A "polarised" motor car had been unsuccessfully tried in the Antarctic by Shackleton, on his 1907–1909 expedition, while his pioneering use of ponies had transported him as far as the foot of the Beardmore Glacier.[29][30] Scott believed that ponies had served Shackleton well, and he thought he could resolve the motor traction problem by developing a tracked snow "motor" (the forerunner of the Snowcat and of the tank). Scott always intended to rely on man-hauling for the Polar Plateau,[31] believing it impossible to ascend the Beardmore Glacier with motors or with animals. The motors and animals would be used to haul loads only across the Barrier, enabling the men to preserve their strength for the later Glacier and Plateau stages.