A cowl unit is a body style of diesel locomotive. The terminology is a North American one, though similar locomotives exist elsewhere. A cowl unit is one with full-width enclosing bodywork, similar to the

cab unit In North American railroad terminology, a cab unit is a railroad " locomotive" with its own cab and controls. "Carbody unit" is a related term, which may be either a cabless booster unit controlled from a linked cab unit, or a cab unit that con ...

style of earlier locomotives, but unlike the cab unit style, the bodywork is merely a casing and is not load-bearing. All the strength is in the locomotive's frame, beneath the floor, rather than the bridge-truss load-bearing carbody of the earlier type. Cowl units were originally produced at the request of the Santa Fe, had a full-width 'cowl' body built on a

hood unit A hood unit, in North American railroad terminology, is a body style for diesel and electric locomotives where the body is less than full-width for most of its length and walkways are on the outside. In contrast, a cab unit has a full-width c ...

frame which provided all the structural strength; the bodywork was cosmetic, rather than a load-bearing bridge truss frame as in cab units. Most cowl units have been passenger-hauling locomotives. In this service, the cowl unit's full width bodywork and sleek sides match the passenger cars, do not allow unwanted riders, and allow the decorative, advertising paintwork desired by passenger operators. An additional benefit is that the locomotive can be more easily cleaned by going through the passenger-car washers. The cowl unit allows the basic structure of the locomotive to be identical to a freight-oriented

type. The main disadvantage of the cowl unit is low rear visibility from the cab of the locomotive. The

EMD SD50F The EMD SD50 is a diesel-electric locomotive built by Electro-Motive Diesel, General Motors Electro-Motive Division. It was introduced in May 1981 as part of EMD's "50 Series"; production ceased in January 1986. The SD50 was a transitional mod ...

and SD60F, GE C40-8M and BBD HR-616 were given a ''Draper Taper'' (named after its creator, William L. Draper, a former

Canadian National The Canadian National Railway Company (french: Compagnie des chemins de fer nationaux du Canada) is a Canadian Class I freight railway headquartered in Montreal, Quebec, which serves Canada and the Midwestern and Southern United States. CN ...

assistant chief of motive power) where the body is narrower immediately behind the cab, and gradually widens further after, although the roof remains full-width the length of the locomotive. This improves rear visibility somewhat, but the locomotives still cannot lead a train in reverse as a hood unit can because they do not have vision in the rear or ditch lights in the rear.

Passenger-oriented cowl units

AMTK 315 Tun17 CZ Nwcstle Mar1995RP - Flickr - drewj1946

EMD FP45 The EMD FP45 is a cowl unit type of C-C diesel locomotive produced in the United States by General Motors Electro-Motive Division (EMD). It was produced beginning in 1967 at the request of the Atchison, Topeka and Santa Fe Railway, which did not ...

EMD SDP40F The EMD SDP40F was a six-axle C-C diesel–electric locomotive built by General Motors Electro-Motive Division (EMD) from 1973–1974. Based on Santa Fe’s EMD FP45, EMD built 150 for Amtrak, the operator of most intercity passenger tra ...

EMD F40C The EMD F40C is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division in 1974 for commuter service in Chicago. EMD only built 15 locomotives; the decline of the 6-axle design for passenger service led to the adopt ...

EMD F40PH The EMD F40PH is a four-axle B-B diesel-electric locomotive built by General Motors Electro-Motive Division in several variants from 1975 to 1992. Intended for use on Amtrak's short-haul passenger routes, it became the backbone of Amtrak's ...

* EMD F40PHR * EMD F40PH-2 * EMD F40PH-2CAT (rebuild) * EMD F40PH-2M * EMD GP40FH-2 (MK/MPI rebuild) *

EMD F59PH The EMD F59PH is a four-axle B-B diesel-electric locomotive built by General Motors Electro-Motive Division from 1988 to 1994. A variant, the F59PHI, was produced from 1994 to 2001. The F59PH was originally built for GO Transit commuter oper ...

* EMD F59PHI * EMD F69PHAC * EMD DE30AC *

EMD DM30AC The EMD DE30AC and DM30AC are a class of 46 locomotives built between 1997–1999 by Electro-Motive Division in the Super Steel Plant in Schenectady, New York, for the Long Island Rail Road of the Metropolitan Transportation Authority (MTA) in ...

* EMD F125 *

GE U30CG The GE U30CG was a passenger-hauling diesel-electric locomotive built by GE Transportation Systems. It was a passenger variant of GE's U30C design purchased by the Atchison, Topeka and Santa Fe Railway. ATSF had purchased ten U28CG locomotive ...

GE P30CH The GE P30CH (nicknamed "Pooch" because of the similarity of the designation) was one of the first brand-new diesel-electric locomotives built for Amtrak by General Electric during Amtrak's early years. The design was based on the GE U30C, but ha ...

GE P40DC General Electric Genesis (officially trademarked GENESIS) is a series of passenger diesel locomotives produced by GE Transportation, then a subsidiary of General Electric. Between 1992 and 2001, a total of 321 units were built for Amtrak, Metro- ...

* GE P32AC-DM * GE P42DC * MPI F40PHL-2 * MPI F40PH-2C * MPI F40PH-3C * MPI MP36PH-3C * MPI MP36PH-3S * MPI MP40PH-3C * MPI MP54AC *

Siemens Charger The Siemens Charger is a family of diesel-electric passenger locomotives designed and manufactured by Siemens Mobility for the North American market. There are five variants of the Charger, tailored for different operators and types of service ...

* Bombardier ALP45DP * EMD/Alstom PL42AC

Freight-oriented cowl units

Austin MT 8 23 05xRPRP - Flickr - drewj1946

EMD F45 The EMD F45 is a C-C cowled diesel-electric locomotive built by General Motors Electro-Motive Division between 1968 and 1971. Power was provided by an EMD 645E3 20-cylinder engine which generated . Design After sponsoring the development of t ...

* EMD GP40FH-2 *

(SDF40-2) *

GMD SD40-2F The GMD SD40-2F is a C-C diesel locomotive built by General Motors Diesel. It was fundamentally an SD40-2 in a cowl unit full-width body. A total of 25 units were built solely for the Canadian Pacific Railway. They were delivered in 1988 and ...

* GMD SD50F * GMD SD60F * GE C40-8M * BBD HR-616

Export/license-built cowl units

* EMD AT42C * EMD FT36HCW-2 * GE UM12C (Philippine service)

LMS 10000 & 10001

The LMS Diesels 10000 & 10001, later classified as

British Rail Class D16/1 LMS No. 10000 and 10001 were the first mainline diesel locomotives built in Great Britain. They were built in association with English Electric by the London, Midland and Scottish Railway at its Derby Works, using an English Electric 1,600&nb ...

, were introduced in 1947. These were Great Britain's first mainline diesel locomotives, coming about a decade after America's first cab units. Despite their streamlined exterior, they are actually cowl units rather than cab units. It is easy to misinterpret this as in North America, cowl designs are more angular, while cab designs have a similar curved streamlining.

References

* Pinkepank, Jerry A., and Marre, Louis A. (1979). ''Diesel Spotter’s Guide Update'', pp. 70–79.

Kalmbach Publishing Kalmbach Media (formerly Kalmbach Publishing Co.) is an American publisher of books and magazines, many of them railroad-related, located in Waukesha, Wisconsin. History The company's first publication was ''The Model Railroader'', which be ...

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