Who invented the Garratt articulated steam locomotive?

Herbert William Garratt invented the Garratt articulated steam locomotive. His design separated a locomotive into three major sections: a central boiler, firebox, and cab, carried between two powered engine units that could pivot beneath it.

Garratt developed the concept while working as a British locomotive engineer and inspecting locomotives for the New South Wales Government Railways. He patented the design in 1908 after earlier manufacturers showed limited interest. By placing water and fuel on the end units and freeing the central frame from rigid wheelbases, the locomotive could carry substantial loads while negotiating curves and lightly built track.

Beyer, Peacock and Company eventually built the first Garratts for the Tasmanian Government Railways. Two K class locomotives entered service in 1909. Garratts later became especially important in Africa, Asia, Australia, and South America, where long distances, steep grades, narrow gauges, and weak track made their combination of power and flexibility valuable.