THE West Somerset Railway’s popular diesel railcar train was this week back in service after a full mechanical overhaul, meaning it will now be good for several years to come.

The dark green train comprises four coaches joined together with the engines underneath the coaches.

It can be driven from either end and is technically known as a diesel multiple unit (DMU).

The trains were first introduced in the 1950s - although their experimental history goes back to the 1930s.

They were cheaper to run than the previous steam trains and were common on the Minehead branch line from the early 1960s onwards.

The West Somerset Railway DMU was originally built more than 60 years ago in 1960 and its technical designation is a Class 115.

It was built by British Railways in Derby, mainly for London suburban use.

One of the big attractions of the WSR’s DMU is that – at the front – passengers can sit right behind the driver, separated only by a glass screen and look ahead down the track.

Passengers at the back can see the track receding behind them.

DMUs were a critical step in railway train development and these days modern DMUs are the type of train on which passengers are likely to travel when on the main line, or their electrically-powered cousin the EMU or electric multiple unit.

West Somerset’s DMU operated its first passenger services last weekend, taking passengers from Bishops Lydeard to Norton Fitzwarren for the annual West Somerset Railway Association Steam Rally. It will also operate a shuttle service between Minehead and Dunster for the Forties weekend on September 10 and 11.