SBB Ce 6/8 II

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Ce 6/8 II
Be 6/8 II
Ce 6 / 8II 14266 in front of the MFO headquarters in Oerlikon
Numbering: 14251–14283
later 14266–14285 1) 		13251 ... 13265
Number: 33 13
Manufacturer : SLM (mechanical part),
MFO (electrical part)
Year of construction (s): 1919-1922 Reconstruction from 1941
Retirement: 1968-1986
Axis formula : (1'C) (C1 ')
Length over buffers: 19,400 mm
19,460 mm 2) 		19,460 mm 3)
Service mass: 128 t 126 t
Friction mass: 104 t 103 t
Top speed: 65 km / h 75 km / h
Hourly output : 1,650 kW (2,240 hp) at 36 km / h 2,700 kW (3,640 hp) at 45 km / h
Continuous output : 1'000 kW (1'340 PS) at 40 km / h 1,810 kW (2,440 hp) at 46.5 km / h
Driving wheel diameter: 1,350 mm
Impeller diameter: 950 mm
1)The Ce 6/8 II 14260 was in 1949 for Ce 6/8 II renumbered 14284, the Ce 6/8 II 14262 was in 1949 for Ce 6/8 II renumbered 14285
2)19,400 with rod buffers , 19,460 with sleeve buffers (from 1930)
3)According to SBB type sketches. In reality it is probably 19,800 mm, since wooden sleepers with a thickness of around 170 mm were added to the bumper beams during the renovation.

The Ce 6/8 II (later partly Be 6/8 II ) are electric locomotives of the SBB , which were mainly used on the Gotthard Railway in front of freight trains and were in operation until the 1980s . Seven of the 33 locomotives built from 1919 onwards have been preserved. The Ce 6/8 II got with the Ce 6/8 III of a similar design, which was developed a little later, the nickname crocodile , known beyond the borders of Switzerland , in short form crocodile .

prehistory

On June 30, 1917, the SBB had put out to order four test locomotives Fb 2x2 / 3 11301 , Fb 2x2 / 3 11302 , Fc 2x3 / 4 and Fb 3/5 11201 . These four locomotives should have been extensively tested after delivery.

The electrification of the Gotthard Railway was imminent after planning (completion 1920). Many specialists were not available due to their active service during the First World War . Furthermore, the social climate in Switzerland was massively affected by the Swiss general strike .

In the spring of 1918 (10 months before delivery of the test locomotives) the SBB therefore ordered the heavy mountain freight locomotives Ce 6/8 II 14251-14260 in addition to the heavy mountain passenger locomotives Be 4/6 12303-12312 and Be 4/7 12501-12506 the axis sequence 1'C + C1 '. Because certain kinematic problems with the Fc 2x3 / 4 test locomotive were feared with the helical rod drive of the Winterthur locomotive factory , the SBB followed the recommendation of the industry for a locomotive with the axle arrangement 1'C + C1 'instead of the bogie arrangement (1'C) (C1' ) with a one-piece locomotive body . Another rod drive has also been proposed. The locomotive no longer consisted of a box, but of three parts, namely two narrow stems and a normal-width middle section that were articulated together. The term “ prototype ” for the Ce 6/8 I locomotive, which is sometimes even mentioned in the specialist literature, is therefore wrong, because the Ce 6/8 II was a completely new design.

Specifications

SLM data sheet, 6 pages, with technical data and factory photos

The SBB required the industry to meet the following specifications :

  • The locomotives must be able to cover the distance between Goldau and Chiasso twice within 28 hours with a respective idle time of 15 minutes in the terminal stations with a trailer load of 860 t. On a slope greater than 10 ‰ may with sliding locomotives be pushed.
  • On the Bellinzona- Chiasso route, it must be possible to tow a trailer load of 625 t alone (single unit). The electrical parts must not exceed the values ​​of the relevant provisions of the American standards during each use and for the entire duration.
  • On a steep section (ramp) of 26 ‰, a trailer load of 430 t at 35 km / h and 300 t at 50 km / h must be able to be carried by a locomotive. On a 10 ‰ gradient, 300 t of trailer load must be able to be carried at 65 km / h.
  • The locomotives must be able to provide 20 percent more power for 15 minutes on a 26 ‰ gradient. The starting performance must be designed in such a way that a train of 430 t / 300 t could be brought to a speed of 35 km / h or 50 km / h in a maximum of four minutes.
  • A recuperation brake must be available.

