SEK series Μα
| SEK series Μα OSE series Μα |
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|---|---|
 The Μα 1002 in 2007 in Rouf
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| Numbering: | 1001-1020 |
| Number: | 20th |
| Manufacturer: | Breda , Ansaldo |
| Year of construction (s): | 1953-1954 |
| Retirement: | until 1974 |
| Axis formula : | 1'E1 ' |
| Type : | h2 |
| Gauge : | 1435 mm ( standard gauge ) |
| Length over buffers: | 24,930 mm |
| Height: | 4510 mm |
| Width: | 3050 mm |
| Fixed wheelbase: | 5190 mm |
| Total wheelbase: | 12750 mm |
| Wheelbase with tender: | 21720 mm |
| Service mass: | 135 t |
| Service mass with tender: | 200 t |
| Friction mass: | 100 t |
| Wheel set mass : | 20 t |
| Top speed: | 100 km / h |
| Indexed performance : | 2900 psi |
| Starting tractive effort: | 360 kn |
| Coupling wheel diameter: | 1600 mm |
| Driving wheel diameter: | 1600 mm |
| Impeller diameter front: | 850 mm |
| Rear wheel diameter: | 1050 mm |
| Control type : | Heusinger / Walschaerts |
| Number of cylinders: | 2 |
| Cylinder diameter: | 660 mm |
| Piston stroke: | 750 mm |
| Boiler overpressure: | 18 bar |
| Heating pipe length: | 6100 mm |
| Grate area: | 5.6 m² |
| Superheater area : | 128 m² |
| Evaporation heating surface: | 316 m² |
| Tender: | 2'2 ' |
| Service weight of the tender: | 68.2 t |
| Water supply: | 25 m 3 |
| Fuel supply: | 12 tons of coal |
| Brake: | Knorr compressed air |
| Locomotive brake: | Compressed air |
| Train brake: | Compressed air |
| Train heating: | steam |
| Coupling type: | Screw coupling |
The SEK series Μα (My-alpha) was a heavy steam locomotive series of the Greek state railway Sidirodromoi Ellinikou Kratos (SEK), the predecessor company of today's state railway Organismos Sidirodromon Ellados (OSE) , which existed until 1973 . The locomotives were built between 1953 and 1954 by the Italian manufacturers Breda and Ansaldo . They were the largest and heaviest standard gauge, single-frame steam locomotives in Europe on standard gauge . The OSE decommissioned the last locomotives by 1974. The locomotives Μα 1002 and 1013 have been preserved.
history
After the devastating destruction of World War II and the subsequent Greek Civil War , the Greek railway network had to be rebuilt at great expense. The number of locomotives had also shrunk significantly due to losses caused by the war. From 1950, continuous train traffic to Western Europe was possible again and the re-established train routes, including the Simplon-Orient-Express , experienced a rapidly increasing demand. The previously existing locomotives were no longer able to cope with the increasing train masses on the steep and curved main line of the SEK from Piraeus to Thessaloniki , with the previously used locomotives of the SEK series Λα , which were already 30 years old and supplied by the Austrian locomotive factory of StEG It was hardly possible to reach a top speed of more than 70 km / h. The SEK therefore ordered 20 heavy multi-purpose locomotives with a 1'E1 ' wheel arrangement from the Italian manufacturers Breda and Ansaldo . They were supposed to transport a 450-ton express train on the flat at 90 km / h and on a gradient of 10 per thousand at 65 to 70 km / h. During test drives in Italy, they reached speeds of up to 120 km / h and thus met the requirements. They were the largest steam locomotives ever built in Italy and also the largest and heaviest steam locomotives used in Greece. Apart from their size, the locomotives were conventional two-cylinder superheated steam locomotives with single steam expansion.
Soon after delivery, it became apparent that Breda and Ansaldo, as designers, no longer had sufficient experience with building such large machines - the last steam locomotives for the Italian state railways had been delivered as early as 1930. The steam engine and the boiler were not properly matched to one another, in particular the grate was too small for the required fuel throughput. The boiler plates used, in particular for the steel firebox, proved to be unsuitable for the high load in the long term. The sheet travel was also insufficient and the machines repeatedly caused considerable operational disruptions.
After two years, the SEK had to take the entire series out of service. As a temporary replacement, locomotives of the ÖBB 258 series from Austria were rented, which were identical to their own denα. The boilers of all Μα were removed and came to Henschel in Kassel for extensive renovation work . There they were fundamentally revised and received, among other things, new fire boxes. The furnace was also switched from coal to oil. After their return to Greece, they were usually able to provide the planned services, such as the transport of the Simplon-Orient-Express, but were still relatively unpopular with the staff - the machines were never able to achieve the originally planned performance. They were still considered to be relatively prone to derailment, and there was also a high level of maintenance required for the running gear and engine. In the superstructure Department of SEK they were also little appreciated as they caused on the bow rich main line from Athens to Thessaloniki increased maintenance costs. A complete elimination of all structural defects would have led to the permissible axle loads being exceeded. In the early 1960s , the SEK received the first diesel locomotives , which quickly took over the most important services and limited the My-alpha primarily to freight train services .
By 1974 the last locomotives were parked by the state railway, which has been operating as OSE since 1973. Most of the specimens stood on the siding for many years, but have since been scrapped. Locomotive 1002 is in poor condition in Rouf at the station as a memorial.
technical features
The largely welded frame of the Μα was made from 38 mm thick steel plates and pulled in a little at the rear end in order to have enough space for the deflection of the towing axle mounted in a delta towing frame. The front running axle and the first coupling axle form a Krauss-Helmholtz steering frame . The middle coupling axle is the driving axle , for better sheet travel it was designed without flange . With this drive, the locomotives could travel on curved tracks with radii of up to 140 meters. The coupling rods received plain bearings , while connecting rod heads and cross heads received roller bearings . A Knorr system air brake was provided as braking equipment , with the running wheels running unbraked. The coupling and tender axles received brake blocks.
The boiler was designed to be extremely large for the conditions on European standard-gauge railways. The fire box was made of steel and welded, it received a combustion chamber . Vanadium steel was used for the long boiler . The grate was equipped with a stoker in ten machines , the other ten machines are partly oil and hand-fired. The double blowpipe was designed according to the Kylchap system . All locomotives were fitted with smoke deflectors , some as conventional large Wagner smoke deflectors , some in the form of small sheets mounted high on the boiler right next to the chimney.
literature
- Adolf Hofbauer: 1E1 superheated steam two-cylinder mountain express locomotive series Μα of the Greek State Railways , in: Eisenbahn , Issue 7, July 1968, Vienna, 21st year, pp. 120–122
- AE Durrant: The Steam Locomotives of Eastern Europe , David & Charles, revised edition, Newton Abbot 1972, ISBN 0-7153-4077-8