SBB-CFF-FFS Be 4/6 12302

The Be 4/6 12302 was one of four test locomotives, the SBB ordered in June 1917. The locomotive should, as well as your three sisters Be 3/5 12201, Be 4/6 12301 and Ce 6/8I14201 come on the Gotthard railway used to obtain experience for series orders. The Be 4/6 12302 came but at the Gotthard never planned to use as their successors Be 4/6 12303-12342 they had already technically obsolete.

  • 5.2.1 Main Circuit
  • 5.2.2 Auxiliary Control
  • 5.2.3 Electric brake
  • 5.2.4 Vielfachsteuerung


In November 1913, the electrification of the Gotthard route from Erstfeld to Biasca was decided by the Board of Directors of SBB. With the outbreak of the First World War, the SBB were forced to increasingly larger timetable restrictions because of the coal shortage. This went so far that in the autumn of 1918 with the exception of milk trains ran on Sundays no more moves.

Among other routes therefore the Gotthard route for electric operation was stepped prepared. This electrification was completed in 1920.

For operation, the SBB much needed passenger and freight locomotives.


SBB is required by the industry to fulfill the following requirements specification:

  • Maximum speed 75 km / h
  • Transport of 300 tonnes trailer load at 26 ‰ slope at 50 km / h
  • Reliable start at 26 ‰ gradient and acceleration the same load at 50 km / h in 4 minutes
  • Three return trips Lucerne - Chiasso within 24 hours ( 1,360 miles)
  • Electric brake for braking the locomotive weight in the gradient
  • Possibility of multiple unit control.

Procurement and project

The order for the passenger locomotive was issued as follows:

Brown, Boveri & Cie. ( BBC ): Design and construction of passenger locomotive

In addition to compliance of the requirements specification the SBB gave the designers great freedom when working out the designs.


On April 19, 1919, the locomotive was delivered as the third sample locomotive. It has been used for numerous test and measurement runs on the Lötschberg.


The mechanical part

Landing gear

The chassis consisted of two bogies. In each bogie were two drive axles, designed as a salmon bites barrel axis and a countershaft. The roll axis had a side game of 2x70 mm relative to the bogie frame.

Tractive force

The transfer of the train and impact forces carried by the drive axles on the two bogies. From there, the forces were outside forwarded to the tow hook and buffers. Inside the bogies of the train and pull force transmission via a so -called back- were connected. The locomotive body was not involved in the transmission of forces.


The bogie frame two traction motors were stored. These two motors driven through both sides sprung sprocket on the big gears each having a countershaft. On the use of elaborate slot rods has been omitted. The drive pin of the countershaft driven by a drive rod directly to each external drive axle of the bogie. A pin on the inner side of a rod via a second drove a rod to the inner drive axle. The position of the engines, and connected to the countershaft, the rods were easily swept up. This drive was certainly seen by the maintenance forth, the Cheaper. In operation, but it was more jagged and therefore came, unlike the slot drive rod for higher speeds do not apply.

Locomotive body

The locomotive body consisted of a continuous bridge with screwed- box parts without stems. He was only supported on both trucks. Train and compression forces were not taken from him.

Brake system

The automatic Westinghouse brake and the Regulierbremse worked per bogie on the drive axles. The following axes were unrestrained. Each cab had a hand brake that acted on each bogie.

The electrical part

Main circuit

Two current collector, which could be controlled by a valve in each cab, initiated the contact line current to two chopping blades on the roof of the locomotive body. From the chopping blades of the power of the lightning protection coil and the main oil switch for 12.5 flowed ton, oil-cooled transformer in the middle of the locomotive body. The cooling of the oil was carried out by the outside on both sides arranged on the locomotive body tube systems, through which the oil was pressed with an oil pump. These conduit systems which the locomotive, as well as their successors, which gave unmistakable appearance, were cooled by the air stream and the underlying ventilation openings. The tap changer transferred the driving current to the two by two series-connected traction motors. He was trained as a flat track (or slide ) switch and had 18 switching stages between 237 V and 1,350 V. To transfer switching the wireless switch stages were present. The drive of the plant was operated by a battery with 36 V control motor. The control was done as a crank (later handwheel) trained travel switch in both cabs. This operation using two polarized relay, the high off until the speed set was reached. Each of the two driving motor groups had a motor driven reversing switch. Furthermore, there was, for protection against overload, per group assigned to an electric motor- driven oil switch with maximum current relay.


On the locomotive to those described below, operated with 220 V auxiliary operations were:

  • Two reciprocating compressors
  • Four fans Group for the drive motors
  • An oil pump for the circulation of the transformer oil
  • A motor generator set for battery charging
  • Cab heater, foot and oil heat plates.

Feeding the Zugsheizung was from the transformer to the voltages 600 V, 800 V and 1000 V.

Electric brake

An electric brake was installed in the form of a dynamic brake and not as recuperation. The engines were separated from the catenary power during braking and functioned as a direct current generators that gave their energy to roof-mounted brake resistors, where it was converted into heat. The braking resistors are cooled by the wind. The decor was indeed tested, but later expanded. This particular also because the locomotive, as their two other loading sisters, was never used on the Gotthard.


The locomotive was equipped with a multiple unit control. However, it was never tested in practice and later removed.

Operational use

The locomotive was delivered as the third of the four test locomotives on April 19, 1919. She was then not in scheduled service on the route Bern -Thun for use. There have been numerous experimental and test drives on the Lötschberg. Later in 1919, she led a regular passenger and freight trains on the route Bern - Thun and Spiez until later in the year. In November 1919 she led, together with her sister 12301 trains to Brig, this together with the April 1920 from emerging series locomotives Be 4/6 12303-12342. At the opening of the electric operation on the Gotthard Railway and this locomotive was a single piece. Your single trips across the Gotthard were rendition trips to the main workshop Bellinzona. Its field was the driving of passenger and freight trains from the depot Berne.

As of May 1956, she was in similar services, but from the depot Biel in use. From the beginning of 1959 she knew your service at the hump of Biel. As of May 1962, she was again active in the line service.

After the fire, the Be 4/6 12301 the loading took 4/6 12302 the service of Tiroir in Renens near Lausanne. In May 1965, but a short circuit occurred in the transformer. Although this did not result in a fire, because of the high repair costs, the locomotive was scrapped but on May 31, 1965

Although the Be 4/6 12301 was a loner, but the simple concept had proven itself in the built according to the same concept, Be 4/6 12303-12342 several times. That, compared with her sister Be 4 / 6 12301 had this extremely poor running, fell at her with the most driven vmax top speed of 50 km / h in the normal operating not so much.


  • Hans Schneeberger: The electric and diesel locomotives of the SBB, Volume I: 1904-1955 model years; Mini rex AG, Lucerne; 1995; ISBN 3-907014-07-3

Further reading

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