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.
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.
Alco PA LocomotivesArguably the most beautiful diesel locomotive ever built, sadly no Alco PAs were originally preserved. Today, one is under restoration.
- YouTube. The Worlds largest diesel locomotive the Union Pacific DD40X #6936 is turned on the old turntable in Cheyenne, Wyoming. The locomotive was built in 1971, weighs 270 tons, and is rated at 6,600 horsepower. This is a active locomotive mostly pulling excursion trains with the Union Pacific #844.
Puffing Billy is the world's oldest surviving steam locomotive, constructed in 1813–1814 by colliery viewer William Hedley, enginewright Jonathan Forster and blacksmith Timothy Hackworth for Christopher Blackett, the owner of Wylam Colliery near Newcastle upon Tyne, in the United Kingdom.
One of the most beautiful steam locomotives ever built, the S1 was designed by Raymond Loewe. Poor balancing caused wheel-spin and only one was ever built, for the Pennsylvania Railroad in 1939.
One of the most beautiful steam locomotives ever built, the S1 was designed by Raymond Loewe. Poor balancing caused wheel-spin and only one was ever built, for the Pennsylvania Railroad in 1939.