In rail transport, a cow-calf (also cow and calf) refers to a set of switcher-type diesel locomotives. The set usually is a pair; some 3-unit sets (with two calves, also known as herds) were built, but this was rare. A cow is equipped with a cab; a calf is not. The two are coupled together (either with regular couplers or a semi-permanent drawbar) and equipped with multiple unit train control so that both locomotives can be operated from the single cab.[1]
EMD TR1 diesel locomotive with two units — cow and calf
Cows are analogous to A units (locomotives with a cab) and calves to B unit (powered locomotives without a cab) road locomotives. The cow and calf are both equipped with prime movers for propulsion. Like the early EMD FT locomotives, the cow-calf sets were typically built as mated pairs, with the cow (or cabbed unit) and calf (or cabless unit) sharing a number. However this was not always the case, as over time many of the sets were broken up and couplers added to aid with versatility. Cow-calf locomotives can be distinguished from the sometimes very similar looking slug and slug mother sets by the fact that both cows and calves are independently powered, while slugs are engineless, and dependent on power from their "mother" units.
This locomotive and slug of the Iowa Interstate Railroad resemble a cow-calf set, but the slug has no engines of its own; this allows it to be cut down for better visibility.
These EMD FP9 locomotives also resemble a cow and calf, but the B unit is designed for mainline speeds, and to be detachable and operate with any other locomotive.
Cow-calf sets are similar to slugs (cut-down locomotives which do not have their own engines, but may have control cabs) and especially B units (powered booster locomotives which do not have cabs).[2] They differ from both in that a B unit is designed to operate with any other locomotives, while cow-calf sets are meant to be semi-permanently coupled to each other with a drawbar and operated together, though some cow-calf sets used standard couplers instead.[2]
A slug is semi-permanently paired with a cabbed unit, but does not have its own engine. At low speeds, many diesel-electric locomotives generate more electrical current than can be used by their motors. Slugs use this excess current to power their traction motors. In contrast, all units in a cow-calf set have their own engines.[2]
History
Design and nomenclature
In a cow-calf set, the cow referred to the locomotive equipped with a cab, while calves lacked a cab.[3] Cow-calf sets with two calves are known as "herds"; the only example of these were two TR3 series sets ordered by the Chesapeake and Ohio Railway.[1][4] The cow, calf, and herd designations were nicknames.[4]
Cow-calf locomotives were designed for both transferring railroad cars between nearby classification yards in urban areas, and for switching within yards. They were built with an emphasis on tractive effort, with top speed of lesser importance.[1]
Most cow-calf sets were built between the 1930s and the 1950s. They were built by several different makers, although General Motors' Electro-Motive Division built far more than the others, chiefly its TR (transfer) series.[1] In addition to the transfer duties they were designed for, cow-calf sets were also used in hump yards to send cuts of cars over the hump for classification.[5]
EMD's TR (transfer) series were the largest group of cow-calf locomotives built. Produced in seven models, eighty were built between 1940 and 1953, along with two additional calves.[1][4]
Baldwin Locomotive Works produced nine cow-calf versions of the Baldwin S-8. Both ALCO and Baldwin's cow-calf sets all went to customer Oliver Mining.[7]
Three pairs of cow-calf locomotives were built in the United Kingdom in the 1960s by combining two British Rail Class 08 locomotives together, these were designated the British Rail Class 13.[8]
^ abcdeSchafer, Mike (1998). Vintage diesel locomotives. Osceola, WI: Motorbooks International. p. 23. ISBN0-7603-0507-2. OCLC 38738930.
^ abcLustig, David (April 1, 2011). "Difference between a cabless booster, a slug, and a calf". Trains. Retrieved November 12, 2022.
^ abcFoster, Gerald L. (1996). A Field Guide to Trains of North America. Houghton Mifflin Harcourt. p. 10. ISBN978-0-395-70112-6.
^ abcMarre, Louis A. (1995). Diesel locomotives : the first 50 years : a guide to diesels built before 1972. Waukesha, WI: Kalmbach Pub. Co. pp. 33–36. ISBN0-89024-258-5. OCLC 34531120.
^ abSolomon, Brian; Blaszak, Michael; Gruber, John; Guss, Chris (2014-10-14). Chicago: America's Railroad Capital: The Illustrated History, 1836 to Today. Voyageur Press. p. 37. ISBN978-0-7603-4603-7.
^Kelso Depot Historic Structure Report: Mojave National Preserve, California : an Oasis for Railroaders in the Mojave. U.S. Department of the Interior, National Park Service. 1998. p. 111.
^ abWilson, Jeff (2009). The Model Railroader's Guide to Diesel Locomotives. Kalmbach Publishing, Co. pp. 22–23, 26–27. ISBN978-0-89024-761-7.
^Strickland, D. C. (1983). D & EG locomotive directory : every single one there has ever been. Camberley: Diesel & Electric Group. pp. 53–55. ISBN0-906375-10-X. OCLC 16601890.
