Locomotive Descriptions and Phases - EMD SD50, SD60
These phases are of my own making.
Phases - SD50
| Phase | 1 | 2a1 | 2a2 | 2b1 | 2b2 | 2c |
|---|---|---|---|---|---|---|
| Dates | 1981-05 - 1981-06 | 1983-01 - 1984-03 | 1984-05 - 1984-06 | 1984-07 | 1984-07 - 1984-09 | 1984-11 - 1986-02 |
| Frame side sill | 5" tall over air reservoirs, 8" tall at ends | 5" over entire length | ||||
| Blower duct | Flat, wide, two ribs, no raised step | Angled, narrow, no ribs, raised step ("laundry chute") | ||||
| Exhaust silencer | Approx. 58" long (spans 3 hood doors; as on late SD40-2) | Approx. 42" long (spans 2 hood doors) | ||||
| Handrail stanchion spacing (1) | Old | New | Old | New | ||
| Dynamic brake intakes | Top edge approx. 2 feet from roofline | Moved upward by approx. 3.5" | ||||
| Dynamic brake inner housing | Angled downward under rear of fan | Horizontal under fan | ||||
| Center hood | Small rectangular clips on hood sides fore/aft of engine compartment | No hood clips | ||||
| Underframe | Air reservoirs over middle of fuel tank | (2) | ||||
| Anticlimber / end sill | Rounded edges, smooth top edge, outer handrail stanchions fastened to outside edge | (3) | ||||
| Coupler cut levers | Outer brackets near pilot edges; lever end routed through bracket | Outer brackets moved inboard; lever end angled straight down | ||||
| Phase | 1 | 2a1 | 2a2 | 2b1 | 2b2 | 2c |
Notes
- Handrail stanchion spacing:
- Old: Symmetrical both sides; 7 x 48" spacing above fuel tank; 2 x 40" spacing ahead of rear jacking pad
- New - left side: 2 x 48", 1 x 40", 5 x 48" above fuel tank; 1 x 40" ahead of rear jacking pad (5 middle stanchions moved forward by 8")
- New - right side: 1 x 48", 2 x 40" above front of fuel tank; 6 x 48" to rear jacking pad (5 middle stanchions moved forward by 16")
- Underframe, Phase 2c: Air reservoirs moved rearward by approx. 31"; revised traction motor cable routing (similar to SD60)
- Anticlimber / end sill, Phase 2c: Angled edges, small ridge around top edge, outer stanchions fastened to top of walkway
Transition: From SD50 to SD60
- Eight access doors under radiators (rather than six)
- First two hood doors (under exhaust stack) widened
- Blower duct/raised handrail section on left side behind cab moved forward
Phases - SD60
No major production variations. A very subtle difference between some units is the 4800 vs. 4500 gallon fuel tank, with a slight difference in both the length and the height of the tank.