DR T 38 3255
| DR T 38 3255 | |
|---|---|
.jpg) |
|
| Numbering: | T 38 3255 (conversion from 38 3255) |
| Number: | 1 |
| Manufacturer: | Henschel |
| Year of construction (s): | 1926 |
| Retirement: | 1960 |
| Axis formula : | 2'C |
| Type : | 2'C h2 |
| Gauge : | 1435 mm ( standard gauge ) |
| Length over buffers: | 22,917 mm |
| Wheelbase with tender: | 19,380 mm |
| Empty mass: | 70.7 t |
| Service mass: | 76.69 t |
| Friction mass: | 50.60 t |
| Wheel set mass : | 17.36 t |
| Top speed: | 100 km / h |
| Driving wheel diameter: | 1,750 mm |
| Impeller diameter front: | 1,000 mm |
| Control type : | Heusinger |
| Boiler overpressure: | 12 bar |
| Number of heating pipes: | 119 |
| Number of smoke tubes: | 26th |
| Heating pipe length: | 4,700 mm |
| Grate area: | 2.58 m² |
| Radiant heating surface: | 14.58 m² |
| Tubular heating surface: | 129.32 m² |
| Superheater area : | 58.90 m² |
| Evaporation heating surface: | 143.28 m² |
| Train heating: | steam |
The T 38 3255 was a steam locomotive converted for test purposes . It originated from a Prussian P 8 with the train number Elberfeld 2607, which was put into service in 1921 , which later became 38 3255 according to the series scheme of the Deutsche Reichsbahn . She received a tender with an additional turbine drive.
development
In the years after 1920, the Deutsche Reichsbahn looked for ways to improve the profitability of its steam locomotives. As an experiment, two steam turbine locomotives were built for this purpose , which were put into service as T 18 1001 and T 18 1002 . The applicability of a full steam expansion in turbines should be examined in order to save coal. Henschel & Sohn, however, suggested equipping a conventional steam locomotive with an additional turbine drive and a condenser in the tender . This should use the exhaust steam down to the negative pressure. This was taken up by the Reichsbahn and so Henschel received the order to convert the 38 3255 they had produced themselves.
technical changes
locomotive
The blowpipe was omitted because the exhaust steam was now to be used in the turbine. Therefore the locomotive got a turbine in the smoke chamber , which kindled the fire with the help of a fan. Only an auxiliary blowpipe was used to fan the fire in the event of a standstill. Because the turbine and fan required more space, the smoke chamber door was extended by 200 mm and made conical. The surface preheater was also arranged across the direction of travel in front of the chimney on the top of the boiler. Together with the exhaust line to the engine tender , which was attached under the circulation, the modifications to the locomotive were kept within limits.
tender
The tender 1B2 'T16 was a new design from Henschel. Its two driving axles were firmly arranged in the frame together with the front barrel axle . The two rear axles were mounted in a unit bogie . The locomotive and tender thus had the wheel arrangement 2'C + 1B2 '. The exhaust steam was used in a three-stage steam turbine of the Zoelly type . The turbine was installed transversely and worked with a reduction gear on a jackshaft , which was arranged in front of the first drive axle. The further drive took place with drive rods on the two drive wheel sets. Initially, the tender had a turbine for reversing, but this was later removed because it worsened efficiency when it was idling when moving forward . Afterwards, only the steam engine of the locomotive was used to drive backwards. Since the condensation of steam to water creates negative pressure, the exhaust steam from the turbine was now passed through condensers. These consisted of parallel brass pipes that were sprinkled with cooling water and circulated with cooling air. The feed water recovered in this way was de-oiled and collected again in the storage tank in order to be used again to generate steam. To generate the cooling air, three fans were arranged in the middle of the tender, which were also driven by steam turbines.
Mission history
The first test drives took place on November 22, 1927 between Kassel and Marburg (Lahn) and in December between Kassel and Nordhausen . Then the locomotive was rebuilt at Henschel. Further tests took place from January to May 1929 on the route between Potsdam and Burg (near Magdeburg) . The tests were carried out with a brake locomotive , but also in front of a 600-ton train. It was found that the boiler efficiency had deteriorated compared to a P 8 in the normal version. Finally, the T 38 3255 was accepted by the Reichsbahn on May 11, 1929.
In order to be able to make a comparison, tests with the 38 1541 were run on the same route from January 4 to April 4, 1929. The constant induced draft through the turbine proved to be a disadvantage compared to the intermittent induced draft of a blowpipe. The bursts of steam from the cylinders, and thus the pressure differences transmitted by the blowpipe, loosened the fire bed. The turbine also required some practice to operate.
After removing the reverse turbine in the tender and making some changes to the steam lines, further tests were carried out from July 14th to August 26th, 1931. An additional performance of 8.1% and a lower coal consumption of 7.2% compared to the test drives in 1929 were determined. Compared to 38 1541, a performance increase of 48% was achieved. However, there was no increase in performance at low speeds because the additional auxiliary units such as the induced draft turbine and the fans for condensation also had to be supplied with steam and their weight required their share of the locomotive's performance. In conclusion, it was found that with the help of the drive tender, the performance could be increased, but this did not pay off in view of the effort. The drive tender therefore never went into series production.
The locomotive was alternately stationed at RAW Kassel and in Berlin-Grunewald until 1936 to run tests. After that she was assigned to the BW Kassel until 1937. In 1932 it was also used in the roster of the larger DR class 39 . However, the damage to the powered tender increased so that the normal version of the locomotive was dismantled in 1937. The tender was scrapped. The locomotive was now in service as an ordinary BR 38 until 1959. It had number 38 3255 on the DB and was last stationed in Minden .
literature
- Wolfgang Stoffels: Locomotive construction and steam engine technology. Birkhäuser, Basel and Stuttgart 1976, ISBN 3-7643-0695-5 , pp. 176ff
- Hansjürgen Wenzel: The Prussian P8 / The series 38.10-40 EK-Verlag 1994, ISBN 3-88255-140-2 , p. 36ff
- Josef Brand: Class 38.10-40 / The Prussian P8 . Book series “Stars of the Rails”, Weltbild-Verlag 2003, p. 56ff