
Locomotive Descriptions and Phases - EMD GP38-2
The GP38-2 was introduced by EMD in 1972 as a replacement for the GP38. It retained the same 2,000 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). The use of an alternator in place of a DC generator, previously standard on higher-horsepower models but optional on the GP38, was made standard on the GP38-2. Production continued until the end of 1986, at which point no direct replacement model was introduced.
Externally, the GP38-2 kept the same general appearance as the GP38, with four axles, two 48" radiator fans and two exhaust stacks. The paper air filter housing created a raised box on the hood roofline ahead of the exhaust stacks. Early in GP38-2 production, the radiator intakes were shortened and the fans moved closer together.
Thanks to their exceptional reliability and versatility, the vast majority of GP38-2's have remained in service more than 50 years after the model first entered production, and hundreds of GP35's, GP38's, GP40's and GP50's have been rebuilt to GP38-2 or GP38-3 specifications.
Transition: From late GP38 to early GP38-2
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 Dash-2 series:
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
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 - GP38-2
The GP38-2 underwent a similar evolution to the GP40-2 and SD40-2. I initially based these phases on SD40-2 phases by Scott Chatfield, with details added based on my own observations. I added a few more sub-phases after refining the phases for the GP40-2, which underwent essentially the same detail evolution but lacked all the Phase 1c variations.
As with most models produced concurrently by EMD in the US and GMD in Canada, the phase details are not entirely the same between the two builders, so these phases do not apply to GMD GP38-2 production.
Phase | 1a | 1b1 | 1b2 | 1c1 | 1c2 | 1c3 | 2a1 | 2a2 | 2b1 | 2b2 | 2c1 | 2c2 | 2d | 3a | 3b |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Radiator intakes | Square wire grid, 2 sections | Square wire grid, single shorter section | Corrugated; relocated lift ring and flag holder aft of intakes | ||||||||||||
Radiator fans | Flat-top radiator fans; curved grabiron behind fans | Fans closer together | Angled grabiron behind fans (late Phase 2b1) | Q-type radiator fans | |||||||||||
Inertial air intakes | Ridge added along top | Ridge added along bottom | |||||||||||||
Cab side panel | 11 rivets along top/bottom | 13 rivets along top/bottom | Welded | ||||||||||||
Battery box covers | Bolted, small louvres | Larger louvres | Horizontal rib added (bolted version only) | Latched, lift-off tabs | |||||||||||
Pilots | 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 (except units with high short hood) | ||||||||||||
ECAFBElectrical cabinet air filter box, located on the left behind the cab
| Separated from cab | Flush with cab (except early SOU units) | |||||||||||||
End handrails | Flush with pilots, inward-facing outer stanchion supports | Wrap around pilots slightly, outward-facing outer stanchion supports | |||||||||||||
Phase | 1a | 1b1 | 1b2 | 1c1 | 1c2 | 1c3 | 2a1 | 2a2 | 2b1 | 2b2 | 2c1 | 2c2 | 2d | 3a | 3b |
Stairwell side sheet | Full-height angled sheet | Handrail notch extending from walkway to second-lowest step, sharper angle creating narrower top step (appeared on SOU Phase 1c3 units) | |||||||||||||
Cab sub-base doors | Hinged | Lift-off tabs | |||||||||||||
Underframe | Revised fuel tank vent pipe | Revised air reservoir piping on conductor's side (appeared on some late Phase 2a2 units) | |||||||||||||
Short hood | 81" length | 88" length; circular vent on right side (except units with high short hood) | Bolted hatch added on top | ||||||||||||
Hand brake | Ratchet | Wheel (many units retained ratchet) | |||||||||||||
Dynamic brakes | Batten strip at rear of dynamic brake housing | No batten strip | Rear edge of dynamic brake housing moved rearward | ||||||||||||
Exhaust | Raised oblong stacks | Flush circular openings | |||||||||||||
Frame side sill | Narrow over air reservoirs, wide at ends | Narrow over entire length | |||||||||||||
Blower duct | Flat, wide, two ribs | Angled "laundry chute" | |||||||||||||
Phase | 1a | 1b1 | 1b2 | 1c1 | 1c2 | 1c3 | 2a1 | 2a2 | 2b1 | 2b2 | 2c1 | 2c2 | 2d | 3a | 3b |
Other details
- Various as-built pilot options: standard footboards (up to 1975), plow (various sizes), sloped (2 types), flat end plate with MU hose pockets
- Two variations in step spacing, depending on railroad
- Oblong cab vent appears on most units (generally on left side, towards rear) starting with Phase 2a
References
Foster, Gerald. (1996). A Field Guide to Trains. New York, NY: Houghton Mifflin.
Unofficial EMD Homepage. (2001). GP38-2 Order Numbers. Retrieved December 2009 from http://www.trainweb.org/emdloco/gp38-2.htm