Suomen valtionrautatiet 4-6-2 Locomotives in Finland

Class Details by Steve Llanso of Sweat House Media

Class Ukko-Pekka/P-1/Hr1 (Locobase 4217)

Data from Markku Karvonen's (visited 29 March 2003). Adhesion weight from [] ...

The largest and fastest of all Finnish passenger steam engines, this class was built primarily by Lokomo over 20 years. (Tampella contributed 8 in 1955.) According to the "Ultimate Narcissist", a Finnish railfan whose website appears as [] (visited 28 Feb 2003), these engines were designed in response to a demand for more power. Their nickname, which translates as "Grandpa Peter", was shared by the then-president of Finland PE Svinhuvud. It stood, says UN, for "greatness and power."

Although the building program was delayed by the war, the Hr1s soon became the premier passenger engines. Even in the 1960s, they averaged a bit under 10,000 km (6,200 miles) per month. The last two -- 1020-1021 -- had roller bearings and were dubbed "Rolla Peter". Photographs in Ziel and Eagleson (1973) show them with slender, tapered main and side rods, spoked drivers, small "elephant-ear" smoke lifters flanking the smokebox, a sloping glacis over a slotted pilot, and plain, straight lines.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID4217
RailroadSuomen valtionrautatiet (VR)
Number in Class21
Road Numbers1001-1021
Number Built21
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)37,479 / 17,000
Weight on Drivers (lbs / kg)114,640 / 52,000
Engine Weight (lbs / kg)205,030 / 93,000
Tender Loaded Weight (lbs / kg)136,686 / 62,000
Total Engine and Tender Weight (lbs / kg)341,716 / 155,000
Tender Water Capacity (gals / ML)7128 / 27
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 9.90 / 9
Minimum weight of rail (calculated) (lb/yd / kg/m)64 / 32
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)74.80 / 1900
Boiler Pressure (psi / kPa)217.60 / 15
High Pressure Cylinders (dia x stroke) (in / mm)23.23" x 25.59" / 590x650
Tractive Effort (lbs / kg)34,146 / 15488.38
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.36
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)38.09 / 3.54
Evaporative Heating Surface (sq ft / m2)2103 / 195.45
Superheating Surface (sq ft / m2)732 / 68.03
Combined Heating Surface (sq ft / m2)2835 / 263.48
Evaporative Heating Surface/Cylinder Volume167.53
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation8288
Same as above plus superheater percentage10,443
Same as above but substitute firebox area for grate area
Power L1
Power MT

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