Union Pacific ZTR hybrid loco (Photo UP)

USA: Union Pacific is to begin testing the first of six diesel-battery-hybrid shunting locomotives during May.

The railway has produced a prototype locomotive at its workshop in North Little Rock, Arkansas, working with loco control technology supplier ZTR which designed the hybrid propulsion system. A second locomotive is expected to be ready for testing next year.

The ‘mother and slug’ set is formed of a conventional diesel locomotive connected to a battery unit converted from an older diesel loco. This retains its traction motors, but its diesel engine has been replaced by a battery pack. The batteries have multiple charging options, including lineside supplies.

The hybrid locos are expected to consume up to 80% less fuel than conventional diesel locos, depending on operating duties, while also reducing emissions, maintenance costs and noise.

‘This is an incredibly exciting pilot project with great potential to improve the fuel efficiency of our locomotive fleet’, said UP President Beth Whited. ‘It underscores our strong commitment to exploring and developing alternative energy sources while reducing our carbon footprint and advancing our sustainability goals.’