In the mid-1970s Southern Pacific borrowed a batch of Burlington Northern SD40-2s and RCC cars (converted F7Bs) in order to test the Locotrol systems installed in them. The tests must have been successful, as the SP purchased units with Locotrol in them. Sitting on the ready tracks at the SP's West Colton Yard is BN SD40-2 6800 (the former BN 6340) and an BN RCC 110 (ex-BN F7B 629, nee-GN 309B). On adjacent tracks are SP C-628 3133 (ex-SP 7122, nee-SP 4863) and SD35 6910 (ex-SP 4826). None of these locomotives has their original numbers! (Colton, California – March 5, 1976)
