Track Rail Transposer
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Ayrshire brothers' invention to transform America's railways

A machine to lay rail track, invented and patented by two brothers from Ayrshire, is set to revolutionise the job in America.

Billy and Danny McCulloch have taken their Track Rail Transposer to New York to renew part of the city's subway.

Until now, the work has been a back-breaking task carried out by gangs of men by hand.

BBC Scotland's Willie Johnston reports.