Railpower GG20B

The Railpower GG20B Green Goat is a low-emissions diesel hybrid switcher locomotive built by Railpower Technologies Corp. It is powered by a single Caterpillar C9 six cylinder inline engine developing 300 hp, which is also connected to a large battery bank where both sources combine for a total power output of 2000 hp. To date, there have been more than 50 GG20B diesel-electric hybrid switchers manufactured since their first introduction in 2004.

Fuel-cell testbed
BNSF Railway and Vehicle Projects converted a GG20B to an experimental testbed, for the use of hydrogen fuel cells. The new locomotive is designated HH20B. The locomotive was publicly demonstrated for the first time on June 29, 2009, at Topeka, Kansas.

The locomotive, BNSF 1205, was originally built in 1957 as Canadian Pacific 8637 (renumbered 1544 in the 1980s), a GMD GP9 locomotive. In 2006, it was rebuilt into a GG20B for the Canadian Pacific, but was not delivered, due to the cancellation of the order. It was sold to BNSF in 2008, and shipped to the railroad's shops at Topeka, Kansas for conversion. The diesel generator set was removed, and the fuel cell power unit was installed in its place. Hydrogen storage is in a set of tanks installed in a heavily vented enclosure on top of the locomotive's long hood, above the batteries. To date, it is the largest land vehicle on earth to be powered exclusively by hydrogen fuel cells.

In 2023, the locomotive (without its hydrogen components) was donated to the Oklahoma Railroad Museum, which plans on using it as a control car and for electricity generation on the end of its excursion trains.