The Union Pacific Railroad



EMD SD40 / SD40-2

One of the largest fleets of near identical diesel locomotives in North America, during the '70s and '80s, was UP's 3000 class of EMD SD40 type units. The 40 in the model number indicated that the locomotive was powered by the 3000 HP 16 cylinder EMD 645E prime mover, an engine shared with other models such as the GP40 and F40-PH.

The 645 was developed to compete with General Electric's FDL16, which could produce more power than EMD's older 567 series engines. The other major series of locomotives that used the 645E were the 38 series that used a 2000 HP 16 cylinder non-turbo version, the 39 series with a 2000 HP 12 cylinder turbo charged design, and the SD45 which had a 3600 hp 20 cylinder turbo variant.

UP was one of the first railroads to buy the SD40, and they also sampled the SD45, early on. However, unlike other western railroads like SP and Santa Fe, UP favored the 3000 HP "40 series", for their main road power.

By 1972, EMD had designed a whole new modular electronic system for their locomotives, along with several mechanical improvements such as the HT-C truck. These improvements became features of the "-2" type locomotives, and the SD40-2 became even more popular than it's predecessor, and also more popular than its stable mate SD45-2.

 
UP SD40 L.gifUP SD40 R.gif
mm/Trackbed
Type Union Pacific SD40
Description
ModelEMD SD40
Dates Built1966 - '71
Road Numbers3000 - 3039, 3048 - 3122
Left Image3001
Right Image3065
Notes

The EMD SD40 used the turbo charged 645E diesel prime mover. This engine produced 3000 HP from 16 cylinders. The SD40 was part of a series of locomotive that introduced the 645E. That series included the non-turbo SD38 and the 20 cylinder SD45.

Other western railroads, like Southern Pacific, Santa Fe, and Great Northern, preferred the 3600 HP SD45, but UP quickly came to favor the 40 series.

The earliest units used the Flexicoil "C" type trucks, with brake cylinders mounted low, between the wheels. This brake configuration soon showed a vulnerability to debris on or near the tracks, and was particularly prone to damage during a derailment. Later units reverted to the earlier configuration, with brake cylinders mounted high on the truck frame, above each axle.

 

UP SD40X L.gifUP SD40X R.gif
mm/Trackbed
Type Union Pacific SD40X
Description
ModelEMD SD40X
Dates Built1965
Road Numbers3040 - 3047
Left Image3044
Right Image3045
Notes

These units started life as EMD's testbeds for the 645E engine. The first six had the flared radiators later seen on the SD45. They were built on SD35 frames, so they looked more like four axle units, and more than one railfan has called them "GP45s"

There was another locomotive called the SD40X. Four of them were built as testbeds for SD50 technology, and they became Kansas City Southern 700-703.

 

UP SD40 L.gifUP SD40 R.gif
mm/Trackbed
Type Union Pacific SD40-2 (early)
Description
ModelEMD SD40-2
Dates Built1972 - '73
Road Numbers3123 - 3242
Left Image3158
Right Image3190
Notes

These were the first of over 500 SD40-2s on the UP. They featured a frame three feet (1m) longer than the SD40, and had an improved electronic control system, featuring modular components.

Like the SD40s before them, the early SD40-2s had 81" (2.06m) long short hoods, and grid type radiator covers.

The SD40-2 also featured EMD's new high traction HTC trucks, which solved the older Flexi Coil design's tendency to "nose up" when power was applied.

 

UP SD40 L.gifUP SD40 R.gif
mm/Trackbed
Type Union Pacific SD40-2 ("snoot")
Description
ModelEMD SD40-2
Dates Built1975
Road Numbers3298 - 3304
Left Image3302
Right Image3299
Notes

The -2 had large "porches" on both ends (because of the oversized frame) and the railroads often made use of the extra space. The most common modification was the "snoot", a 116" (2.95m) short hood. The extra space was usually used for "Locotrol" equipment, a radio system used to control unmanned helper engines, placed part way back in heavy freight trains.

