Under theWhyte notation for the classification ofsteam locomotives bywheel arrangement, the2-4-2+2-4-2 is aGarratt locomotive. The wheel arrangement is effectively two2-4-2 locomotives operating back to back, with theboiler andcab suspended between the two power units. Each power unit has a single pair ofleading wheels in a leading truck, followed by two coupled pairs ofdriving wheels, with a single pair of trailing wheels in a trailing truck.
This was the rarest of all Garratt types, with only one class of four locomotives constructed to this wheel arrangement.[1] It most likely evolved from the2-4-0+0-4-2 Double Porter Garratt, with the trailing wheels added on each engine unit to improve stability at speed.
All four 2-4-2+2-4-2 locomotives were built in 1943 byBeyer, Peacock and Company for the1,000 mm (3 ft 3+3⁄8 in)metre gauge Leopoldina Railway inBrazil. The locomotives were allocated engine numbers in the range from 400 to 403 on that system.[1]
