Bavarian ML 2/2
| Bavarian ML 2/2 | |
|---|---|
 Bavarian ML 2/2
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| Numbering: | 4001–4024 DR 98 361–384 (planned) |
| Number: | 24 |
| Manufacturer: | Maffei |
| Year of construction (s): | 1906-1908 |
| Retirement: | 1924 |
| Type : | B h2t (opposed piston) |
| Gauge : | 1435 mm ( standard gauge ) |
| Length over buffers: | 6,570 mm |
| Service mass: | 22.0 t |
| Friction mass: | 22.0 t |
| Wheel set mass : | 11.0 t |
| Top speed: | 50 km / h |
| Indexed performance : | 145 kW |
| Driving wheel diameter: | 990 mm |
| Number of cylinders: | 2 |
| Cylinder diameter: | 265 mm |
| Piston stroke: | 280 mm |
| Boiler overpressure: | 12 bar |
| Grate area: | 0.83 m² |
| Evaporation heating surface: | 35.50 m² / 42.00 m² |
| Locomotive brake: | Air brake |
The locomotives of the class ML 2/2 of the Bavarian State Railroad were light and very compact superheated steam locomotives for operation on local railways . They were an alternative design by Maffei to the locomotives of the class PtL 2/2 ("glass box") built by Krauss .
ML 2/2, PtL 2/2, DR 98 36
In common with the Krauss machines, the ML 2/2 had the B wheel arrangement, the semi-automatic bulk firing that allowed one-man operation, and circulations with railings that enabled safe access to the train of cars at the front and rear. The engine, however, was completely different; the locomotives had two outer cylinders, each with two opposing pistons, which were arranged between the two axles. The axles were connected via internal coupling rods.
In 1906 Maffei initially delivered three locomotives (track numbers 4001-4003). Despite the unusual and extremely complicated engine for a two-cylinder locomotive, the machines proved their worth and Maffei delivered a further 21 units by 1908 (No. 4004-4024). The positive experience with these locomotives also led to the construction of the MCCi class steam railcars , whose motor bogie and boiler essentially corresponded to the ML 2/2.
Three locomotives were sold to the United Schamottefabriken in Marktredwitz in 1922. The remaining machines were completely included in the provisional redesignation plan of the Reichsbahn from 1923 as 98 361–384; however, they were retired by 1924. The reason for this was the cumbersome and maintenance-intensive engine.
MÁV 12
For suburban traffic in Budapest, the Magyar Királyi Államvasutak Gépgyára (machine factory of the State Railways) built two machines with the serial no. 1976 and 1977 of the later series 12. These were licensed builds of the ML 2/2 from Maffei. The unconventional basic construction promised better compensation of the moving masses and thus a smoother running of the machines than with locomotives previously used in the same service. The maximum permitted speed for the construction in Hungary was 60 km / h. As in Bavaria, in Hungary the maintenance of the engine parts within the frame required more effort than expected.
The original company numbers MII 10101 and 10102 were changed to 12.001 and 12.002 with the new numbering scheme in 1911.
literature
- H. Obermayer, G. Scheingraber: The «glass box» . The local rail tank locomotives of the Bavarian classes ML 2/2 and PtL 2/2. In: Hermann Merker (Ed.): Eisenbahn Journal . Special edition, no. III / 87 , 1987, ISSN 0720-051X .
