Anatole Mallet
Jules T. Anatole Mallet (born May 23, 1837 in Lancy ( canton of Geneva ), † October 10, 1919 in Paris ) was a Swiss engineer and at the time one of the most successful designers of steam locomotives .
education
Mallet initially studied and taught at the Ecole Centrale des Arts et Manufactures in Paris and later began designing and planning port facilities , including for the Suez Canal .
Steam engines
In 1867 he dealt with the construction of steam engines for the first time and developed the idea of the compound machine . He tried to apply this principle to steam locomotives as well. In the same year and in close connection with the first patent, a start-up device was patented , which made it possible to introduce live steam into the low-pressure cylinder of the compound steam engine and thus to accelerate the start-up process of a locomotive.
Mallet caused a sensation in 1876 when he put two tank locomotives with a two-cylinder compound engine into service on the Bayonne - Biarritz railway . In principle, the locomotives worked, but ran unevenly at higher speeds due to the not completely balanced performance differences of the high-pressure and low-pressure cylinders. At the time, Mallet was unable to convince the railway companies of the group principle. Even after the development of improved designs with high and low pressure cylinders installed in pairs, the complexity of the machines had a rather daunting effect on the majority of railway companies. Steam overheating , which was developed later, proved to be a more successful way of utilizing energy compared to the compound principle.
The development of the Malletlok
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The increasing traffic on narrow-gauge railways opened up another field of activity for Mallet. These railways required more powerful and therefore larger machines than the tight curves of the narrow-gauge lines would allow. The only solution here seemed to be locomotives with swiveling bogies. For this purpose, the types of Fairlie and Meyer , which used pivoting machine units, were already widespread. The individual units were fed with steam via flexible connections, which, however, always proved to be the weak point of the machines. Instead, Mallet developed a design with two undercarriages, of which only the front undercarriage located under the smoke chamber was pivoted, while the boiler rested firmly on the other undercarriage. This reduced the number of flexible connections by half.
The main difference in the construction of Mallet compared to the Fairlie and Meyer types was the perfect application of a compound engine. The live steam is first directed to the high-pressure cylinders of the fixed landing gear and, after the outlet, into the low-pressure cylinders of the front movable landing gear. The moving steam line connection leading there was easier to control because of the lower pressure than with a pure live steam supply. Mallet had this design patented in 1884 . The first Mallet locomotive built in this way was presented in Belgium in 1888 for Paul Decauville's 600 mm narrow-gauge railway at the Paris Exhibition in 1889 , where it carried over six million visitors. Later, other narrow-gauge locomotives that were successful with this principle were built, mostly with the B'B wheel arrangement, i.e. with two two-axle engines each.
In 1904, the Baltimore & Ohio Railroad introduced the mallet concept in the United States by ordering a C'C locomotive from the American Locomotive Company . In 1911 there were already more than 500 mallets in the USA . During World War I , the Virginian Railway took the original mallet concept to extremes by ordering wheel arrangement (1'E) 'E1' machines with low pressure cylinders 48 inches (120 cm) in diameter. This also made the limits of the mallet concept visible. The overhang of the boiler and the low-pressure cylinders were so large that it was hardly possible to develop suitable valves for them. They could only be operated at low speeds. In later, larger locomotives, which continued to be called mallets, the composite principle of separate running gears was dispensed with and both running gears were supplied with live steam. Further improvements have been made in order to achieve higher speeds with the machines on standard gauge tracks. The Mallet design produced the largest steam locomotives ever built in the USA.
Anatole Mallet himself no longer took part in the further improvements, as he primarily pursued his principle for the use of the compound machine. Around 1888 he still designed the original locomotives for the Lartigue monorail . In the 20th century, Mallet was considered the "Grand Old Man" of French engineers, who wrote occasional treatises on locomotives for the annals of the French Society of Civil Engineers. The people Mallet beyond his success as a mechanical engineer, little is known, though one of the three main locomotive engineers after the era of Stephenson applies.
In November 1913, had Royal Bavarian State Railways for the pusher service a first Gt 2 × 4/4 placed on the tracks. It was followed by 24 other machines, the last of which were taken out of service in West Germany in 1948 and in 1954 by the Deutsche Reichsbahn . In Germany today you can still find mallet steam locomotives on the tracks of the Harz narrow-gauge railway in daily use according to the timetable.
literature
- Stefan Vockrodt: Jules T. Anatole Mallet . In: Eisenbahngeschichte , vol. 7 (2009), issue 36, p. 54f. ISSN 1611-6283
Web links
- Everything about steam locomotives of the Mallet type (website in the web archive)
- Harzer Schmalspurbahnen GmbH (HSB)
Individual evidence
- ^ Konrad Koschinski: Mallet giants for the ramps . In: Frankenwaldbahn . Railway Journal special, No. 1 , 2018, p. 38 ff .
| personal data | |
|---|---|
| SURNAME | Mallet, Anatole |
| ALTERNATIVE NAMES | Mallet, Jules T. Anatole |
| BRIEF DESCRIPTION | Swiss engineer |
| DATE OF BIRTH | May 23, 1837 |
| PLACE OF BIRTH | Lancy ( Canton of Geneva ) |
| DATE OF DEATH | October 10, 1919 |
| Place of death | Paris , France |