Their design was radically different from the boxcab locomotives previously provided by General Electric for the initial electrification of the Mountain Division two years earlier.

This design was almost entirely noiseless, as it eliminated not only gear tooth growl, but also the whine of higher-RPM electric motors typically used in standard nose-mounted applications.

The EP-2s were not the first electric locomotives to use bipolar motors, which had first been designed by Asa F. Batchelder for the New York Central S-motors over a decade earlier, but at the time they were the largest.

Their unique appearance and power made them ideal for publicity purposes, and there was a series of demonstrations in which a Bipolar was able to out-pull contemporary steam locomotives.

In 1953 all five of the EP-2s, which were 35 years old and worn out from heavy wartime service, were heavily rebuilt by the Milwaukee Road at a cost of about $40,000 per locomotive, equal to $455,522 today.

The rebuild included additional traction motor shunts for increased speed, roller bearings, multiple unit capability, flash boilers, and streamlining.

Unfortunately the Milwaukee Shop forces, unaccustomed to working on electric locomotives, did a "poor job" in the opinion of Electrification Department Head Laurence Wylie.

(Wylie's successor, T. B. Kirk, stated that he saw a group of disconnected wires in a newly rebuilt EP-2 bundled together and tagged with a written message, "We don't know where these go".)