An EMD GP50 is a 4-axle diesel–electric

locomotive A locomotive is a rail transport, rail vehicle that provides the motive power for a train. Traditionally, locomotives pulled trains from the front. However, Push–pull train, push–pull operation has become common, and in the pursuit for ...

built by General Motors Electro-Motive Division (EMD). It is powered by a 16- cylinder EMD 645F3B diesel engine, which can produce between 3,500 and 3,600 hp (2,610 and 2,685 kW). 278 examples of this locomotive were built by EMD between 1980 and 1985. BN 3110-3162 were all delivered with five cab seats, the final five of these having the cab lengthened 23 in (584 mm) vs. the standard EMD cab. The GP50 retains the same overall length of 59 feet 2 inches (18.03 meters) as the GP38, GP39, and GP40 series locomotives.

History

EMD delivered the first GP50s to Chicago Northwestern in the summer of 1980. Much of the GP50's new technology was tested and developed with the experimental GP40X. Changes to the 645F3B engine compared to older versions, include a stronger crankcase, new turbocharger, new plate crab for clamping the power assemblies to the crankshaft, a camshaft of increased hardness, one-half-inch-diameter plunger injectors, laser-hardened cylinder liners, rocking piston pins, and a slower idle speed. A new traction motor, the D87, has a continuous rating of 1170 amps, compared to 1150 amps for its predecessor, the D77, with new interpole and main field coils that use 16% more copper, the number of turns increased from 14 to 17 to improve commutation at high currents, longer brush life, and sturdier gearing with increased surface hardness. The new motors are connected in permanent parallel to a new AR15

alternator An alternator (or synchronous generator) is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field wit ...

rated at 4,680 amps. The GP50 was the first production locomotive to feature EMD's Super Series wheelslip control system, first seen on the GP40X. Super Series employs a

Doppler radar A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the fre ...

unit mounted under the front coupler pocket to measure the locomotive's speed and adjusts the power to each axle to provide maximum adhesion while eliminating wheelslip. This system provided an increase in adhesion of at least 33% compared to conventional locomotives. Other changes compared to the GP40-2 include an underframe with a lighter, deeper sill that reduced the frame's weight and a new exhaust system and "Q-type" cooling fans to meet January 1980 Federal noise regulations. The GP50 was the first production locomotive series to be fitted with a

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

, and EMD fitted the 60 series with microprocessors as standard following the success of LARS which was developed in partnership with Burlington Northern and

Rockwell Collins Rockwell Collins, Inc. was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radi ...

Original Owners

Rebuilds

Norfolk Southern

In 2015–2016 the

Norfolk Southern Railway The Norfolk Southern Railway is a Class I freight railroad operating in the Eastern United States. Headquartered in Atlanta, the company was formed in 1982 with the merger of the Norfolk and Western Railway and Southern Railway. The comp ...

rebuilt 28 of their GP50s into the low-emission GP33ECO. And in early 2016, Norfolk Southern rebuilt one GP50 into their first GP59ECO. These units, most of which utilized GP59 cores, have similar specifications as the earlier GP33ECO program but have been built without public funding contributing to their construction.

BNSF

In 2004,

BNSF BNSF Railway is the largest freight railroad in the United States. One of six North American Class I railroads, BNSF has 36,000 employees, of track in 28 states, and over 8,000 locomotives. It has three transcontinental routes that provide ...

started rebuilding and derating GP50s and reclassifying them as GP25s. These locomotives are regoverned to using new load control systems (LCS). The original D87 traction motors may have also been replaced by D78 traction motors, since the original traction motors would not have supported this rebuild. Many of these GP25s have been put to use as remote control locomotives.

References

External links

* Sarberenyi, Robert.
EMD GP39X, GP49, and GP50 Original Owners
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