Swiiss Elec Locos

Swiss Electric Locomotive Development
Text by Art Peterson; photos from the Krambles/Peterson Archives.
Electrification of the Swiss Federal Railways (SBB in German; CFF in French; and, FFS in Italian) became essential as Switzerland had to import coal and the price of coal increased by a factor of 10 between 1914 and 1920. In addition, with two long tunnels on its key trans-Alpine routes - the 15 km Gotthard tunnel had opened in 1882, while the 20 km Simplon tunnel opened in 1906 - use of steam was unsafe for both crews and passengers. There were two camps in Switzerland when it came to electrification - Machinefabrik Oerlikon (MFO) advocated use of single-phase AC and trialed this on the Zurich-Wettingen line from 1905. Conversely, Brown Boveri & Co. (BBC) came out in favor of three-phase AC, which they installed on the Simplon Tunnel line from May 10, 1906. With Walter Boveri (of BBC) a member of the SBB Board, you might think that the selection would be a foregone conclusion, but it didn't turn out that way. The SBB Board decided in favor of single-phase AC at their February 18, 1916 meeting. Progress installing the single-phase AC was rapid - the Simplon line's single-phase installation went into operation from December 12, 1920. By 1928, 55% of the SBB network was electrified and that reached 93% by 1939. The Swiss were adept at getting outstanding service life out of their locomotives - many of the locomotives built throughout the 1920s were still in service 60 years later. In addition, with a rapidly expanding electrified network, SBB's appetite for additional electric locomotives was considerable. Demands of the key corridors, especially the Gotthard route, meant that continued refinement of locomotive design and power output was required. These images are presented in the order in which the subject locomotives were delivered. SBB Ae 3/5 #10214 - July 30, 1948 - Art Peterson photo SBB received a total of 26 Ae 3/5 locomotives from SLM (Swiss locomotive works - mechanical contractor)/SAAS (Secheron - electrical components) between 1922 and 1925. The 10214 was delivered on February 19, 1924. This is a 1-C-1 locomotive, so three of the five axles are driven, hence the 3/5 designation. This design offered an improved power-to-weight ratio compared to previous designs. However, the arrangement was not suitable for higher-speed operation. Consequently, the locomotives moved into regional train service, such as Train 2546 shown at Palezieux (in the French [western] section of Switzerland) on August 22, 1971. The 1,830 locomotive was retired on June 30, 1981. The last of the Ae 3/5 locomotives remained in service until 1983. SBB Ae 3/6 I #10641 - Art Peterson Photo SLM (mechanical) and BBC (electrical) next combined on a locomotive that would address the limitations of the Ae 3/5. The answer was the Ae 3/6 (a 2-C-1 configuration locomotive). Experience with these engines was so favorable that the original 90 kmh speed limit was raised to 110 kmh. In addition, 114 examples of the Ae 3/6 I were built, followed by a further 60 Ae 3/6 II variants. Locomotives of these classes were built throughout the 1920s, as more and more miles of SBB line were under wire. The design also featured the single-axle "Buchli" drive, which was used on more than 1,000 locomotives world-wide. With a total weight of 208,898 pounds, the Ae 3/6 I was about 17% heavier than the Ae 3/5. The Ae 3/6 I also produced 20% greater horsepower, with the hourly rating being nearly 2,200 hp. Delivered from SLM on July 16, 1925, the 10641 is shown in Rorschach, about 45 miles east of Zurich, as the crow flies (towards Austria). This engine was not retired until the last day of May in 1993. SBB Be 6/8 II #13317 - Art Peterson Photo What Swiss electric locomotive survey would be complete without a "Crocodile?" The increasing demands of the freight traffic on the Gotthard route led to the development of an engine that incorporated two sets of close-coupled running gear, but that did not transmit any tractive forces through the carbody. Built as Class Ce 6/8 II, 13 of the 33 locomotives of this type were converted to Class Be 6/8 II in 1941. This conversion saw total locomotive weight reduced by under 2%, but saw a big jump in the hourly horsepower rating - the Ce's had been rated at 2,213 hp, but the Be's were now rated at 3,621 hp. Top speed for the Be's was also boosted to 47 mph. Locomotive 13317 had been delivered by SLM in 1926; it was retired on Halloween Day 1973. Some members of this class were converted to yard switcher duty, with the last of these being retired in 1986. Seven of the 33 locomotives have been preserved. In 2022, the ASME designated the "Crocodile" locomotive an Historic Mechanical Landmark, citing the locomotive's integrated mechanical and electrical elements in a large-capacity locomotive that was able to traverse tight curves on a steeply-graded line. SBB Ae 4/7 #11014 - George Krambles Photo Over a 7-year period, starting from 1927, SLM and electrical suppliers (BBC, Oerlikon or Secheron [SAAS]) built a total of 127 Ae 4/7 locomotives for SBB. The Secheron-equipped locomotives used a Westinghouse quill drive. Increasing train weights on the Gotthard and Simplon lines drove the development of this class. The 11014 was delivered on March 1, 1933. Type Ae 4/7 locomotives weighed 30% more than the Ae 3/6's (total engine weight - 271,830 lbs) and produced 40% more horsepower (3,084 hp). A 62-year working career was completed by the 11014 with its retirement on the last day of