EMD SD40-2 Nose Lengths
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This page was last updated on November 20, 2010.
During 1999 and 2000 there was a discussion about SD40-2 nose lengths on the Diesel Modelers discussion group. Kato had just announced their new HO scale model and several modelers were wondering about Kato's choice of nose length compared to what Athearn used on its model released in late 1983.
During the discussion I added that during 1977 and 1978 I was able to measure each of the various nose lengths on UP's units. This was while I was employed by Union Pacific as a boilermaker and carried a tape measure with me at all times. Don Dover of Extra 2200 South and I were talking regularly about compiling an all-time roster of Union Pacific diesel locomotives, and Don mentioned the need for definite measurements of nose length variations on newly delivered Union Pacific SD40-2s. I was able to provide the needed information within a couple days.
The first SD40-2s built by EMD from 1972 had the original 81-inch low nose.
In June 1974 Union Pacific began receiving new SD40-2s with an extended low nose, which railfans immediately began calling "snoots." This early version of the extended low nose consisted of the standard 81-inch nose and a 35-inch flat extension, making a total length of 116 inches.
In January 1977, EMD changed the dual-slope design to a constant-slope design, retaining the overall 116-inch length.
In December 1978, starting with UP 3410, Union Pacific began receiving locomotives with EMD's new standard 88-inch low nose.
The first units with extended low noses were the 45 units in the 3243-3287, which included the 32 units that were delivered as UP 8003-8034, and later renumbered back to their 3243-3274 number slots. These units were built in June and July 1974 and have the grid style radiator screens, and ratchet style hand brakes.
Next came the 17 units in the UP 3288-3304 group, delivered in March and April 1975. These units have the grid style radiator screens and wheel style hand brake.
Next came the 30 units in the UP 8035-8064 group, delivered in July 1976. These units had the corrugated radiator screens and wheel style hand brakes. They were renumbered to, and currently operate as, UP 3305-3334.
All later UP snoots are the 116" one-slope design, numbers as UP 3335-3488 (154 units, built from February 1977 to June 1978)
Here is a summary of UP's SD40-2s, not counting the MP, C&NW, and MKT units (sixteen orders spanning eight years of production, from 1972 to 1980).
- 120 units with 81 inch low nose.
- 92 units with Phase I 116 inch low nose (early extended 81 inch version) (3243-3334)
- including 62 units as 8003-8064, renumbered to 3243-3274 and 3305-3334
- 154 units with Phase II 116 inch low nose (3335-3488)
- including 10 units as 8065-8074, renumbered to 3400-3409
- 320 units with 88 inch nose (3489-3808)
- including 25 units as 8075-8099, renumbered to 3584-3608
- 165 units with ratchet style hand brakes (3123-3287)
- 521 units with wheel style hand brakes (3288-3808)
- 176 units with grid style radiator screens (3123-3297)
- including 32 units as 8003-8034, renumbered to 3243-3274
- 510 units with corrugated radiator screens (3298-3808)
- including 65 units as 8035-8099, renumbered to 3305-3334, 3400-3409, and 3584-3608
Exhaust Stacks and Radiator Fans
- 150 units with Q-style radiator fans and exhaust silencer
Steve Orth wrote the following summary in June 2000.
EMD built two versions of the 116" nose. From June 1974 through December 1977, the 116" extended nose was constructed by adding a 35" extension onto the rear of the existing 81" nose, for a total length of 116". The extension had a flat top, while the 81" nose had a sloped top. Therefore, the resulting nose has two slopes, and has recently become known as a "dual slope 116" nose" by UP railfans and modelers. This can be seen with careful study of prototype photographs. The second 116" nose, which went into production concurrent with the 88" standard nose, in January 1977, has a constant slope from the cab windshield to the tip of the nose. This nose has become known as a constant slope 116" nose.
The Union Pacific was the only railroad to receive the dual slope 116" nose. Two handbrake options were available on this nose, the ratcheted lever and brake wheel. UP units 3243 through 3287 were equipped with the ratcheted lever, and units 3288 through 3304 received the brake wheel.
In February 1977, the UP began receiving constant slope 116" nose SD40-2s, and all were equipped with brake wheels. The SP received 14 SD40-2s with the constant slope noses, but all of them were equipped with the ratcheted lever handbrake.
There were also variations on the access door behind the handbrake, with all of the UP units receiving a flush fitting door with two or three hinges and two vertical latches.
The UP received no SD40-2s with 123" noses.