DB Class VT 24
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 A class 624 at Oldenburg main station |
|
| Power type | Diesel-hydraulic |
|---|---|
| Builder | MAN AG, Waggonfabrik Uerdingen |
| Build date | 1961 (prototypes) 1964-1968 (regular) |
| AAR wheel arr. | B'2' + 2'2' + 2'B' (standard configuration) |
| Gauge | 1435 mm |
| Top speed | 120 km/h (class 624) 140 km/h (class 634) |
| Power output | 2x 331 kW |
| Career | Deutsche Bahn, PKP |
| Locale | Germany Poland |
Class 624 and class 634 are types of diesel multiple unit, originally operated by Deutsche Bahn.
Contents |
[edit] Development
Whereas the first years after the second world war the focus of the Deutsche Bundesbahn was on repairs of rolling stock, lines and buildings, with the beginning of the 1950s attention shifted to renewal of the trains. Regarding passenger services on not electrified lines, first prototypes of main line diesel locomotives such as the class 220 were commissioned in 1953. Subsequently DB ordered the rail industry to develop new DMUs in order to replace pre-war classes and to replace steam traction.
In 1961 MAN and Waggonfabrik Uerdinge both delivered two prototypes each. Even though both prototypes were quite similar, the can be easily discriminated by the different front design. DB put the prototypes into service as class VT 23.5 (MAN) and class VT 24.5 (Uerdingen). After the new numbering scheme the prototypes were listed as class 624 together with the regular units. The prototypes underwent intensive tests, including comparrison to conventional push/pull trains with class V 100.
The regular trainsets were delivered from 1964-1968, jointly produced by both manufacturers. Only minor changes were made compared to the prototypes. A total of 80 front cars and 55 middle cars were delivered, allowing the use of 40 three-part or two-part trainsets. Starting in 1968, a number of units was equipped with penumatic shock absorption and passive tilting systems. These units were listed as class 634 and approved for a higher speed of 140 km/h. As the tilting system turned out to be of limited use (the clearance allowed only very limited tilting), in 1979 the tilting system was removed [1].
In 1970 a number of trainsets derived from class 624 were delivered to Yugoslavia (Slovenia) as SŽ class 711. The units are still in use by Slovenian Railways.
[edit] Service
Upon entering service the new class 624 units were often used for fast regional and express trains in various parts of Germany. This slowly changed, and by 1980 nearly alls units were stationed in Osnabrück und Braunschweig, performing duty on regional and local trains. Regional and local passenger traffic in the Harz region was almost exclusively carried out by these trainsets.
Whereas the successing class 614 units supplemented DB's DMU fleet, the class 628.2 regular types coming into service after 1986 began to displace class 624 into subordinate services. Retirement of class 624 / 634 started in 2003, when DB lost a couple of tender procedures to private companies and also modern light-weight DMUs came into service in large numbers. The last class 624 / 634 units were retired in 2005.
14 trainsets were sold to Poland's PKP as class SA110 and are used in regional and local service since [2].
[edit] Technical information
Due to the fact that only the fronts cars were motorized, the trainsets could be assembled without or with up to two middle cars. Up to three trainsets (i. e. six engines) could be operated as multiple traction, connected by Scharfenberg couplers (also used to connect front and middle cars). Each front car is equipped with a 331 kW MAN diesel engine. The power is transferred hydro-dynamically to the front-end bogey.
The passenger compartment's layout was derived from the so-called Silberling (silverling) polished stainless steel short-line passenger coaches, with open-plan compartments. The trainsets had oil heating.
Class 624 / 634 was compatible with its successor DB Class 614, so all units could be in mixed plans (including mixed use of middle cars).
