It didn’t take more than about 20 years after passenger service was nationalized in Canada & the USA for the Parsons Vale to start to regret not joining Amtrak and losing the dispatching regularity imposed by scheduled trains (plus, to be honest, as the memories of the deficits faded there was nostalgia for the old days of passenger trains), so – after a short negotiation with VIA, Amtrak & the governments of Massachusetts, Vermont, and Québec – the agreement was reached to resurrect the old Alouette as a jointly funded (PV&T plus the various provincial governments) day train between Montréal and Boston.

Part of the PV&T’s funding was to provide motors to power the train, so the Portland shops designed a variant of the class K suitable for passenger operation.

The class K3 is differentiated from the base class K by an extended carbody to accomodate the electronics needed to provide 800 HP of head-end power This modestly increases the tractive effort of the machine, but otherwise does not impact its performance.

Three were built (numbered in the old E60CP slots of 954-956) and went into service – two pulling the trains, one as a reserve locomotive that occasionally pulled a section of the Adriondack between Albany & Montréal – in 1998.

In the late 2010s, Amtrak & the MBTA wanted to remove the switchable DC tracks into south station, so the K3s were taken out of Amtrak service and replaced by a pair of new K5ps, while the PV&T switched the Boston Terminal subdivision from 3kvdc to 25kvac to match the SLR & Northeast Corridor electrifications, moving the voltage cutover to Lowell (MBTA) Station.

The three now-disused units went up to Portland, were rewired as multisystem units, and had the old HEP compartments chopped off to make room for rear platforms, then sent west to the CSS&SB for operation on the CSS&SB, I&M, and CTRC.