A Garratt locomotive is a type of steam locomotive invented by British engineer Herbert William Garratt that is articulated into three parts. Its boiler, firebox, and cab are mounted on a centre frame or "bridge". The two other parts, one at each end, have a pivot to support the central frame; they consist of a steam engine unit – with driving wheels, trailing wheels, valve gear, and cylinders, and above it, fuel and/or water storage.
South African Railways 2 ft (610 mm) gauge SAR NGG 16 Class Garratt, preserved in operating condition on the Welsh Highland Railway
Beyer-Garratt locomotive William Francis at the Garratt 100 festival
This works drawing of K1, the first Garratt built, shows how the boiler and firebox are not inhibited by the running gear.
South African Union Garratt
A Mallet locomotive is a type of compound articulated steam locomotive, invented by the Swiss engineer Anatole Mallet (1837–1919).
A typical European Mallet type, a narrow gauge 0-4-4-2 tank locomotive for a mountain railway, the RhB G 2/2+2/3 in Switzerland
A 2-10-10-2 Mallet locomotive in Winslow, Arizona, in 1913–14
MÁV Class 601 in 1914
1928 Baldwin 2-6-6-2PT Mallet hauls a Black Hills Central Railroad excursion train in 2013.
