taken in response to the previous incidents at Hardendale and Cheddington (RAIB report 12/2009).
RAIBs investigation is independent of any investigations by the railway industry or safety authority.
We will publish our findings at the conclusion of the investigation. This report will be available on our website.
You can subscribe to automated emails notifying you when we publish our reports and bulletins.