Supriya Ghosh (Editor)

EMD SD40 2

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Power type  Diesel-electric
Total produced  3,982
Model  SD40-2
AAR wheel arr.  C-C
EMD SD40-2
Builder  GM Electro-Motive Division (EMD) General Motors Diesel (GMD)
Build date  January 1972 – October 1989

The EMD SD40-2 is a 3,000-horsepower (2,200 kW) C-C diesel-electric locomotive built by EMD from 1972 to 1989.


The SD40-2 was introduced in January 1972 as part of EMD's Dash 2 series, competing against the GE U30C and the ALCO Century 630. Although higher-horsepower locomotives were available, including EMD's own SD45-2, the reliability and versatility of the 3,000-horsepower (2,200 kW) SD40-2 made it the best-selling model in EMD's history and the standard of the industry for several decades after its introduction. The SD40-2 was an improvement over the SD40, with modular electronic control systems similar to those of the experimental DDA40X.

Peak production of the SD40-2 was in the mid-1970s. Sales of the SD40-2 began to diminish after 1981 due to the oil crisis, increased competition from GE's Dash-7 series and the introduction of the EMD SD50, which was available concurrently to late SD40-2 production. The last SD40-2 delivered to a United States railroad was built in July 1984, with production continuing for railroads in Canada until 1988, Mexico until February 1986, and Brazil until October 1989. As of 2013, nearly all built still remain in service.

The SD40-2 has seen service in Canada, Mexico, Brazil and Guinea. To suit export country specifications, General Motors designed the JT26CW-SS (British Rail Class 59) for Great Britain, the GT26CW-2 for Yugoslavia, South Korea, Iran, Morocco, Peru and Pakistan, while the GT26CU-2 went to Zimbabwe and Brazil. Various customizations led Algeria to receive their version of a SD40-2, known as GT26HCW-2.

SD40-2s are still quite usable nearly fifty years after the first SD40 was made, and many SD40s and locomotives from the pre-Dash-2 series (GP/SD 40s, 39s and 38s, and even some SD45s) have been updated to Dash-2 specifications, possibly including downgrading from 20-645E to 16-645E engines, including, certainly, Dash-2 electrical controls, although the pre-Dash-2 frames cannot accommodate the somewhat similar HT-C truck in the space allocated to the Flexicoil C truck (the frame is not long enough). Most SD40-2s which remain in service have by now been rebuilt "in-kind" for another 30 to 40 years of service, although a few (under 30) have been rebuilt to incorporate a 12-cylinder EFI-equipped 710G engine.

Appearance and spotting features

As the SD38, SD39, SD40, and SD45 shared a common frame, so too did the SD38-2, SD40-2, and SD45-2. It was 3 ft (0.91 m) longer than the previous models, giving a length of 68 ft 10 in (20.98 m) over the coupler pulling faces. The SD38-2 and SD40-2 shared the same basic superstructure, since they used the same 16-645 engine (in Roots-blown and turbocharged form respectively); the long hood was 18 inches (457 mm) longer than the SD38 and SD40, but since the increase in frame length was even greater, the SD38-2 and SD40-2 had even larger front and rear "porches" than the earlier models. These empty areas at front and rear are spotting features to identify the Dash 2 models of both units. The SD40-2 can be distinguished from the SD38-2 by its three roof-mounted radiator fans instead of two, and a single large exhaust stack instead of two smaller stacks.

The increase in the frame length between the preceding 40 Series and the 40-2 Series six-axle locomotives was made to accommodate the new HT-C truck design, in which the traction motors all face the same direction, making the trucks longer. After a series of derailments involving Amtrak SDP40F units that were equipped with "hollow bolster" HT-C trucks, applied only to the SDP40F, Conrail ordered the SD40-2 units and several orders of SD50s with the older Flexicoil trucks, but the HT-C truck was vindicated and it ultimately went under most 40 Series, 50 Series and 60 Series six-axle locomotives, and this truck is still found under many remanufactured locomotives.

As of 2008 some SD45 units have been modified by replacing their 20-cylinder engine with the 16-cylinder removed from scrapped SD40-2 units; this was common on Union Pacific and possibly other railroads. In many cases these are identified by the owner as SD40-3, SD40M-2 or some such. Confusingly, what appears to be an SD45 is labeled as an SD40-2. Older SD40-2 units used in low-power modes such as yard switching or hump service have been de-turbocharged, resulting in the mechanical equivalent of a SD38-2. Units so modified may or may not be re-labeled.