Ordering and project planning

The order was placed by SBB with the Swiss locomotive industry in spring 1918. The Swiss Locomotive and Machine Factory (SLM) took over the mechanical part, while the Oerlikon machine factory (MFO) took over the electrical part.

technology

Boxes, machines, apparatus

Driver's cab for standing operation

In contrast to the four test locomotives, the SBB industry proposed a completely different design. The locomotive was to consist of two narrow, low stems and a normal-wide and normal-high box between them, which were articulated to one another. This was a departure from the trial locomotives under construction with a frame or with bogies. First experiences with the test locomotive Fc 2x3 / 3 of the Bern-Lötschberg-Simplon-Bahn could have led to this decision. There were also prototypes for steam locomotives, such as the Garratt locomotives .

The mechanical part

landing gear

In each of the two stems there are three drive axles coupled with coupling rods and one running axle in a Bissel frame . The middle drive axis of each part has a lateral displacement of 25 mm for better driving characteristics in the curves. The running axles can move 83 mm on both sides. The cushioning of the drive axles via leaf springs to the frame of the stems, wherein to compensate for the Achsdrücke between the drive axles, as well as the adjacent barrel axis equalizer levers are fitted.

Traction transmission

The transmission of the tensile and impact forces takes place from the drive axles to the frames of the stems. From there, the forces are passed on to the draw hooks and buffers . On the other hand, the forces are transmitted from one drive frame to the other via a spring-loaded close coupling . In contrast to other locomotives of the "crocodile" type, the central box is not used to transfer power from one motor frame to the other (see also the locomotive box in this article). The close coupling also acts as a cross coupling and in particular improves the run-in of the trailing drive unit in curves.

drive

In each frame of the stem, two drive motors are installed between the first and second drive axles . Each of the two motors drives common gears via spring-loaded pinions on both sides, which are located on the countershaft , which is also located between the first and second drive axles . The transmission from the countershaft takes place with a triangular frame , which is supported by cranks on a pendulum sprung jackshaft , via a slide bearing to the first drive axle. From a point of articulation on the triangular frame, the drive force is transmitted to the second and third drive axles with coupling rods . The suspension of the jackshaft was dismantled from 1945, as the horizontal forces that occurred turned out to be low. In the follow-up series, the Ce 6/8 III, the drive form was replaced by the helical rod drive of the Winterthur type, which is one of the main external distinguishing features of the two types.

  • Rod drive with triangular frame. Left countershaft, right jackshaft

Locomotive body

The locomotive body is designed in three parts. The two outer parts (stems) are firmly connected to the engine frames. The actual box in the middle is supported by spherical pivot pans on pivot pins in the drive frames. One swivel pan is immovable, the other can be moved lengthways so that no tensile or compressive forces are transmitted via the central box (see tensile force transmission in this article). Furthermore, spring-loaded pressure supports are arranged on both sides of the rotary sockets.

Air brake

The locomotives have a Westinghouse compressed air double brake . Like the handbrake, this acts on the two brake pads on each drive axle. The running axles are not braked. Stopex brake slack adjusters were installed between 1959 and 1963. There are four sandboxes per drive frame .

The electrical part

Main circuit

The Ce 6/8 II were mechanically more or less the same. However, there were considerable electrical differences.

The two pantographs and the lightning protection coil were located on the middle car body . The electro-pneumatic drive switch control (" hopping control ") was arranged in the box on the windowless side. The transformer was located in a shaft in the middle of the box . The lightning protection coil was removed later.

