Dala-Ockelbo-Norrsundet Articulated Locomotives in Sweden

Class Details by Steve Llanso of Sweat House Media

Class 8-12 (Locobase 5069)

See [] (11 July 2004) for data.

Possibly the only Mallets to run on a Swedish railway, this class (Atlas works #113, 114 & 1 more) was delivered in 1910 to serve the oddly sized Dala -Ockelbo - Norrsundets JSrnvSg (DONJ). This narrow gauge (891 mm) railway between Linghed and Norrsundet, 86 kilometres long, closed in 1970.

In 1983, A 6-km (3.6-mile) part of the DONJ between Jadraas and Tallas was revived as a museum road and the three Mallets formed part of its rolling stock. Two (8 & 12) actually operate, although the 8 entered long-term overhaul in 2014 when the boiler was deemed to be in poor condition.

Masma of Mariestad began restoration of the boiler from October 2015-February 2016. In February 2017, the DONJ sent the boiler back to Masma to be mated to a new firebox. Then the overhaul was suspended to allow work on more critical projects and to raise funds to continue a 2 million kronr (equivalent to US$220,000 in April 2018) update.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID5069
RailroadDala-Ockelbo-Norrsundet (DONJ)
Number in Class3
Road Numbers8, 11, 12
Gauge891 mm
Number Built3
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)34.78 / 10.60
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)127,427 / 57,800
Engine Weight (lbs / kg)127,427 / 57,800
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)127,427 / 57,800
Tender Water Capacity (gals / ML)2112 / 8
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.20 / 2
Minimum weight of rail (calculated) (lb/yd / kg/m)35 / 17.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)39.40 / 1001
Boiler Pressure (psi / kPa)170.70 / 11.80
High Pressure Cylinders (dia x stroke) (in / mm)12.99" x 19.69" / 330x500
Low Pressure Cylinders (dia x stroke) (in / mm)19.69" x 19.69" / 500x500
Tractive Effort (lbs / kg)17,050 / 7733.76
Factor of Adhesion (Weight on Drivers/Tractive Effort) 7.47
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)18.29 / 1.70
Evaporative Heating Surface (sq ft / m2)1151 / 106.97
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1151 / 106.97
Evaporative Heating Surface/Cylinder Volume381.10
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3122
Same as above plus superheater percentage3122
Same as above but substitute firebox area for grate area
Power L1
Power MT

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