I have not seen documentation that there’s been this extensive of an attempt to document the entire La Grange SD40-2 production history in the context of “phase” changes.  Current commonly-referenced phase rosters (Eby/Sarberenyi) are not inaccurate per se, but do make some generalizations, simplifications, and omissions, presumably to simplify the phases to the most major changes.  However, to understand the complete picture, we need to dig a little deeper, and that’s what I attempted to do with a complete timeline of showing the characteristics of each and every La Grange SD40-2 order in chronological order. 

I took the liberty of adding a fourth phase, as it has always bothered me that the transition to exhaust silencers and Q-Fans didn’t warrant a different major phase.  The new phase definitions are more for my own personal use as it applies to this database, so it isn’t my intention to “correct” the current phase lists out there, but I do feel that these phase definitions more accurately represent the production timeline, as well as provide more information at a first glance.  

There is much more information in this database that can’t be defined into the phase variations below, including optional equipment.  And of course, there ARE exceptions and regressions to these phases, as shown in the database, but great effort was made to define the subphases such that “asterisk” phases or transitional subphases were minimized.  But this of course required many more subphases than is normal, as you can see. 

While I did include some major options such as class lights, short hood lighting packages, options within the phase definitions, etc., including a comprehensive list of all options such as horns, plows, etc., was beyond the scope of this project and will require the modeler and manufacturer to do further order-specific research, including road number-specific research for some details that changed or transitioned mid-order, such as inertial intake rails, reservoir piping, etc.

Brian Bennett

Northwood, NH



Ia1, Jan. ’72, appx. 440-450 units (some orders with mixed upper inertial rails), KCS, BN, BN(C&S), UP, SOO, MILW, SOU, C&NW, MP, N&W, ROCK:

Full-cornered pilots with downward cut levers, 11 bolts on top and bottom of cab side panels, end handrail stanchion supports face inward, 81” short hood, shallow (narrow) stepwell plates, wire-mesh radiator grilles, narrow battery box louvers, separate ECAFB, angled handbrake chain housing

Ia2, Aug. ’73, appx. 110 units (some Ia1 orders with mixed upper inertial rails), MP, N&W, SOU, BN, ROCK, KCS, BN(C&S), C&NW, L&N:

Upper rail on inertial intake

Ia3, Apr. ’74, appx. 233 units (mixed chain housings within orders), BN, MILW, UP, N&W, C&NW, SOO, L&N, BN(C&S), MP:

Straight handbrake chain housing, snoot noses introduced with 116” short hood, two-plane hood roof with level section immediately ahead of cab

Ib1, Jan. ’75, 112 units, C&NW, N&W, SOU:

Notched pilot corners (except large anticlimbers and UP)

Ib2, Aug. ’75, 21 units, MP, SOO, ICG:

Two longer louvers on battery box

Ic1, Feb. ’76, 45 units, BN + 7 UP production Ib1s w/brakewheels and corrugated grills:

Corrugated radiator grill

Ic2, Jul. ’76, 60 units, MP, UP, KCS:

13-bolts on top and bottom of cab side panel

Id, Nov. ’76, 10 units, C&NW:

Welded/attached ECAFB, revised end handrail stanchion arrangement


IIa1, Nov. ’76, 20 units, BN:

Clean cab/88” short hood, engineer’s side short hood vent becomes standard (low), dropout hinges on cab equipment doors

IIa2, Jan. ’77, 20 units, B&O:

Deep stepwell plates

IIa3, Feb. ’77, 75 units, UP:

Revised fuel tank vent piping with junction box, 116” snoot short hood roofs changed to constant plane

IIb, May ’77, appx. 265 units (some orders start to see intermittent short jack pads), BN, BN(C&S), CR, FLS(L&N), ATSF, SOU:

Large anticlimbers narrowed for pilot notches, short hood vent moved upward, high oval pilot cutouts standard if not equipped with stepwell lifting lugs, 123” snoot short hood with single-plane roof introduced as option

IIc1, Jan. ’78, appx. 57 units (some IIb orders started to mix in short jack pads), SOU, BN, KCS:

Short jack pads, fireman’s side aft oval cab vent becomes standard

IIc2, Mar. ’78, appx. 300 units (some orders mixed in IIc3 angled grabs), UP, N&W, SOU, KCS, BN, SLSF, BN(C&S), MKT, KCCX:

No batten strip, revised HTC center axle snubber

IIc3, Aug. ’78, appx. 150 units (started to mix in with IIc2 orders), MP, CR, MKT, ATSF, UP, BN:

Angled radiator fan grab iron

IIc4, Feb. ’79, appx. 50 units (started to appear in IIc2 and IIc3 orders), UP, BN, BN(C&S):

Revised reservoir piping, fireman’s side aft

IId1, Feb. ’79, appx. 218 units (started to appear mixed in with IIc orders), SOU, FLS(L&N), BN(C&S), BN, ATSF, MP, UP, CR:

Welded cab side panel

IId2, May ’79, appx. 286 units (some earlier orders mixed with IId1s, top-only inertial rails), BN(C&S), BN, MP, FLS(SCL), UP, CR, FLS(L&N), MKT, OWTX, ATSF:

Bottom inertial intake rail added


IIIa, Dec. ’79, 2 units, SOO:

Exhaust silencer, exhaust opening aft in housing

IIIb1, Jan. ’80, 376 units, UP, BN, BN(C&S), MP, SOO, FLS(L&N), FLS(SCL), KCS, MKT, FLS(CRR):


IIIb2, Sep. ’80, 103 units, ATSF, UP, N&W:

Middle strengthening rib added to battery box doors

IIIc, Mar. ’81, 3 units, SOO:

Engineer’s side reservoir sill notch moved aft as standard, bumped EFCOs (aft & bumped EFCOs or forward & flush EFCOs optional beforehand)

IIId1, Aug. ’81, 40 units, MKT, FLS(CRR), FLS(L&N):

Bolted toilet hatch on short hood

IIId2, Oct. ’81, 23 units, ATSF:

Exhaust opening forward in silencer housing


IV, Jul. ’84, 6 units, SOO:

Dropout hinges on battery box, 2x2 louvers, straight sill, modified handrail spacing, raised over blower housing, 50-Series blower housing