Prussian T 14 (attempt)
| T 14 (Prussia) | |
|---|---|
 The "combat locomotive" at Henschel in Kassel, 1913
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| Numbering: | Berlin 8508 Breslau 8508 Est 4651 |
| Number: | 1 |
| Manufacturer: | Henschel |
| Year of construction (s): | 1913 |
| Retirement: | after 1919 |
| Type : | 1'D1 'h3t |
| Gauge : | 1435 mm ( standard gauge ) |
| Service mass: | 101.0 t |
| Friction mass: | 68.0 t |
| Top speed: | 65 km / h |
| Coupling wheel diameter: | 1350 mm |
| Driving wheel diameter: | 1350 mm |
| Impeller diameter front: | 1000 mm |
| Rear wheel diameter: | 1000 mm |
| Cylinder diameter: | 490 mm |
| Piston stroke: | 630 mm |
| Boiler overpressure: | 15 bar |
| Grate area: | 3.65 m² |
| Superheater area : | 67.6 m² |
| Evaporation heating surface: | 249.4 m² |
| Coupling type: | Screw coupling |
In 1913, the Association of North German Locomotive Builders commissioned the Henschel company to build a test locomotive for the Berlin city, ring and suburban railways . The machine, also known as the "combat locomotive" , was intended to prove that steam operation is on a par with a possible electrical operation. On the Prussian State Railways , the locomotive was run under the class T 14 .
prehistory
The industrialization of Greater Berlin led to rapid population growth and the expansion of the populated area at the end of the 19th and beginning of the 20th century. Due to the migration of industrial companies such as Siemens & Halske , Borsig and AEG , the workers had to cover longer distances. The railway was challenged by the fact that the trains had to run more frequently while the number of passengers per train increased. Between 1882 and 1912, the volume of traffic on the Stadt- und Ringbahn increased from eleven million to 201 million passengers. The total traffic including the suburban railways in 1906 was over 250 million passengers. The train length was limited by the platform length of 150 m . In order to be able to increase the transport capacity, the next step was to increase the train density. A two-and-a-half-minute cycle was already possible since 1896 thanks to several block densifications , which corresponds to 24 trains per hour and direction. Theoretically, 30 trains per hour and direction would have been feasible.
Regardless of the fact that further consolidation also required corresponding signaling changes - such as those implemented with the Sv signal system from 1928 - the idea arose to convert the lines for electrical operation. Various tram companies and the elevated and underground railway that opened in 1902 were already using the traction current at that time. Between 1900 and 1902 Siemens & Halske carried out an electrical test operation on the Wannsee Railway . The Union-Elektricitäts-Gesellschaft (UEG) carried out electric journeys on the Lichterfeld suburban railway from 1903 . At about the same time, the UEG submitted a project for the electrification of urban, ring and suburban railways to the Ministry of Public Works . The aim was a two-minute cycle on the tram (equivalent to 30 journeys per hour and direction). Since it was mathematically proven that steam locomotives could also achieve this performance, KED Berlin initially procured several tank locomotives of the types T 6 , T 11 and T 12 . At the same time, it was to be determined whether the maximum speed of the tram could be increased from 45 km / h to 60 km / h. The T 12 turned out to be the most reliable, which is why later purchases were aimed at this type.
A change became apparent after Paul von Breitenbach became Minister of Public Works in 1906. Breitenbach was convinced of the advantages of electrification and in 1907 informed KED Berlin about the intention to electrify the city, ring and suburban railways. In 1908, the KED Berlin presented a paper on this question and discussed the advantages of electrification. KED Berlin continued to work on the implementation of the project over the next few years. From the spring of 1911, the Prussian state parliament dealt with the subject. In order to inform the responsible commission, the government issued a memorandum in 1912 in which electrical operation was again discussed. The authors came to the conclusion that with the current increase in passenger numbers, steam operation would be sufficient until 1916, but would no longer be sustainable if the number of trains running every hour increased to 30 or even 40 trains per hour and direction. The memorandum also stated that this train density would require a twelve-axle steam locomotive with eight coupled axles or, correspondingly, two six-axle machines with four coupled axles - and two personnel. The Association of North German Locomotive Manufacturers took this statement as an opportunity to produce a test locomotive that should provide the required performance. Henschel & Sohn in Kassel was then commissioned to build the "combat locomotive". It was completed in the comparatively short time of two and a half months and left to the management free of charge.
Construction and use
The locomotive had a three-cylinder engine . The second coupled axle was driven by the middle cylinder . The two outer ones powered the third coupled axle. For the first time, a hot steam regulator was used behind the superheater , which was later replaced by a wet steam regulator. The running axles were designed as Adam axles. Pop safety valves were also used for the first time . In order to reduce smoke and noise, the machine received an additional oil firing system and a silencer to protect against the exhaust blows. The boiler was noticeably large and the grate was dimensioned in such a way that the locomotive could reach a speed of 50 km / h with a light rail train with passengers at the shortest station distance of 700 meters between the Alexanderplatz and Börse stations (today: Hackescher Markt). This corresponded to a train sequence of 40 trains per hour.
