Locomotive Descriptions and Phases - EMD GP40-2
The GP40-2 was introduced by EMD in 1972 as a replacement for the GP40. It retained the same 3,000 horsepower 645-series engine but received a host of mechanical and electrical upgrades geared at improving reliability and ease of maintenance, the most substantial of which was the introduction of modular electronic components (which had been tested on the DDA40X starting in 1969). Production continued until the end of 1986. The GP50, introduced in 1980, was built concurrently with late GP40-2 production, and both were succeeded by the GP60.
Like the GP40, the GP40-2 can be identified by having four axles, three 48" radiator cooling fans and a clean-lined hood with a single turbocharger exhaust stack (changed to a flat silencer housing on later units). The differences between the GP40 and GP40-2 are listed below; for the differences between the GP40-2 and GP50, see GP50 Phases.
Transition: From late GP40 to early GP40-2
While all the overall dimensions and proportions were retained with the start of the Dash-2 series, many small detail changes were made to the entire locomotive. As a result, almost every part of the cab and hood was changed in some way. The following external changes were made with the introduction of the GP40-2:
Cab and cab sub-base
- Battery box covers bolted rather than hinged
- Left-side battery box cover lengthened rearward
- Right-side battery box cover lengthened forward
- Left front handrail stanchion moved rearward
- Right front handrail stanchion moved forward
- Riveted, rectangular cab side panel added around the cab side windows
- Rear cab roof overhang added
- Larger electrical cabinet air filter box
- Larger handbrake notch in the short hood
- Modified central air intake and blower duct
- Shorter dustbin hatch (on the roof behind the cab) with differences between the GP38-2 and GP40-2
- Oblong water-level sight glass (at the right rear of the hood)
- Rear hood doors grouped 2-2-2-1 instead of 1-2-4
- Circular access hatches at the top corners of the long hood end
Underframe and walkway
- Single-shoe (M-type) Blomberg trucks introduced, although many units rode on the previous clasp-brake version
- Air reservoirs moved rearward
- Lengthened walkway blower duct
- Walkway handrail stanchions reverted to uneven spacing - similar to (but not the same as) early GP40 production (closer-spaced at rear)
- Jacking pads used a rectangular (rather than trapezoidal) underside plate and a wider face plate
Phases - GP40-2
The GP40-2 underwent a similar evolution to the GP38-2 and SD40-2. I initially based these phases on SD40-2 phases by Scott Chatfield, with details added based on my own observations. I later added Phase 1a2, 1b and 2a2 based on the GP40-2 roster compiled by Robert Sarberenyi. While phases often differed between EMD and GMD versions of the same model, in this case all GMD GP40-2(W) and GP40-2L(W) units had Phase 1a1 or 1a2 GP40-2 spotting features.
Numbers correspond to the illustrations shown below.
|Inertial air intakes 1||Ridge added along top||Ridge added along bottom|
|Radiators, fans 2||Square wire grid intakes;|
curved grabiron behind fans;
flat-top radiator fans
relocated lift ring and flag holder aft of intakes
|Angled grabiron behind fans|
(late Phase 2b1)
|Q-type radiator fans|
|Underframe 3||Revised fuel tank vent pipe||Revised air reservoir piping on conductor's side|
(appeared on some late Phase 2a2 units)
|Cab 4||Hinged sub-base doors;|
riveted side panel
11 rivets along top/bottom
|Sub-base doors with lift-off tabs;|
riveted side panel
13 rivets along top/bottom
|Welded side panel|
|Battery box covers||Bolted, small louvres||Larger louvres||Horizontal rib added|
(bolted version only)
|Latched, lift-off tabs|
|Short hood 5||81" length||88" length; circular vent on right side||Bolted hatch added on top|
ECAFBElectrical cabinet air filter box, located on the left behind the cab6
|Separated from cab||Flush with cab|
|Pilots, steps 7||Straight upper end plate corners;|
straight coupler cut levers
|Notched upper end plate corners;|
raised coupler cut levers; revised upper pilot/drop step area;
front anticlimber/sill extension added; notched stairwell side sheet
|End handrails 8||Flush with pilots;|
inward-facing central handrail stanchion supports
|Wrap around pilots slightly;|
outward-facing central handrail stanchion supports
|Dynamic brakes 9||Batten strip at rear of dynamic brake housing||No batten strip||Dynamic brake housing moved rearward|
|Exhaust 10||Raised exhaust stack||Silencer with opening at rear||Silencer with opening at front|
|Blower duct||Flat, wide, two ribs||Angled "laundry chute"|
|Frame side sill||Narrow over air reservoirs, wide at ends||Narrow over entire length|
- Various as-built pilot options were available: standard footboards (up to 1975), plow (in various sizes), sloped rock deflector (2 types), or a flat end plate with MU hose pockets.
- There were two variations in step spacing, depending on railroad
- An oblong cab vent appears on most units starting with Phase 2a, generally on the left side toward the rear of the cab
- Some units (such as CR GP40-2's and CN GP40-2L(W)'s) were built with lower-clearance radiator fans and (on CN units) a slightly lower inertial intake roof hatch and exhaust stack.
These two drawings illustrate typical early (Phase 1a2) and late (Phase 2d) GP40-2's built to similar Chessie System specs. A few details represent railroad-specific options, such as rock deflector pilots, a box behind the ECAFB, slotted battery box covers (on the Phase 2d version) and horn variations.
Click on the links to toggle between the images.
Foster, Gerald. (1996). A Field Guide to Trains. New York, NY: Houghton Mifflin.
Sarberenyi, R. EMD's GP40-2 - Original Owners. Retrieved November 2014 from http://www.trainweb.org/jaydeet/gp40-2.htm
Unofficial EMD Homepage. (2001). GP40-2 Order Numbers. Retrieved November 2014 from http://www.trainweb.org/emdloco/gp40-2.htm