June 1995. Twelve years previous, the engine was shown with a local freight in Aigle, about 9 miles south of Montreux. SBB Ae 4/6 #10806 - George Krambles Photo Just 12 examples of the Ae 4/6 locomotives were built between 1941 and 1944. SLM partnered with either BBC or SAAS on these deliveries. As delivered, these locomotives were set up for 78 mph top speed and produced 49,008 lbs of tractive effort. A 1961-66 rebuild program, saw locomotive weight increased by 6% to 244,713 pounds. Top speed was dropped to 68 mph, but tractive effort was boosted to 61,598 lbs. Bellinzona, where the 10806 was photographed on January 5, 1978, is about 12 miles south of Biasca on the Simplon Tunnel route into Italy. This particular locomotive was wrecked at Osonga, just 8 miles north of Bellinzona on July 17, 1982. SBB Re 4/4 I #10033 - Art Peterson Photo Two batches of trucked (bogies, in European parlance) locomotives were delivered to SBB post-World War II. The 1946-48 build included electric braking and multiple controls, while the 1950-51group deleted these features. The earlier build had train doors and full height side ventilators, while the second batch deleted these features and were intended for "express train" duties. All 50 locomotives of this class were specified with a 14-ton axle load and a higher top speed (78 mph). The lower axle loading and higher performance standards also recognized that the nature of European coach stock was changing to lighter-weight steel cars. Locomotive 10033 was part of the later build, having been delivered on March 29, 1951. These locomotives included a 3% boost in the hourly horsepower rating over the previous batch, for a total of 2,548 hp. The locomotive is shown with the Geneva-bound Trans-Europ Express (TEE) "Rheingold" leaving Basel on August 23, 1971. This engine was retired on September 11, 2002. SBB Ae 6/6 #11449 - Art Peterson Photo The dual-service capabilities of the 120 members of the Ae 6/6 class are shown in this shot of the 11449 arriving in Zurich with a substantial passenger train in tow on January 2, 1978. Increasing train weights on the Gotthard and Simplon lines led SBB into the modular construction used on these 5,766 horsepower (continuous) locomotives. A 1950 design for the French National Railways (SNCF Class CC6051) was the basis for this design. In production from 1952 to 1966, these locomotives produced a starting tractive effort of 88,125 lbs. The 11449 was delivered on February 19, 1960 and was retired on March 17, 2011. In the 1970s and 80s, SBB added a considerable amount of passenger service and saw its total passenger traffic increase by 71%. By 1982, SBB was implementing the "Taktfahrplan" (a nationwide regular interval timetable). The results of all these improvements are that the Swiss network has the highest level and quality of rail passenger service. SBB Re 4/4 II #11158 - Art Peterson Photo Over a 21-year period, starting from prototype builds in 1964, SBB acquired a total of 273 Re 4/4 II locomotives from SLM. This allowed the replacement of many of the earlier classes of locomotives, as well as a considerable improvement in the service offered. All the Re 4/4 II locomotives were 87 mph-capable units and each developed 6,303 hp (hourly rating). SBB 11158 was delivered by SLM on April 3, 1969. Given Switzerland's central/key location in Europe, TEE trains were still traversing the country at the time of this photo. The 11158 wears the TEE livery to match the consists for trains such as the "Rheingold" or the "Roland" that traversed Switzerland on a daily basis. Improvements to the European rail network and the growth of high-speed train services, including the TGV and networks, led to the end of TEE-branded services in the 1980s-90s. SBB Re 4/4 III #11292 - Art Peterson Photo Winter storms have cleared the Alps leaving a stunning New Year's Day 1978 throughout the country. SBB Train 377 is just a few minutes away from tying up at Chur in the Romansch section of Switzerland. Tracks in the foreground are those of the meter-gauge Rhaetian Railway, which serves Haldenstein (depot behind the photographer). The engine on the point of this train is one of 26 Re 4/4 III units built between 1967 and 1972 and specially equipped to address the demands on the Gotthard and Simplon routes. These locomotives had a top speed of 78 mph, but a starting tractive effort of 62,947 lbs, a 10% increase over the Re 4/4 II locomotives. SBB Re6/6 11646 - Art Peterson Photo Waiting with SBB Train 383 (an international train destined for Zurich) at Bellinzona, the named locomotive "Bussigny" (see crest between the middle set of side windows) was less than a year old at the time of this January 5, 1978 photo. Delivered by SLM on March 4, 1977, this locomotive was one of 89 in this class delivered between 1972 and 1980. These locomotives were named for Swiss cities, Bussigny is just outside of Lausanne on Lac Leman, through which the Swiss-French border passes. This group of engines were designed for dual-service, capable of running at a top speed of 87 mph, while also producing 88,800 pounds of starting tractive effort. This represents nearly a three-fold increase over the starting tractive effort that the 1925 build of Ae 3/6 locomotives could produce. Overall locomotive weight between these two classes increased only 27%, to 264,554 lbs for the Re 6/6 Acknowledgements: Many books and websites were consulted in the preparation of this piece, including the "Schweierische Lokomotivbau 1871-1971" and the loc-info.com site.
New: 1 June 2022

