Hi,
what are the visible difference of EMD SD40 and EMD SD40-2?
Thanks, Christian!
Wiki has two nice pages of the SD40 and SD40-2. The main difference is the enhanced electronic of the -2 family. Same as with GP38 vs. GP38-2 etc.
One of the more obvious spotting features, at least if you are the engineer’s side of the loco, is the little window for the water sight glass in one of the doors back by the radiator. This is on -2 locos but not the older ones.
–Randy
The SD40-2 is longer, has different trucks, and has several carbody spotting features. Notice the longer ‘porch’ on the front and rear of the units. This extra length was due to using the new HTC trucks rather than the Flexicoil trucks on the SD40. To keep the same fuel tank length, EMD stretched out the frame.
On the carbody, the battery box doors are different, there is a tapered drip edge on the roof behind the cab, and the ‘water glass’ on the engineers side of the long hood. A casual glance does not notice these features, but they are there.
Jim
I’m surprised no one has mentioned what to me is one of the more visible differences, the Dynamic Brake blister on the SD40 is tapered sharply to the sides, whereas the SD40-2 has a shallower taper at the front and this is flat. (similar to the GP40 vs GP40-2 dyamic break blister).
Personally, I’ve never seen an SD40, but I have a circa 1977 Conrail SD40-2, and the exhaust stack is before any of the fans on the back of the hood behind the cab. And the dynamics on each of the three truck frame halves (this thing is second hand, and one truck frame half was gone) are more or less can cylinders with flat ends and pigtail hoses. This is from a guy that has never seen an SD40 before so, don’t take my word for it.
SD40.
!(http://i184.photobucket.com/albums/x218/MFJ_album/WSOR engines/WSOR 4076/5-9-08036.jpg)
SD40-2.
!(http://i184.photobucket.com/albums/x218/MFJ_album/WSOR engines/WSOR 4003/8-13-08020.jpg)
Tank size is pretty much the same, but the Dash-2 trucks are longer, so the frame is longer, some parts of the carbody are a bit longer, etc.
The SD45-2 is built on the same frame. To house the longer 20-cylinder engine, and the longer radiator section, the carbody fills up the frame, no big porches on the ends.
The big porches on the SD40-2 leave a lot of room for snow to pile up on.
!(http://i184.photobucket.com/albums/x218/MFJ_album/WSOR engines/WSOR 4002/2-26-08010.jpg)
However, some late SD40s, at least on the UP, had the dynamic drake blister taper similarly to the extended range dynamic brakes on the Dash Twos.
As a rule, the difference in the blisters seems to be are fairly reliable spotting feature from what I’ve seen.
If it looks like you could hold a party on the back deck it’s a -2