The Prussian Class P 8 steam locomotive of the Prussian state railways (DRG Class 38.10-40 of the Deutsche Reichsbahn) was built from 1906 onwards by the Berliner Maschinenbau (previously Schwartzkopff) and the Linke-Hofmann factory in Breslau by Robert Garbe. It was intended as a successor to the Prussian P6, which was regarded as unsatisfactory.
| Prussian P 8 DRG Class 38.10–40 |
|
|---|---|
| Quantity: | ca. 3,700 |
| Year(s) of manufacture: | 1908 - 1926 |
| Retired: | 1974 |
| Wheel arrangement: | 4-6-0 |
| Axle arrangement: | 2'C h2 |
| Type: | P 35.15 |
| Gauge: | 1,435 mm |
| Length over buffers: | 18,585 mm |
| Service weight: | 69-76.69 t |
| Adhesive weight: | 50.60 t |
| Axle load: | 17.36 t |
| Top speed: | 110 km/h (forwards) 50 km/h (backwards) 85 km/h (backwards with tub tender) |
| Indicated Power: | 868 kW |
| Driving wheel diameter: | 1,750 mm |
| Leading wheel diameter: | 1,000 mm |
| Cylinder bore: | 630 mm |
| Piston stroke: | 691 mm |
| Boiler Overpressure: | 12 bar |
| Grate area: | 2.58 m² |
| Radiative heating area: | 14.58 m² |
| Superheater area: | 58.90 m² |
| Evaporative heating area: | 143.28 m² |
| Brakes: | Knorr automatic, single-chamber compressed-air brakes, working both sides of the coupled wheels, from 1913 bogie wheels also braked |
| Train heating: | steam |
Contents |
Because Garbe was an advocate of the simplest possible designs, a straightforward, superheated steam, two-cylinder driving gear was envisaged. The P 8 benefited especially from superheated steam technology, which had just been developed by Wilhelm Schmidt (nicknamed 'hot steam Schmidt'), that led to outstanding performance for those times. The P 8 was a very economical locomotive that did not make great demands on the ability of the engine driver. At the outset Garbe even designed the P 8 as an express train locomotive, with the expectation of attaining a top speed of 110 km/h (68 mph). As a result the first units were fitted with low wind-resistance, tapered driver's cabs.
The enthusiasm of crews for the new locomotive was at first muted. The boiler was very effective at evaporation (there was already evidence of a combustion chamber at the front end of the firebox), however against that there were numerous teething troubles, e.g. the driving rod bearings were too small, which continually led to overheating, and the loosely coupled Prussian box tender, which led to disturbing riding qualities when running tender-first. Its riding performance was never fully satisfactory. As a result of poor weight compensation the top speed estimated by Garbe was never achieved and it was eventually assessed at 110 km/h.
One characteristic feature of the P 8 is the large distance between the centre and rear coupled axles. At the outset the P 8 only had a steam dome behind the sandbox; later a forward feed dome was added. Further constructional changes affected, inter alia, the driver's cab roofs, the smoke deflectors and various external assemblies.
There would appear to be been a number of boiler variations. The following combinations can be seen in photographs:
1/. boiler feeds on sides on boiler, steam dome in front of sandbox 2/. boiler feeds on sides of boiler, steam dome behind sandbox 3/. boiler feeds on top of boiler without feed dome, steam dome behind sandbox 4/. boiler feeds on top of boiler with feed dome, steam dome behind sandbox
At least some of very early engines (those with the "V" cabs) carried type (1) boilers and this type appears to have been the standard in the early years. Types (3) and (4) do not seem to have appeared until after WWI but ultimately became prevalent. See "100 Jahre Preussische P8" (Eisenbahn Kurier).
In order to be able to turn the locomotive even on small turntables, the Prussian state railways fitted the P 8 with tenders that originally held 21.5 m³ of water and 7 t of coal. Later the Deutsche Bundesbahn coupled the Class 38 with the tenders of withdrawn wartime locomotives the so-called 'Kriegslokomotiven', especially the bathtub tenders (Wannentender), which could carry more fuel. In addition the top speed when running tender-first was increased from 50 km/h (31 mph) to 85 km/h (53 mph).
