In the late 1950s, the Milwaukee Road’s electrification was starting to slowly unravel as their electric fleet started to collapse from old age. Coincidentally, the industrial base of the northeast started to unravel in the 1950s and the PV&T found itself with too many locomotives for its operational needs. The electrification departments of the PV&T and Milwaukee Road had many contacts (being the only two large mainline freight 3000VDC electrifications in North America) and an agreement was made to loan the Milwaukee Road a pair of surplus class Bs so that they could evaluate them (and give the PV&T a small revenue source instead of simply storing, retiring, or scrapping the unused engines.)

Class B 214-216 & 218 became Milwaukee Road EF-6’s E90-E93 for about 15 years (before that electrification imploded) before returning home.