Polar Bear was a 2 ft (610 mm) gauge battery-electric locomotive built by Wingrove & Rogers in 1921 as works no. 314 for the Groudle Glen Railway on the Isle of Man. Together with its sister, Sea Lion, they were intended to replace two Bagnall steam locos of the same names. The locos were not a success and, despite Polar Bear being rebuilt with bogies and a battery truck, the steam locos were reboilered and returned to traffic. Polar Bear was eventually scrapped acround 1926.