SBB Fb 2x2 / 3 11302
| SBB Fb 2x2 / 3 11302 SBB Be 4/6 12302 |
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| Numbering: | 11302 (until 1920) , 12302 |
| Number: | 1 |
| Manufacturer: | Brown, Boveri & Cie. |
| Year of construction (s): | 1919 |
| Retirement: | May 1965 |
| Axis formula : | (1'B) (B1 ') |
| Length over buffers: | 16,500 mm |
| Service mass: | 107 t |
| Friction mass: | 76 t |
| Top speed: | 75 km / h |
| Hourly output : | 1,415 kW (1,920 hp) at 51 km / h |
| Continuous output : | 1'240 kW (1'680 PS) at 57 km / h |
| Driving wheel diameter: | 1,350 mm |
| Impeller diameter: | 950 mm |
Fb 2x2 / 3 11302 was until May 1920 the name of one of four test locomotives that the SBB ordered in June 1917. Since then it has been referred to as Be 4/6 12302 .
The locomotive, like its three sisters Fb 3/5 11201 , Fb 2x2 / 3 11301 and Fc 2x3 / 4 , was to be used on the Gotthard Railway in order to gain experience for series orders.
The Fb 2x2 / 3 11302 was never used on the Gotthard as planned, as its successors Be 4/6 12303-12342 had already technically overtaken it.
prehistory
In November 1913, the SBB board of directors decided to electrify the Gotthard route from Erstfeld to Biasca . With the outbreak of the First World War , the SBB were forced to increasingly restrict their timetables due to the scarcity of coal. This went so far that in autumn 1918 there were no more trains running on Sundays with the exception of the milk trains.
In addition to other routes, the Gotthard route was therefore also being prepared for electrical operation. This electrification was completed in 1920.
The SBB urgently needed passenger and freight locomotives for operation.
Specification book
The SBB required the industry to meet the following specifications:
- Top speed 75 km / h
- Transport of 300 t trailer load on a 26 ‰ gradient at 50 km / h
- Safe starting on a 26 ‰ incline and acceleration of the same load to 50 km / h in 4 minutes
- three return journeys Lucerne - Chiasso within 24 hours (1,360 km)
- Electric brake to slow down the weight of the locomotive on slopes
- Possibility of multiple control .
Ordering and project planning
The order for the passenger locomotive was placed as follows:
Brown, Boveri & Cie. (BBC): Design and construction of the passenger locomotive
In addition to complying with the specification, SBB gave the designers great freedom in working out the designs.
Installation
On April 19, 1919, the locomotive was delivered as the third test locomotive. It was used for numerous test and measurement drives on the Lötschberg .
technology
The mechanical part
landing gear
The chassis consisted of two bogies . In each bogie, two were driving axles , one as bites salmon trained Wheel shaft and a countershaft . The running axles had a side play of 2x70 mm compared to the bogie frame.
Traction transmission
The tensile and impact forces were transmitted from the drive axles to the two bogies. From there, the external forces were transferred to the draw hooks and buffers. Inside, the bogies for the transmission of tensile and compressive forces were connected via a so-called close coupling . The locomotive body was not involved in the transfer of forces.
drive
Two traction motors were stored in the bogie frame. These two motors drove the large gear wheels on each of the countershafts via pinions that were sprung on both sides . The elaborate slot drive rods were not used. The drive journals of the countershafts directly drive the outer drive axle of the bogie via a drive rod . A pin on the inner side of this drive rod drove the inner drive shaft via a second drive rod. Due to the position of the motors and the associated countershaft, the drive rods were swept slightly upwards. This type of drive was certainly cheaper in terms of maintenance. In operation, however, it was much more restless and, unlike the slot drive rod , was therefore not used for higher speeds.
Locomotive body
The locomotive body consisted of a continuous bridge with screwed-on box parts without a front end. It was only supported on both bogies. Tensile and compressive forces were not taken over by him.
Braking system
The automatic Westinghouse brake and the regulating brake acted on the drive axles for each bogie. The running axles were unbraked. Each driver's cab had a handbrake that worked on the respective bogie.
