the Nattrass Rail Tractor, made in New Zealand by a race car driver, car salesman, and inventor Harold Nattrass, winning driver of the 1921 New Zealand Motor Cup

http://www.freerails.com/view_topic.php?id=6070&forum_id=46

http://www.teara.govt.nz/en/photograph/39905/first-new-zealand-motor-cup-race-1921

In November 1924 Nattrass was granted a patent for his rail tractors using Fordson farm tractor engines and transmissions. The Nattrass was a simple, lightweight machine, available at an affordable price which allowed the sawmillers to expand their operations into areas previously inaccessible with horse teams.

 As a prolific inventor Nattrass held a number of patents additional to the rail tractor, including an electric car jack, a rotating viewing screen for ships, and a rotary car engine

 http://www.shantytown.co.nz/Attractions/Ride+the+Steam+Train/More+info+on+our+Locos/Natrass.html
http://trainrover.blogspot.com/2016/02/new-zealand-january-2016-2-internal.html

both photos by DJ Maciulaitis http://www.maciulaitis.com/nzrolling/inddiesel.html

http://www.trainweb.org/loggingz/nattrass.html