South African Class 61-000
Encyclopedia
Between May and July 1959, in order to also gain experience with other forms of diesel motive power, the South African Railways placed seven Class 1-DH diesel-hydraulic locomotives in service. These were later reclassified to Class 61-000. The Class 1-DH was acquired a year after the South African Railways had acquired its first diesel-electric locomotives to be built in quantity, the Class 1-DE that had entered service in 1958 and that was later reclassified to Class 31-000
.
in Kassel
, Germany
, and imported.
Six of them were later sold to the Rhodesian Railways (RR), later renamed the National Railways of Zimbabwe
(NRZ), where they became the RR Class DH1 and were renumbered 3101 to 3106.
prime mover
to propel either a generator
(DC) or an alternator
(AC) to generate electric power, which is then used to propel axle hung electric traction motors, one per powered axle, to drive the locomotive wheels. It therefore works on the same principle as a regular electric locomotive
, the only difference being that it generates its own electric power
instead of collecting it from an external supply like overhead catenary
or a third rail
.
Diesel-hydraulic locomotives, on the other hand, use hydrokinetic transmission (also known as hydrodynamic transmission) in the form of torque converter
s to transmit power from prime mover to wheels.
The Class 61-000 was a centre cab locomotive that used two V6 GM type 6/567C
prime movers, each with a Voith
type L306r triple-converter torque converter and each driving the wheels of one bogie. Power was transferred to the axles through drive shafts. Unlike diesel-electric locomotives where each axle is driven by its own traction motor, individual wheel slip was not possible since each bogie’s two axles were interconnected through the drive shafts.
The cab had two control stands and, since it was possible to start the six prime movers in three consisted locomotives from one engine cab, each control stand had six engine start buttons and six engine stop buttons. The electrical system was very complicated and unreliable and the locomotives were completely rewired in 1963.
In 1971 the remaining six were sold to the RR, where they became the RR Class DH1. They were eventually resold to the Zimbabwe Iron and Steel Company
(ZISCO) steel works at KweKwe
in Zimbabwe
. Most if not all were scrapped by 2001.
South African Class 31-000
In June and July 1958 the South African Railways placed forty-five Class 31-000 GE U12B diesel-electric locomotives in service.- Manufacturer :...
.
Manufacturer
The South African Class 61-000 type DH 1420 diesel-hydraulic locomotive was designed and built for the South African Railways (SAR) by Henschel and SonHenschel & Son
Henschel & Son was a German company, situated in Kassel, best known during the 20th century as a maker of transportation equipment, including locomotives, trucks, buses and trolleybuses, and armoured fighting vehicles and weapons....
in Kassel
Kassel
Kassel is a town located on the Fulda River in northern Hesse, Germany. It is the administrative seat of the Kassel Regierungsbezirk and the Kreis of the same name and has approximately 195,000 inhabitants.- History :...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, and imported.
Reclassification and renumbering
Upon delivery the locomotives were classified as Class 1-DH and numbered from D745 to D751. When the SAR adopted a new classification and numbering system for electric and diesel powered locomotives circa 1960, they were reclassified as Class 61-000 and renumbered 61-001 to 61-007.Six of them were later sold to the Rhodesian Railways (RR), later renamed the National Railways of Zimbabwe
National Railways of Zimbabwe
The National Railways of Zimbabwe is the parastatal railway of Zimbabwe. The Zimbabwe railway system was largely constructed during the time of British colonial rule, and part of it represents a segment of the Cape-Cairo railway...