The electrical part
Main circuit
Two pantographs , which could be controlled by a tap in each driver's cab, conducted the catenary current to two disconnecting knives on the roof of the locomotive body. The current flowed from the cutting blades via the lightning protection coil and the main oil switch to the 12.5 t heavy, oil-cooled transformer in the middle of the locomotive body. The oil was cooled by pipe systems arranged on both sides of the outside of the locomotive body, through which the oil was pressed with an oil pump. These pipe systems, which gave the locomotive, like its successors, its unmistakable appearance, were cooled by the airflow and the ventilation openings behind them.
The step switch transferred the traction current to the traction motors connected in series in pairs . It was designed as a flat track (or sled) switch and had 18 switching levels between 237 V and 1,350 V. Spark switches were available to switch the levels over. The system was driven by a 36 V servomotor powered by the battery. The control took place via a travel switch designed as a crank (later handwheel) in both driver's cabs. This drove two polarized relays , which switched up until the set speed was reached.
Each of the two drive motor groups had a reversing switch driven by an electric motor . In addition, an electric motor driven oil switch with maximum current relay was assigned to each group to protect against overload .
Auxiliaries
The following described, 220 V-operated auxiliaries were located on the locomotive:
- two reciprocating compressors
- four fan groups for the traction motors
- an oil pump for circulating the transformer oil
- a motor generator group for battery charging
- Driver's cab heating, foot and oil heating plates.
The train heating was fed from the transformer with voltages of 600 V, 800 V and 1,000 V.
Electric brake
An electric brake was installed in the form of a resistance brake and not as a recuperation brake . When braking, the motors were disconnected from the catenary network and functioned as direct current generators, which transferred their energy to braking resistors mounted on the roof , where it was converted into heat. The braking resistors were cooled by the airstream.
The facility was tried out, but later expanded. In particular, because the locomotive, like its two other Be sisters, was never used on the Gotthard.
Multiple controls
The locomotive was equipped with a multiple control. However, it was never tested in practice and was later removed.
Operational use
The locomotive was the third of the four test locomotives to be delivered on April 19, 1919. It was then not used in scheduled service on the Bern-Thun route. Numerous test and measurement drives were carried out on the Lötschberg . Later in 1919 she regularly ran passenger and freight trains on the Bern - Thun route and later that year to Spiez . In November 1919, together with her sister Fb 2x2 / 3 11301 trains to Brig , they also ran them together with the series locomotives Be 4/6 12303-12342 , which appeared from April 1920 . When electrical operations began on the Gotthard Railway , this locomotive was also a one-off. Her only trips over the Gotthard were transfers to the main Bellinzona workshop . It was used to drive passenger and freight trains from the Bern depot.
From May 1956 she was in similar service, but from the Biel depot in use. From the beginning of 1959 she did her job on the downhill mountain in Biel. From May 1962 she was back in service.
After the fire of the Fb 2x2 / 3 11301, the Fb 2x2 / 3 11302 took over the service at the Tiroir in Renens near Lausanne . In May 1965, however, a short circuit occurred in the transformer. Although this did not result in a fire, the locomotive was scrapped on May 31, 1965 due to the high repair costs.
The Fb 2x2 / 3 11301 was a loner, but the simple concept had proven itself several times in the Be 4/6 12303-12342 built according to the same concept . The fact that it had extremely poor running properties compared to its sister Fb 2x2 / 3 11301 was not so much noticeable with the mostly driven maximum speed of v max of 50 km / h in normal operation.
Source
- Hans Schneeberger: The electric and diesel traction vehicles of the SBB, Volume I: years of construction 1904–1955; Minirex AG, Lucerne; 1995; ISBN 3-907014-07-3
Further literature
- Claude Jeanmaire: The electric and diesel locomotives of the Swiss railways, The locomotives of the Swiss Federal Railways (SBB)
See also
Individual evidence
- ↑ Schneeberger, pages 35 and 45