The locomotive arrived in Berlin at the beginning of February 1913. In addition to the combat locomotive , a T 12 with a smoke tube superheater was also used for the test runs. The trips took place during the nightly breaks on the city's north ring, i.e. the ring trip on the city railway and the northern ring railway. The trip had a scheduled turnaround time of 86 minutes. In the case of electrical operation, this should be reduced to 70 minutes. For the steam locomotives, the renewal of supplies had to be deducted with an estimated three and a half minutes at this time, which resulted in the planned travel time of 66.5 minutes. The wagon train comprised 39 axles (equivalent to 13 three-axle wagons) and weighed 300 tons, which corresponded to an overcrowding of 70 percent. The test locomotive easily achieved acceleration and travel time values that corresponded to a train sequence of 40 trains, the performance could even be increased to 42 trains. The coal consumption is said to have been "extremely low". During a demonstration run on the Wannsee Railway on February 20, 1913, during which the budget commission of the Prussian House of Representatives was also present, some disadvantages of the machine became clear. The locomotive started up faster than the T 12 machines used on the line, but the passenger would find it less of a nuisance to start in the electric railcar. When starting up, it was found that the locomotive had a loud exhaust blow despite the silencer. When passing bridges and other crossings, the machine made a "thunder-like noise". The Vossische Zeitung , which had accompanied the trip, came to the conclusion that the machine was on a par with electrical operation in terms of performance, but questioned its suitability for local traffic.
On May 5, 1913, the law overcame the last legal hurdle concerning the electrification of the city, ring and suburban railways . Thereupon the experiments with the "combat locomotive" on the city and ring railways were stopped. After the third cylinder had been removed, it was handed over to the Royal Railway Directorate in Wroclaw . After the end of the First World War , it went to the then French Chemin de fer de l'Est as part of the reparations payments in 1919 .
Individual evidence
- ↑ Dietrich Kutschik: Steam versus electricity. The conflict between profitability and progress . In: Verkehrsgeschichtliche Blätter eV (Ed.): Electricity instead of steam! 75 years of the Berlin S-Bahn. The great time of electrification . Verlag GVE, Berlin 1999, ISBN 3-89218-275-2 , p. 23-25 .
- ^ Bernd Neddermeyer: The electrical operation on the Berlin S-Bahn. Volume 1: Steam or Electricity? 1900 to 1927 . VBN Verlag B. Neddermeyer, Berlin 1999, ISBN 3-933254-05-1 , p. 10-11 .
- ^ A b Bernd Neddermeyer: The electrical operation on the Berlin S-Bahn. Volume 1: Steam or Electricity? 1900 to 1927 . VBN Verlag B. Neddermeyer, Berlin 1999, ISBN 3-933254-05-1 , p. 53-57 .
- ^ A b c d e f Kurt Pierson: Steam trains on Berlin's city and ring railways. The past and present of Berlin as reflected in its urban, ring and suburban railways . Franckh'sche Verlagshandlung, Stuttgart 1969, p. 86-100 .
- ↑ Bernd Kuhlmann: Signal connections. The signal system of the light rail from 1928 . In: Verkehrsgeschichtliche Blätter eV (Ed.): Electricity instead of steam! 75 years of the Berlin S-Bahn. The great time of electrification . Verlag GVE, Berlin 1999, ISBN 3-89218-275-2 , p. 52-61 .
- ^ Bernd Neddermeyer: The electrical operation on the Berlin S-Bahn. Volume 1: Steam or Electricity? 1900 to 1927 . VBN Verlag B. Neddermeyer, Berlin 1999, ISBN 3-933254-05-1 , p. 51-53 .
- ^ Bernd Neddermeyer: The electrical operation on the Berlin S-Bahn. Volume 1: Steam or Electricity? 1900 to 1927 . VBN Verlag B. Neddermeyer, Berlin 1999, ISBN 3-933254-05-1 , p. 59-62 .
- ↑ a b Chronicle of the Railway . HEEL Verlag, Königswinter 2005, ISBN 3-89880-413-5 , p. 99 .
- ^ A b Lothar Spielhoff: Länderbahn steam locomotives . tape 1 . Prussia, Mecklenburg, Oldenburg, Saxony and Alsace-Lorraine. Weltbild, Augsburg 1995, ISBN 3-89350-819-8 , p. 84 (first edition: Franckh-Kosmos, Stuttgart 1990).
- ^ Bernd Neddermeyer: The electrical operation on the Berlin S-Bahn. Volume 1: Steam or Electricity? 1900 to 1927 . VBN Verlag B. Neddermeyer, Berlin 1999, ISBN 3-933254-05-1 , p. 72 .