Our Journey...

Sam Mackwell founded Mackwell Locomotive Company Ltd in 2016. Today it’s simply known as ‘Mackwell’.

Sam’s pursuit of low-carbon energy began with an early foray into hydrogen. His  early high school experiments resulted in a lot of hot water, a number of loud bangs and a sizeable dent in his parent’s garage roof. From this experience Sam gained a firsthand lesson in the practical difficulties of working with hydrogen as a fuel.

Sam completed his high school education and enrolled in university, however it did not hold his attention for long. Instead, he led his own career path directly towards developing a zero emissions ‘turbine’ engine. The prototype was successful but the engine relied on liquid or gaseous biofuels with a low energy return on investment (Energy-ROI). Sam realised that biofuel production was flawed and an inefficient use of land. The technology wasn't making biophysical sense and so the project was put aside, but important lessons were learned.

At this time Sam had begun working on heritage railways in Christchurch to learn more about steam dynamics. One local railway in Christchurch sourced its entire fuel supply from firewood grown and harvested on site. The relative ease and cost effectiveness at which this century old technology could convert biomass into mechanical power impressed Sam and he directed his attention to exploring this unique combination of biomass and steam.

Sam discovered that the energy yield per unit area of land for biomass was up to 10 times higher than for liquid biofuel crops. Trees are unrivalled in their ability to capture and store the sun's energy with very little support or processing. In its solid form, biomass has an incredibly  high Energy-ROI of 25:1. 


Sam recognised that external combustion steam engines were unmatched in their ability to use almost any solid biomass fuel. With a much clearer understanding of the problem he was trying to solve, Sam set about about researching, developing and prototyping advanced steam technology. 

The inspirational work of Argentinian steam locomotive engineer, Ing. Livio Dante Porta confirmed to Sam that advanced steam engines are the most efficient means of converting the sun’s energy into traction. Solar, hydrogen, diesel, EV/battery, wind are all compromised when it comes to mobility, efficiency and practicality. Refining an early Mackwell Boiler prototype in 2017, Sam raised then some modest capital to build a larger 400hp boiler which he completed in 2019.

Sam continues to develop advanced steam locomotive technology. The Mackwell  philosophy that incorporates a number of fundamental principles (both old and new) is what separates Mackwell technology from  other forms of motive power. Mackwell is a world leader and is globally unique. There is a patent pending in a number of countries around the world – PCT/IB2021/057697.