Electric Locomotives, the Epitome of Efficiency

The electric power used in railroad applications was initially provided via direct current, or DC. DC has fundamental drawbacks such as providing relatively low voltage, usually no higher than 3,000 volts, requires large amounts of equipment to properly retain power throughout the system because of the current’s considerable size, and needs power supplies (i.e., substations) located at regular intervals along the line to likewise maintain sufficient power as the high currents result in tremendous power losses across the system.

Instead, alternating current, or AC, has become the favored means of electrical power for many systems worldwide since the 1930s. AC has none of the inherent drawbacks of DC systems, requires relatively cheaper overhead wires (or catenary), and can employ thousands of volts of power (although AC’s significant drawback is lower traction in comparison to what DC allows).

To operate electric locomotives, energized systems require a number of components, of which result in much of the tremendous expensive involved to employ electrification. For overhead systems, these components include the trolley pole; a simple support system that holds the bow collector; the bow collector in turn holds the overhanging catenary which in turn holds the actual energized wires, catenary. To pick up the electricity electric locomotives are equipped with pantographs, booms that extend above, and over the locomotive with “shoes” to collect the electricity and then convert it into whatever horsepower the locomotive is rated for.

The other type of system is called third rail and is very effective in subways.

Aside from traditional electric locomotives, which pick up electricity using an overhead or third-rail application, other types include dual-powered locomotives and AC rectifiers. Dual-powered locomotives can operate using either electricity or a traditional diesel engine. This system is very efficient in territory that is both electrified and non-electrified as the same locomotive can be used in both territories without having to switch the motive power. AC rectifiers are a truly exceptional and an efficient type of motive power. Since by the 1930s AC was the preferred method of electrification most new electric locomotives were likewise built to AC specifications. However, AC, again did not provide quite such high tractive efforts as could be achieved with DC systems.

To counter this railroads, particularly those which found high tractive efforts very beneficial in mountainous territory like the Great Northern, Virginian Railway, Pennsylvania Railroad, and the Norfolk & Western Railway, needed a new locomotive that operated on AC power but could use DC traction motors to gain the best of both worlds. What resulted were the very successful AC rectifiers in versions such as Virginian’s EL-2B and EL-C; Pennsylvania’s E44s; and New Haven’s EP5s.

Today, while electric locomotives in our country are used solely for passenger service the technology has come a long way, even since the AC rectifiers of the 1950s and 1960s. Types like AEM-7s, ALP-44s, and HHLs provide over 4,000 horsepower, operate using three-phase traction systems, provide tractive efforts over 150,000 pounds, and are no longer built by American firms with most manufactured in Europe by firms such as ASEA, Alstom, and Siemens.

While electric locomotives may no longer be used in the U.S. to haul freight trains their reliability and efficiency in passenger service will likely keep them operating for decades to come, particularly as oil prices continue to rise. Extremely quiet and fast, electric locomotives are a very unique and interesting aspect of our nation’s rail system, even if they are somewhat rare in comparison to the U.S. railroad industry as a whole, and other systems around the world.

http://www.american-rails.com/electric-locomotives.html

Writing (200-250 words)

Locomotive production in Russia.

http://www.alstom.com/transport/about-us/alstom-TMH-alliance/

http://www.alstom.com/press-centre/2009/3/alstom-and-the-russian-rail-manufacturer-transmashholding-sign-a-strategic-partnership-agreement/

Date: 2016-01-03; view: 1101