On the Byrd Antarctic Expedition II a third mode of transportation was added to the existing means of dogs and aircraft—the use of tractors. Previous attempts had been made to use motor transport, first on Shackleton's Expedition in 1908, Scott's in 1910, and on the Byrd Antarctic Expedition in 1928–30. Shackleton had taken a regular motor car, which was of use on the hard bay ice, for handling supplies, but it proved inadequate for the softer surface of the barrier. Scott used special tractors, but they were not a success.