Data from "A-Loken" in "Rullande Materiel", Historiskt om Svenska Jarnvagar, on the web at [], last accessed 12 May 2018.
These were the first passenger locomotives to be bought in volume by the SJ. It's no accident that the design drew heavily on BP's experience in building similar locomotives for British railways. Cylinders and motion lay inside the plate frames. One difference was the longer cab roof. An A could reach a maximum speed of 90 kph (56 mph).
The first eight--delivered in 1863--drew names from Norse mythology: Vidar, Vanadis, Muspell, Sleipner, Blixten, Saga, Vala, and Heimdal. BP delivered eight more in 1864, four in 1866. In 1870, Swedish builder Nydquist & Holm of Trollhattan received the next order for four, and BP finished the class with eight more in 1873.
Traction gained with a single driven axle soon proved insufficient for most mainline traffic trains. The A-Loken entry illustrates the problem by comparing the 75 tonne train weight (locomotive, tender, and carriages) with the later weight of 72 tonnes for the tender and carriages alone.and by 1875, the As were relegated to local traffic. Eight were converted to 0-4-0ST saddle tanks and redesignated Oc.
Fifteen received new boilers in 1881-1884 and redesignated Ab1 and Ab2.
Two--77 Svea and 125 Einar collided head-on in Lagerlunda in 1875. They were written off as unrepairable. The others in the class were withdrawn in 1899-1910. A class 75 Gota was donated to the Swedish Railway Museum in 1905,
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | A (I) |
| Locobase ID | 20373 |
| Railroad | Statens Jarnvagar (SJ) |
| Country | Sweden |
| Whyte | 2-2-2 |
| Number in Class | 32 |
| Road Numbers | 33-40, 56-63, 74-77, 99-102, 123-130 |
| Gauge | Std |
| Number Built | 32 |
| Builder | several |
| Year | 1863 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | |
| Engine Wheelbase (ft / m) | 14 / 4.27 |
| Ratio of driving wheelbase to overall engine wheelbase | |
| Overall Wheelbase (engine & tender) (ft / m) | 30.20 / 9.20 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 16,755 / 7600 |
| Weight on Drivers (lbs / kg) | 26,896 / 12,200 |
| Engine Weight (lbs / kg) | 55,116 / 25,000 |
| Tender Loaded Weight (lbs / kg) | 38,140 / 17,300 |
| Total Engine and Tender Weight (lbs / kg) | 93,256 / 42,300 |
| Tender Water Capacity (gals / ML) | 1637 / 6.20 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3.60 / 3 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 45 / 22.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 73.80 / 1874 |
| Boiler Pressure (psi / kPa) | 124.70 / 860 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 15" x 20" / 381x508 |
| Tractive Effort (lbs / kg) | 6463 / 2931.57 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.16 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 9.61 / 2.93 |
| Firebox Area (sq ft / m2) | |
| Grate Area (sq ft / m2) | 13.99 / 1.30 |
| Evaporative Heating Surface (sq ft / m2) | 743 / 69.06 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 743 / 69.06 |
| Evaporative Heating Surface/Cylinder Volume | 181.64 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1745 |
| Same as above plus superheater percentage | 1745 |
| Same as above but substitute firebox area for grate area | |
| Power L1 | |
| Power MT | |