SBB-CFF-FFS Ae 4/6
SBB Ae 4/6 | |
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Pantograph | |
Gear ratio | 1:3.19 |
Train brakes | Air |
Performance figures | |
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Maximum speed | 125 kilometres per hour (78 mph) 110 kilometres per hour (68 mph) After rebuilding[1] |
Power output: | |
• Continuous | 3,848 kilowatts (5,160 hp)[2] |
Tractive effort: | |
• Starting | 218 kilonewtons (49,000 lbf)[2] |
• Continuous | 172 kilonewtons (39,000 lbf)[2] |
Career | |
---|---|
Numbers | 10801–10812 |
The Swiss locomotive class Ae 4/6 was a class of
Origins
The SBB Ae 4/6 was needed for service on the steep gradients of the
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/07/SBB_Ae_8_14_11851.jpg/220px-SBB_Ae_8_14_11851.jpg)
In the 1930s, three new prototype 'double locomotives' were produced, the
Design
Precursors and the 'Java bogie'
![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e8/Fahrwerk_ESS_3000.svg/220px-Fahrwerk_ESS_3000.svg.png)
The SBB Ae 4/6 design originates with four
Only a few examples of the (1A)Bo(A1) were ever built. The bogie was arranged so that the pivot axis was just behind the pivoted driven axle. The axles were driven by Buchli drives, to permit suspension movement, and as the pivot was so close to the axle this linkage could also absorb the bogie's movement, as the driven axle twisted in place but did not move sideways by much.
Gotthard 'double locomotives'
A derivative design of this layout was used for the Swiss
The third of these was built as the '
SBB Ae 4/6
The Ae 4/6 was derived from half of the 'double locomotive',
They were also intended for use on the Gotthard route, but more flexibly as they could be used as individual units for lighter trains, or run in multiple as pairs for heavier trains.[4] Multiple working equipment was fitted from the outset, although not much used in service as both it, and the locos, were considered unreliable.[1] This was also the first class to be driven from the left of the cab, rather than the right.
Both these and the Ae 8/14 had used regenerative braking, useful for descending the Gotthard's steep gradients without overheating and also returning electrical power to the network. The Ae 4/6 had a simplified and lighter system, where one traction motor could serve as the
A problem with the Ae 8/14 was that it had a large number of transformer tappings, and could only change slowly between them. This limited their best acceleration, no matter how light the train, to a minimum of a minute to reach full speed.[6] The Ae 4/6 avoided this by using fewer tappings, with faster actuation between them. An air-blast main high voltage circuit breaker was also used.
The Winterthur drive is a geared drive on the centreline of the locomotive, giving room for a traction motor each side, two to an axle. The two motors were geared by spur gears to a central layshaft carrying a third gear which drove a drive wheel on the axle. This drive wheel was not fixed rigidly, but was connected to the axle by four pivoted links in a square arrangement.[7] The large number of gears used, and that these were straight-cut spur gears, led to high noise levels. When combined with some issues from wartime construction, the drive transmissions were not perfectly reliable.
In service, the Ae 4/6 performed well in some aspects for measured power, but had problems with a lack of adhesion and mechanical unreliability. Some aspects of their wartime construction may have reduced their mechanical build quality, leading to high noise levels in the final drives, and a susceptibility to overheated bearings and gear failures, particularly after wheelslip.
Service
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/04/Ae_4_6_10808.gif/220px-Ae_4_6_10808.gif)
Construction
Construction was by Swiss Locomotive and Machine Works (SLM) for the mechanical construction and Brown, Boveri & Cie (BBC), Maschinenfabrik Oerlikon (MFO) and Société Anonyme des Ateliers de Sécheron (SAAS) for the electrical equipment. They were built in two batches, the first six being delivered in 1941–1942, the second six in 1944–1945.
