Oldenburgische Staatsbahn 4-4-0 Locomotives in Germany


Class Details by Steve Llanso of Sweat House Media

Class P4.1/BR 36.12 (Locobase 15130)

Data from 1896: Personenzuglokomotive, P 4.1 (2 B-PL), Baureihe 36.12 in Laenderbahn.info ( []). See also Albert Gieseler, "Baureihe 36.12" on his Dampmaschinen und Lokomotiven website at [], last accessed 29 September 2019.

Very similar to the Hanover P4.1s described in Locobase 5841 , the first five of the class arrived in 1896. They had no steam dome and only a small sand dome on the boiler. They proved very efficient for their size, managing 368 -tonne (405 short ton) trains on the level at speeds up to 42 mph (68 km/h).

Fourteen more arrived from Hanomag in1902. The whole class was gathered into the DRG as Bau Reihe 36.12. They only served a short while with the last being withdrawn in 1931.


Class P4.2 / BR 36.12 (Locobase 8962)

Data from Albert H Bone, "Some Recent Designs of Locomotives for Service on Continental Railways", Cassier's Magazine, 1910, pp. 561-609, supplemented and amended by [], last accessed 14 May 2011; and "Passenger Locomotive for the Duchy of Oldenburg Railroads", Railroad Gazette, Volume 43, No 3 (19 July 1907), pp. 73-74. Locomotive 178 bore Hannover works number was 5000. (Works numbers for the class were 4996-5000 in 1907, 548-5410 in 1909.

Bone concedes that there's nothing remarkable about this Eight-wheeler, but he included it in the tabulation of recent designs for its Lentz valves, "...a form of double-seated valve, actuated by means of a reciprocating rod having hardened, cam-shaped surfaces which engage with hardened steel rollers mounted in the valve spindles." The valve was fitted to the 1909 trio (road numbers 188-190).

He observed that the Lentz valve would be a "formidable rival" to the slide valve and, while this did not happen, many locomotives would be so equipped. Bone summarized well the advantages of such cam-operated "drop valves" (Caprotti valves were another example) over slide valves: "Owing to their quick opening and closing, a better indicator diagram can be obtained, with an absence of wire-drawing." In the presence of highly superheated steam, "...they have the advantage of being without rubbing surfaces under pressure."

Although not described as a superheated engine, the design did have a Ranafier steam dryer fitted between the HP and LP cylinders that included 154 sq ft of heating surface.

Bone noted that these engines attained speeds of 68 km/h (42.25 mph) betweeen Wilhelmshaven and Oldenburg with a trailing load of 34 axles totalling 342 tons and 45-55 km/h (28-34 mph) trailing 425 tons.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassP4.1/BR 36.12P4.2 / BR 36.12
Locobase ID15130 8962
RailroadOldenburgische StaatsbahnOldenburgische Staatsbahn
CountryPrussiaGermany
Whyte4-4-04-4-0
Number in Class198
Road Numbers107-111 / BR 36 1201-1219174-178, 188-190/BR 36 1251-1258+
GaugeStdStd
Number Built198
BuilderHanomagHannover
Year18961907
Valve GearHeusingerHeusinger
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.05 / 2.15 8.53 / 2.60
Engine Wheelbase (ft / m)20.80 / 6.3424.28 / 7.40
Ratio of driving wheelbase to overall engine wheelbase 0.34 0.35
Overall Wheelbase (engine & tender) (ft / m)48.39 / 14.7547.29 / 14.41
Axle Loading (Maximum Weight per Axle) (lbs / kg)30,644 / 13,90033,290 / 15,100
Weight on Drivers (lbs / kg)60,407 / 27,40066,580 / 30,200
Engine Weight (lbs / kg)99,649 / 45,200115,081 / 52,200
Tender Loaded Weight (lbs / kg)106,399 / 48,262
Total Engine and Tender Weight (lbs / kg)221,480 / 100,462
Tender Water Capacity (gals / ML)3168 / 125280 / 20
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 4.40 / 4 5.50 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)50 / 2555 / 27.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)68.90 / 175068.90 / 1750
Boiler Pressure (psi / kPa)174 / 12169.70 / 11.70
High Pressure Cylinders (dia x stroke) (in / mm)18.11" x 23.62" / 460x60018.11" x 23.62" / 460x600 (1)
Low Pressure Cylinders (dia x stroke) (in / mm)26.77" x 23.62" / 680x600 (1)
Tractive Effort (lbs / kg)16,629 / 7542.8011,126 / 5046.67
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.63 5.98
Heating Ability
Tubes (number - dia) (in / mm)248 - 1.732" / 44231 - 1.535" / 39
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)11.98 / 3.6512.80 / 3.90
Firebox Area (sq ft / m2)93.86 / 8.7296.66 / 8.98
Grate Area (sq ft / m2)20.67 / 1.9224.43 / 2.27
Evaporative Heating Surface (sq ft / m2)1286 / 119.471285 / 119.35
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1286 / 119.471285 / 119.35
Evaporative Heating Surface/Cylinder Volume182.62364.96
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation35974146
Same as above plus superheater percentage35974146
Same as above but substitute firebox area for grate area16,33216,403
Power L149814479
Power MT363.57296.62

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