BN Ea 3/6
| BN Ea 3/6 | |
|---|---|
 |
|
| Numbering: | 31, 32 |
| Number: | 2 |
| Manufacturer: | SLM |
| Year of construction (s): | 1913 |
| Retirement: | 1933 |
| Axis formula : | 1'C'2 |
| Genre : | Ea 3/6 |
| Gauge : | 1435 mm ( standard gauge ) |
| Length over buffers: | 14050 mm |
| Fixed wheelbase: | 1700 mm |
| Total wheelbase: | 10950 mm |
| Empty mass: | 69.3 t |
| Service mass: | 87.9 t |
| Friction mass: | 52.8 t |
| Top speed: | 90 km / h |
| Driving wheel diameter: | 1600 |
| Number of cylinders: | 4th |
| Cylinder diameter: | 425 mm |
| Piston stroke: | 640 mm |
| Boiler overpressure: | 12 bar |
| Number of heating pipes: | 164 |
| Number of smoke tubes: | 18th |
| Heating pipe length: | 4500 mm |
| Grate area: | 3 m² |
| Water supply: | 9 m³ |
| Fuel supply: | 2.5 t |
The two tank locomotives Ea 3/6 of the Bern-Neuenburg-Bahn ( BN ) were delivered by the SLM in 1913 . The purchase price is given as 114,500 Swiss Francs. They had road numbers 31 and 32.
Technical
The tank locomotive has an inverted Pacific chassis, which is powered by a four-wheel superheated steam engine. The engine consists of four cylinders of the same size, which lie next to each other in one axis, with an inclination of 1: 8. One outer and one inner cylinder each had a piston valve with inner edge inflow. This was possible because the internal and external engines were offset from one another by 180 ° on one side. The two engine sides were offset by 90 ° to each other. That is why the inner and outer cylinders on one side could be controlled together, only the steam supply to the inner cylinder, since it runs in opposite directions, had to be crossed. For this reason, only one control was necessary on each side of the machine. It was almost unique for a Swiss steam locomotive that all four drive rods acted on the central coupling axis, which is why the cylinder inclination of 1: 8 was necessary so that the drive rods of the inner cylinder come to lie above the first coupling axis. Since all four cylinders were supplied with live steam, the locomotive actually had eight exhaust blows per revolution, but a four-stroke was audible, as two blows always coincided due to the 180 ° offset. The boiler is at a height of 2900 mm. The braking, idling and sand spreading devices were duplicated in the driver's cab.
They had the serial numbers 2350 and 2351 on the SLM's nameplates.
The locomotives were able to move a train with a train weight of 300 tons on an 18-per-thousand gradient at 40 km / h.
Operational
As with the SBB C 5/6 with the quadruple engine, this locomotive also had to struggle with increased consumption. It was therefore anything but economical and could only exploit its advantages under full load, which was rather rare.
Due to the high axle pressure, use outside of their home route was only possible to a limited extent.
For these two reasons, after the electrification of their main line in 1928, no suitable area of application could be found. The machine was scrapped in 1933 and then scrapped.
literature
- Alfred Moser: The steam operation of the Swiss railways 1847-1966 . 4th updated edition, Birkhäuser, Stuttgart 1967. p. 310