BLS Fb 5/7
| BLS Fb 5/7 BLS Be 5/7 |
|
|---|---|
 Fb 5/7 152 shortly after delivery with a reinforced pole triangle
|
|
| Numbering: | 151-163 |
| Number: | 13 |
| Manufacturer: | SLM , MFO , BBC |
| Year of construction (s): | 1913 |
| Retirement: | 1964 |
| Axis formula : | 1'E1 ' |
| Length over buffers: | 16,000 mm |
| Service mass: | 107 t |
| Friction mass: | 78 t |
| Top speed: | 75 km / h / 80 km / h |
| Hourly output : | 1,840 kW |
| Driving wheel diameter: | 1,350 mm |
| Power system : | 15 kV 15 Hz (later 16 2/3 Hz) |
| Power transmission: | 2 pantographs |
| Number of traction motors: | 2 |
The Fb 5/7 were 13 electric locomotives of the Berner Alpenbahn-Gesellschaft Bern-Lötschberg-Simplon (BLS), which were developed and built in 1913 by SLM , MFO and BBC . When they were delivered they were the most powerful electric locomotives in the world. With the introduction of the new designations for electric locomotives , which was decided shortly thereafter, the designation was changed to Be 5/7 .
history
Test locomotives and specifications
After the MFO's attempts to operate electrically on the Seebach – Wettingen line , the BLS decided to electrify its mountain line with 15 kV 16⅔ Hz - the first major electrification with this power system. So that vehicles could be tested in advance, the Spiez - Frutigen line was spanned with contact wire so that three railcars and two locomotives could be tested.
The following locomotives were available for the tests:
| Designation upon delivery |
Designation later |
Manufacturer | Axis formula | technology | Intended use |
image |
|---|---|---|---|---|---|---|
| Fb 2x2 / 3 101 | no | Krauss , AEG | 1'B + B1 ' | Repulsion engines | Express trains |
|
| Fc 2x3 / 3 121 | Ce 6/6 121 | SLM , MFO | C'-C ' | Single-phase series motor | Freight trains |
|
After the first test drives, it quickly became apparent that the AEG locomotive had good cornering, but often had hot jackshaft bearings . In addition, the locomotive had too high an axle load and required a high apparent power when approaching . It was therefore declared unsuitable and returned to the manufacturer. The MFO locomotive proved itself from an electrical point of view, but had poor running characteristics.
Specifications and construction
Due to the characteristics of the Fc 2x3 / 3, it was decided, instead of ordering two different types of locomotives for express and freight trains, to order a single type for both tasks, which for the first time paved the way for a universal locomotive. The locomotive should be able to pull a 330 ton train at 50 km / h on the 27 ‰ ramp. The power should endure at least 2500 hp - a fifth more than the test locomotive Fc 2x3 / 3. The maximum speed should be 75 km / h.
The undercarriage should no longer consist of bogies , because these were made responsible for the restless running of the Fc 2x3 / 3. Instead, a frame construction with running axles was to be used, with at least five drive axles being provided so that the tractive force of the locomotive could be brought onto the rails. In order to improve the running characteristics, the locomotive was also equipped with leading axles. The locomotives were built in series without a prototype. In addition to the companies SLM and MFO already involved in the Fc 2x3 / 3, BBC joined as a manufacturer of electrical equipment parts so that the delivery time could be shortened.
commitment
The first locomotive was delivered to Spiez on April 10, 1913, further locomotives followed, so that on July 15, 1913, twelve locomotives were available when the line through the Lötschberg tunnel was opened . Until the delivery of the stronger Ae 6/8 in 1926, the Be 5/7 were the only locomotives used on the mountain route. In 1942/43, the maximum speeds of some locomotives were increased to 80 km / h through small improvements, with these locomotives being given numbers from 161 upwards. The locomotive 151 was converted to four engines in 1940/41, the gearbox was changed and the top speed increased to 90 km / h, it was redrawn as Ae 5/7 171.
With the delivery of the Ae 4/4 , the locomotives were pushed more and more into freight traffic and when the Re 4/4 appeared the last Be 5/7 was scrapped.
The Be 5/7 161 has been preserved in the Swiss Museum of Transport since 1959 . The locomotive was originally number 155, but was redesignated as the 161 as the speed increased. In the exhibition it is exhibited with the number 151 as the first locomotive of its series.
technology
Two traction motors were mounted in the middle of the frame. Each of the 16-pole motors weighed 14 tons and had an assigned transformer with 12 taps that was placed next to the motor. The step switch switched the transformers in such a way that the voltage at the traction motor terminals increased alternately for traction motor 1 and traction motor 2, so that 24 speed levels were created. In order to avoid interruptions in tractive force between the individual speed steps, the step switch was provided with choke coils to avoid short circuits to limit the current during the uninterrupted switching process. The locomotives did not have an electric brake. The insulation of the transformers had to be improved after multiple flashovers occurred in the catenary network caused by switching operations.
Under the engines were the two jackshafts, which were driven by Citroën gearboxes with a ratio of 1: 2.23. The jackshafts were initially connected to the central drive axle via a rod triangle, which in turn was connected to the four other driven axles with coupling rods. The triangle bar was not up to the driving forces and broke very often, so that it was first reinforced and then replaced by a cast part. The middle drive axle was designed to be laterally displaceable, the running axles together with the adjacent drive axle formed a Krauss-Helmholtz frame .
Like the Fc 2x3 / 3, the Fb 5/7 had a battery-backed control power network. The battery was charged by a group of converters while the locomotive was in operation.
literature
- Harald Schönfeld: Swiss top executives. In: eisenbahn-magazin 3/2013, pp. 6–12
