D&H 599 is the prototype for a batch of high horsepower locomotives that were built for the electrification of the D&H line from Schenectady to Montréal. It is based on the EMD/ASEA GM10B locomotive (except taking DC power from the overhead wire) and was (almost) a perfect success.

The problem that the PV&T was trying to solve was that high powered DC drive locomotives tended to be really slippery, so being able to get >8kHp out of an 8 axle machine was an iffy proposition. The GM10B’s being able to get 10kHP to the rails on a six axle machine, now that was something that was worth looking at.

The PV&T wanted to be involved with the manufacturing, so the deal was that EMD & ILW would design & make the carbody, EMD would install the drivetrain, and and final tweaks would be done at the Portland shops. The final design was an extension of the traditional class B-style two-section unit – two (stretched) sections on 5 class E trucks, with the center truck supporting an articulation joint between the sections.

ILW made one of their typically prismatic turret cab designs, which the electric department hated, so despite the success of this engine followup orders had the carbodies fabricated by the Portland shops.

The class I’s are ~220 tons (the Portland-built I2s are slightly lighter), putting out 10000HP, and capable of pulling long freights at line speed over the more mountainous parts of the railroad.

This engine is still in operation, and is one of the few electric locomotives based at St-Jean-Sur-Richelieu.