Bergslagsbanans 2-6-2 Locomotives in Sweden


Class Details by Steve Llanso of Sweat House Media

Class Y3/S7 (Locobase 4067)

Data from "Tank-lok Litt. S7" one of a series of SJ locomotive diagrams archived by Anders Lundbing on [link], last accessed 10 June 2017 (Snabcon AB advertised its tools for mounting RJ45 connectors on bundled cables.) ; and builders' information "SJ Littera S7" in Svenska.lok.se at [link], last accessed 20 April 2024.

Originally built for this privately run railroad, the Y3 design proved attractive for other railroads in Sweden.The Hassleholm-Markaryds Jarnvag (HMJ) bought some in 1921, followed by the Landsrona & Halsingsborgs (L&HJ) in 1928-1929. Motala work numbers were 540-542 in 1915, 598 in 1917, 670-671, 697 in 1921; AB Svenska Järnvägsverkstäderna, Falun works numbers were 341-345 in 1927; NOHAB works numbers were 1669-1671 in 1924, 1850 in 1928.

NB: Locobase uses the external (water side) diameters for the tube and flue heating surface area to match Anglo-North American practice. Measured using the internal (fire side) diameters, tube and flue heating surface area calculated to 67.9 sq m (731 sq ft).

Nationalization in the early 1930s meant a gradual migration of these engines to the SJ (Statens Jarnvagar) over the next decade.

Those that had been counter-balanced for a 12.5 metric ton axle loading (27,558 lb) were eventually rebalanced to the 14.5-ton standard represented by the specifications.

The last of these engines were withdrawn from SJ service by 1970.

Principal Dimensions by Steve Llanso of Middle Run Media
ClassY3/S7
Locobase ID4067
RailroadBergslagsbanans (BJ)
CountrySweden
Whyte2-6-2T
Number in Class25
Road Numbers1874-1879, 1489, 1880-1882, 1883-1887, 1624
GaugeStd
Number Built25
Builderseveral
Year1915
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.14 / 3.70
Engine Wheelbase (ft / m)27.89 / 8.50
Ratio of driving wheelbase to overall engine wheelbase 0.44
Overall Wheelbase (engine & tender) (ft / m)27.89 / 8.50
Axle Loading (Maximum Weight per Axle) (lbs / kg)31,967 / 14,500
Weight on Drivers (lbs / kg)95,460 / 43,300
Engine Weight (lbs / kg)136,686 / 62,000
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)2350 / 8.90
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.20 / 2.90
Minimum weight of rail (calculated) (lb/yd / kg/m)53 / 26.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55.10 / 1400
Boiler Pressure (psi / kPa)156.60 / 1080
High Pressure Cylinders (dia x stroke) (in / mm)18.5" x 24.02" / 470x610
Tractive Effort (lbs / kg)19,860 / 9008.36
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.81
Heating Ability
Tubes (number - dia) (in / mm)100 - 1.89" / 48
Flues (number - dia) (in / mm)15 - 5" / 127
Flue/Tube length (ft / m)11.81 / 3.60
Firebox Area (sq ft / m2)83.96 / 7.80
Grate Area (sq ft / m2)19.38 / 1.80
Evaporative Heating Surface (sq ft / m2)900 / 83.60
Superheating Surface (sq ft / m2)220 / 20.40
Combined Heating Surface (sq ft / m2)1120 / 104
Evaporative Heating Surface/Cylinder Volume120.43
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3035
Same as above plus superheater percentage3642
Same as above but substitute firebox area for grate area15,778
Power L16350
Power MT439.95

All material Copyright © SteamLocomotive.com
Wes Barris