EMD SD50
From Wikipedia, the free encyclopedia
 |
|
| Power type | Diesel-electric |
|---|---|
| Builder | General Motors Electro-Motive Division (EMD) |
| Build date | 1980 – January 1986 |
| Total production | 427 |
| Gauge | 4 ft 8½ in (1,435 mm) |
| Prime mover | EMD 16-645-F3B |
| Power output | 3,500 hp (2,610 kW) |
| Disposition | most still in service as of 2005 |
The EMD SD50 was 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", but prototype SD50S locomotives were built from 1980; production ceased in January 1986. The SD50 was in many respects a transitional model between EMD's Dash 2 series which was produced throughout the 1970s and the microprocessor-equipped SD60 and SD70 locomotives.
Contents |
[edit] History
The SD50 was produced in response to increasingly tough competition from GE Transportation Systems, 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 (2,680 kW) with more modern technology, as well as very competitive finance and maintenance deals.
GM-EMD had previously produced 3,600 hp locomotives, the SD45 and later SD45-2, but these used huge, 20-cylinder engines with high fuel consumption, and demand for them dropped sharply after the 1970s fuel crises. The SD50 used the same V16 645 as the SD40-2, but uprated to 3,500 hp from 3,000 hp (2,240 kW). This proved to be a step too far; the 50 series models were plagued by engine problems which harmed both sales and the reputation of EMD.
The subsequent SD60 model replaced the overstressed 645 engine with a new engine series, the 710.
The SD50's long hood saw changes from previous EMD models. The overall frame length was increased, and the long hood was made substantially longer. The resistors for the dynamic brake grid were moved from their previous location above the prime mover to a new, cooler location in front of the engine compartment air intakes, where they were more effectively separated from the rest of the locomotives' systems.
[edit] Technical
The SD50 is powered by V16 16-645F3 series diesel engine driving either an EMD AR11A-D14 or an EMD AR16A-D18 main alternator. The power generated by the main alternator drove 6 EMD D87 traction motors rated at 1170 amps each.
Depending on customer options, the SD50 was available with a multitude of traction-motor gearing ratio and wheel size options, the most common of which being the 70:17 ratio with 40 inch wheels, this allowed for a top speed of 70 mph (110 km/h). Other gearing options for the SD50 with 40 inch wheels include 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). 42 inch wheels were also available.
The SD50 could be equipped with fuel tanks sizes from 3,200 US gallons (12,100 l) up to 4,400 US gallons (16,700 l), had a lube oil capacity of 396 US gallons (1,500 l) and a cooling water capacity of 276 US gallons (1,040 l).
[edit] SD50S
The SD50S ("short frame") were prototype units built in December 1980. They were shorter than production locomotives by approximately 2 feet. All of these prototypes were sold to the Norfolk & Western and passed to the Norfolk Southern; they were withdrawn in the early 2000s as non-standard.
The designation also applies to five locomotives built by EMD Australian licensee Clyde Engineering for Hamersley Iron. These were also shorter than production SD50s, and were equipped with a special double cab roof for insulation against the hot Australian desert sun. When withdrawn from Hamersley Iron service, they were sold to National Railway Equipment Company and exported to the U.S. in February 1999 and used in national lease service. They were subsequently sold to the Utah Railway in June 2001, where they remain.
[edit] SD50F
The SD50F was a Canadian cowl unit version equipped with a "Draper taper" (inset section aft of cab for limited rear visibility). 60 were built for the Canadian National Railway as road numbers 5400-5459.
[edit] Original Buyers
[edit] Current owners
As of 2005, current owners and operators include:
- CSX: inherited SD50s from the Baltimore & Ohio, Chesapeake & Ohio, Conrail (split with Norfolk Southern), and Seaboard System.
- Kansas City Southern Railroad: retains the SD50s it originally bought, also it received first SD50 built.
- National Railway Equipment Company (NREX): lease operator owning ex CSX ex Conrail locomotives.
- Norfolk Southern Railway: Its own purchases, and some of Conrail's.
- Reading, Blue Mountain and Northern Railroad: 6 units purchased from the Union Pacific Railroad.
- Union Pacific Railroad: inherited SD50s from the Missouri Pacific (60, bought immediately pre-merger and delivered in UP colors), the Chicago & North Western (35 units) and the Denver & Rio Grande Western via the Southern Pacific (17 units).
[edit] References
- Lytle, Stan. EMD SD50 list. Retrieved on February 16, 2005.
- TrainWeb.com. The Unofficial EMD homepage. Retrieved on January 7, 2005. Contains fairly complete builders' records for EMD production.
- Union Pacific Railroad Locomotive Department (1994). Locomotive Diagram Book. Union Pacific Railroad Company.
- Electo-Motive Division of General Motors (1980). SD50 Operator's Manual 1st Edition November 1980. Electo-Motive Division of General Motors.
|
|||||||||||
|
|||||||||||
