About

Resilient Rail, Regenerative Future

Mackwell Locomotive Company Ltd., based in Canterbury, New Zealand, specialises in the design, development and construction of zero-carbon steam locomotives. Energy resilience, pragmatic design and environmental regeneration drive the company to create transport solutions for a world moving beyond fossil fuel.

Sam Mackwell founded Mackwell Locomotive Company Ltd in 2016.


Sam’s pursuit of sustainable energy began with an early foray into hydrogen. Enthusiastic high school experiments that resulted in a numerous explosions and a sizeable dent in the ceiling of his parent’s garage, marked the end of that journey. After Sam completed his high school education, he forewent a typical career path and income in order to develop a zero emissions turbine engine. Whilst a successful prototype, the engine relied on liquid or gaseous biofuels, which, due to their low energy return on investment (EROI), are a very inefficient use of land. The technology didn’t make biophysical sense so the project was put aside, but a lot was learnt.

In 2015 and now with a much clearer understanding of the problem he was trying to solve, Sam directed his attention to solid-biofuel, realising that the energy yield per unit area of land, per annum, was up to 10 times higher than for liquid biofuel crops (due to a high EROI >25:1). The inspirational work of Argentinian steam locomotive engineer, Ing. Livio Dante Porta demonstrated to Sam that advanced steam engines are the most efficient means of converting the sun’s energy into traction. Sam has been developing advanced steam locomotive technology ever since.

Mackwell Locomotive company and ZeroLoco™ are the culmination of Sam’s extensive research and development journey into advanced steam technology. AgLoco®, a Mackwell subsidiary, is developing advanced steam tractors for the primary industries. The short documentary “Loco” tells the AgLoco story.