Currently, the most powerful diesel locomotive is the EMD DDA40X. This was essentially two GP40 type locomotives built on one frame, with a single cab, and massive 4 axle trucks. It had a roughly 6,600 HP rating.
As wireless technologies advanced in the 1960s, freight railroads began adding extra locomotives to the rear of trains to give them enough power to climb steep hills. This is how distributed power was born.
The average fuel consumed per kilo- meter for all passenger and cargo trains is 7.97 L/ km. This value for local, trafficking, railway track laying and maneuvering trains is 7.92 L/km.
Most yard-switching and short-haul locomotives are equipped with diesel engines ranging from 600 to 1,800 horsepower; road units commonly have engines ranging from 2,000 to 4,000 horsepower.
The Big Boy has the longest engine body of any reciprocating steam locomotive, longer than two 40-foot buses. They were also the heaviest reciprocating steam locomotives ever built; the combined weight of the 772,250 lb (350,290 kg) engine and 436,500 lb (198,000 kg) tender outweighed a Boeing 747.
Steam locomotives can be more powerful than diesel locmotives depending upon the size, capacity, weight and other specifications of the different engines. Steam locos used coal and/ or fire wood to heat the water, and hence the amount of heat and steam generated would not be/ can't be even all the time.
Japan: L0 Series Maglev (374 mph)Although not yet in regular service, this Japanese train, which is currently being developed and tested by the Central Japan Railway Company (JR Central), holds the land speed record for rail vehicles, clocking in at 374 mph.
The original goal of the Maglev project was to produce a train that could cover the route from Tokyo to Osaka in less than one hour. This will be achieved when the Maglev line is extended from Nagoya to Osaka, expected to be in operation by 2045.