KPEV 2-10-2 Locomotives in Germany

Class Details by Steve Llanso of Sweat House Media

Class T20 / BR 95 (Locobase 4207)

Some data from the US Military Railway Service Equipment Data Book for German Locomotives supplied by Allen Stanley from his extensive Rail Data Exchange in March 2004. See also []; "Baureihe 95" on Albert Gieseler's Dampfmachinen und Lokomotiven website at [], last accessed 29 November 2021; and "New German State Railway Tank Locomotive for Steep Gradients", Locomotive Magazine, Volume XXIX [29] (15 October 1923), p 290.

Originally entered service as the Prussian Railways T20 class built by Borsig and Hartmann in 1922-1924. Although based on the "Giant" quartet of decapod tanks (Locobase 5764), the T20s' cylinders had a relatively longer stroke, although it was still an "oversquare" ratio.

(Although they usually recorded the external diameters (water side) of the tubes, German locomotive designers calculated the tube heating surface using the interior diameter (fire side). In this locomotive, fire side heating surface area was 181.0 sq m 1,948 sq ft). Adding 6.7 sq m of direct heating surface area brought total area to 241.0 sq m (2,594 sq ft). Locobase specs show the water side area calculated from the tubes' external diameters.)

As can be imagined given the wheel arrangement, power, and driver diameter, these decapods scaled the steep grades on the lmenau - Suhl and Arnstadt - Suhl sections in Thuringer Walde, Frankenwalde's Probstzella - Rothenkirchen churches), the Geislinger increase, the inclined plane at Neuenmarkt-Wirsberg and on the Dresden-Chemnitz line's challenging Tharandt - Klingenberg Colmitz section.

[] (a German steam locomotive parts supplier) gives the normal steaming capacity as 13,000 kg/hr. The same site says these were rated as capable of hauling a 320-short ton train up a 2% grade at 40 kph. [] (3 May 2003) backs up this claim with a table of tonnage ratings from 1924 and 1962 (the latter in parenthesis)

1/2% 50 km/h 960 (765) t

1% 35 km/h 830 (715) t

2% 30 km/h 480 (415) t

2 1/2% 25 km/h 430 (390) t

The data -- particularly the boiler, grate, and factor of adhesion and and the heating surface to cylinder volume ratio -- suggest that these engines could run out of steam if not confined to relatively short trips.

After World War II, all of the 31 remaining locomotives stayed in East Germany. Of these, 24 were rebuilt by the DDR between 1964-1973.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassT20 / BR 95
Locobase ID4207
Number in Class45
Road Numbers95 001-95 045
Number Built45
Valve GearHeusinger
Locomotive Length and Weight
Driver Wheelbase (ft / m)21.65 / 6.60
Engine Wheelbase (ft / m)39.04 / 11.90
Ratio of driving wheelbase to overall engine wheelbase 0.55
Overall Wheelbase (engine & tender) (ft / m)39.04 / 11.90
Axle Loading (Maximum Weight per Axle) (lbs / kg)42,990 / 19,500
Weight on Drivers (lbs / kg)210,100 / 95,300
Engine Weight (lbs / kg)280,869 / 127,400
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)280,869 / 127,400
Tender Water Capacity (gals / ML)3168 / 12
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 4.40 / 4
Minimum weight of rail (calculated) (lb/yd / kg/m)70 / 35
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55.10 / 1400
Boiler Pressure (psi / kPa)203.10 / 14
High Pressure Cylinders (dia x stroke) (in / mm)27.56" x 25.98" / 700x660
Tractive Effort (lbs / kg)61,827 / 28044.29
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.40
Heating Ability
Tubes (number - dia) (in / mm)218 - 1.772" / 45
Flues (number - dia) (in / mm)34 - 5.236" / 133
Flue/Tube length (ft / m)14.76 / 4.50
Firebox Area (sq ft / m2)182.99 / 17
Grate Area (sq ft / m2)46.93 / 4.36
Evaporative Heating Surface (sq ft / m2)2364 / 219.60
Superheating Surface (sq ft / m2)673 / 62.50
Combined Heating Surface (sq ft / m2)3037 / 282.10
Evaporative Heating Surface/Cylinder Volume131.79
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9531
Same as above plus superheater percentage11,628
Same as above but substitute firebox area for grate area45,342
Power L19707
Power MT509.29

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