Rebuilding
The second batch, 10807–10812, were rebuilt between 1961 and 1966 to try and improve their reliability. The flexible drive wheels of the Winterthur Drives were replaced with Brown Boveri spring drives,
Operation
Number | Commissioning | Withdrawal |
---|---|---|
10801 | 26 April 1941 | July 1965 |
10802 | 14 June 1941 | February 1977 |
10803 | 26 May 1941 | October 1980 |
10804 | 25 July 1941 | October 1980 |
10805 | 12 September 1942 | May 1983 |
10806 | 31 December 1942 | October 1982 |
10807 | 31 August 1944 | February 1977 |
10808 | 1 November 1944 | March 1981 |
10809 | 5 April 1945 | March 1981 |
10810 | 31 May 1945 | April 1982 |
10811 | 27 March 1945 | May 1983 |
10812 | 5 February 1945 | December 1982 |
The locomotives were in service from their arrival until the mid-1960s. After this they began to be replaced in first-line service by their successors, the SBB Ae 6/6. With a 375-tonne (369-long-ton; 413-short-ton) train, they could reach a speed of 75 km/h (47 mph) on a 26‰ gradient.[9]
The first out of service withdrawals begin in 1977. Selling the whole class to
NS 1000
A Dutch class, the NS 1000, were ordered from the same makers but were delayed by the war until 1948. Three were built by SLM, but the remainder were licence-built by Werkspoor in the Netherlands. Although designed as passenger locomotives with a top speed of 160 kilometres per hour (99 mph), they were soon found to be unreliable when used at speed and spent their working lives restricted to 100 kilometres per hour (62 mph) and mostly freight services. Despite this, they stayed in service until 1982.
Accidents
- 10802, 24 December 1947 in Oerlikon.
- 10807 and Ce 6/8III, 27 May 1950 in Maroggia. One of the drivers was killed.[10]
- 10802 and a Be 4/6 No. 12339, May 30, 1954, in Castione. There was a single fatality.[11]
- 10808, 8 August 1958 in Aargau).
- 10801, 9 July 1965 in Maroggia.
Withdrawal
After 10801's fire in 1965, it was scrapped.[2]
General withdrawals began with 10802 and 10807 in 1977, then the whole class was withdrawn from 1980 and scrapped at Biasca, the last in 1983.[2]
None were preserved, although one side of a driving cab is preserved in the Museum of Transport at Lucerne.
References
Notes
- ^ a b c d e f g Guggiari (2018).
- ^ a b c d e f g h "Ae 4/6 10801 - 10812". le-rail (in German).
- ^ Ransome-Wallis (1959), p. 220.
- ^ a b c d e Ransome-Wallis (1959), p. 154.
- ^ Leichty (1943), p. 89.
- ^ Erstfeld (2010).
- ^ a b Ransome-Wallis (1959), p. 218.
- ^ Ransome-Wallis (1959), p. 209.
- ^ Jeanmaire (1979).
- ^ "Grave scontro ferroviario alla stazione di Maroggia" [Serious railway accident at Maroggia station] (PDF). Gazetta Ticinese. 30 May 1950.
- ^ "Il grave scontro ferroviario di ieri pressi Castione" [The serious railway clash yesterday near Castione] (PDF). Gazetta Ticinese. 1 June 1954.
Bibliography
- Erstfeld, Bruno Lämmli (2010). "SBB CFF FFS Ae 4/6 No. 10'801-10'812". lokifahrer.ch (in German). Retrieved 9 August 2018.
- Guggiari, Sandro (2018). "Locomotive dimenticate Ae 4/6" [Locomotive dimensions Ae 4/6]. sguggiari.ch (in German). Retrieved 9 August 2018.
- Jeanmaire, Claude (1979). Die elektrischen und Diesel-Triebfahrzeuge schweizerischer Eisenbahnen:Die Lokomotiven der Schweizerischen Bundesbahnen (SBB). Vol. 2. Villigen: Verlag Eisenbahn.
- Leichty, Roman (1943). "Neue Lokomitiven de SBB". Die Lokomtiv (in German). 40 (5).
- Ransome-Wallis, P., ed. (2001) [1959]. Encyclopedia of World Railway Locomotives. Dover Transportation. Courier Corporation. ISBN 0486412474.
External links
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