Electrification of the Swiss Federal Railways (SBB in German; CFF in French; and, FFS in Italian) became essential as Switzerland had to import coal and the price of coal increased by a factor of 10 between 1914 and 1920. In addition, with two long tunnels on its key trans-Alpine routes - the 15 km Gotthard tunnel had opened in 1882, while the 20 km Simplon tunnel opened in 1906 - use of steam was unsafe for both crews and passengers.

There were two camps in Switzerland when it came to electrification - Machinefabrik Oerlikon (MFO) advocated use of single-phase AC and trialed this on the Zurich-Wettingen line from 1905. Conversely, Brown Boveri & Co. (BBC) came out in favor of three-phase AC, which they installed on the Simplon Tunnel line from May 10, 1906. With Walter Boveri (of BBC) a member of the SBB Board, you might think that the selection would be a foregone conclusion, but it didn't turn out that way. The SBB Board decided in favor of single-phase AC at their February 18, 1916 meeting.

Progress installing the single-phase AC was rapid - the Simplon line's single-phase installation went into operation from December 12, 1920. By 1928, 55% of the SBB network was electrified and that reached 93% by 1939.

The Swiss were adept at getting outstanding service life out of their locomotives - many of the locomotives built throughout the 1920s were still in service 60 years later. In addition, with a rapidly expanding electrified network, SBB's appetite for additional electric locomotives was considerable. Demands of the key corridors, especially the Gotthard route, meant that continued refinement of locomotive design and power output was required. These images are presented in the order in which the subject locomotives were delivered.

SBB Ae 3/5 #10214 - July 30, 1948 - Art Peterson photo

SBB received a total of 26 Ae 3/5 locomotives from SLM (Swiss locomotive works - mechanical contractor)/SAAS (Secheron - electrical components) between 1922 and 1925. The 10214 was delivered on February 19, 1924.

