RER - Blacolvesley

In private hands, this is widely regarded as the oldest workable internal combustion locomotive. Built in 1909 by Bassett-Lowke; it retains many original parts.
In 2016 the court imposed a custodial sentence of 10 years on the arsonist responsible for starting three fires on L'aal Ratty, including the one in the paint shop on December 4th 2012 which damaged Blacolvesley.
Partly as a result of the fires and the current (2016/17) extension to the Ratty Museum, the loco is not stored on the railway.

en.wikipedia.org/wiki/Ravenglass_and_Eskdale_Railway_locomotives#Blacolvesley