W-50-4 Work Cars:
SP 10580-10879 12/1913-2/1914 SP 12640-12839 9-12/1913 NWP 10001-10020 7/1913 GH&SA 40800-40899 7-9/1913 (to T&NO 40800-40899) T&NO 40900-40999 3-4/1914
These work gondolas were built by Bettendorf as above in 1913-1914. They featured 1825 ft3 capacity.
For more detailed information, consult Tony Thompson's book Southern Pacific Freight Cars Vol. I: Gondolas and Stock Cars.