Locomotives Phases - EMD SD40-2

These phases are partly of my own making and partly based on SD40-2 phases by Scott Chatfield.

Phases

Phase 1a

• Battery covers: Bolted, small louvers
• Cab sub-base doors: Hinged
• Jacking pads: Tall
  
• ECAFB: Separated from cab
• Electrical cabinet air filter box, located on the left behind the cab
• Radiator intakes: Square wire grid
• Regular short hood: 81" length
• "Snoot" short hood: 116" length, sloped section ahead of flat section near cab
• Hand brake: ratchet
  
• Cab side panel: Bolted, 11 bolts along top/bottom
• Pilot/ends: Straight upper end plate corners, no raised coupler cut lever, no front anticlimber
• Some units ordered with anticlimber
  
• Rear upper pilot/drop step area: Version 1, inward-facing handrail stanchion supports
• Radiator fans: Flat top
• Exhaust: Raised stack
• Blower duct: Flat, wide, two ribs, no raised walkway
• Frame side sill: Narrow over air reservoirs, wide at ends

Phase 1b

• Radiator intakes: corrugated

Phase 2a1

• Battery box covers: Bolted, large louvers
• Cab sub-base doors: Lift-off tabs
• Hand brake: wheel
• some units retained ratchet
  
• ECAFB: Flush with cab
• Regular short hood: 88" length, circular vent on right side
• "Snoot" short hood: 116" or 123" length, constant slope on top
  
• Cab side panel: Bolted, 13 bolts along top/bottom
• Pilot/ends: Notched upper end plate corners, raised coupler cut lever, front anticlimber (2 versions, depending on railroad)
• Rear upper pilot/drop step area: Version 2, outward-facing handrail stanchion supports

Phase 2a2

• Jacking pads: short

Phase 2b

• Cab side panel: Welded

Phase 2c

• Battery box covers: Horizontal rib added (some railroads)
• Radiator fans: Q-type
• Exhaust: Raised silencer, opening at rear

Phase 2d

• Short hood: Bolted hatch added on top

Phase 3

• Battery box covers: Latched, lift-off tabs
• Blower duct: Angled, narrow, no ribs, raised walkway ("laundry chute")
• Exhaust: Raised silencer, opening at front
• Frame side sill: Narrow over entire length

Other details

• Various as-built pilot options: standard footboards (up to 1975), plow (various sizes), sloped (2 types), flat end plate
• 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