The SD50 was produced in response to increasingly tough competition from GE Transportation, whose Dash 7 line was proving quite successful with railroads. While EMD's SD40-2 was a reliable and trusted product, GE's line included locomotives up to 3,600 hp (2,685 kW) with more modern technology, as well as very competitive finance and maintenance deals. EMD responded throughout the SD50 program by offering discounts on large orders.
The GM-EMD locomotives that immediately preceded the SD50, the 3,600 hp (2,685 kW) SD45 and SD45-2, used huge, 20-cylinder engines that consumed large amounts of fuel and suffered from reliability problems when first introduced. Demand for the 45 series dropped sharply after the 1970s fuel crisis. The SD50 used an updated version of the V16645 from the SD40-2, uprated to 3,500 hp (2,600 kW) at 950 rpm from 3,000 hp (2,240 kW) at 900 rpm, and uprated again in November 1984 to 3,600 hp (2,685 kW). This proved to be a step too far; the 50 series models were plagued by engine and electrical system problems which harmed EMD's sales and reputation.
Compared with their predecessors, the SD50 had a longer frame and a substantially longer long hood. In addition, the resistors for the dynamic brake grid were moved from their location on previous models above the prime mover to a new, cooler location in front of the engine compartment air intakes, closer to the electrical switchgear. This increased their separation from other systems, simplifying maintenance for the prime mover and the electrical system.
One former SD50 engineer praised the locomotives' wheel-slip control system and dynamic braking power, stating "they were able to give more adhesion than a SD40-2".[2]
Technical
The SD50 is powered by V16 16-645F3 series diesel engine driving either an EMD AR11A-D14 or an EMD AR16A-D18 traction alternator. The power generated by the traction alternator drove 6 EMD D87 traction motors rated at 1170 amps each.
The SD50 was available with multiple traction motor gearing ratios and wheel sizes, the most common of which was the 70:17 ratio with 40-inch (1,016 mm) wheels, which allowed for a top speed of 70 mph (110 km/h). Other gearing options for the SD50 with 40-inch (1,016 mm) wheels included 69:18 for 76 mph (122 km/h), 67:19 for 82 mph (132 km/h) and 66:20 for 88 mph (142 km/h). The SD50 was also available with 42-inch (1,067 mm) wheels.
The SD50 was also available with either HT-C trucks (identified with a hydraulic shock on the side of the middle axle of each truck) or the earlier Flexicoil trucks. Some investigators implicated the HT-C truck in derailments of Amtrak's SDP40Fs, so Conrail chose the Flexicoil C trucks for their SD40-2s and their first order of SD50s—the only customer to do so. The controversy surrounding the HT-C truck was eventually disproved, and Conrail chose HT-C trucks for their second order of SD50s and SD60s.
SD50S
The SD50S ("short frame") were prototype units built in December 1980. They were shorter than production locomotives by approximately 2 feet (0.61 m). There were six SD50Ss built, all of which were sold to the Norfolk & Western and eventually passed to Norfolk Southern. They were withdrawn in the early 2000s as non-standard. Two were rebuilt in 2008 as "SD40E" models by Norfolk Southern's Juniata Shops, along with several standard length SD50s.
The SD50F was a Canadian cowl unit version equipped with a "Draper taper" (inset section aft of cab for limited rear visibility). Sixty were built for the Canadian National Railway as road numbers 5400–5459. Early engine problems resulted in a temporary down-rating to 3,300 horsepower (2,500 kW). Eventually the units were re-rated to 3,500 horsepower (2,600 kW); however, like their U.S. cousins, they continued to suffer from relatively low reliability, frequently suffering engine, power assembly, and crankshaft failures.
A number of SD50s have been rebuilt into the equivalent of SD40-2s. The Dash 2 features are already contained within the SD50. The units are derated from 3,500 hp (2,600 kW) at 950 rpm to 3,000 hp (2,200 kW) at 900 rpm. This is actually a quite simple change to the locomotive's Woodward PGE engine governor.
Preservation
In late October 2022, the Illinois Railway Museum acquired former Chicago & North Western #7009, believed by the museum to be the first preserved SD50.[2]
^Oberg, Leon (2010). Locomotives of Australia 1850s-2010s. Kenthurst: Rosenberg Publishing. pp. 390–391. ISBN9781921719011.
