SBB Fc 2x3 / 4

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SBB Fc 2x3 / 4
SBB Ce 6/8 I.
SLM type image of the Ce 6/8 I
SLM type image of the Ce 6/8 I
Numbering: 12201 (until 1929) , 14201
Number: 1
Manufacturer: BBC
Year of construction (s): 1919
Retirement: Late May 1982
Axis formula : (1'C) (C1 ')
Length over buffers: 19,240 mm
Height: 4,450 mm
Service mass: 118 t
Friction mass: 99 t
Top speed: 65 km / h
Hourly output : 1,750 kW (2,370 hp) at 41 km / h
Continuous output : 1,440 kW (1,960 hp) at 44 km / h
Driving wheel diameter: 1,350 mm
Impeller diameter: 850 mm

Fc 2x3 / 4 12201 was until May 1920 the designation of one of four test locomotives that the SBB ordered in June 1917. Since then it has been referred to as Ce 6/8 I 14201.

The locomotive, like its three sisters Fb 2x2 / 3 11301 , Fb 2x2 / 3 11302 and Fb 3/5 11201 , was to be used on the Gotthard Railway in order to gain experience for series orders. It was not foreseeable at the time of the order that the development of freight locomotives would then be completely different (see Ce 6/8 II ). The fact is that the Fc 2x3 / 4 12201 did not start operating until after the first Ce 6/8 II .

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

SLM data sheet

The SBB required the industry to meet the following specifications:

  • Running meter weight maximum 7 t / m
  • maximum axle load 18 t, later 20 t after adapting the infrastructure
  • Transporting a trailer load of 430 t on an incline of 26 ‰ at 35 km / h
  • Safe starting of this load at 26 ‰ and acceleration to 35 km / h within 4 minutes
  • two return journeys Arth-Goldau - Chiasso within 28 hours (780 km)
  • electric brake to slow down the weight of the locomotive on slopes
  • Overload by 20% for 15 minutes without damage

Ordering and project planning

The order for the freight locomotive was placed as follows:

  • BBC : Design and construction of the freight locomotive
  • SLM : mechanical part.

Apart from compliance with the specification, SBB gave the designers great freedom in working out the designs.

Installation

The machine was delivered on July 7, 1919 and stationed at the Bern depot. Commissioning took a long time. It was only in use as planned in December 1919 (one week after the first crocodile Ce 6/8 II ).

technology

Boxes, machines, apparatus

Like the test locomotive F 2x3 / 3 of the Bern-Lötschberg-Simplon-Bahn, the freight locomotive was planned as a locomotive without running axles with a C'C ' wheel arrangement. However, it soon turned out that the weight limits of the specifications could not be adhered to. The bogie frames were therefore lengthened to create space for one axle each . The axle sequence changed to (1'C) (C1 '). With the arrangement of the two running axles, there were no more weight problems. The locomotive could be made extremely massive. The running axles only had an axle load of just under 10 t. This arrangement also made the load distribution on the drive axles very uneven. Each of the six driving axles, apart from the two middle ones, had a different axle load (between 13.4 t and 18.7 t).

The mechanical part

landing gear

The chassis consisted of two bogies in which the drive axles were stored. The middle drive axis had a side clearance of 2 × 25 mm. The running axles were located outside in the bogies . These were constructed as Adam's axes. They had a side clearance of 2 × 31 mm. The two suitcase-like stems were mounted on the outside of the bogie frame.

Traction transmission

The tensile and impact forces were transmitted from the drive axles to the bogies. From there the forces were transferred to the draw hooks and buffers. The transmission of the forces between the bogies was carried out by a spring-loaded coupling similar to the tender couplings on steam locomotives. No tensile or compressive forces were transmitted via the locomotive body.

drive

Two traction motors were installed in each bogie between the second and third drive axles. These drove the common large gear on the countershaft by means of spring-loaded pinions . The transmission from the countershaft was carried out with a helical rod (Winterthur helical rod drive) that acted on a journal. This pin sat on the coupling rod from the first to the second drive axis at an angle above the crank pin of the first drive axis. The drive force was then transmitted from the second drive axle to the third drive axle with a further coupling rod.

Locomotive body

The locomotive body consisted of a continuous bridge girder. The box elements were screwed onto this. The box was fastened to the bogies with pivot pins. These pivot pins had longitudinal play so that no tensile or compressive forces were transmitted through the box. The locomotive body was additionally stabilized on the side with springs. It was almost identical to that of the Fb 2x2 / 3 11302.

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

The current flowed through the pantographs to the pantograph disconnectors. From these it was forwarded to the earthing disconnector. The electricity was fed to the oil-cooled transformer via the main oil switch . This was in the middle of the locomotive body. The powerful lightning protection coil on the box roof was later removed as it turned out to be unnecessary.

