HOME | DD

Description

KSEB Class E78

The KSEB Class E78 is a heavy freight locomotive in service with the KSEB. It is the most powerful locomotive in the KSEB's fleet and is primarily used for long coal unit trains and heavy freight transportation in mountainous regions. It complements the E70 series in heavy freight transport and replaces the pre-war class E33 and E37.



Development History

When the E70 series failed to prove itself after a long and complicated development and testing period, KSEB and VEfb decided to abandon further procurement of that type in favor of a new design based on it. The goal was to combine the high-performance components of the E70, such as the transformer and traction motors, with a more sophisticated and powerful control system, housing them in an entirely new locomotive body. Development began in 1974 when the last of the only 53 E70s rolled off the production line.

The latest developments in locomotive construction were considered during the development. Unlike its predecessor, thyristor technology was used to control the traction motors. However, revolutionary technology like phase-fired control, as tested in the E74 of that time, was avoided to prevent delays in development. Another innovation was the transformer winding changer, designed to meet the increased power demands of the locomotive. This had previously been tested in West Germany in the Class 103 locomotives of the Deutsche Bundesbahn, a locomotive of similar size and power.

The design responsibility fell on the locomotive factory Steiner Guerrero, which had established itself as an expert in the construction of heavy electric freight locomotives since the founding of SRRK and the subsequent nationalization of the locomotive industry. In 1978, three prototypes rolled off the factory premises in Keikweiß and were handed over to the KSEB for testing. After the prototypes proved themselves in test runs and regular service despite minor issues, KSEB ordered the series production of the locomotive.

Mass production of the improved type began in 1980. The locomotive factory SG could not handle the high workload, so other factories in the railway vehicle construction industry were chosen as additional production sites. Since the E80 series was also in production at that time, the locomotive industry was constrained by tight production schedules for several years. The delivery of the 541 series locomotives lasted until 1992.

In 1988, the E78 series was chosen as a potential new basis for a heavy express train locomotive. The following year, two prototypes of the E78.1 series for long-distance travel were delivered, capable of reaching speeds of up to 200 km/h, intended to allow the operation of heavier trains in Intercity service. However, only the two prototypes were produced.



Technology

The mechanical structure of the E78 differs little from that of the E70. The traction motors and quill drives of the E70 could be adopted for the new locomotive without changes. The bogies are a new design, with the frame hanging below the axle bearing rather than resting on top. All locomotives are equipped with a combined coupler that works with both the UIC chain coupler and the Scharfenberg coupler type 140.

For the E78.1, the gear ratio of the traction motors was changed to enable speeds up to 200 km/h. This necessitated the installation of yaw dampers.

The transformer was inherited from the E70. However, new to the E78 was the thyristor control unit of the HT34ss type. This innovation replaced the cam switch controller HN34mss, commonly used until the early 1970s. For the first time, a transformer winding changer was integrated into the control system. This allows the locomotive driver to increase the voltage of the 34 power settings by 30% each, enabling the E78 to maintain its tractive effort even at high speeds. To prevent overheating of the traction motors and transformer at a maximum short-term power of 9732 kW, the E78 is equipped with enormously powerful fans. However, the use of the winding changer is only allowed when the train weight and the gradient of the track necessitate it and when it is permitted on the specific track section. The reasoning behind this is not only material preservation but also the high current of 750 amperes, which can lengthen the overhead wire through heating and sometimes result in a drop in overhead wire voltage when multiple E78 locomotives climb a steep gradient.

For the first time in a long time, the E78 was equipped with a dynamic brake, which can feed energy back into the overhead line. The use of brake grid resistors for braking could be omitted.

The driver's cabs of the E78 conforms to the standards of that time. The locomotive driver selects the power steps using a handwheel, and the controller executes the command. The current power setting is displayed to the locomotive driver via two seven-segment displays. The locomotives are equipped with an analog push-pull control system, which, however, only serves to control other vehicles in a consist. The locomotives can run using cab signaling.

Deployment

The E78 is deployed in heavy freight transport, especially on the steep tracks of the Kirirgen Mountains. Its flagship performance includes hauling coal and iron ore block trains to the steelworks in Keikweiß, weighing up to 7000 tons. However, servicing quarries or heavy industry on branch lines is also a frequent task for the E78. The locomotives are only used for lighter freight trains when no other locomotives are available.

The Class 78.1 locomotives were used in express trains until 2004. While E78.1 002 was cannibalized and scrapped, E78.1 001 is preserved non-operational in a museum.



Color Variations

Most E78 locomotives were delivered in the DVR design. A small number of locomotives were painted dark gray for service on coal unit trains, making coal dust less visible. Since 2009, the locomotives have been gradually repainted into the current red Millennium color scheme. The two locomotives of the 78.1 series appeared in light gray with yellow and orange stripes.

General Information

Power type: electric

Configuration: Co'Co'

Build date: 1978-1992

Numbers build: 544

Specifications

Gauge: 1 435mm

Lenght: 20 475mm

Weight: 132t

Axle load: 22t

Electric systems: 15 kV 16.7 Hz overhead

Control unit: high speed thyristor switch controller with 34 power settings

Performance figures

Maximum speed: 120km/h

Short term power output: 9732kW

Sustainable power output: 7486kW

Tracive effort starting: 494kN

Carrer

Usage: heavy freight trains, banking

Periode of use: 1978-today

Used by: KSEB

Description

KSEB Class E78

The KSEB Class E78 is a heavy freight locomotive in service with the KSEB. It is the most powerful locomotive in the KSEB's fleet and is primarily used for long coal unit trains and heavy freight transportation in mountainous regions. It complements the E70 series in heavy freight transport and replaces the pre-war class E33 and E37.



