






.
Last updated
2009-05-31
.
Trainiax
> Drawings > Locomotive
Phases > 6-axle EMD Locomotives
Trainiax
> Info > Locomotive
Phases > 6-axle EMD Locomotives
.
Locomotive Phases - 6-axle EMD Locomotives
.
SD7
No major production
variations.
Other details:
Units with steam generators have extra vents on top of short hood;
units without have bare top of short hood.
.
.
From SD7
to SD9
--Classification
lights mounted at an angle at corners of hood ends, rather than flush and
closer to middle
--Redesigned
steps
.
.
SD9
Phase 1:
cast/fabricated handrail stanchions, 4 36" radiator fans
Phase 2:
stamped handrail stanchions, front left ladder replaced by single grabiron
Phase 3:
2 48" radiator fans
Phase 4:
Higher battery boxes (raising cab and short hood)
Other details:
Units with steam generators have extra vents on top of short hood;
units without have bare top of short hood.
.
.
SD40 (US-built)
Phase 1a:
1966-- button-top fans, flat battery boxes under cab (some ribbed),
top-mounted nose grabirons, handbrake in nose, low-mounted brake cylinders
on trucks
Phase 1b1:
1966-1967-- ribbed battery boxes under cab, handbrake at rear of hood
Phase 1b2:
1967-- 1 high/3 low brake cylinders on trucks
Phase 1c:
1967-- open-top fans
Phase 2a:
1967-1968-- high-mounted brake cylinders on trucks, electrical cabinet
box
Phase 2b:
1968-1971-- drop-mounted nose grabirons
Phase 2c:
1971-- longer dynamic brake taper, ribbed equipment blower duct
Other details:
--Phase 2b1/2b2 are not distinguished
in drawings. Phase 2b1 has chickenwire radiator intake subscreen;
Phase 2b2 has square grid subscreen.
.
.
From late
non Dash-2 to early Dash-2:
--Frame length
increased from 65' 9-1/2" to 68' 10" (Note: The locomotive frame
was lengthened to accomodate the new and longer HT-C trucks while still
maintaining a 4000-gallon fuel tank. HT-C trucks have all traction
motors oriented in the same direction, creating an overhang over the innermost
axle that makes each truck 1 1/2 feet longer than the earlier Flexicoil.
--Bolted (rather
than hinged) front battery boxes
--Oblong water-level
sight glass (right rear of hood)
--Modified
central air intake and blower duct
--Modified
rear hood doors
--Lengthened
walkway blower duct
--Bolted,
rectangular cab side panel
--Enlarged
electrical cabinet box
.
.
SD40-2
(US-built)
Phase 1a: 1972-1975-- chickenwire
radiator intakes, 81" short hood, ratchet handbrake, bolted cab side panel
Phase 1b: 1976-1977-- 88"
short hood (except early Phase 1b), corrugated radiator intakes
Phase 2a: 1978-- wheel handbrake
(appeared on some late Phase 1b), new jacking pads, new electrical
cabinet box, new battery box hinges
Phase 2b: 1978-1979-- welded
cab side panel
Phase 2b2: 1979-- flush exhaust
stack
Phase 2c: 1980-1981-- Q-type
fans
Phase 3: 1983-1984-- new
blower duct, straight frame profile
Other details:
--BN units were built with hinged
(rather than bolted) front battery boxes through all production.
UP units were retrofitted with similar hinged battery boxes after production.
--CR units were built with Flexicoil
trucks in place of HT-C trucks.
--ICG and MP units were built with
additional jacking pads next to the stepwells.
--NW units were built with triple-clasp
brakes.
The following details vary between
units of all phases:
--The right side notch in the sideframe
over the air reservoir ends either at the 7th handrail stanchion (ahead
of left side notch) or between the 7th and 8th handrail stanchions (equal
to left side notch).
--Emergency fuel cutoff is either
ahead of or behind the 2nd handrail stanchion. The surrounding sideframe
is either straight or extended in a small downward notch.
--Dynamic brake blister may or may
not have a hatch ahead of the main intake.
.
.
SD40-2
(Canadian)
Phase 1a:
1972-1975-- chickenwire radiator intakes,
louvers at rear of hood
Phase 1b1:
1977-1979-- corrugated radiator intakes,
new battery box hinges, new electrical cabinet box, no louvers at rear
of hood
Phase 1b2:
1979-- winterization hatch, new truck
bearings
Phase 2a:
1980-1982-- flush exhaust stack, Q-type
fans, new jacking pads, front anticlimber, no winterization hatch
Phase 2b1:
1982-1983-- new blower duct, altered handrail
stanchion spacing, winterization hatch
Phase 2b2:
1983-1985-- straight frame profile
.
