An inquest into the deaths of Roy Wilkinson, of Peck Avenue, Boston, and Victor John Bee, of Clampgate Road, Fishtoft, was held this week. The men died when a Central Trains engine collided with their van at an unmanned farm crossing in Helpringham Fen on December 6, 2004.

The two work colleagues, who were employees of power company Central Networks, had been carrying out routine maintenance work at a substation before the incident occurred at around 1.30pm.

Train driver Ross Hamilton told the inquest he had not seen the van on the line. He said: "I remember hearing a dull thud, then the front windscreen of my cab shattered and the door separating me from the gangway came in towards me. I didn't know initially what had happened."

Sheila Stevens, a passenger on the train, said: "There was all of a sudden a deafening sound of metal on metal, a really loud screech. It was so loud that it drowned out all other sound."

After the de-railed train had ground to a halt, Mr Hamilton ventured forward to investigate.

He said: "There was a large hole at the front of the train and I could clearly see a mangled mess which resembled a car."

He saw the bodies of the two men inside the van, and both were pronounced dead at the scene by paramedics. No traces of alcohol were found in either man's blood.

Mr Wilkinson, 47, who was married with two sons, had been driving the van, and Mr Bee, 50, who had a wife and three children, was in the passenger seat.

The van was pushed more than 100m along the line by the Sleaford-bound train before jamming in a bridge over the South Forty-Foot Drain.

Bryan Jackson, an electrical fitter for Central Networks, told the inquest he was not aware of any proper risk assessment of the crossing ever having been carried out.

He said he had only visited the site "infrequently".

The jury was also told that a telephone positioned beside the crossing to contact local signalmen had only been installed since the tragedy occurred.

The inquest is expected to conclude on Thursday.