MÁV Class 242

MÁV class 242

242.001, restored at the Hungarian Railway Museum
Type and origin
Power type Steam
Builder MÁVAG, Budapest
Order number 129th
Build date 1936–1939
Total produced 4
Specifications
Configuration 4-4-4T
UIC class 2′B2′St
Gauge 1,435 mm (4 ft 8 12 in)
Driver dia. 2,000 millimetres (6 ft 7 in)
Wheelbase 10,580 millimetres (34 ft 9 in)
Wheel spacing
(Asymmetrical)
2,185 millimetres (7 ft 2.0 in)
Length 14,275 millimetres (46 ft 10.0 in)
Height 4,303 millimetres (169.4 in)
Axle load 14.6 tonnes (14.4 long tons; 16.1 short tons)
Adhesive weight 29.2 tonnes (28.7 long tons; 32.2 short tons)
Loco weight 85.4 tonnes (84.1 long tons; 94.1 short tons)
Fuel type coal
Fuel capacity 4.9 tonnes (4.8 long tons; 5.4 short tons)
Water cap 10 cubic metres (2,200 imp gal)
Firebox:
  Firegrate area
2.75 square metres (29.6 sq ft)
Boiler pressure 18 standard atmospheres (260 psi)
Heating surface 155.4 square metres (1,673 sq ft)
  Firebox 12.4 square metres (133 sq ft)
Superheater:
  Type Schmidt
  Heating area 35.2 square metres (379 sq ft)
Cylinders 2
Cylinder size 430 mm × 650 mm (16.93 in × 25.59 in)
Valve gear Heusinger
Train brakes Knorr compressed-air
Performance figures
Maximum speed 120 kilometres per hour (75 mph) (service)
152 kilometres per hour (94 mph) (in tests)
161 kilometres per hour (100 mph) (Hungarian speed record in 1961)
Career
Operators MÁV
Class 242
Nicknames Coffin
Retired 1961

MÁV Class 242 was a 4-4-4T steam locomotive of Hungarian State Railways. A small class of only four examples, they were built between 1936 and 1939. They were highly unusual in that they were both streamlined, as was the fashion of that period for fast express service, but they were also tank locomotives.

Design

Hungarian railways after World War I were in a poor state. Together with the Great Depression of the late 1920s and early 1930s, they had lagged behind developments in other countries. By the mid-1930s though, there was a demand for a faster express service. The Hungarian demand was for an express locomotive that would be fast, with a design speed of up to 120 kilometres per hour (75 mph), but owing to the state of the track and also because the running distance and the train weights of 4-5 coach trains were relatively low, it would yet be possible for it to be small and lightweight. Following the fashion of the day, the locomotive was to be streamlined.

The symmetrical wheel arrangement of 4-4-4T, particularly with the use of a tank locomotive rather than a tender, was chosen to allow high-speed running in either direction, without the need to reverse the locomotive on a turntable. This was following the earlier practice of 2-4-2T of around 1900 for suburban passenger services, although with their pony trucks replaced by bogies to allow faster running. For the express locomotives of the 1930s though, like the similar DRG Class 61, the intention was to reduce turn-around time at stations, rather than for use at small stations without turntables.

The use of four-coupled wheels for a fast express was unusual by this time, as the Atlantic arrangement, a four-coupled tender locomotive with a four-wheel leading bogie for high-speeds, had by now largely been replaced by the larger Pacific. One exception was the US Hiawatha , a 4-4-2 of the same period. US track loadings were higher though, and this locomotive had a driving axle loading twice that of the Hungarian design. With the relatively short range of 250 kilometres (160 mi) required, the Class 242 could afford to be a tank locomotive, even though this reduced the water and fuel capacity available. Avoiding the weight of a tender, and a large fuel capacity, further reduced the axle loading. A modern feature required by these increased speeds, and the lack of braking weight in the locomotive itself, was improved continuous braking throughout the train, by compressed air brakes to the Knorr system.

As was typical Hungarian practice, the first two locomotives were built with steel fireboxes. To cope with the high ash production of Eastern European coal, a rocking grate was fitted. The later two locomotives were fitted with copper fireboxes, owing to cracking problems with the steel. The class was considered successful, although the shadow of World War II meant that no further examples were built, even though Hungary did not enter the war until 1941.

Streamlining

As for the LNER A4 class, the class retained its overall streamlining throughout service but the lower valances were later cut higher, to improve access to the running gear for maintenance.

Service

The locomotives were successful on delivery and performed well. Their 120 km/h design speed was achieved easily, 20–30 km/h faster than other trains then in service. Their ride quality was particularly noted, being smooth and stable at high speeds in both directions.

In tests over the high-speed running lines of the Berlin–Hamburg Railway, also used for the Flying Hamburger service, they achieved 152 kilometres per hour (94 mph).

Their main service was from Budapest and also the short Miskolc-Košice[note 1] line, which was short enough to be within the range of their coal capacity. In later years they were double-headed to haul the heavy Orient Express on the section from Budapest to Biharkeresztes.

In 1961, 242.002 was used to test new rolling stock and set a speed record for Hungarian steam traction of 161 kilometres per hour (100 mph).

Preservation

242.001 as a static exhibit in a park in 1995

One example, 242.001, survives. After static exhibition in a park for some years it was restored to running order in 2002 as part of the Hungarian Railway Museum and is in use for enthusiast special trains.[1]

Comparable locomotives

Further reading

(Hungarian)

References

  1. Košice, in modern-day Slovakia had been ceded to Hungary by the First Vienna Award in 1938
  1. "Image gallery". railfaneurope.net.
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