.
SD40-2W
CN was the
only buyer. Cab shared with GP38-2W and GP40-2W; dimensions and most
other details shared with standard SD40-2.
Phase 1a1:
1975-- dynamic brakes, chickenwire radiator
intakes, circular sand hatches, single-loop brake chain, single louver
set under short rear hood door, dipped handrail behind cab
Phase 1a2:
1976-- no dynamic brakes, rectangular
sand hatches, brake wheel moved forward, two louver sets on tall rear hood
door
Phase 1a3:
1978-- dynamic brakes, double-loop brake
chain
Phase 1b1:
1979-- dynamic brakes, straightened handrail
behind cab, new jacking pads
Phase 1b2:
1980-- dynamic brakes, winterization hatch
Phase 2:
1980-- no dynamic brakes, winterization
hatch, corrugated radiator intakes, flush exhaust stack
.
.
SD40T-2
(consistent with US-built SD40-2)
Phase 1a: 1974-1975-- 81"
short hood (D&RGW version), ratchet handbrake, bolted cab side panel
Phase 1b: 1977-- 88" short
hood, wheel handbrake, new battery box hinges
Phase 2a: 1978-- new jacking
pads
Phase 2b: 1978-1979-- welded
cab side panel
Phase 2c: 1980-- flush exhaust
stack
.
.
SD45T-2
Details are
consistent with Phase 1a US-built SD40-2 and SD40T-2.
Other details:
--Phase 1a1
(1972-1973) has standard jacking pads, no front anticlimber and no air
conditioner on cab roof.
--Phase 1a2
(1974) has air conditioner.
--Phase 1a3
(1975) has front anticlimber.
--Phase 1a4
(1975) has new jacking pads.
.
.
SD50
Phase 1:
Notched frame profile, flat/ribbed blower duct, angled inner dynamic
brake housing
Phase 2a1:
Straight frame profile, angled blower duct, new exhaust stack
Phase 2a2:
New handrail stanchion spacing (middle stanchions moved forward)
Phase 2b1:
Old handrail stanchion spacing, straight inner dynamic brake housing,
higher dynamic brake intake
Phase 2b2:
New handrail stanchion spacing
Phase 2c:
Air reservoir moved rearward
From SD50
to SD60:
--Eight access
doors under radiators (rather than six)
--First two
hood doors (under exhaust stack) widened
--Blower duct/raised
handrail section on left side behind cab moved forward
.
.
SD60
No major production
variations. A very subtle difference between some units is the 4500
vs. 4800 gallon fuel tank, with a difference in length of only a few inches.
.
.
SD60M,
SD60I
Phase 1a:
Three-piece windshield, single set of louvers under left side of cab,
angled hood seam behind cab, bolted square panel under right side of cab
Phase 1b:
Three sets of louvers under left side of cab
Phase 1c:
Dynamic brake intake and fan moved forward, order of hatches over intake
reversed, vertical hood seam behind cab, latched square panel under right
side of cab
Phase 1d:
Short hood beveled downwards on top front corners, straight raised
walkway on left behind cab
Phase 2a:
Two-piece windshield
Phase 2b:
No raised walkway on left behind cab
Other details:
--Seven access
doors under radiators (instead of eight on SD60) to make room for rear-mounted
handbrake
--Inclusion
of nose door window varied both throughout production and over individual
units' lifespans
--Phase 2a
and 2b produced concurrently
--SD60I ordered
by Conrail only; identical to Phase 2b SD60M except for isolated cab
.
.
SD70M vs.
SD70MAC
--Overall
length increased from 72' 4" to 74' (Length increase visible in gap between
fuel tank and rear truck; hood extends beyond rear radiator intakes)
--Different
central air intake area
--SD60-style
blower duct (compared to simple box style on SD70M)
--Raised walkway
on left side (not on SD70M)
.
.
SD70MAC
Phase 1a: 4 steps, HTCR Ia
trucks, horizontal electrical cabinet box,
straight end handrails, 2 foremost engine compartment
doors, cab headlight
Phase 1b1: 5 steps, end handrails
bent outwards
Phase 1b2: vertical electrical
cabinet box
Phase 1c: HTCR Ib/HTCR II
trucks, 3 foremost engine compartment doors
Phase 2: canted radiator
intake
Other details:
--Isolated cab introduced partway
through Phase 1b1 production (SD70MAC-I designation)
--Nose headlight introduced on late
Phase 1c BNSF units
.
.
Michael
Eby 2008-2009