English: The New Measurement Train at London Kings Cross. The New Measurement Train is a measurement train used by Network Rail to determine where engineering work needs to be done. The train is essentially a specially converted InterCity 125 (the world's fastest diesel train, also called the High Speed Train or HST). It can work on most lines of the Great British rail network, but some lines are not suitable for the InterCity 125. Other measurement trains are used where the New Measurement Train cannot run. It was converted in 2003, but the train itself was built in the 1970s/80s, and was previously used by Virgin Trains, who replaced their InterCity 125 sets with newer diesel high-speed trains built in Belgium in 2003.