Smith graduated with honours from University of Sydney and was a locomotive designing and test engineer with the New South Wales Government Railways.
As well as his Mechanical Branch responsibilities, in the role of Acting Chief Civil Engineer, he also supervised the construction of the standard gauge line from Stirling North to the Leigh Creek Coalfield.
Smith also managed the transition from steam to diesel traction in the 1950s and also the accompanying modern air-conditioned rolling stock.
It is not known what speed the pick-a-back train could achieve, possibly 80km/h maximum, but it is noted that the standard gauge line was brand new with gentle curves and gradients.
The term piggy-back referred to road freight vehicles loaded on rail flat cars.