On the other hand, the Deutsche Reichsbahn also used tenders of DRG Class 17 steam locomotives that had been taken out of service. These were the so-called long-distance tenders.
The P 8 could haul 300 t at 100 km/h (62 mph) and 400 t at 90 km/h (56 mph) on the flat and, after the world wars, could be found in almost the whole of Europe. The order to build the first 10 machines was issued to the firm of Schwartzkopff (later the Berliner Maschinenbau) in January 1908. With up to 14 express coaches attached, the trial runs went brilliantly. The first engine of this, soon internationally famous, class was placed into service in the Lower Rhine with the designation "Coeln 2401".
The P 8 could be used for a variety of duties and was found in heavy express train and goods train services heading almost every train. Even the railway authorities were very pleased with these engines, because the last P 8 locomotives were not mustered out by the Deutsche Reichsbahn until 1972, and by Deutsche Bundesbahn until 1974. More than 500 P 8 engines were in service for 50 years.
The majority of the P 8 class engines were built by Schwartzkopff (later Berliner Maschinenbau) who produced 1027 units, followed by Henschel in Kassel with 740 units. Besides the Prussian state railways, the Grand Duchy of Oldenburg State Railways (Grossherzoglich Oldenburgische Staatseisenbahnen) also bought five and the Grand Duchy of Mecklenburg Friedrich-Franz Railway (Grossherzoglich Mecklenburgische Friedrich-Franz-Eisenbahn) 13 machines. All German locomotive manufacturers later built Class P 8 locomotives including Hartmann and Esslingen.
In order to compensate for the shortage of locomotives after the First World War as a result of ceasefire reparations and the large number of damaged locomotives, the Karlsruhe railway division reproduced 40 Prussian P 8 engines at the Maschinenbau-Gesellschaft Karlsruhe. They were stationed in Villingen, Mannheim and Karlsruhe, and were given running numbers 1153 to 1192. Under the Deutsche Reichsbahn they were renumbered as 38 3793 to 38 3832 in 1925.
Before the First World War about 2350 P8 engines were made. Of these, 628 had to be transferred to the victorious powers as reparations after the end of the First World War. Poland received 190 (reclassified as the Ok1), Belgium 168 and France 162 locomotives. Up to 1923, the newly-founded Deutsche Reichsbahn replenished the fleet of P 8 locos with new machines. The last engine was built in 1926 by AEG at its locomotive works in Hennigsdorf, Berlin. A total of 3948 P 8 locomotives were built (including the inter-war copies in Romania), which makes it the most numerous passenger train locomotive ever to be built in the world.
After the Second World War, numbers 38 1069, 1391, 1434, 1677, 1809, 1818, 2052, 2692, 3264, 3495 und 3525 remained in Austria. Number 38 2052 was returned to the Deutsche Bundesbahn in 1952. Locomotives 38 1391, 1434, 1818, 3495 and 3525 went to the Soviet Union. The remaining machines formed the Austrian ÖBB Class 638. In 2004, the Austrian Society for Railway History (ÖGEG) acquired two machines of this type from Romania (the P 8 'copies'), one of which carries out steam 'specials' under the fictitious number of ÖBB 638.1301. Three of the class were impounded by British forces after World War II in Norway. They were sent to Copenhagen for repair and eventually were purchased by the Danish State Railways where they became DSB class T numbered 297, 298 & 299. The last survivor was scrapped in 1973.
As early as the end of the 1930s the Deutsche Reichsbahn planned to replace the now ageing P8 by a new locomotive. This led to the development of the DRG Class 23, of which only 2 examples had been built, however, by 1941. In 1950 the Deutsche Bundesbahn began to used the more advanced DB Class 23 as a replacement for the P8. The factories produced 105 examples by 1951. The change of motive power meant that the last Class 23 was withdrawn by the DB only one year after the last P8 had been retired.
D1 613 401(2) 28. Encyclopedic Leaflet system.
|
|||||||||||||||||||||||||