SLSF 60-61, Baldwin VO-660 SLSF 200-237, Baldwin VO-1000 SLSF 238-241, Baldwin DS-4-4-1000 These Baldwin switchers were the heart of the early Frisco diesel fleet. The two VO-660s, SLSF 60-61, were originally numbered SLSF 600-601 when purchased. They were renumbered to 60-61 in 1951 to make room for the large fleet of new Frisco EMD GP7s. The 38 VO-1000s, SLSF 200-237, served long and well. A number of them were later repowered by EMD using the EMD 567 engine to replace the VO. These diagrams reflect the 1957 repowering of SLSF 205, 210, and 215, the first three to be repowered with the 567. Later, in 1959, SLSF 200-204 and SLSF 206 were also repowered by EMD. In 1948, the Frisco went back to Baldwin for four more units, this time the improved DS-4-4-1000. These proved to be the last Baldwin diesels purchased by the Frisco. It was the end of an era - Baldwin VOs were the first diesels purchased by the Frisco. Ken