Specifically, the M-497. I have had one picture of this train up before, but a little more info on it shows that it consists of two General Electric J-47-19 jet engines, which had been designed as boosters for the Convair B-36 intercontinental bomber being grafted onto the front of a "Budd" car. Given the dubious distiction of "The Black Beetle" by rail workers, this beast clocked in at 183.85 mph, which is a record that has yet to be broken in the US. Check this bad boy out:

I really like how the rail workers look like they are flinching at the beast....