Polish State Rwys 2-6-2 Locomotives in Poland


Class Details by Steve Llanso of Sweat House Media

Class OL-49 (Locobase 1685)

Replaced aging P8 and Austrian Prairies, but came in at a higher adhesion weight and proved capable of handling all expresses. The high running board gave an open, striding look to the drivers, but the ironing-board smoke deflectors at either side of the stack, small leading truck wheels, and a glacis under the smokebox distorted the overall proportions.

Data from Polish museum website [] and AE A[nthony] E[dward] Durrant, The steam loc. [] (August 2002) says that the firebox was equipped with circulators.


Class Okl-27 (Locobase 1687)

Data from Tomas Galka's English-language Polish locomotives website [], last accessed 10 January 2007.

Local mixed-traffic engine that was the largest of its wheel arrangement in Europe and the very first locomotive of entirely Polish design.

The design was not an immediate success, particularly because of a tendency to derail. The solution proved to be replacing the lead Adams axle with a Krauss-Helmholz design that combined the lead truck and the first driven axle. Even so, says Galka, the design was still "somewhat uneasy" at speeds over 50 km/h (31 mph), a problem that didn't greatly affect the locomotive's ability to deliver suburban passenger service.

Most of the class wound up serving the heavy Warsaw-area suburban traffic, where they were quite satisfactory: "They soon earned a reputation of good, reliable locomotives [Galka comments], well suited to fulfill demands they had been designed for. Suburban traffic remained their prime domain for a long time"

A[nthony] E[dward] Durrant, The steam loc

Principal Dimensions by Steve Llanso of Sweat House Media

ClassOL-49Okl-27
Locobase ID1685 1687
RailroadPolish State RwysPolish State Rwys
CountryPolandPoland
Whyte2-6-22-6-2T
Number in Class116122
Road Numbers
GaugeStdStd
Number Built116122
BuilderChrzanowCegielski
Year19491928
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.12 / 412.47 / 3.60
Engine Wheelbase (ft / m)33.63 / 10.2529.53 / 8.80
Ratio of driving wheelbase to overall engine wheelbase 0.39 0.42
Overall Wheelbase (engine & tender) (ft / m)57.33 / 17.4729.53 / 8.80
Axle Loading (Maximum Weight per Axle) (lbs / kg)37,810 / 17,15037,038 / 16,800
Weight on Drivers (lbs / kg)113,316 / 51,399119,490 / 54,200
Engine Weight (lbs / kg)183,533 / 83,249187,613 / 85,100
Tender Loaded Weight (lbs / kg)150,355 / 68,200
Total Engine and Tender Weight (lbs / kg)333,888 / 151,449187,613 / 85,100
Tender Water Capacity (gals / ML)6525 / 24.72
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)13.20 / 12
Minimum weight of rail (calculated) (lb/yd / kg/m)63 / 31.5066 / 33
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)68.90 / 175059.10 / 1500
Boiler Pressure (psi / kPa)232.10 / 16203.10 / 14
High Pressure Cylinders (dia x stroke) (in / mm)19.7" x 24.8" / 500x63021.26" x 24.8" / 540x630
Tractive Effort (lbs / kg)27,559 / 12500.5732,743 / 14851.99
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.11 3.65
Heating Ability
Tubes (number - dia) (in / mm)102 - 2" / 51
Flues (number - dia) (in / mm)38 - 5.25" / 133
Flue/Tube length (ft / m)15.80 / 4.8213.62 / 4.15
Firebox Area (sq ft / m2)179.69 / 16.70123.09 / 11.44
Grate Area (sq ft / m2)39.81 / 3.7026.25 / 2.44
Evaporative Heating Surface (sq ft / m2)1715 / 159.401336 / 124.15
Superheating Surface (sq ft / m2)735 / 68.30454 / 42.20
Combined Heating Surface (sq ft / m2)2450 / 227.701790 / 166.35
Evaporative Heating Surface/Cylinder Volume196.02131.11
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation92405331
Same as above plus superheater percentage12,0126664
Same as above but substitute firebox area for grate area54,21831,249
Power L128,11311,853
Power MT1640.86656.07

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