To cool the transformer oil , the transformer tank (housing) on ​​the locomotives 14251–14273 (without 14264) was provided with ribs on the outside. There were two groups of fans below the floor frame. These blew cooling air from bottom to top past the ribs through the shaft.

The locomotives 14264 and 14274-14283 had transformer tanks with smooth outer walls. The oil was pressed through the oil cooler with a separate oil pump.

The transformers of the locomotives 14251–14273 could be switched over for operation with 7,500 V contact line voltage instead of 15,000 V upon delivery. This was necessary because the Gotthard Railway was initially only operated with half the overhead line voltage. This was intended to prevent flashovers on the insulators, which were still covered with soot by the steam operation.

On the low-voltage side ( secondary side ) the transformers had two step windings, each with eleven taps from 113 V to 567 V. The taps of these two windings had opposite voltages. Via two step switches, voltages of up to 1,100 V could be supplied to the traction motor groups connected in parallel in the two drive frames in 20 or 23 steps. Since the two traction motors of a bogie were connected in series, the maximum voltage per motor was approximately 550 V.

  • Main transformer for locomotives 14251–14273, excluding 14264

  • Main oil switch, lifted out of the boiler

The tap changers were on both sides of the transformer. They were only separated from the driver's cabs by sheet metal walls. The locomotive staff therefore did not have the quietest workplace.

The locomotives 14251-14255 and 14258-14260 had roller switches similar to the test locomotive Fb 2x2 / 3 11301. They were driven by electric servo motors. It was operated with a control controller or a small, vertical handwheel on the driver's desk.

The roller switch was cumbersome, so the locomotives 14256, 14257 and 14261–14283 received electrically operated lever switches. On the locomotives 14261–14265, each lever switch had a servo motor. The locomotives 14266-14283 had only one servo motor, as the two tap changers were mechanically linked. It was operated using a horizontal handwheel on the driver's desk. This enabled 20 steps (14261–14265) or 23 steps (14266–14283) to be switched.

A completely different concept was chosen for the 14256 and 14257 locomotives. Here, too, the two step switches were mechanically coupled. The activation and gradual deactivation took place here with a huge, vertical handwheel on the driver's desk. There was only a small lever on the driver's desk for switching off to zero, which started a servo motor. Operating these two machines was quite a physical effort.

  • Step switch as roller switch with drive by servo motor

  • Step switch as a lever switch

In each of the two stems there were two traction motors and the electro-pneumatically operated reversing switch.

  • Built-in drive motor group with fan and mounted reversing switches

  • Extended drive motor group seen from the other side

Electric regenerative brake

The Ce 6/8 II had an electrical regenerative brake ( recuperation brake ) which, when braking, feeds the electrical energy of the traction motors acting as generators back into the catenary . Inductive shunts and brake chokes were used as additional elements in the circuit, while the ohmic reversing pole shunts required for driving were not used in the brake circuit.

To initiate the electrical braking, the step switch first had to go down to zero. Then the reversing switch could be switched from forwards (V) to braking forwards (BV) and the step switch switched on again. Incorrect use of the regenerative brake led to the serious accident in Wädenswil in 1948.

  • Driving motor circuit of the crocodile locomotive. Drive left, brake right

  • Driver's table of the crocodile engine. Top left: pantograph, bottom left: main switch, middle: reversing switch with positions R (reverse), 0, V (forwards) and BV (braking forwards), right: handwheel for operating the multiple switch

Auxiliaries

Converter group for the control power supply

The auxiliary services listed below were supplied with 220 V by the transformer:

  • One piston compressor in each stem
  • One fan for each of the two drive motor groups
  • Two fans for the transformer (14251–14263, 14265–14273) or a motor to drive the oil pump and fan to the oil cooler (14264, 14274–14283)
  • Converter group for battery charging, power approx. 1.5 kW
  • Cab heating
  • Foot heating plates
  • Oil heating plate (driver's cab I)

There was a permanently installed lamp in each porch. There was a flap to the left above the driver's desk. If you opened it, you could see, hear and smell whether everything was in order at the front.