(NRZ), where they became the RR Class DH1 and were renumbered 3101 to 3106.
| SAR 1-DH no |
SAR 61-000 no |
Henschel works no |
RR & NRZ no |
|---|---|---|---|
| D745 | 61-001 | 29745 | 3101 |
| D746 | 61-002 | 29746 | 3102 |
| D747 | 61-003 | 29747 | 3103 |
| D748 | 61-004 | 29748 | 3104 |
| D749 | 61-005 | 29749 | 3105 |
| D750 | 61-006 | 29750 | Scrapped |
| D751 | 61-007 | 29751 | 3106 |
Diesel-hydraulic transmission
The more commonly used diesel-electric locomotive makes use of a diesel engineDiesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
prime mover
Prime mover (locomotive)
In engineering, a prime mover is an engine that converts fuel to useful work. In locomotives, the prime mover is thus the source of power for its propulsion. The term is generally used when discussing any locomotive powered by an internal combustion engine...
to propel either a generator
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
(DC) or an alternator
Alternator
An alternator is an electromechanical device that converts mechanical energy to electrical energy in the form of alternating current.Most alternators use a rotating magnetic field but linear alternators are occasionally used...
(AC) to generate electric power, which is then used to propel axle hung electric traction motors, one per powered axle, to drive the locomotive wheels. It therefore works on the same principle as a regular electric locomotive
Electric locomotive
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...
, the only difference being that it generates its own electric power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...
instead of collecting it from an external supply like overhead catenary
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
or a third rail
Third rail
A third rail is a method of providing electric power to a railway train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway track. It is used typically in a mass transit or rapid transit system, which has alignments in its own corridors, fully or almost...
.
Diesel-hydraulic locomotives, on the other hand, use hydrokinetic transmission (also known as hydrodynamic transmission) in the form of torque converter
Torque converter
In modern usage, a torque converter is generally a type of hydrodynamic fluid coupling that is used to transfer rotating power from a prime mover, such as an internal combustion engine or electric motor, to a rotating driven load...
s to transmit power from prime mover to wheels.
The Class 61-000 was a centre cab locomotive that used two V6 GM type 6/567C
EMD 567
The EMD 567 is a line of diesel engines built by General Motors' Electro-Motive Division. This engine, which succeeded Winton's 201-A, was used in EMD's locomotives from 1938 until its replacement in 1966 by the EMD 645. It has a bore of , a stroke of and a displacement of 567 in³ per cylinder...
prime movers, each with a Voith
Voith
The Voith GmbH, which is headquartered in Germany, is a family-run corporation in the mechanical engineering sector with worldwide operations....
type L306r triple-converter torque converter and each driving the wheels of one bogie. Power was transferred to the axles through drive shafts. Unlike diesel-electric locomotives where each axle is driven by its own traction motor, individual wheel slip was not possible since each bogie’s two axles were interconnected through the drive shafts.
The cab had two control stands and, since it was possible to start the six prime movers in three consisted locomotives from one engine cab, each control stand had six engine start buttons and six engine stop buttons. The electrical system was very complicated and unreliable and the locomotives were completely rewired in 1963.
Service
The Class 61-000s spent their entire SAR working lives stationed at the Germiston diesel depot. One of them, 61-006, was involved in a head-on collision at Kaserne on 8 October 1966 and was eventually scrapped at Koedoespoort in September 1968. Problems with cracked axles resulted in the rest of the fleet being staged for repairs in 1967.In 1971 the remaining six were sold to the RR, where they became the RR Class DH1. They were eventually resold to the Zimbabwe Iron and Steel Company
Zimbabwe Iron and Steel Company
Zimbabwe Iron and Steel Company is the largest steel works in Zimbabwe. It is located just outside Kwekwe, in Redcliff. Over the years the company has faced many operational problems and has been dogged with countless corruption scandals. As of early 2008, the company was producing less than...
(ZISCO) steel works at KweKwe
Kwekwe
Kwekwe or Kwe Kwe , formerly spelt Que Que, is a city in central Zimbabwe. It is located in the centre of the country —roughly equidistant from Harare to the northeast and Bulawayo to the southwest. Its population stood at 47,607 in 1982, 75,425 in 1992 and the preliminary result of the 2002...
in Zimbabwe
Zimbabwe
Zimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...
. Most if not all were scrapped by 2001.
Gallery
See also
- Diesel-hydraulic locomotive numbering and classification
- List of South African locomotive classes