^Motive Power Roundup Motive Power issue 119 September 2018 page 104
External links
Media related to EMD SD50 locomotives at Wikimedia Commons
Lytle, Stan. . Retrieved 16 February 2005.
TrainWeb.com. The Unofficial EMD homepage. Retrieved 7 January 2005. Contains fairly complete builders' records for EMD production.
Union Pacific Railroad Locomotive Department (1994). Locomotive Diagram Book. Union Pacific.
Electo-Motive Division of General Motors (1980). SD50 Operator's Manual 1st Edition November 1980. Electro-Motive Diesel.
January 07, 2023
sd50, this, article, includes, list, general, references, lacks, sufficient, corresponding, inline, citations, please, help, improve, this, article, introducing, more, precise, citations, december, 2021, learn, when, remove, this, template, message, horsepower. This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations December 2021 Learn how and when to remove this template message The EMD SD50 is a 3 500 horsepower 2 610 kW diesel electric locomotive built by 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 model between EMD s Dash 2 series which was produced throughout the 1970s and the microprocessor equipped SD60 and SD70 locomotives A total of 431 were built 1 EMD SD50An SD50 operated by Kansas City Southern RailwayType and originPower typeDiesel electricBuilderElectro Motive DieselGeneral Motors DieselClyde EngineeringBuild dateDecember 1980 July 1987Total produced431SpecificationsGauge4 ft 8 1 2 in 1 435 mm standard gaugeLength71 ft 2 in 21 69 m over the coupler pulling facesPrime moverEMD 16 645F3BEngine typeV16 dieselAlternatormain AR11Cylinders16Performance figuresPower output3 500 hp 2 610 kW at 950 rpm increased to 3 600 hp 2 685 kW November 1984 CareerOperatorsSee Original buyersDispositionSome in service some retired one preserved Contents 1 History 2 Technical 3 SD50S 4 SD50F 5 Original owners 6 Rebuilds 7 Preservation 8 See also 9 References 10 External linksHistory EditThe SD50 was produced in response to increasingly tough competition from GE Transportation whose Dash 7 line was proving quite successful with railroads While EMD s SD40 2 was a reliable and trusted product GE s line included locomotives up to 3 600 hp 2 685 kW with more modern technology as well as very competitive finance and maintenance deals EMD responded throughout the SD50 program by offering discounts on large orders The GM EMD locomotives that immediately preceded the SD50 the 3 600 hp 2 685 kW SD45 and SD45 2 used huge 20 cylinder engines that consumed large amounts of fuel and suffered from reliability problems when first introduced Demand for the 45 series dropped sharply after the 1970s fuel crisis The SD50 used an updated version of the V16 645 from the SD40 2 uprated to 3 500 hp 2 600 kW at 950 rpm from 3 000 hp 2 240 kW at 900 rpm and uprated again in November 1984 to 3 600 hp 2 685 kW This proved to be a step too far the 50 series models were plagued by engine and electrical system problems which harmed EMD s sales and reputation Compared with their predecessors the SD50 had a longer frame and a substantially longer long hood In addition the resistors for the dynamic brake grid were moved from their location on previous models above the prime mover to a new cooler location in front of the engine compartment air intakes closer to the electrical switchgear This increased their separation from other systems simplifying maintenance for the prime mover and the electrical system One former SD50 engineer praised the locomotives wheel slip control system and dynamic braking power stating they were able to give more adhesion than a SD40 2 2 Technical EditThe SD50 is powered by V16 16 645F3 series diesel engine driving either an EMD AR11A D14 or an EMD AR16A D18 traction alternator The power generated by the traction alternator drove 6 EMD D87 traction motors rated at 1170 amps each The SD50 was available with multiple traction motor gearing ratios and wheel sizes the most common of which was the 70 17 ratio with 40 inch 1 016 mm wheels which allowed for a top speed of 70 mph 110 km h Other gearing options for the SD50 with 40 inch 1 016 mm wheels included 69 18 for 76 mph 122 km h 67 19 for 82 mph 132 km h and 66 20 for 88 mph 142 km h The SD50 was also available with 42 inch 1 067 mm wheels The SD50 was also available with either HT C trucks identified with a hydraulic shock on the side of the middle axle of each truck or the earlier Flexicoil trucks Some investigators implicated the HT C truck in derailments of