This was a Simplex Petrtol Locomotive - Motor Rail 4217/31.  The Industrial Railway Society record this as being rebuilt from Motor Rail 3880/c1930

This locomotive was noticed out of use at Berry Wiggins, Kingsnorth on Medway by David Compton during 1973.  He noticed that it was stored out of use and enquired about it's fate.  It was confirmed that it was no longer required and was due to be cut up for scrap.  He informed the Society about this locomotive and Berry Wiggins were approached to see if it could be saved.  Berry Wiggins generously donated the Simplex Locomotive to the Society and it was duly transported to Herefordshire for restoration.

The Societies priorities at the time were restoring the Pannier Tank and Kitson Locomotives so the restoration of the Simplex locomotive was not actively progressed.   It wasn't running and problems with the magneto hampered all attempts to start the engine.  Outbased at MOD Moreton on Lugg the engine was placed into long term store for attention at a later date.

During 1986 there was a period of heightened security and the MOD asked the Society to remove all items placed in store at MOD Moreton on Lugg.  Funds were tight and so while key items were relocated to the Bulmers Railway Centre it was decided to offer the Simplex locomotive to the National Railway Museum as it had been identified as a rare survivor.

They accepted the donation and the Simplex was whisked away.

Currently on display at Sheldon the locomotive has reappeared from secure storage and questions about the locomotive prompted research and the drafting of this page.