The passenger trains on the Ashburton Branch (now the South Devon Railway), in common with most small country branch lines operated by the Great Western Railway, where serviced by "AutoTrains"  These trains were the forerunners to today's modern multiple units in that they could be driven from either end without the need for the engine to change ends.  The Great Western Railway started with Steam Rail Cars which where self powered coaches, but due to the lack of versatility, these where converted into driving trailers and coupled to specially adapted locomotives.  The classes of locomotive used where 14xx (Née 48xx) and 64xx such as our own 6412 (though a few 45xx did gain auto gear which our own 5526 has since restoration).

When the Ashburton Branch was first preserved the trains where initially Auto units consisting of four trailers and a 64xx locomotive (either 6412 or 6435).  The reason for this method of operation was the lack of station or run-round facilities at Totnes.  AutoTrain operations where abandoned by the Dart Valley Railway plc as soon as practical because of the time taken to form the train.

AutoTrains, being early multiple units, used mechanical linkages under the coaches to relay the driver's regulator to the locomotive regulator making the safe physical limit  two trailers due to play in the linkages and the effort needed by the driver to move the system.

Braking application was controlled by the driver since the trains where fitted with continuous  vacuum powered brakes, though the driver had to instruct the Fireman to release the brakes because the apparatus requires steam to create a new vacuum.

The Driver, Guard and Fireman communicated with on another via a system of bell codes (hence the extra cable on the locomotives).

It is the stated aim of the South Devon Railway to return the typical Great Western Railway Branch Line AutoTrain to our metals as soon as practical, hence our significant investment in locomotives 1420, 6412 and 5526 as well as Auto trailers W225 and W228.  Auto trains run on our Special Event days.  (We also have a historically import example W240 which was the most modern one built in that it used "bus" seats and light fittings from the then new British Railway's Standard Mark I coaches.  Unfortunately it was used as a mess vehicle for the permanent way department and has been stripped of its seating.  When funding or sponsorship becomes available this vehicle will make a valuable addition to our fleet).