The SW7 was EMD's 1,000 horsepower switcher option in the 1950's. Conrail inherited many of these SW7's and they appeared in scattered number blocks in the 8836 to 9098 range and were of NYC, EL, CNJ, IHB, LV, CR&I, P&E and PRR origins. All of these units were removed from the Conrail roster by the early 1990's although many remain in service throughout the country on shortlines and industrials.
The SW9 was a 1,200 horsepower offering from EMD at the same time as the SW7, and at first glance appears almost identical in outward appearance, but it has less louvers on the hood doors. Again Conrail inherited these units from a variety of original owners (LV, EL, CNJ, PRR, NYC) and had them scattered in the 8922 to 9141 number range. During the great switcher purge of the late 1980's and early 1990's, these too were removed from the CR roster, although many also see service elsewhere to this day.
The SW1200 was also a 1,200 horsepower locomotive from EMD, purchased by CR predecessors RDG, DL&W (EL), New Haven (later PC) and PRR (later PC). These units occupied the 9315 to 9382 number block on Conrail. CR 9301 to 9319 (ex Reading 2701 to 2719) are of note as they were rebuilt by EMD from Baldwin switchers and are rated as only 1,000 horsepower. All the others are pure 1,200 hp SW1200's. Some of these saw service much later into Conrail, not being retired until 1995, and almost alll work for other railroads and industrials.