The class BS1 slugs are part of an attempt to reduce the emissions from the PV&T’s venerable Alcos by converting them into a hybrid locomotive by the simple expedient of semi-permanently coupling one (or two) to a slug made from the trucks & frames from a retired DL17, a hood made from sheetmetal and hoods from scrapped EMD carbodies, and a huge pile of batteries wired to a battery charger & regulated power supply.

#1266 was constructed by the BAR’s shops in Milo, Maine, and is putting in miles (and providing tasty tasty data for the mechanical department in Portland) mainly on the Montpelier & Barre’s quarry branch, which is steeply enough graded so the energy regenerated coming down from from the quarry is enough to make up for most of the energy consumed getting there in the first place.