Development History

When the E70 series failed to prove itself after a long and complicated development and testing period, KSEB and VEfb decided to abandon further procurement of that type in favor of a new design based on it. The goal was to combine the high-performance components of the E70, such as the transformer and traction motors, with a more sophisticated and powerful control system, housing them in an entirely new locomotive body. Development began in 1974 when the last of the only 53 E70s rolled off the production line.

The latest developments in locomotive construction were considered during the development. Unlike its predecessor, thyristor technology was used to control the traction motors. However, revolutionary technology like phase-fired control, as tested in the E74 of that time, was avoided to prevent delays in development. Another innovation was the transformer winding changer, designed to meet the increased power demands of the locomotive. This had previously been tested in West Germany in the Class 103 locomotives of the Deutsche Bundesbahn, a locomotive of similar size and power.

The design responsibility fell on the locomotive factory Steiner Guerrero, which had established itself as an expert in the construction of heavy electric freight locomotives since the founding of SRRK and the subsequent nationalization of the locomotive industry. In 1978, three prototypes rolled off the factory premises in Keikweiß and were handed over to the KSEB for testing. After the prototypes proved themselves in test runs and regular service despite minor issues, KSEB ordered the series production of the locomotive.

Mass production of the improved type began in 1980. The locomotive factory SG could not handle the high workload, so other factories in the railway vehicle construction industry were chosen as additional production sites. Since the E80 series was also in production at that time, the locomotive industry was constrained by tight production schedules for several years. The delivery of the 541 series locomotives lasted until 1992.

In 1988, the E78 series was chosen as a potential new basis for a heavy express train locomotive. The following year, two prototypes of the E78.1 series for long-distance travel were delivered, capable of reaching speeds of up to 200 km/h, intended to allow the operation of heavier trains in Intercity service. However, only the two prototypes were produced.



Technology

The mechanical structure of the E78 differs little from that of the E70. The traction motors and quill drives of the E70 could be adopted for the new locomotive without changes. The bogies are a new design, with the frame hanging below the axle bearing rather than resting on top. All locomotives are equipped with a combined coupler that works with both the UIC chain coupler and the Scharfenberg coupler type 140.

For the E78.1, the gear ratio of the traction motors was changed to enable speeds up to 200 km/h. This necessitated the installation of yaw dampers.

The transformer was inherited from the E70. However, new to the E78 was the thyristor control unit of the HT34ss type. This innovation replaced the cam switch controller HN34mss, commonly used until the early 1970s. For the first time, a transformer winding changer was integrated into the control system. This allows the locomotive driver to increase the voltage of the 34 power settings by 30% each, enabling the E78 to maintain its tractive effort even at high speeds. To prevent overheating of the traction motors and transformer at a maximum short-term power of 9732 kW, the E78 is equipped with enormously powerful fans. However, the use of the winding changer is only allowed when the train weight and the gradient of the track necessitate it and when it is permitted on the specific track section. The reasoning behind this is not only material preservation but also the high current of 750 amperes, which can lengthen the overhead wire through heating and sometimes result in a drop in overhead wire voltage when multiple E78 locomotives climb a steep gradient.

For the first time in a long time, the E78 was equipped with a dynamic brake, which can feed energy back into the overhead line. The use of brake grid resistors for braking could be omitted.

The driver's cabs of the E78 conforms to the standards of that time. The locomotive driver selects the power steps using a handwheel, and the controller executes the command. The current power setting is displayed to the locomotive driver via two seven-segment displays. The locomotives are equipped with an analog push-pull control system, which, however, only serves to control other vehicles in a consist. The locomotives can run using cab signaling.

Deployment

The E78 is deployed in heavy freight transport, especially on the steep tracks of the Kirirgen Mountains. Its flagship performance includes hauling coal and iron ore block trains to the steelworks in Keikweiß, weighing up to 7000 tons. However, servicing quarries or heavy industry on branch lines is also a frequent task for the E78. The locomotives are only used for lighter freight trains when no other locomotives are available.

The Class 78.1 locomotives were used in express trains until 2004. While E78.1 002 was cannibalized and scrapped, E78.1 001 is preserved non-operational in a museum.



Color Variations

Most E78 locomotives were delivered in the DVR design. A small number of locomotives were painted dark gray for service on coal unit trains, making coal dust less visible. Since 2009, the locomotives have been gradually repainted into the current red Millennium color scheme. The two locomotives of the 78.1 series appeared in light gray with yellow and orange stripes.

General Information

Power type: electric

Configuration: Co'Co'

Build date: 1978-1992

Numbers build: 544

Specifications

Gauge: 1 435mm

Lenght: 20 475mm

Weight: 132t

Axle load: 22t

Electric systems: 15 kV 16.7 Hz overhead

Control unit: high speed thyristor switch controller with 34 power settings

Performance figures

Maximum speed: 120km/h

Short term power output: 9732kW

Sustainable power output: 7486kW

Tracive effort starting: 494kN

Carrer

Usage: heavy freight trains, banking

Periode of use: 1978-today

Used by: KSEB