New South Wales Government Railways ground shunt signal. Two vertically-separated dwarf, lower-quadrant semaphore arms are hinged to enable recovery from hitting by a passing train. The signal is mechanically operated by signal wires pulling to the rear of the signal.
The upper semaphore permits shunting ahead onto a track with the same running direction as the shunting movement. The lower semaphore permits setting back on a track with an opposing running direction to the shunting movement. For correct automatic operation the signal must be used with directional feathers to uniquely identify the 2 possible paths indicated by each semaphore. Use <kuid2:60850:23911:4> 'Sig T Feather Left 1 (pos 1)' to mark the path of the upper semaphore; and <kuid2:60850:23901:4> 'Sig T Feather Straight' to mark the path of the lower semaphore.