
Locomotive Phases - GMD SD40-2, SD40-2(W)
For the development of the US-built EMD SD40-2 and relevant phases, see the EMD SD40-2 phases.
The transition from the GMD SD40 to the SD40-2 was generally the same as for their EMD counterparts. Most of the phase changes occurred at the same time as in EMD SD40-2 production, although a few minor changes occurred later.
Some of the features generally associated with GMD locomotive production (such as vertical corner steps and nose-mounted headlights) were more a question of railroad specifications than of differences from EMD. When GMD built several orders of SD40-2's for BN while EMD was at capacity, they were virtually identical to their US-built counterparts. Likewise, when EMD built an order of early CP SD40-2's, they were built to GMD/CP specs.
These phases are based on my own observations in combination with sources I used for US-built SD40-2 phases. In March 2025 I revamped my phases for EMD-built SD40-2's, and in the process I relabelled my former GMD Phase 2c, 2d, 2e1 and 2e2 as Phases 3a through 3d.
Phases - SD40-2
Phase | 1a1 | 1a2 | 1b | 2a | 2b | 3a | 3b | 3c | 3d |
---|---|---|---|---|---|---|---|---|---|
Dates | 1972-02 - 1972-12 | 1972-12 | 1973-04 - 1976-02 | 1977-10 - 1979-01 | 1979-10 - 1979-11 | 1980-09 - 1981-03 | 1982-12 - 1983-02 | 1983-02 - 1983-09 | 1984-10 - 1985-07 |
Blower duct | Flat, wide, no ribs | 2 ribs (EMD-built) | No ribs | Angled "laundry chute" | |||||
Cab sub-base (right side) | Hinged, middle latch offset toward front | Middle latch offset toward rear | Hinged, middle latch centered (as on early EMD SD40-2) | ||||||
Cab sub-base (left side) | Hinged | Lift-off tabs | |||||||
Battery box cover (right side) | Hinged, same as EMD SD40 | Bolted, 2 small louvres (as on early EMD SD40-2) | Latched, lift-off tabs, 2 x 2 louvres | ||||||
Battery box cover (left side) | Bolted, 2 small louvres (as on early EMD SD40-2) | Larger louvres | Horizontal rib added | Latched, lift-off tabs, 2 x 2 louvres | |||||
Cab side panel around window | None | Riveted, 11 rivets along top/bottom | Riveted, 13 rivets along top/bottom | Welded | |||||
Phase | 1a1 | 1a2 | 1b | 2a | 2b | 3a | 3b | 3c | 3d |
Pilots | Straight upper end plate corners, straight coupler cut levers | Notched upper end plate corners, raised coupler cut levers | Shorter corner handrails | ||||||
Short hood | 81" | 81" or 102" Small rectangular vent on right side (102" only) | 88" (BCOL Phase 3a) or 102" Larger rectangular vent | Rectangular vent moved rearward | |||||
Radiators, fans | Square wire grid intakes; flat-topped fans | Corrugated intakes | Q-type fans | ||||||
Stepwell corners | Rounded | Angled, beveled | Notched bottom corners | ||||||
ECAFBElectrical cabinet air filter box, located on the left behind the cab
| Separated from cab | Flush with cab | |||||||
Trucks | Revised center axle shock strut | ||||||||
Jacking pads | Tall | No casting hole | Short | ||||||
Underframe | Vertical fuel gauge added to front of fuel tank | Revised fuel tank vent pipe | Revised air reservoir piping on left side | MU shutoff valves moved from behind steps to above truck | |||||
Phase | 1a1 | 1a2 | 1b | 2a | 2b | 3a | 3b | 3c | 3d |
Traction motor cables | #1 motor cables on left side, #2 motor cables on right side, both routed to near fuel tank | Revised rear left cable routing | #2 cables on left side, #1 and #2 cables routed under cab | Revised front left (#1) cable routing | |||||
Inertial air intake | Ridge added along bottom (inconsistent on earlier units) | ||||||||
Dynamic brakes | Batten strip at rear of dynamic brake housing | No batten strip, dynamic brake housing moved rearward, lift rings moved closer to fans | |||||||
Exhaust | Raised exhaust stack | Silencer with opening at rear | Silencer with opening at front | ||||||
Frame side sill, handrails | Side sill 8" tall at ends, 5" over air reservoirs | Revised left-side handrail stanchion spacing | Side sill 5" over entire length | ||||||
Phase | 1a1 | 1a2 | 1b | 2a | 2b | 3a | 3b | 3c | 3d |
Phases - SD40-2(W)
The SD40-2(W) followed some of the same detail changes as the GMD SD40-2. However, it was not affected by changes specific to the standard cab, such as the side panel around the windows, cab sub-base, battery box covers or the length of the short hood. It also retained wire mesh radiator intakes significantly later before adopting corrugated intakes. As CN was the only buyer, there were no railroad-specific variations.
