EMD SD40-2

Infobox Locomotive Auto
name=EMD SD40-2
powertype=Diesel-electric
serviceclass=cab
gauge=

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caption = Montana Rail Link XDM SD40-2 diesel locomotive #250 at Everett, Washington, USA, January 1994.
poweroutput= convert|3000|hp|abbr=on|lk=in|sigfig=3
aarwheels=C-C
builder=GM-EMD
buildmodel=SD40-2
builddate=January 1972 – February 1986
totalproduction=3,957
length= convert|68|ft|10|in|abbr=on over the coupler pulling faces
primemover=EMD 16-645-E3
cylindercount=V16
wheelbase= convert|43|ft|6|in|abbr=on between bolsters; convert|13|ft|7|in|abbr=on between axles in each truck
width= convert|10|ft|3+1/8|in|abbr=on over the grabirons
height= convert|15|ft|7+1/8|in|abbr=on
driversize=40 in (1.02 m) diameter
fuelc

aspiration=turbocharged
weight=368,000 lb (167,000 kg)
The EMD SD40-2 is a convert|3000|hp|lk=in|sigfig=3 model of C-C diesel-electric locomotive built by General Motors' Electro-Motive Division between January 1972 and February 1986; 3,957 examples were built, and most larger North American railroads have operated the type. Part of the EMD Dash 2 line, the SD40-2 was an upgraded SD40 with modular electronic control systems, HT-C trucks, and many other detail improvements. The SD40-2 is one of the best-selling diesel locomotive models of all time. BNSF, Union Pacific and Canadian Pacific operate some of the largest fleets of the type.

The SD40-2 was not the most powerful locomotive type even when introduced; EMD's SD45 and SD45-2 delivered convert|3600|hp|abbr=on|sigfig=3, as did GE Transportation Systems' U36B/C and ALCO's C636. However, the SD40-2 was significantly more reliable and economical than the higher-powered units, the latter becoming increasingly important with the oil crises of the 1970s.

The British Rail Class 59 was derived from the SD40-2.

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 it was decided that it was cheaper 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.

Appearance and spotting features

Just as the SD38, SD40, and SD45 shared a common frame, so too did the SD38-2, SD40-2, and SD45-2. It was convert|3|ft|abbr=on longer than the previous models, giving an overall locomotive length of convert|68|ft|10|in|abbr=on over the coupler pulling faces. The SD38-2 and SD40-2 shared the same basic superstructure, since they both used the same 16-645E3 engine (in naturally aspirated and turbocharged form respectively); the long hood was convert|18|in|cm longer than the SD38 and SD40, but since the increase in frame length was even greater, the SD38-2 and SD40-2 were left with even larger front and rear "porches" than the earlier models. These empty areas at front and rear are distinctive spotting features to identify the Dash 2 models of both units. The SD40-2 can be distinguished from the SD38-2 by having three roof-mounted radiator fans instead of two. Another distinguishing feature of the SD40-2 as compared to the SD40 is the SD40-2's trucks (HT-C truck), which have shock absorbers on the outside of middle axle. However, this is not true of the former Conrail SD40-2s. After a rash of derailments involving Amtrak SDP40F units that were equipped with HT-C trucks, Conrail ordered the SD40-2 units and several orders of SD50s with the older flexicoil trucks.

Additional specifications

Original Owners

Rebuilds

A number of SD40-2s have been rebuilt into other models. Some of the oddest are the narrow gauge BB40-2s.

Conversely, several other models of EMD locomotive have sometimes been rebuilt to SD40-2 standards, including the SD40, SD45 and SD45-2.