Amtrak s SDP40Fs so Conrail chose the Flexicoil C trucks for their SD40 2s and their first order of SD50s the only customer to do so The controversy surrounding the HT C truck was eventually disproved and Conrail chose HT C trucks for their second order of SD50s and SD60s SD50S EditThe SD50S short frame were prototype units built in December 1980 They were shorter than production locomotives by approximately 2 feet 0 61 m There were six SD50Ss built all of which were sold to the Norfolk amp Western and eventually passed to Norfolk Southern They were withdrawn in the early 2000s as non standard Two were rebuilt in 2008 as SD40E models by Norfolk Southern s Juniata Shops along with several standard length SD50s NS SD50 5443 EX CR 6776 The SD50S designation was also used for five locomotives built by EMD Australian licensee Clyde Engineering Adelaide for Hamersley Iron 3 Shorter than production SD50s they were equipped with a special double cab roof for insulation against the hot Australian desert sun in the Pilbara region Withdrawn in November 1995 they were sold to National Railway Equipment Company and exported to the United States in February 1999 and used in national lease service 4 They were subsequently sold to the Utah Railway in June 2001 5 6 In June 2017 6063 and 6064 were sold to the Chicago Fort Wayne amp Eastern Railroad 6064 was relocated by Genesee amp Wyoming to the Indiana amp Ohio Railway and renumbered 5017 7 SD50F EditThe SD50F was a Canadian cowl unit version equipped with a Draper taper inset section aft of cab for limited rear visibility Sixty were built for the Canadian National Railway as road numbers 5400 5459 Early engine problems resulted in a temporary down rating to 3 300 horsepower 2 500 kW Eventually the units were re rated to 3 500 horsepower 2 600 kW however like their U S cousins they continued to suffer from relatively low reliability frequently suffering engine power assembly and crankshaft failures CN SD50F 5438Original owners EditThis section does not cite any sources Please help improve this section by adding citations to reliable sources Unsourced material may be challenged and removed December 2021 Learn how and when to remove this template message Railroad Qty Road numbers NotesSD50Baltimore amp Ohio Chessie System 20 8576 8595Chicago amp North Western 35 2 7000 7034 7009 donated to the Illinois Railway MuseumChesapeake amp Ohio Chessie System 43 8553 8575 8624 8643Conrail 135 6700 6834Denver amp Rio Grande Western 17 5501 5517Kansas City Southern Railway 10 704 713Missouri Pacific Railroad 60 5000 5059Seaboard System Railroad 81 8500 8552 8596 8623Norfolk Southern 20 6506 6525Hamersley Iron 5 6060 6064SD50SNorfolk amp Western Railway 6 6500 6505 SD50S short frameSD50FCanadian National 60 5400 5459 Cowl unitsRebuilds EditA number of SD50s have been rebuilt into the equivalent of SD40 2s The Dash 2 features are already contained within the SD50 The units are derated from 3 500 hp 2 600 kW at 950 rpm to 3 000 hp 2 200 kW at 900 rpm This is actually a quite simple change to the locomotive s Woodward PGE engine governor Preservation EditIn late October 2022 the Illinois Railway Museum acquired former Chicago amp North Western 7009 believed by the museum to be the first preserved SD50 2 See also EditList of GM EMD locomotives List of GMD LocomotivesReferences Edit Coming to Terms With EMD s SD50 Trains Magazine May 2005 pp 24 25 a b c Smedley Steve 2 November 2022 Illinois Railway Museum acquires SD50 Trains Magazine Retrieved 3 November 2022 Super Series Locomotives for Hamersley Iron Network February 1981 page 27 Hammersley Loco Update Railway Digest November 1998 pages 33 36 Here amp There Australian Railway Historical Society Bulletin issue 771 January 2002 page 32 Oberg Leon 2010 Locomotives of Australia 1850s 2010s Kenthurst Rosenberg Publishing pp 390 391 ISBN 9781921719011 Motive Power Roundup Motive Power issue 119 September 2018 page 104External links Edit Media related to EMD SD50 locomotives at Wikimedia Commons Lytle Stan EMD SD50 list Retrieved 16 February 2005 TrainWeb com The Unofficial EMD homepage Retrieved 7 January 2005 Contains fairly complete builders records for EMD production Union Pacific Railroad Locomotive Department 1994 Locomotive Diagram Book Union Pacific Electo Motive Division of General Motors 1980 SD50 Operator s Manual 1st Edition November 1980 Electro Motive Diesel Retrieved from https en wikipedia org w index php title EMD SD50 amp oldid 1123971036, wikipedia, wiki, book, books, library,
