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  • SD40 verses SD45 locomotives

  • Discussion of the operations of CSX Transportation, from 1980 to the present. Official site can be found here: CSXT.COM.
Discussion of the operations of CSX Transportation, from 1980 to the present. Official site can be found here: CSXT.COM.

Moderator: MBTA F40PH-2C 1050

 #1042960  by conductorbob
 
A question... What was the major differences between the SD40 and the SD45 engines. I worked on both of them when I was with Conrail(CSX),and I only remember the SD40's had a very large rear platform on them. Also what years were they built and used. Thanks in advance. Conductor Bob
 #1042974  by scottychaos
 
Bob,
the one with the large "rear porch" is the SD40-2, which is not exactly the same as the SD40..
actually, there are four variants in the locomotives you are talking about, you probably worked on all four:

SD40 - built 1966 to 1972, most retired by the 1990's, very few still operating today, probably none on Class-1 railroads.

SD40-2 - built 1972 to 1989 - one of the most successful diesel models of all time, many still operating today.

SD45 - built 1965 to 1971 - most out of service by the 1990's, a few still solder on today, although many have been rebuilt
and are no longer technically SD45's, but many still retain their unique SD45 carbody..

SD45-2 - built 1972 to 1974 - the least common of the four, very few still in service today, and probably none in original form,
as most that are still running have been rebuilt.

The SD40-2 is, by far, the most common, and that's the one with the large rear porch.
The SD45 is easily identified by having the flared radiators. (which the SD45-2 did not have)
Today, only the SD40-2 remains still in service in large numbers, on the Class-1 railroads..
SD40 and SD40-2 have 16 cylinder engines, SD45 and SD45-2 have 20 cylinder engines..
there are other differences..both Conrail and CSX rostered all four models:

SD40
http://paintshop.railfan.net/images/eby/sd40-cn.html

SD40-2
http://paintshop.railfan.net/images/eby ... h2-cr.html

Note the longer front and rear "porches" on the dash-2.
the SD40 and SD40-2 are quite visually different, the dash-2 being noticeably longer, and with the
pronounced "porches" that the SD40 lacks.

SD45, the "flared radiators" at the rear are an easy SD45 spotting feature:
http://www.railpictures.net/viewphoto.p ... 816&nseq=6
http://www.trainweb.org/girr/tips/tips8/sd45_rear.jpg

SD45-2, no flared radiators:
http://www.railpictures.net/viewphoto.p ... 96&nseq=10

Scot
Last edited by scottychaos on Fri May 04, 2012 9:34 pm, edited 2 times in total.
 #1042975  by lvrr325
 
SD45 has a 20-cylinder diesel rated for 3500 HP, SD40 has a 16-cylinder diesel rated at 3000 HP.

SD40 and SD40-2 production ran from 1966 through around 1980, SD45 and SD45-2 only through about 1974 or 1975. The -2 variant has a different electrical system and was introduced in 1972; while the SD40-2 only had minor visual changes, the SD45-2 was greatly changed from the SD45.

The '45 tended to use more fuel and cost more to maintain and most railroads dumped them in the 1980s, although secondhand they contined in use into the last decade (NYS&W, MRL, WC). While some SD45s are still active, most of them have been rebuilt internally with the 16-cylinder diesel and newer electrical systems.

On Conrail Shared Assets you may also have run into SDP45s, former Erie Lackawanna units which were built on a longer frame to allow a bigger fuel tank for greater fuel capacity (in theory, they could run NY-Chicago without refueling); some of these still run. The P in SDP45 means passenger; although the EL units were not equipped, some western roads had SDP45s which had steam heating equipment for use on passenger trains.

The SD40 with all it's variations was the biggest selling diesel for EMD and many continue in service today.
 #1042976  by lvrr325
 
Visual differences between the SD40 and SD40-2 are minor; both have the "porch" at each end. Some "SD40-2" units in service today are in fact rebuilt from SD40 models; the differences are internal and probably more detail than the OP Is after.
 #1042990  by Noel Weaver
 
I ran both the SD-40's and SD-40-2's a lot during my career and BOTH of these models had the porches on both the front and rear end. The reason for the porch the SD-40 etc had the same frame as the SD-45 with a shorter 16 cylinder engine on the 40 vs a longer 20 cylinder engine on the 45. The diesel engine on the SD-40 and SD-40-2 was essentially the same engine that was on the GP-40 and GP-40-2 but on a longer frame to accomodate the six motor trucks thus the porches.
Noel Weaver
 #1043001  by roadster
 
Scott, Just note that the SD40 version list in the link is a CN version. It has a larger electrical cabinet behind the cab (CN specific appliances I believe) which shortened the porches a little due the body being stretched. The frames were all SD45 frames. The only real spotting features between standard SD40's and the -2's were the sight glass window on the engineers side of the long hood and the longer tapered dynamic brake blister front, to the short and stubby SD40 models. Rebuilds and parts swapping at amoungst the units being rebuilt or scrapped have made these features virtually inapplicable anymore. Suffice to say that most all SD40s, and SD45s have been rebuilt to SD40-2 standarads and upgraded with the most up to date electronics. Some even becoming a whole separate beast like CSX's SD40-3 program with the unique cab designs.
 #1043115  by roadster
 
