No.17 Viking was built by Schöema of Dortmund, Germany in 1958 as one of three identical units.  It was purchased by the railway in 1992 as a replacement for railcars No.19 and No.20 which at the time were in bad need of attention.  Arriving on the island and performing a number of successful test trains, it was found that the locomotive was capable of substituting a steam engine and could generally maintain line speed.  As part of the Year Of Railways in 1993 it received the name Viking, a name originally to have been allocated to No.3 Pender back in 1873 but deferred and was the subject of a competition to name it (despite rumours nameplates had already been made!)  Outshopped in the pre-war Brunswick Green livery which No. 10 G.H.Wood also carried, it was lined out in orange and black.  To quoth the experts of Wikipedia, it was beset in latter years by problems through lack of maintenance and was repainted into Spring Green after an opinion voiced in Manx Steam Railway News that "there should be a Spring Green one" (!)  Normally on non-passenger services, the unit did see some use in traffic during the 2010 and 2011 seasons owing to steam locomotive failure; it last saw use during the 2012 Manx Heritage Transport Festival when it failed and was withdrawn.  It is currently stored in the carriage shed at Douglas Station, with the announcement in 2012 that the railway was to obtain a new £750,000 new-build, it was in December of 2012 that diesel-electric No.21 was delivered and trialled.  No.17 remains in storage.