Baden IV e

Baden IV e
DRG Class 38.70
Number(s) G.Bad.St.E: 18…356,
552–556, 575–595,
622–628, 664–690
DRG: 38 7001–7007,
38 7021–7025,
38 7031–7034,
38 7041–7046,
38 7061–7073
Quantity 83
Manufacturer Grafenstaden,
MBG Karlsruhe
Year(s) of manufacture 1894–1901
Retired by 1932
Wheel arrangement 4-6-0
Axle arrangement 2′C n4v
Gauge 1,435 mm (4 ft 8 1⁄2 in)
Length over buffers 16,960 mm (55 ft 8 in)
Height 4,150 mm (13 ft 7 in)
Bogie wheelbase 1,900 mm (6 ft 3 in)
Overall wheelbase 7,450 mm (24 ft 5 in)
Wheelbase incl. tender 14,875 mm (48 ft 9.6 in)
Empty weight 52.80 t
Service weight 58.30 t
Adhesive weight 41.70 t
Axle load 13.90 t
Top speed 90 km/h (56 mph)
Indicated Power 778–811 indicated horsepower (580–605 kW)
Coupled wheel diameter 1,600 mm (5 ft 3 in)
Driving wheel diameter 1,600 mm (5 ft 3 in)
Leading wheel diameter 850 mm (2 ft 9 in)
Valve gear Walschaerts (Heusinger)
No. of cylinders 4
LP cylinder bore 350 mm (14 in)
HP cylinder bore 550 mm (22 in)
Piston stroke 640 mm (25 in)
Boiler Overpressure 13 bar (189 psi)
No. of heating tubes 191
Heating tube length 4,250 mm (13 ft 11 in)
Grate area 2.10 m2 (22.6 sq ft)
Radiative heating area 11.17 m2 (120.2 sq ft)
Evaporative heating area 125.93 m2 (1,355.5 sq ft)
Tender bad. 2'2' T 15
Water capacity 15 m3 (4,000 US gal)
Fuel 5 t coal
Locomotive brakes Westinghouse Henry brake

The locomotives of Baden Class IV e were designed and built for the Grand Duchy of Baden State Railway in the late 19th century by the Elsässischen Maschinenbau-Gesellschaft Grafenstaden, who supplied the first eight examples in 1894. They were the first locomotives in Germany with a 4-6-0 wheel arrangement. Another 75 locomotives were built up to 1901 by the Maschinenbau-Gesellschaft Karlsruhe.

History

The Baden IV e engines were created primarily for express and passenger train duties on the steep lines of the Schwarzwaldbahn. This had become necessary, because the locomotives that had been employed hitherto, the IV b, IV c tender locomotives and the IV d tank engines, were unable to meet the growing demands placed on them.

In 1914 all the engines were still on the books of the Baden state railway. However they were replaced in the express service role as early as 1903 by the II d and IV f. In 1925, the Deutsche Reichsbahn incorporated the remaining 35 examples into DRG Class 38.70; they were given – in groupings based on their delivery batches – the running numbers 38 7001 – 38 7007, 38 7021 – 38 7025, 38 7031 – 38 7034, 38 7041 – 38 7046 and 38 7061 – 38 7073. The engines were all withdrawn from service by 1932.

Fifteen locomotives were surrendered as reparations:

Number 38 7001 was sectioned in September 1936 and is displayed today in the University of Karlsruhe (TH).

Design features

In spite of the shortcomings in ride of the Grafenstaden outside-frame bogies, the locomotive had smooth riding qualities. The engine had a riveted interior sheet-metal frame and the coupled wheels had springs under the axle boxes, that were not linked by compensating levers.

An innovative feature, for Germany, of the IV e was the use of a four-cylinder, de Glehn compound, that was employed for the first time on a locomotive with three coupled axles. The Alsace engineering company had previously built four-coupled locomotives with De-Glehn engines – especially for the Chemins de Fer du Nord. Very similar engines to the Baden IV e were soon delivered to Prussia (as the Prussian P 7), to the Imperial Railways in Alsace-Lorraine (as the P 7 and S 9), and to most French railways, as well as to Belgium, Spain and Portugal.

The high-pressure cylinder was outside and drove the middle coupled wheels, whilst the inside low-pressure cylinders drove the leading coupled axle. These two cylinders were slightly angled.

The compound engine was chosen to strike a balance between the high tractive effort required when hauling uphill which would be provided by smaller diameter wheels and the lower axle forces when running downhill that favoured larger wheel diameters. The low and high pressure engines could be controlled separately. This made it easier to start up. On trial runs on routes with an incline of 17.6‰ (1 in 56.8) a power of 581 to 636 indicated horsepower (433 to 474 kW) was measured for a speed of 30 km/h (19 mph). The highest value was between 778 and 811 ihp (580 and 605 kW). With a 250 tonne train, it could reach a speed of 75 km/h (47 mph) on the level and 40 km/h (25 mph) on an incline of 10‰ (1 in 100).

The locomotives were equipped with tenders of the Baden classes 3 T 13,5, bad 3 T 14 and bad 2′2′ T 15.

See also

References

External links


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