The transformer was oil-cooled, whereby a rotating oil pump, which was connected in parallel with the traction motors, pressed the cooling oil through the cooling pipes on the outside of the box, where it was cooled by the airflow. This arrangement gave this locomotive, like the Fb 2x2 / 3 11302 and later the Be 4/6 12303-12342, its unmistakable appearance.

The voltage was regulated with a flat-track step switch , which tapped the 18 taps on the low-voltage side of the transformer. This enabled 230 V to 1,300 V to be fed to the traction motors connected in series . Each of the two drive motor groups had a reversing switch .

Auxiliaries

The following auxiliary services were connected via a main fuse to the lowest transformer tap with 230 V:

  • the two compressors
  • the converter for battery charging
  • the cab heater
  • the foot heating plates
  • the fans of the traction motors
  • the oil pump
  • the oil heating plate in driver's cab I.

The power supply for the train heating was connected via the 1000 V tap on the transformer via an electropneumatically operated heating hopper.

The control and lighting circuits were supplied with 36 V direct current from the batteries. A converter was installed in front building II to charge the batteries.

Electric brake

In the originally planned six-axle locomotive, the desired electric brake for the long downhill stretches could not be installed for weight reasons.

But as early as 1920, shortly after commissioning, a recuperation brake was installed and tested , initially with only two motors, between Kandersteg and Frutigen . The results have been encouraging. The system was therefore completed for operation on the Gotthard.

The braking took place according to the following principle: A rotating phase converter fed the motor fields ( stators ) of the traction motors. The separately excited rotors returned electricity to the catenary via the transformer.

The brake was extremely efficient. At the Gotthard it was possible to keep 300 t at 26 ‰ with it. However, it was complicated in its structure and difficult to operate. From time to time huge rollovers should have happened. There were also several main switch explosions. In 1931 the whole facility was therefore expanded.

Operational use

The Fc 2x3 / 4 was put into service in December 1919. It ran freight and passenger trains between Bern and Spiez .

On January 20, 1920, the locomotive was taken over by the SBB. The recuperation brake between Frutigen and Kandersteg was tested from March 1920 to October 1920.

As Ce 6/8 I 14201 she resumed her planned service on October 18, 1920. The journeys never led further than Spiez. In March 1921 she was transferred to the Gotthard.

Since the Fc 2x3 / 4 came into operation almost at the same time as the first Ce 6/8 II and the second Ce 6/8 II followed immediately, there was nothing else to try with the test locomotive except the recuperation brake. The term “prototype” for the Fc 2x3 / 4 locomotive, which is sometimes even mentioned in the specialist literature, is therefore wrong, because the Ce 6/8 II was a completely new design.

Her first field of work on the Gotthard was from the Erstfeld depot , where she performed Ce-6/8 II services. From 1925 to 1930 the locomotive was assigned to the Biasca depot . Your tasks here were pre-tensioning services to Airolo at the south portal of the Gotthard tunnel . The presence of the recuperation brake proved to be advantageous because the locomotive, braked in this way, could return to Biasca on its own.

After the recuperation brake was removed, it returned to Erstfeld in 1931. In 1938 he was transferred to the Basel depot . Here she was responsible for leading various freight trains. The Basel locomotive drivers did not appreciate their somewhat poor running properties, but on the other hand their tractive power in the lower speed range.

In 1961 two traction motors were badly damaged. But since the Expo 64 ( Swiss National Exhibition ) was just around the corner, it was decided to rewind the two defective engines. The machine was used with ballast weights in Ticino while the traction motors were being repaired. Then the two engines were reinstalled and the other two overhauled.

She then achieved considerable mileage:

  • 1963: 101,000 km
  • 1964 (Expo year): 65,000 km

Later, however, the performance decreased rapidly:

  • 1965: 19,000 km
  • 1966: 4,000 km

At the end of its career, the Ce 6/8 I was still used as a brake test locomotive before it was scrapped in 1982 and handed over to the Swiss Museum of Transport . It has been preserved for posterity as an exhibition locomotive together with the locomotives of the Seebach-Wettingen experimental operation ( Fc 2x2 / 2 12101 and Fc 2x2 / 2 12102 ) as an exhibit of the beginning of electrical traction . At this point in time she had covered 2,500,000 km.

See also

literature

  • 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 .
  • Claude Jeanmaire: The electric and diesel locomotives of the Swiss railways , The locomotives of the Swiss Federal Railways (SBB)

Individual evidence

  1. ^ Schneeberger: The electric and diesel traction vehicles of the SBB. 1995, pp. 35 and 47