Found on http://bangshift.com/general-news/motorized-freak-of-the-week-the-euclid-tc-12-bulldozer/
The machine weights about 35 tons and is powered by not one, but two 6-71 Detroit Diesels. The secret to the tractor’s power is the fact that each motor drove one side of the tracks. In the video clip you can hear this thing in all its cantankerous glory. Those two-strokes certainly sound good when they are working hard.
The first version of this beast was built in 1953 after GM had acquired Euclid. Engineers figured out a way to join two Euclid C-6 bulldozers side by side and make one humongous machine. Everything was doubled. There were two motors, two Allison transmissions with torque converters, two hoods, two radiators, but only one operator.