This is a 1-C-1 locomotive, so three of the five axles are driven, hence the 3/5 designation. This design offered an improved power-to-weight ratio compared to previous designs. However, the arrangement was not suitable for higher-speed operation. Consequently, the locomotives moved into regional train service, such as Train 2546 shown at Palezieux (in the French [western] section of Switzerland) on August 22, 1971. The 1,830 locomotive was retired on June 30, 1981. The last of the Ae 3/5 locomotives remained in service until 1983.

SBB Ae 3/6 I #10641 - Art Peterson Photo

SLM (mechanical) and BBC (electrical) next combined on a locomotive that would address the limitations of the Ae 3/5. The answer was the Ae 3/6 (a 2-C-1 configuration locomotive). Experience with these engines was so favorable that the original 90 kmh speed limit was raised to 110 kmh. In addition, 114 examples of the Ae 3/6 I were built, followed by a further 60 Ae 3/6 II variants. Locomotives of these classes were built throughout the 1920s, as more and more miles of SBB line were under wire. The design also featured the single-axle "Buchli" drive, which was used on more than 1,000 locomotives world-wide.

With a total weight of 208,898 pounds, the Ae 3/6 I was about 17% heavier than the Ae 3/5. The Ae 3/6 I also produced 20% greater horsepower, with the hourly rating being nearly 2,200 hp. Delivered from SLM on July 16, 1925, the 10641 is shown in Rorschach, about 45 miles east of Zurich, as the crow flies (towards Austria). This engine was not retired until the last day of May in 1993.

SBB Be 6/8 II #13317 - Art Peterson Photo

What Swiss electric locomotive survey would be complete without a "Crocodile?" The increasing demands of the freight traffic on the Gotthard route led to the development of an engine that incorporated two sets of close-coupled running gear, but that did not transmit any tractive forces through the carbody. Built as Class Ce 6/8 II, 13 of the 33 locomotives of this type were converted to Class Be 6/8 II in 1941. This conversion saw total locomotive weight reduced by under 2%, but saw a big jump in the hourly horsepower rating - the Ce's had been rated at 2,213 hp, but the Be's were now rated at 3,621 hp. Top speed for the Be's was also boosted to 47 mph.

Locomotive 13317 had been delivered by SLM in 1926; it was retired on Halloween Day 1973. Some members of this class were converted to yard switcher duty, with the last of these being retired in 1986. Seven of the 33 locomotives have been preserved. In 2022, the ASME designated the "Crocodile" locomotive an Historic Mechanical Landmark, citing the locomotive's integrated mechanical and electrical elements in a large-capacity locomotive that was able to traverse tight curves on a steeply-graded line.

SBB Ae 4/7 #11014 - George Krambles Photo

Over a 7-year period, starting from 1927, SLM and electrical suppliers (BBC, Oerlikon or Secheron [SAAS]) built a total of 127 Ae 4/7 locomotives for SBB. The Secheron-equipped locomotives used a Westinghouse quill drive. Increasing train weights on the Gotthard and Simplon lines drove the development of this class. The 11014 was delivered on March 1, 1933.

Type Ae 4/7 locomotives weighed 30% more than the Ae 3/6's (total engine weight - 271,830 lbs) and produced 40% more horsepower (3,084 hp). A 62-year working career was completed by the 11014 with its retirement on the last day of June 1995. Twelve years previous, the engine was shown with a local freight in Aigle, about 9 miles south of Montreux.

SBB Ae 4/6 #10806 - George Krambles Photo

Just 12 examples of the Ae 4/6 locomotives were built between 1941 and 1944. SLM partnered with either BBC or SAAS on these deliveries. As delivered, these locomotives were set up for 78 mph top speed and produced 49,008 lbs of tractive effort. A 1961-66 rebuild program, saw locomotive weight increased by 6% to 244,713 pounds. Top speed was dropped to 68 mph, but tractive effort was boosted to 61,598 lbs.

Bellinzona, where the 10806 was photographed on January 5, 1978, is about 12 miles south of Biasca on the Simplon Tunnel route into Italy. This particular locomotive was wrecked at Osonga, just 8 miles north of Bellinzona on July 17, 1982.

