Locomotive Phases - EMD SD60M, SD60I
The SD60M was introduced in 1989 as a safety cab-equipped version of the SD60, using the 3-window cab previously used on the F59PH and SD40-2F. Compared to the SD60, the underframe was lengthened 5" toward the front to accomodate the new cab and the hand brake was moved from the short hood to the rear of the long hood, but the rest of the frame and hood remained largely the same. Later units saw the introduction of the 2-window cab that would be carried over to the SD70 series, along with changes to the front of the hood and underframe that were not incorporated into the standard SD60. The SD60I was a refinement of the SD60M, with an isolated cab identified by the rubber seam running under and behind the cab and across the short hood.
Phases
These phases are of my own making. SD60M production spanned phases 1a to 2c, while all SD60I units (except one prototype, CR 5544) were phase 2d.
| Phase | 1a | 1b | 1c | 1d | 2a | 2b | 2c | 2d |
|---|---|---|---|---|---|---|---|---|
| Date | 1989-01 - 1989-02 | 1989-04 - 1989-11 | 1989-12 - 1990-03 | 1990-09 - 1990-12 | 1991-01 - 1991-03 | 1991-11 - 1992-10 | 1992-12 - 1993-06 | 1994-11 - 1995-09 |
| Left cab sub-base hatches | 5 standard latches, 1 set of louvres | 4 small latches, 3 sets of louvres (1 set on Phase 1c units as-built) | ||||||
| Right cab sub-base hatches | Bolted rear panel | Latched rear panel | ||||||
| Left traction motor cables | Enter underframe below cab (as on SD60) | Enter underframe above fuel tank; significantly revised cable routing | Slightly revised routing above fuel tank | |||||
| Right traction motor cables | Extend farther forward on underframe above fuel tank | |||||||
| Electrical cabinet air filter box | Attached to rear of cab (as on SD60) | On walkway behind cab | ||||||
| Hood seam behind cab | Zig-zag | Vertical | ||||||
| Phase | 1a | 1b | 1c | 1d | 2a | 2b | 2c | 2d |
| Center hood section | 8 latched doors | 6 latched doors, revised seams & lift ring location under exhaust stack | ||||||
| Short hood, cab | 3 windows, straight angled section | Beveled angled section | Redesigned cab/short hood with 2 windows | |||||
| Fuel tank supports | Flat plate bolted to underframe, angled bottom edges | Straight vertical connection, squarer bottom edges | ||||||
| Panel around cab side windows | Rectangular metal strip | Smooth panel | ||||||
| Rib below cab side windows | No | Yes | ||||||
| Right side air pipes, dryers | Revised pipe routing | |||||||
| Phase | 1a | 1b | 1c | 1d | 2a | 2b | 2c | 2d |
Detail variations
Burlington Northern
The first order of BN SD60M's (9200-9249, Phase 1c) were equipped for use with fuel tenders, resulting in a fuel pipe visible running the length of the locomotive on the engineer's side and behind the steps on all four corners, and a connecting hose on each pilot. Units in the first order initially had a winterization hatch over the first radiator fan, an amber strobe light on the cab roof, and no louvres on the larger cab sub-base door on the left (conductor's) side. Soon after delivery, the winterization hatch was removed, the cab sub-base door received two sets of louvres like most other SD60M production, and the amber strobe light was replaced by two strobes on the front platform. The strobes were in turn replaced by ditch lights in the late 1990s.
The second order of BN SD60M's (1991, 9250-9298, Phase 2a) were apparently not equipped for operation with fuel tenders (judging by the absence of fuel pipes or connections). They had two strobe lights on the front platform either as built or added shortly after delivery, which were replaced by ditch lights in the late 1990s.
Conrail
Conrail units were built with class lights on both hood ends. SD60M's had flush (early) or recessed (late) lights at the front and recessed lights in a square housing at the rear. SD60I's (except for 5544) changed to a circular rear recess. The radiator fans were lowered into a recess in the rear of the hood by about an inch (I measured about 1.25" from photos), and the side walkway handrails on both the SD60M and SD60I were built with a stanchion and a gap from the rear of the cab wall, in order to reduce vibrations transmitted to the cab.
References
Norfolk Southern. (2006). Locomotive Equipment. Retrieved August 2015 from http://www.railfandepot.com/product/norfolk-southern-2006-diesel-locomotive-diagrams/
Strack, D. (2015). UP Diesel Roster, 1934-2009, Part 59. Retrieved December 2017 from http://utahrails.net/up-diesel-roster/up-diesel-roster-59.php.
Unofficial EMD Homepage. (2004). SD60M, SD60I Order Numbers. Retrieved December 2017 from http://www.trainweb.org/emdloco/sd60m.htm
Wallace, R. (2002). EMD SD60M Prototype Information. Retrieved December 2017 from http://crcyc.railfan.net/locos/emd/sd60m/sd60mproto.html