NOB Ed 2/2
| NOB Ed 2/2 from 1892 NOB E 3/3 |
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|---|---|---|---|
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| number | 3 | ||
| numbering | NOB 251-253 SBB 8661-8662 |
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| Manufacturer | Esslingen | ||
| Commissioning | 1876 | ||
| Retirement | 1876 a , 1935, 1938 | ||
| modification | Original Ed 2/2 | Conversion 3/3 (2nd boiler) | 3rd boiler |
| Axis formula | B. | C. | |
| Service mass | 24.2 t | 26.9 t | 27.5 t |
| Axle load | k. A. | ||
| Length over buffers | 7160 mm | 7445 mm | |
| Ø driving wheel | 893 mm | 910 mm | |
| Top speed | 35 km / h | ||
| Boiler pressure | 12 kgf / cm² | 11 kgf / cm² | |
| Piston stroke | 530 mm | ||
| Cylinder diameter | 380 mm | 350 mm | |
| Grate surface | 1.3 m² | 1.1 m² | 1.0 m³ |
| Evaporation heating surface | 85.9 m² | 63.5 m² | 62.4 m² |
| Superheater heating surface | no | ||
| power | 280 hp | ||
| traction | 5000 kg | ||
| Brake design | Spindle brake | ||
In 1876 the Swiss Northeast Railway ( NOB ) procured a total of three tender steam locomotives with roller drive type Wetli for the operation of the Wädenswil-Einsiedeln-Bahn (WE) , which from 1887 were designated as type Ed 2/2 .
The machines were supplied by the Esslingen machine factory; the purchase price was 54,265 Swiss francs.
Actually, the designation Edh 2/2 would have been appropriate in 1876, since it was a machine of the type . But since it lost its gear drive within a year, it is listed in all archives under NOB Ed 2/2. At the NOB itself it was referred to as Series E until 1887; only then did the NOB take over the Swiss type designations , and it became Ed 2/2.
backgrounds
Since the Wädenswil-Einsiedeln-Bahn had concluded an operating contract with the NOB, it was up to the NOB to procure the necessary operating resources. The three machines were the only locomotives for operational use that were ever equipped with the Wetli roller wheel system, a special gear system. It is true that the director Charles Brown of the Swiss Locomotive Factory Winterthur (SLM) built a makeshift locomotive in 1874 in order to test the system. After modifications that were necessary to develop the drive system, this test machine was taken out of service in 1876 and canceled in 1880.
The accident of November 30, 1876, in which one of these machines (number 263) was destroyed, was the fatal blow for this system. It was also the reason why the NOB withdrew from the operating contract with the WE. Thus, after WE had procured its own machines, the machines were deprived of their procurement route.
Because of the accident and because the line could also be operated at 50 per mil as a pure adhesive track , the roller wheel was immediately removed and the two remaining machines continued to operate as Ed 2/2. In 1892 both machines were rebuilt. In place of the already removed roller wheel, another drive axle was installed, so that a type E 3/3 steam tender locomotive was created.
technology
The installation of the Wetli roller system, which was developed by Kaspar Wetli , made the steam locomotive a special feature, because this roller could be raised and lowered with steam pressure. Operation as an adhesion or rack-and-pinion locomotive was therefore not only dependent on the installation of a rack in the track, but also on the operating condition of the locomotive.
Like most of the machines at the NOB at that time, these were also influenced by Maey's basics. The 12 millimeter thick inner frame was provided with strong struts and supported itself on the axle bearings via four suspension springs, which were located under the running plate on the frame. The Maey's cauldron had neither a dome nor an anchor for the fire box. Inside there were 195 boiler tubes with a length of 2910 millimeters. The safety valve was on the manhole cover. Since a strong exhaust impact was to be expected, an air chamber was installed between the outlet opening of the valve box and the blowpipe, which had a variable opening. The drive rods were massive, but milled out to reduce weight. The control was carried out in the Allan type with control via screw and wheel. The piston rods were carried forward. A four-block spindle brake was installed, which acted on the drive wheels. The water tanks were arranged to the side of the boiler and had a very small volume of 3 m³ for the performance of the machine. The same applies to the coal supply of 0.6 tons, which was housed in two lateral containers behind the driver's cab. The sandboxes were integrated in the front of the water tanks. Steam heating was installed.
The machines were never equipped with a power brake and a speedometer.
Wetli roller wheel system
The drum was stored in the main frame and supported itself on the adhesion rails with flanged running wheels. The drive took place from the rear drive axle via separate drive rods. The roller wheel could be raised and lowered using a small steam cylinder and radial axle guide . When the system intervened, this cylinder was pressurized to such an extent that the pressure on the roller wheel increased by 3.5 tons. After the accident on November 30, 1876, the roller wheel and the drive rods required for it were removed.
Conversion E 3/3
Since the removal of the roller wheel created enough space between the two drive axles, it was advisable to install a third drive axle. The renovation took place in the Zurich workshop in 1892, with a new frame made using old parts. It is all the more astonishing that the company's inventories were not increased. The cylinder diameter was even reduced to 350 millimeters and the boiler pressure of the new boiler was reduced to 11 bar.
In 1905 a third boiler was installed in both machines, which did not differ significantly from the second. In the second boiler there were 130 boiler tubes 2855 millimeters long; the grate area was reduced to 1.1 m². The third boiler had 142 boiler pipes, 2855 millimeters long; the grate area was still 1 m².
After the renovation, the machines could carry 3 m³ of water and 0.8 tons of coal.
In 1930 an eight-block external brake was also installed.
| NOB until 1879 |
NOB 1879-1895 |
NOB 1895-1902 |
SBB from 1902 |
Factory number |
Construction year | Manufacturer | 2nd boiler | modification | 3rd boiler | Discarded | Remarks |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 251 | 251 | 451 | 8661 | 1519 | 1876 | Esslingen | 1892 | 1892 | 1905 | 1935 | from 1892 E 3/3 |
| 252 | 252 | 452 | 8662 | 1520 | 1876 | Esslingen | 1892 | 1892 | 1905 | 1938 | from 1892 E 3/3 |
| 253 | - | - | - | 1521 | 1876 | Esslingen | - | - | - | 1876 | Wadenwil accident |
Operational
The two remaining machines with removed roller wheels were only in service at the WE until 1878 the ordered E 3/ 3s arrived. After that, they traveled on the NOB routes.
After the reconstruction in E 3/3, they were the most time in heavy shunting and for the Belad the Trajektfähren used Romanshorn in the station.
swell
- Alfred Moser: The steam operation of the Swiss railways 1847–1966 , p. 93ff