SBB Re 4/4 I #10033 - Art Peterson Photo

Two batches of trucked (bogies, in European parlance) locomotives were delivered to SBB post-World War II. The 1946-48 build included electric braking and multiple controls, while the 1950-51group deleted these features. The earlier build had train doors and full height side ventilators, while the second batch deleted these features and were intended for "express train" duties. All 50 locomotives of this class were specified with a 14-ton axle load and a higher top speed (78 mph). The lower axle loading and higher performance standards also recognized that the nature of European coach stock was changing to lighter-weight steel cars.

Locomotive 10033 was part of the later build, having been delivered on March 29, 1951. These locomotives included a 3% boost in the hourly horsepower rating over the previous batch, for a total of 2,548 hp. The locomotive is shown with the Geneva-bound Trans-Europ Express (TEE) "Rheingold" leaving Basel on August 23, 1971. This engine was retired on September 11, 2002.

SBB Ae 6/6 #11449 - Art Peterson Photo

The dual-service capabilities of the 120 members of the Ae 6/6 class are shown in this shot of the 11449 arriving in Zurich with a substantial passenger train in tow on January 2, 1978. Increasing train weights on the Gotthard and Simplon lines led SBB into the modular construction used on these 5,766 horsepower (continuous) locomotives. A 1950 design for the French National Railways (SNCF Class CC6051) was the basis for this design. In production from 1952 to 1966, these locomotives produced a starting tractive effort of 88,125 lbs. The 11449 was delivered on February 19, 1960 and was retired on March 17, 2011.

In the 1970s and 80s, SBB added a considerable amount of passenger service and saw its total passenger traffic increase by 71%. By 1982, SBB was implementing the "Taktfahrplan" (a nationwide regular interval timetable). The results of all these improvements are that the Swiss network has the highest level and quality of rail passenger service.

SBB Re 4/4 II #11158 - Art Peterson Photo

Over a 21-year period, starting from prototype builds in 1964, SBB acquired a total of 273 Re 4/4 II locomotives from SLM. This allowed the replacement of many of the earlier classes of locomotives, as well as a considerable improvement in the service offered. All the Re 4/4 II locomotives were 87 mph-capable units and each developed 6,303 hp (hourly rating). SBB 11158 was delivered by SLM on April 3, 1969.

Given Switzerland's central/key location in Europe, TEE trains were still traversing the country at the time of this photo. The 11158 wears the TEE livery to match the consists for trains such as the "Rheingold" or the "Roland" that traversed Switzerland on a daily basis. Improvements to the European rail network and the growth of high-speed train services, including the TGV and networks, led to the end of TEE-branded services in the 1980s-90s.

SBB Re 4/4 III #11292 - Art Peterson Photo

Winter storms have cleared the Alps leaving a stunning New Year's Day 1978 throughout the country. SBB Train 377 is just a few minutes away from tying up at Chur in the Romansch section of Switzerland. Tracks in the foreground are those of the meter-gauge Rhaetian Railway, which serves Haldenstein (depot behind the photographer).

The engine on the point of this train is one of 26 Re 4/4 III units built between 1967 and 1972 and specially equipped to address the demands on the Gotthard and Simplon routes. These locomotives had a top speed of 78 mph, but a starting tractive effort of 62,947 lbs, a 10% increase over the Re 4/4 II locomotives.

SBB Re6/6 11646 - Art Peterson Photo

Waiting with SBB Train 383 (an international train destined for Zurich) at Bellinzona, the named locomotive "Bussigny" (see crest between the middle set of side windows) was less than a year old at the time of this January 5, 1978 photo. Delivered by SLM on March 4, 1977, this locomotive was one of 89 in this class delivered between 1972 and 1980. These locomotives were named for Swiss cities, Bussigny is just outside of Lausanne on Lac Leman, through which the Swiss-French border passes.

This group of engines were designed for dual-service, capable of running at a top speed of 87 mph, while also producing 88,800 pounds of starting tractive effort. This represents nearly a three-fold increase over the starting tractive effort that the 1925 build of Ae 3/6 locomotives could produce. Overall locomotive weight between these two classes increased only 27%, to 264,554 lbs for the Re 6/6

Acknowledgements: Many books and websites were consulted in the preparation of this piece, including the "Schweierische Lokomotivbau 1871-1971" and the loc-info.com site.

Swiss Electric Locomotive Development