461 was the first of a handful of RS-351s that the TdM shops built for the PV&T. It was also the prototype and demonstrator for the Iberville RS-351 remanufactured locomotive, which had some modest success in the few remaining north american Alco strongholds in the early 1980s.

The (much more reliable) 251 prime mover is a central part of this semi-new locomotive, as are the Century-level electronics & pressurised sealed engine compartment. Note that the dynamic brakes are perched in a little cupola above the generator end of the engine room; clearances are a little cramped inside the engine room, as you might expect from a 3/4rds height long hood, but it’s primarily to get it out of the envelope of the sealed compartment.

461 was rebuilt with a 251B for 1800 HP, but had the prime mover updated to 251E specs (2400HP) when (D&H) 498-500 were rebuilt as RS-351s.