RAIL workers narrowly escaped serious injury after being forced to jump clear of runaway railway transporters, which ran free for more than five miles down the Amman Valley line.

At about 9.40pm on Saturday, November 1, a pair of trolleys – known as ironmen – which were being used to transport a 52-foot length of rail from Gwaun Cae Gurwen to the Raven level crossing in Garnant, ran out of control.

The ironmen travelled more than five miles along the line towards Ammanford, with two track workers forced to jump clear, just in time to warn colleagues working down the line.

According to the Rail Accident Investigation Branch (RAIB), “one of the men who had travelled with the ironmen required hospital treatment for injuries he sustained when he jumped clear; there were no other injuries.”

The ironmen, which had no lights, continued down the track, in heavy rain, through three road crossings and two footpath crossings before they had slowed down enough for a Network Rail manager to be able to stop and secure them near Ammanford.

The General Secretary of the Transport Union, RMT, Mick Cash, said the incident had sent “shock waves” through the railway community.

In a statement for the RAIB, a spokesman said: “The RAIB’s investigation will seek to identify the sequence of events and will include consideration of the planning of the work, the design and maintenance of the brakes on the ironmen, the rules governing the use of manual-propelled wheeled plant, of gradients and the effect of the weather conditions.”

The RAIB’s investigation is independent of any investigation being conducted by the railway industry, Office of Rail Regulation and British Transport Police.