The EMD DDA40X is a 6,600 hp (4,943 kW) D-D locomotive, built by EMD from 1969 to 1971 exclusively for the Union Pacific Railroad. [1] It is the most powerful diesel–electric locomotive model ever built on a single frame, having two 16-645E3A diesel prime movers. [2]

The EMD DD40A was a proposed Eight-axle diesel locomotive that was supposed to be built by the Electro-Motive Division (EMD). The locomotive was designed to have two GP40 locomotives on a single frame instead of two GP35 locomotives, with two EMD 645 prime movers that produced 3,300 hp (2,461...

Jan 15, 2003 · These 47 locomotives were the longest diesel locomotives ever built, at 98 feet, 5 inches. Their frames were too long for EMD to manufacture and were fabricated by the John Mohr Company of Chicago.

Dec 16, 2024 · The DDA40X was an experimental, high-horsepower diesel locomotive designed by Electro-Motive for Union Pacific during the late 1960s. It received its classic nickname as the "Centennial" to commemorate the 100th anniversary of the completion of the Transcontinental Railroad at Promontory Point, Utah.

Jun 3, 2019 · The DD40A was the replacement in the "645 line" catalog for the DD35A, replacing the concept of two GP35s on one frame with two GP40s, producing a total of 6000 horsepower. Unlike the DD35/DD35A, the DD40A did not have a DD40 (cabless) companion.

Union Pacific 6936 is an EMD DDA40X locomotive built for the Union Pacific Railroad (UP). Previously a part of UP's heritage fleet, 6936 was for several decades the last remaining operational "Centennial" type, and thus the largest operational diesel-electric locomotive in …

Feb 5, 2025 · Would that improve the diesel's chances of winning the tug of war? The DD40AX has 8 electric traction motors turning it's driving wheels and all axles are powered. The Big Boy has 4 steam pistons turning it's drivers. An electric motor produces more low end torque than a …

The Electro Motive Division DDA40X (nicknamed "Centennial") is a 6,600 hp, twin-engine (consisting of two modified 3,300 hp 16-645E3A engines), eight-axle diesel locomotive built specially for the Union Pacific Railroad (UP) from 1969 to 1971.

Aug 26, 2013 · And EMD’s 1966 introduction of the 645 engine line included a DD40 with a pair of 3,000 HP 16 cylinder 645’s, spartan cab, and standard electronics for the time before EMD quickly killed the model off.

Built by EMD exclusively for Union Pacific between 1969 & 1971, the DDA40X Centennial locomotives were the modern equivalent of the railroad’s famed Big Boy steam locomotives. These massive 98-foot double-engine diesels were UP’s mainstay hotshot power for a decade until they were sidelined by the recession of the early 1980’s.