Roadster eats a bit o crow. After taking a close look at what I believe was an SD40 rebuilt by CSX as an SD40-2.(an 8400 series used as an RCU puller engine at Dewitt) It still has the same size electrical compartment behind the cab as the CN unit on Scotty's link. It is fairly obvious that the SD40's had a shorter porch area (maybe a couple feet at each end) than SD40-2s, due to the larger compartment. I also looked at a couple other obvious SD40-2s at Dewitt today(a HLCX X-BNSF SD40-2 and CSX 8811 X-CR SD40-2). Both had larger porch areas, but again maybe a couple feet at each end.
 #1043187  by scottychaos
 
Thanks Roadster! Image
yep, the SD40-2 definitely has a noticeably larger rear porch than the SD40..
I think they both might have the same long hood length, but the SD40-2 has a longer frame..
65' 8" for the SD40, vs. 68' 10" for the Sd40-2.
the dash-2 is three feet longer.

When I was a teenage railfan in Sayre, PA in the early 1980's I stood on the LV walkbridge and taught myself the difference between diesel models,
fans on the roof, etc..I used the rear porch, and also the last set of wheels, to identify a SD40 vs. a SD40-2..actually, the rear wheels work even better than
the porch, to tell the two models apart at a glance..

SD40:
http://trainiax.net/drawings/55-paint/w ... d-sd40.GIF

SD40-2
http://trainiax.net/drawings/55-paint/b ... sd40-2.GIF

(open them in two separate browser windows, then its easy to toggle between them to compare)

Not only is the rear porch longer on the dash-2, the but the real wheel placement is a great ID feature..
on the SD40, the rear wheelset is nearly even with the rear of the longhood,
on the SD40-2, the rear wheelset sticks out quite a bit past the rear of the long hood, so that the entire rear wheel set
is beyond the edge of the longhood..
That rear axle placement, along with the expansive porch, is the main way I have always ID'd a SD40 vs. a SD40-2.

Scot
 #1043226  by mmi16
 
scottychaos wrote:Thanks Roadster! Image
yep, the SD40-2 definitely has a noticeably larger rear porch than the SD40..
I think they both might have the same long hood length, but the SD40-2 has a longer frame..
65' 8" for the SD40, vs. 68' 10" for the Sd40-2.
the dash-2 is three feet longer.

When I was a teenage railfan in Sayre, PA in the early 1980's I stood on the LV walkbridge and taught myself the difference between diesel models,
fans on the roof, etc..I used the rear porch, and also the last set of wheels, to identify a SD40 vs. a SD40-2..actually, the rear wheels work even better than
the porch, to tell the two models apart at a glance..

SD40:
http://trainiax.net/drawings/55-paint/w ... d-sd40.GIF

SD40-2
http://trainiax.net/drawings/55-paint/b ... sd40-2.GIF

(open them in two separate browser windows, then its easy to toggle between them to compare)

Not only is the rear porch longer on the dash-2, the but the real wheel placement is a great ID feature..
on the SD40, the rear wheelset is nearly even with the rear of the longhood,
on the SD40-2, the rear wheelset sticks out quite a bit past the rear of the long hood, so that the entire rear wheel set
is beyond the edge of the longhood..
That rear axle placement, along with the expansive porch, is the main way I have always ID'd a SD40 vs. a SD40-2.

Scot
Off the drawings you linked - the SD40 has no Shock Absorber attached to either truck - The SD40-2 has a Shock Absorbers attached at the middle wheel set of each truck.
 #1043258  by RSD15
 
The drawing is of a Conrail SD40-2. Conrail chose not to equip it's SD40-2's with the new HTC trucks and used the older flexicoils without the
dampers.It was rumored that Conrail did this because of Amtrak's problems with their HTC equipped SDP40F's.The extra length of the
SD40-2's was because of the new longer HTC trucks, all traction motors are on the same side of the wheel.

Some more spotting help,

On the SD40 on the firemans side the battery box under the cab is square with the cab and has latches and hinges.
On the -2 the box extends under the cab and is bolted on.

The blower bulge on -2's has two horizontal ribs,straight 40's are smooth.

Radiator covers on the 40's are wire mesh and rods, -2's have grills.

On the rear of the long hood -2's have extra knock out holes near the roof for class lights.
Charles

Oh and SD45's have 3600 hp.
 #1044133  by Leo_Ames
 
scottychaos wrote:SD40 - built 1966 to 1972, most retired by the 1990's, very few still operating today, probably none on Class-1 railroads.
The vast majority survived the 1990's. Many still operate to this day (Including an original unit as built on CSX). And hundreds of rebuilds to SD40-2 specifications and beyond still are in operation on railroads from CSX to shortlines.

Lots of SD45-2's around as well (Both standard and Tunnel Motor versions), although many of the survivors have been rebuilt with 16 cylinder engines. But I believe some 20 cylinder versions survive on Montana Rail Link, in BNSF's surge fleet, and probably elsewhere (Particularly the Tunnel Motor versions).