Built by General Electric in 1914, Panama Canal Mule No. 686 pulled ships through the Gatun, Pedro Miguel, and Miraflores lock stations of the Panama Canal. Powered by three-phase, 220-volt, 25-cycle motors geared directly to traction equipment, it operated on rails paralleling the canal and exerted 25,000 pounds of towing force. With dual controls, it could be operated from either end. At one time, more than 100 canal mules were in operation. No. 686 was retired in 1964 and brought to the museum in 1972 by Roanoke Chapter NRHS.