There are several variations of the SD40-2 such as the SD40T-2s (Informally: T for tunnel motor; the actual EMD designation is "SD40-2 With Cooling System Modification", as stated on this model's EMD manuals) bought by the former Southern Pacific, and Denver and Rio Grande Western railroads; now operated by Union Pacific. The SD45 tunnel motor equivalent, the SD45T-2 model, was also utilized by Southern Pacific. Many tunnel motors were rebuilt and sold second-hand to a handful of American shortlines including, Bessemer and Lake Erie, Illinois Railway and Missouri and Northern Arkansas, as well as Canadian shortline Goderich-Exeter Railway. There is the SD40-2W (W for the 4-Window Safety Cab) bought and operated by the Canadian National railway. High-nosed versions of the SD40-2 were bought by Norfolk & Western, & Southern Railway. These units are now operated by the Norfolk Southern Railway (Resulting merger of N&W and Southern Railway). A narrow gauge version produced for Ferrovia Central Atlantico in Brazil is the BB40-2.

There are distinguishable differences between the EMD models and the Canadian GMD-built models. Most notable are the headlight configurations. The biggest giveaway is the rear light. GMD SD40-2s have a single beam, where EMD has twin-beam styled lights, usually placed next to each other. GMD models also have lights mounted on the nose, and EMD is above the cab between the numberboards. Some EMD variations have a nose headlight, although the headlight style and placement usually isn't the same as seen on the GMDs. Other features on the GMD models include the bell mounted above the cab between the numbers, triple-style classification lights above the numbers(since trains don't use classlights anymore, many locomotives have had them removed), and no numberboards on the back.

Three cabless SD40-2Bs were also rebuilt from standard SD40-2s by the Burlington Northern Railroad in the early 1980s. The units had been in collisions and BN decided that it was more economical to rebuild them without cabs. Canadian Pacific also owns a few SD40-2Bs. These were created by welding metal plates over the cab windows of many of its ex-Norfolk Southern and some of its original SD40-2s.


A variant of the SD40-2 was created for several western railroads for extended periods in tunnels and snow sheds. Originally purchased by Southern Pacific and Rio Grande railroads, these were transferred to the Union Pacific Railroad in 1996. They have since found their way into the used locomotive market and many have been sold to regional railroads around the U.S.

British Rail Class 59

Another variant of the SD40-2 was created for Foster Yeoman, a British quarrying and aggregates company, which features a unique body design specifically for the European railway markets. Designated as Class 59 the initial production batch of four locomotives entered service in 1986.


The GMD SD40-2(W) is a Canadian-market version of the SD40-2 diesel-electric locomotive, built for the Canadian National Railway by the Diesel Division of General Motors of Canada Ltd. (formerly General Motors Diesel) of London, Ontario; 123 were constructed between May 1975 and December 1980. The major difference between the SD40-2(W) and a regular SD40-2 is the fitment of a wide-nose Canadian comfort cab, commonly denoted by adding a 'W' in the model name (although the GMD designation on the builders plates remained 'SD40-2').


The EMD SD40-2F is a locomotive operated by Canadian Pacific Railway. It's essentially an SD40-2 with a full cowl hood. CP was the only buyer, buying 25 units, numbered 9000-9024.


The EMD SD40-2S (also incorrectly known as the SD40-2SS or SD40SS) was an experimental test bed variant of the SD40-2. Nine of these locomotives were constructed, five in April and May 1978 for Burlington Northern as EMD order #776083 (BN 7049–7053), and four for Union Pacific in November 1980 as EMD order #80653. (UP 3805–3808).

These locomotives were fitted with improved engine blocks, larger turbochargers, and two-speed radiator fans which were expected to improve cooling and reliability. The four UP units, but not the five BN locomotives, were fitted with an extended long hood, about 28 inches (710 mm) longer, to take enlarged radiators. Instead of the standard seven access doors under the radiators, the units had eight.

It has been commonly believed these units were fitted with higher-capacity AR16 alternators, traction motors, possibly increased engine power, and Super Series wheel slip control; however, Don Strack's research in Union Pacific's archives has proven that the UP units at least were not so equipped.

