Neil Martin, 46, from Essex, had been helping move a cherry-picker machine out of Edinburgh's Waverley Station when he was killed in 2006.

LH Access Technology and Border Rail and Plant were each fined £240,000 by an Edinburgh sheriff last May.

Both firms claimed the fines were well in excess of English guidelines.

Appeal judges were told the penalty was five times LH Access Technology's average annual profit and more than the company was worth at the time.

But the Court of Justiciary Appeal in Edinburgh backed Sheriff Nigel Morrison QC who said the fatal accident in the early hours of March 2006 was "a serious failure of duty."

Fitter Mr Martin died when he was trapped under the wheels of an mobile platform used for access to overhead wiring.

He was helping move it from Edinburgh's Waverley Station to a nearby low loader for repairs.

The court heard that using "banksmen" to ensure the machinery was moving safely might have prevented Mr Martin's death.

Border Rail were Mr Martin's employer and LH Access Technology were the makers of the platform.