When I first made these phase descriptions back in the mid-2000s, I limited "Phase 2" to units with corrugated radiator intakes in an attempt to bring the details in line with EMD SD40-2 production. However, that left the first four phases grouped tightly together as Phases 1a1, 1a2, 1a3, and 1b. In March 2025, while revamping SD40-2 phase descriptions, I relabelled them as Phases 1, 2a, 2b, 2c and 3 - which makes more sense for the sequence of detail changes and is a closer match with the timeline for standard-cab units.
Phase | 1 | 2a | 2b | 2c | 3 |
---|---|---|---|---|---|
Dates | 1975.05 - 1975.07 | 1976.01 | 1978.07 - 1978.10 | 1979.12 - 1980.05 | 1980.12 |
CN Numbers | 5241-5261, 5262-5278 | 5279-5293 | 5294-5313 | 5314-5323, 5324-5353 | 5354-5362 |
Hand brake | Connected to 1 brake cylinder, chain around pulley below wheel | Housing moved forward, straight chain below wheel, chain pipe more horizontal | Connected to both brake cylinders, chain pipe more steeply angled | ||
Cab | Round sand hatches, connected windshield wipers | Rectangular sand hatches | Independent windshield wipers, ridge along front corners of cab roof | ||
Handrails | Horizontal jog on left side behind cab to clear door latch | Rear handrail stanchions near brake wheel moved forward | Vertical dip and shorter stanchion on left side behind cab to clear door latch | ||
Rearmost hood door | Welded panel with louvered bolted panel underneath | Tall hinged and louvered door | |||
Stepwell corners | Rounded | Angled, beveled | |||
Jacking pads | Tall | No casting hole | Short | ||
Trucks | Revised center axle shock strut | ||||
Dynamic brakes | Batten strip at rear of dynamic brake housing | No batten strip | Dynamic brake housing moved rearward, lift rings moved closer to fans | ||
Exhaust | Raised exhaust stack | Silencer | |||
Radiators, fans | Square wire grid intakes; flat-topped fans | Corrugated intakes, Q-type fans | |||
Phase | 1 | 2a | 2b | 2c | 3 |
Other details
- Several SD40-2(W) orders came either with or without dynamic brakes while being otherwise identical.
- CN 5324 and up were initially equipped with speed recorders on every axle, similar to GP40-2L(W) units
- All units were built with ditch light brackets without ditch lights installed. Ditch lights were later permanently installed to these brackets.
Modifications
CN made a number of modifications to these units over the years:
- Relocation of the horn from the cab to the long hood
- Revised front cab window gaskets
- Addition of a ridge along the front of the cab roof
- Addition of snow shields over the inertial air intakes
- Replacement of the horizontal jog in the left handrail behind the cab with a vertical notch on Phase 1a1 through 1a3 units
- Addition of sheetmetal lift rings near the rear of the long hood
- Replacement of welded panel at the rear of the long hood on Phase 1a1 units with a hinged door, and larger louvres on the bolted panel underneath
- Removal of speed recorder cables (from units with recorders on every axle)
- Addition of coupler knuckle holders on rear pilots
- Installation of a pollution collector tank behind the fuel tank
- Removal of rerailing frogs initially suspended over the trucks
References
CNRPhotos. (2005). 5200s - SD40-2(w). Retrieved October 2014 from http://www.cnrphotos.com/gallery2/main.php?g2_itemId=10320
Unofficial EMD Homepage. (2005). SD40-2 Order Numbers. Retrieved January 2017 from http://www.trainweb.org/emdloco/sd40-2.htm
van Schoonhoven, W. (2016). CPR Diesel Roster. Retrieved January 2017 from http://www.mountainrailway.com/Diesel%20Roster%20Page.htm