The Red Devil is the nickname of the South African Railways' sole Class 26 4-8-4 steam locomotive, so called because of its bright red paint.
It was rebuilt from a standard Class 25NC locomotive in the early 1980s by the Englishman David Wardale, along the lines advocated by L.D. Porta of Argentina. Porta argues that the steam locomotive, even though abandoned by most industrialised nations, had not even come close to being fully developed. In fact, locomotive builders and railroads had rarely applied any rigorous scientific method to the development of the locomotives.
Wardale, a devoted steam enthusiast, proved that his ideas had weight through minor modification to older locomotives, and finally he was given a large locomotive to experiment with - a Class 25NC 4-8-4 express passenger locomotive. These were pretty much up to the state of the art as far as it went in the 1950s, the last decade of steam locomotive production in most of the world, with cast steel engine beds, large boilers, roller bearings on axles and rods, etc.
Although Wardale was given free rein over what modifications to attempt, budget limitations still restricted him. Parts had to be hand-made in a machine shop, or appropriated from other locomotives.
He equipped the locomotive with a Gas Producer Combustion System firebed, enlarged steam chests, improved piston valves, a feedwater heater, a new double Lempor exhaust system, improved insulation, and other detail improvements. The locomotive was painted a bright red, and given the official name "L.D. Porta".
The modifications were successful; almost 40% reduction in fuel usage, and a similar increase in power. A sustained reading in excess of 4,000 hp was achieved regularly in testing, and peaks of 5,000 hp or more were recorded. Given this is a locomotive that runs on 3'6" gauge track and is thus 3/4 scale compared to American locomotives, these figures are quite astounding.
Despite this success, however, SAR management were not discouraged from their plans to replace steam traction by new diesel locomotives except for tourist service, and Wardale left, disillusioned, to work on other similar projects elsewhere in the world. The Red Devil, however, still runs on SAR tracks, pulling tourist and excursion trains.