Speedy (5 Gauge)

Overview
Speedy was an 0-6-0 locomotive designed by LBSC and based on the British Rail Class 1500 Tank locomotive. It is sometimes referred to as a GWR locomotive as the GWR designed it, however they were entirely manufactured by British Railways. Cylinder bore is 1.562" and the driving wheel diameter is 4.937".

There is an entire Wiki just about building Speedy Here