Train heating

Single pole oil switch for the train busbar.

The electricity for the train heating was taken from the transformer. In the first ten locomotives, 800 V, 1'000 V and 1'200 V could be switched, whereby the 1'200 V could only be used when stationary. The other locomotives only had 800 V and 1'000 V available. The 1,200 V stage was later removed from the first ten locomotives. Before 1950, the 800 V stage was also expanded on all locomotives.

Operational use

After delivery in 1919, they drove the Bern – Thun – Spiez line, as this line was the only one that was electrified by the SBB. The crocodiles ran under a voltage of 7,500 V instead of the 15,000 V which was later customary. This was necessary at the beginning because the soiling of the insulators by steam locomotives did not allow a higher voltage.

With the electrification of the Gotthard route from October 1920, the crocodiles were primarily used in Gotthard traffic. There they replaced the C 5/6 steam locomotives , which were only three to six years old.

The crocodiles were to be found in freight traffic all over Switzerland .

From 1941 the machines were extensively rebuilt. In this context, the top speed could be increased from 65 km / h to 75 km / h; the locomotives were therefore given the designation Be 6/8 II and 13 thousand numbers.

After the Second World War and with the emergence of the Ae 6/6 , which was henceforth responsible for the Gotthard, the crocodiles were increasingly used in the plains. In the 1970s and 1980s, they were mainly working in front of gravel trucks, sugar beet trucks and in shunting services.

Scrapping

The first Ce 6/8 II were scrapped in 1968. Crocodiles modified in shunting vehicles, which were at the end of their service life in the Rhine ports of Basel, drove until 1986.

Seven locomotives have been preserved:

gallery

  • Ce 6/8 II No. 14251 from the SLM data sheet

  • Be 6/8 II No. 13254 in the Swiss Museum of Transport

  • Ce 6/8 II No. 14270 as a technical monument in Erstfeld (2011)

  • Ce 6/8 II No. 14253 in Erstfeld

  • Ce 6/8 II No. 14253 - front

  • Ce 6/8 II No. 14253 in Erstfeld, with light steel car (SBB)

Lego model

The Lego Creator Model 10277 was released on July 1, 2020 . It was sold out within a short time and the delivery date was postponed to September 15th.

See also

literature

  • Christian Zellweger (SBB Historic): Crocodile, queen of the electric locomotives . AS Verlag & Buchkonzept AG, Zurich 2005, ISBN 3-909111-19-X .
  • Hans-Bernhard Schönborn: Crocodiles, legend on rails: normal and narrow gauge . Geramond Verlag, Munich 1999, ISBN 3-932785-54-1 .
  • 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 traction vehicles of Swiss railways. The locomotives of the Swiss Federal Railways (SBB) .
  • 1C + C1 freight train locomotives for the Gotthard line of the SBB In: Schweizerische Bauzeitung . tape 75 , 1920.

Web links

Commons : SBB Ce 6/8 II  - collection of images, videos and audio files

Individual evidence

  1. ↑ The locomotive monument in Erstfeld is no longer there . In: Loki . No. 3 , 2013, p. 72–73 ( sbbhistoric.ch (via archive.org) (PDF; 927 kB) [accessed on November 3, 2013]).
  2. ↑ Stefan Hotz: A crocodile returns | NZZ . In: Neue Zürcher Zeitung . September 15, 2013, ISSN  0376-6829 ( nzz.ch [accessed December 18, 2018]).
  3. ↑ OERLIKON industrial stories: Arrival crocodile on Monday, June 15, 2020, 8 p.m. In: OERLIKON industrial stories. June 10, 2020, accessed June 15, 2020 .
  4. ↑ Lukas Kurth: LEGO 10277 crocodile locomotive: designer video available & subsequent delivery only in September. In: stonewars.de. Lukas Kurth, July 2, 2020, accessed on July 5, 2020 .