The DDA40-X is the most powerful diesel locomotive ever built (as of 2002).
The first few delivered to Union Pacific were rated at 7000 horse power!
Sometime after delivery
their power was reduced to 6600 hp by changing the injectors
and all other units were delivered at 6600 hp.
Former UP 6930 now at the Illinois Railway Museum
It is in rough shape, but at least it still exists!