The PV&T’s original plan for the Portland to Bangor electrification was to order sleds from ALCO & build them up as locomotives with new GE electricals. Alas, this was not to be so! Worthington was starting to make noises about shutting their new subsidiary down and the order was declined as not being profitable enough.

So plan B – with the slow running down of industry in the NE, two of the old B1s’s were sitting out of service as parts locomotives, and could be used as a platform for a new locomotive design. So off they went into the Portland shops, to emerge a couple of months later as the heavily modified 6100 HP class B4.

A regular class B would be super slippery with this sort of power, but the B1s’s were ballasted to make them better switchers, and that made it possible to put a ridiculous amount of power onto the wheels without making them into a skate when starting a heavy train.

No further B’s were rebuilt like this, but these two were used as a design basis for the completely home-built E2’s that came out of the Portland shops a year later.