When the Old Colony electrified their cape cod branch to Hyannis, they also wanted to serve it with electric locomotives, including the power they provided to (their former subsidiary) the Cape Cod Central Railroad. Bids were recieved from several companies, but ILW (Schenectady) won the bid and delivered a pair of streamlined eco-435/50e units.

These units are almost identical to the narrow-long-hooded eco-435/50e units that the Parsons Vale already operates, except for a little bit of shuffling of the electronics compartment to accomodate the head end power module.

Despite having the Old Colony’s last dieselised route (the branch to Falmouth) electrified out from under them, these units remain in service as Old Colony units.