After a year's testing, UP's locomotives were fitted with standard engines and turbochargers. It is probable that the BN locomotives were also similarly refitted. All BN units are still in service with successor BNSF Railway, while of the UP locomotives two remain in service with UP, renumbered to UP 3412 and 3277 from UP 3806 and 3807. Former UP 3805 is now in service with the Iowa, Chicago and Eastern Railroad as ICE 6406, and former UP 3808 now belongs to the Evansville Western Railway as EVWR 6003.


The Dash 3 suffix is not part of any official lineup, and is a loose designation for rebuilt Dash 2 series EMDs, not just the CSX rebuilds. One example of an SD40-3 rebuild program is the one conducted by CSX. It started in 2010 with 10 units upgraded and numbered 4000-4009; in 2011, 20 units went through the program and were numbered 4010-4029 and in 2012 another 20 units followed and were numbered 4030-4049. CSXT 4040-4049 are painted in the new CSX "RAILCAR LOGO" paint scheme. CSX plans to rebuild 300 locomotives. The plan has been to have the new units serve an additional 30 years and cost far less than brand new locomotives. The new cabs can withstand crashes better, have new heating and air-conditioning systems, a new control stand, including visual displays, a modern WABCO braking controller, and modernized starting systems. The engine retain the original 3,000 horsepower (2,240 kW) rating, with rated tractive power increased to 130,000 lb (58,970 kg) from the former 86,000 lb (39,010 kg) rating.


The SD40M-2 is another loose designation, being used to cover both upgrades of pre-Dash 2 units to Dash 2 or higher specs and the derating of the more powerful EMD SD45 from 3,600 horsepower to the SD40's power output of 3,000 hp, for various reasons.


A number of SD40-2s have been rebuilt into other models. Some of the most unusual are the metre gauge BB40-2s for use in Brazil.

Conversely, several other models of EMD locomotive have sometimes been rebuilt to SD40-2 standards, including the SD40, SD45 and SD45-2. Normally, this consists of electrical upgrades (-2) and replacing the 20-cylinder prime mover with a 16-cylinder version, ironically often built for GE Capital in Poland using EMD's manufacturing drawings and specifications. An outgrowth of this may be GE Transportation's second-sourcing of EMD repair parts.

The unusually troublesome SD50s have also been rebuilt into the equivalent of SD40-2s, rather than scrapping them. The 645F block and crankshaft are inherently good designs (indeed, the lessons learned with the 645F became part of the 710G); lowering the rating from 3,500 horsepower (2,600 kW) at 950 rpm to 3,000 horsepower (2,200 kW) at 900 rpm solved the mechanical and electrical reliability issues.


The SD22ECO is an EMD SD40-2 or similar, repowered with an EMD 8-710-ECO engine. The resulting locomotive is rated at 2,150 horsepower (1,600 kW), and meets EPA Tier II emissions regulations.


The SD30C-ECO is an EMD SD40-2 re-powered with an EMD 12-710 prime mover. The locomotive is rated at 3,000 horsepower (2,200 kW) and meets EPA Tier 0 emissions regulations.


In June, 2009, Union Pacific had donated 3028 (former Chicago & North Western 6847) to the Illinois Railway Museum in Union, Illinois. The unit still wears its original factory paint from when it was built for the CNW in March, 1974. CNW 6847 was patched by UP in February, 2003, to UP 3028, and retired in December, 2008. The locomotive has since had its UP patches removed, and CNW herald and numbers restored.

Union Pacific had traded SD40-2 #3105 and other equipment to the Rail Giants museum in Fairplex in Pomona, California for Union Pacific 4-8-8-4 #4014 "Big Boy", which UP is restoring to operational status. The #3105 locomotive was originally built in 1979 as Missouri Pacific #6027, and one of the few that the Missouri Pacific ordered with dynamic braking.

Union Pacific donated SD40-2 #9950 to Western America Railroad Museum in Barstow, California in the 2004. 9950 was built in 1980 for the Missouri Pacific as their #3320.

While not a true SD40-2, Union Pacific also donated Rio Grande SD40T-2 #5371 to Utah State Railroad Museum in Ogden, Utah in 2008. 5371 held the significance of being the last un-patched Rio Grande locomotive on the UP roster. An ex-Southern Pacific SD40T-2 is preserved in Boone, Iowa at the Boone and Scenic Valley railroad, donated by Union Pacific in 2010.


EMD SD40-2 Wikipedia

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