Bavarian State 2-4-4 Locomotives in Germany


Class Details by Steve Llanso of Sweat House Media

Class D XII / BR 73.0 (Locobase 5931)

Data from Christian Lindecke's website [link] (visited 28 Nov 2003) (translated by Google); additional data from US Military Railway Service Equipment Data Book -- German Locomotives supplied by Allen Stanley from his extensive Rail Data Exchange in March 2004 and from "New Locomotives for the Bavarian State Railways", Locomotive Magazine, Vol V (March 1900), pp. 37-38. Works numbers were 3500-3510 in 1897; 3846-3865 in 1898, 3910-3915 in 1899, 4315-4340 in 1900; 4401, 4465-4482 in 1901m 4957-4598 in 1903, and 4858-4970 in 1904.

These tanks ran in the Munich area and were apparently ideally suited to the duty because the Pfalzbahn procured 31 more from 1900 to 1903 (Locobase 20201) and the Elass-Lothringen (Alsace-Lorraine) railway bought 37 from 1903-1912 (see Locobase 15589). The Bayern established their maximum speed at a useful 90 kph (56 mph).

In 1907, another nine locomotives - now designated Pt 2/5 N -- that put another 1.3 metric tons on the drivers were built to the same dimensions.

NB: German sources give the tube diameter as 45 mm, as shown in Locobase's specs, but also calculate the tube heating surface as 104.64 sq m (1,126 sq ft). The latter figure equates to an inside (fire side) tube diamter of 40 mm (1.57").

By the time the DRG began absorbing locomotive classes, 94 locomotives remained from the Bavarian stock.and these engines continued to serve for several more years. Retirements began in 1931 and were completed by 1936.


Class Pt 2/5 H // BR 73.2 (Locobase 5932)

Data from Christian Lindecke's website [link] (visited 28 Nov 2003) (translated by Google), supplemented by [link], last accessed 14 may 2011.

This was something of an experiment in which the K.Bay.Sts.B tried superheating the basic, and quite successful, D XII tank locomotive.

It was too little engine for increasing traffic demands so it remained a one-only display piece (first shown at the 1906 Nuremburg exhibition). The larger cylinders meant the boiler was increasingly hard pressed and the factor of adhesion had dropped into the slippery range.

Even so, the DRG granted the locomotive its own class and number DRG 73 201. Not until 1933 did the BR 73 2 leave service.

Principal Dimensions by Steve Llanso of Middle Run Media
ClassD XII / BR 73.0Pt 2/5 H // BR 73.2
Locobase ID5931 5932
RailroadBavarian StateBavarian State
CountryGermanyGermany
Whyte2-4-4T2-4-4T
Number in Class631
Road Numbers2201-2296/73 031-125DRG 73 201
GaugeStdStd
Number Built631
BuilderKraussKrauss
Year18971906
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 6.73 / 2.05
Engine Wheelbase (ft / m)28.87 / 8.8028.87 / 8.80
Ratio of driving wheelbase to overall engine wheelbase 0.23
Overall Wheelbase (engine & tender) (ft / m)28.87 / 8.8028.87 / 8.80
Axle Loading (Maximum Weight per Axle) (lbs / kg)32,187 / 14,60035,274 / 16,000
Weight on Drivers (lbs / kg)65,257 / 29,60070,548 / 32,000
Engine Weight (lbs / kg)149,473 / 67,800155,867 / 70,700
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)2402 / 9.102402 / 9.10
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.30 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)54 / 2759 / 29.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)64.60 / 164064.60 / 1640
Boiler Pressure (psi / kPa)174 / 1200174 / 1200
High Pressure Cylinders (dia x stroke) (in / mm)17.72" x 22.05" / 450x56019.69" x 22.05" / 500x560
Tractive Effort (lbs / kg)15,852 / 7190.3519,572 / 8877.72
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.12 3.60
Heating Ability
Tubes (number - dia) (in / mm)200 - 1.772" / 45125 - 1.772" / 45
Flues (number - dia) (in / mm)14 - 5" / 127
Flue/Tube length (ft / m)12.57 / 3.8312.57 / 3.83
Firebox Area (sq ft / m2)92.89 / 8.6396.95 / 9.01
Grate Area (sq ft / m2)21.10 / 1.9621.09 / 1.96
Evaporative Heating Surface (sq ft / m2)1271 / 118.12958 / 89.07
Superheating Surface (sq ft / m2)217 / 20.19
Combined Heating Surface (sq ft / m2)1271 / 118.121175 / 109.26
Evaporative Heating Surface/Cylinder Volume201.95123.28
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation36713670
Same as above plus superheater percentage36714330
Same as above but substitute firebox area for grate area16,16319,906
Power L151668186
Power MT349.05511.62

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