Another new feature was the corrugated screen type radiator covers, which differed from the earlier grid style.

These units also show the first variation in paint scheme. The cab-side slogan was changed to "We can handle It!"

 

UP SD40 L.gifUP SD40 R.gif
mm/Trackbed
Type Union Pacific SD40-2 (mid)
Description
ModelEMD SD40-2
Dates Built1978 - '79
Road Numbers3489 - 3658
Left Image3648
Right Image3564
Notes

Here we see the next UP paint scheme. Lettering on the long hood is now 20"(508mm) high, and the UP "Shield" has replaced the slogan on the cab side

These units had the standard "late" type short hood, which was 88"(2.24m) long.

 

UP SD40 L.gifUP SD40 R.gif
mm/Trackbed
Type Union Pacific SD40-2 (late)
Description
ModelEMD SD40-2
Dates Built1980
Road Numbers3769 - 3804
Left Image3800
Right Image3770
Notes

In 1980, new regulations required that all new locomotives produce less noise. EMD addressed the issue by replacing the older radiator fans with a new design called the "Q fan". They also fitted a silencer to the exhaust stack of all turbo charged engines, to further reduce noise.

This series also sports another UP paint scheme. The large numbers were moved from the long hood to the cab sides. This was done because UP used a video system to read locomotive numbers, and the handrails obscured the view of the hood side. They also show the change from Aluminum paint on the trucks to Harbor Mist Gray. This was done because the Aluminum paint required a great deal more maintenance than the gray did.

 

UP SD40 L.gifUP SD40 R.gif
mm/Trackbed
Type Union Pacific SD40-2S
Description
ModelEMD SD40-2 special
Dates Built1980
Road Numbers3805 - 3808
Left Image3805
Right Image3808
Notes

These four were UP's last "native" SD40-2s, not counting units "assimilated"1 from other railroads.

Another illustration of the creative use of the porch space, these units had longer radiator compartments, as well as different engine blocks and turbo chargers. These changes were made in order to test improved methods of cooling a diesel, and probably led to the 50 series locomotives of the mid '80s.

(1 - UP is known as "The Borg" to many railfans, because of the many railroads they've absorbed over the last 20 years, without loosing their original identity)

 

UP SD40 L.gifUP SD40 R.gif
mm/Trackbed
Type Union Pacific SD40-2H ("Fast Forty")
Description
ModelEMD SD40-2
Dates Built1974 - '76
Road Numbers8003 - 8064
Left Image8050
Right Image8033
Notes

With the vast distances that need to be covered, the western railroads are always in search of more speed. Santa Fe assigned surplus passenger locomotives to freight service and the "Super C" was born.

UP took a different approach. The gigantic DD40AXs were built geared for 80mph (128 km/h), and soon UP re-geared several SD40-2s to the same specifications, and re-numbered them in to the 8000 series.

The railroad purchased new several more with the same high speed modifications, but corresponding slots were left open in the 3000 series. That proved a good idea, when a downturn in business forced UP to rethink it's fast freight policy. It seemed that the high speed units weren't flexible enough to justify maintaining the fleet. Starting in 1980, UP rebuilt the 100 Fast Fourties to standard specifications, and renumbered them into the 3000 class.

 

UP DD40 l.gifUP DD40 R
mm/Trackbed
Back To Main
Type Union Pacific DD40AX
Description
ClassCentennial
Dates Built1969
Road Numbers6900 - 6946
Left Image6922
Right Image6900
Notes

Ever since the early part of the 20th century, Union Pacific had shown an interest in high powered locomotives. During the diesel era, this included large dual-engined units. EMD had built several types of dual-engined, 8-axle locomotives, of the DD35 and DD35A types, as part of this trend.

1969 marked the 100th anniversary of the completion of the Union Pacific's original mainline, which at the time formed part of the transcontinental route between Omaha Nebraska and Sacramento California.

To commemorate this anniversary, the UP named its new locomotives the Centennial Class.