February 28, 2023
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For the production of beef cattle see cow calf operation For the rocks in Yorkshire England see Ilkley Moor In rail transport a cow calf also cow and calf refers to a set of switcher type diesel locomotives The set usually is a pair some 3 unit sets with two calves also known as herds were built but this was rare A cow is equipped with a cab a calf is not The two are coupled together either with regular couplers or a semi permanent drawbar and equipped with multiple unit train control so that both locomotives can be operated from the single cab 1 EMD TR1 diesel locomotive with two units cow and calf Cows are analogous to A units locomotives with a cab and calves to B unit powered locomotives without a cab road locomotives The cow and calf are both equipped with prime movers for propulsion Like the early EMD FT locomotives the cow calf sets were typically built as mated pairs with the cow or cabbed unit and calf or cabless unit sharing a number However this was not always the case as over time many of the sets were broken up and couplers added to aid with versatility Cow calf locomotives can be distinguished from the sometimes very similar looking slug and slug mother sets by the fact that both cows and calves are independently powered while slugs are engineless and dependent on power from their mother units Most cow calf sets were built by Electro Motive Division EMD although other examples were built by the American Locomotive Company Baldwin Locomotive Works and British Rail the latter by combining existing locomotives together Cow calf sets were made obsolete by the development of road switcher locomotives which could handle both mainline trains and switching duties Contents 1 Distinctions between cow calf B units and slugs 2 History 2 1 Design and nomenclature 2 2 Production and operations 3 List of cow calf models 3 1 TR series 3 2 Other cow calf models 4 See also 5 ReferencesDistinctions between cow calf B units and slugs Edit This locomotive and slug of the Iowa Interstate Railroad resemble a cow calf set but the slug has no engines of its own this allows it to be cut down for better visibility These EMD FP9 locomotives also resemble a cow and calf but the B unit is designed for mainline speeds and to be detachable and operate with any other locomotive Cow calf sets are similar to slugs cut down locomotives which do not have their own engines but may have control cabs and especially B units powered booster locomotives which do not have cabs 2 They differ from both in that a B unit is designed to operate with any other locomotives while cow calf sets are meant to be semi permanently coupled to each other with a drawbar and operated together though some cow calf sets used standard couplers instead 2 A slug is semi permanently paired with a cabbed unit but does not have its own engine At low speeds many diesel electric locomotives generate more electrical current than can be used by their motors Slugs use this excess current to power their traction motors In contrast all units in a cow calf set have their own engines 2 History EditDesign and nomenclature Edit In a cow calf set the cow referred to the locomotive equipped with a cab while calves lacked a cab 3 Cow calf sets with two calves are known as herds the only example of these were two TR3 series sets ordered by the Chesapeake and Ohio Railway 1 4 The cow calf and herd designations were nicknames 4 Cow calf locomotives were designed for both transferring railroad cars between nearby classification yards in urban areas and for switching within yards They were built with an emphasis on tractive effort with top speed of lesser importance 1 Production and operations Edit A Belt Railway of Chicago cow calf set in 1985 Most cow calf sets were built between the 1930s and the 1950s They were built by several different makers although General Motors Electro Motive Division built far more than the others chiefly its TR transfer series 1 In addition to the transfer duties they were designed for cow calf sets were also used in hump yards to send cuts of cars over the hump for classification 5 The Union Pacific Railroad made use of cow calf sets as helpers on a steep grade near Kelso California until 1959 when the use of multiple unit train control made them obsolete 6 Most American examples were replaced by road switcher locomotives 3 The Belt Railway of Chicago was the final holdout continuing to operate TR2 and TR4 sets into the 1980s and 1990s 5 3 List of cow calf models Edit EMD TR4 British Rail Class 13 TR series Edit EMD s TR transfer series were the largest group of cow calf locomotives built Produced in seven models eighty were built between 1940 and 1953 along with two additional calves 1 4 EMD TR EMD TR1 EMD TR2 EMD TR3 EMD TR4 EMD TR5 EMD TR6Other cow calf models Edit The American Locomotive Company ALCO built two cow calf sets derived from the ALCO S 6 and designated SSB 9 7 Baldwin Locomotive Works produced nine cow calf versions of the Baldwin S 8 Both ALCO and Baldwin s cow calf sets all went to customer Oliver Mining 7 Three pairs of cow calf locomotives were built in the United Kingdom in the 1960s by combining two British Rail Class 08 locomotives together these were designated the British Rail Class 13 8 See also EditSlug railroad Twin unitReferences Edit a b c d e Schafer Mike 1998 Vintage diesel locomotives Osceola WI Motorbooks International p 23 ISBN 0 7603 0507 2 OCLC 38738930 a b c Lustig David April 1 2011 Difference between a cabless booster a slug and a calf Trains Retrieved November 12 2022 a b c Foster Gerald L 1996 A Field Guide to Trains of North America Houghton Mifflin Harcourt p 10 ISBN 978 0 395 70112 6 a b c Marre Louis A 1995 Diesel locomotives the first 50 years a guide to diesels built before 1972 Waukesha WI Kalmbach Pub Co pp 33 36 ISBN 0 89024 258 5 OCLC 34531120 a b Solomon Brian Blaszak Michael Gruber John Guss Chris 2014 10 14 Chicago America s Railroad Capital The Illustrated History 1836 to Today Voyageur Press p 37 ISBN 978 0 7603 4603 7 Kelso Depot Historic Structure Report Mojave National Preserve California an Oasis for Railroaders in the Mojave U S Department of the Interior National Park Service 1998 p 111 a b Wilson Jeff 2009 The Model Railroader s Guide to Diesel Locomotives Kalmbach Publishing Co pp 22 23 26 27 ISBN 978 0 89024 761 7 Strickland D C 1983 D amp EG locomotive directory every single one there has ever been Camberley Diesel amp Electric Group pp 53 55 ISBN 0 906375 10 X OCLC 16601890 Retrieved from https en wikipedia org w index php title Cow calf amp oldid 1139782363, wikipedia, wiki, book, books, library,
