Norwegian State Railways types 19a and 28a, b
For the Ofotbanen, which connected the ore mines in Kiruna with the Norwegian port in Narvik, SLM in Switzerland developed the type 19a freight locomotives. These were 2-8-0 two-cylinder compound machines, which were the SLM's most powerful machines to date. To accommodate a wide firebox, the boiler was mounted high. After testing on the Gotthard, the six were delivered to Norway. In 1909 and 1910 three more were built in Norway by Hamar Jernstøberi.
In 1911, two more were built at Hamar, which now were superheated two-cylinder simples. They were designated Type 28a and initially remained two in number. When the Ofotbanen was electrified in 1922, the steam locomotives were relocated to other regions. It was only between 1939 and 1945 that the six remaining members of type 19a were also superheated and simpled and designated type 28b. They were withdrawn between 1955 and 1960.
Technical data
General
| Property | 19a | 28a, rebuilt 28b |
|---|---|---|
| Built | 1902, 1909-1910 | 1911, 1939-1945 |
| Manufacturers | SLM, Hamar Jernstøberi | Hamar Jernstøberi |
| Wheel arrangement | 2-8-0 (Consolidation) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | 19a | 28a, rebuilt 28b |
|---|---|---|
| Length | 16.70 m | 16.94 m |
| Wheelbase | 6.70 m | |
| Empty mass | 63.6 t | |
| Service mass | 71.6 t | |
| Adhesion mass | 62 t | |
| Total mass | 106.1 t | |
| Rigid wheelbase | 2.83 m | |
| Axle load | 15.5 t | |
| Water capacity | 15,000 l | |
| Fuel capacity | 4 t (coal) | 6 t (coal) |
Boiler
| Property | 19a | 28a, rebuilt 28b |
|---|---|---|
| Grate area | 2.8 m² | |
| Firebox surface | 11.7 m² | |
| Tube heating surface | 166 m² | |
| Evaporative heating surface | 177.7 m² | 150.5 m² |
| Total heating surface | 177.7 m² | 196.3 m² |
| Superheater surface | 45.8 m² | |
Power plant
| Property | 19a | 28a, rebuilt 28b |
|---|---|---|
| Driver diameter | 1,250 mm | |
| Boiler pressure | 13 bar | |
| Expansion type | compound | simple expansion |
| Cylinders | two, HP: 550 x 640 mm and LP: 820 x 640 mm | two, 600 x 640 mm |
Power
| Property | 19a | 28a, rebuilt 28b |
|---|---|---|
| Power source | steam | |
| Estimated power | 650 kW | 800 kW |
| Top speed | 40 km/h | 45 km/h |
| Starting effort | 118.0 kN | 203.7 kN |
| Starting effort simple | 141.6 kN | |
Calculated values
| Property | 19a | 28a, rebuilt 28b |
|---|---|---|
| Factor of adhesion | 1 : 5.15 | 1 : 2.99 |
| Optimal speed | 34 km/h | 24 km/h |
| Power-to-weight ratio | 9.1 kW/t | 11.2 kW/t |
| Heating Surface Equivalent | 236.2 m² | |
| Cylinder volume/HSE | 1 : 1,359.21 | |
| Adhesive weight/Total | 1 : 1.15 | |
| Tractive force/Heating surface | 1 : 13.87 | 1 : 21.67 |
| Grate area/Heating surface | 1 : 63.46 | 1 : 70.11 |
| Firebox/Tube surface | 1 : 14.19 | |
| Total/Superheater | 1 : 3.29 | |