The Re 620, Re 6/6 in the old numbering scheme, are six-axle, electric locomotives of Swiss Federal Railways (SBB CFF FFS), which were acquired as a replacement for the Ae 6/6 for heavy services on the Gotthard Railway. They were produced between 1972 and 1980 and are the most modern of the so-called "Gotthard locomotives".

Construction and Technology To reach the necessary tractive effort, a construction comprising six driven axles was necessary. In order to still get good running characteristics in curves, they were built into three two-axle bogies instead of two three-axle bogies as on the Ae 6/6. The middle bogie can move sideways, and the three bogies are connected by elastic cross couplings. Two of the four prototypes (11601, 11602) were built with a split locomotive body, whereby the joint may only move on an horizontal transverse axis to allow for changes in gradient, similar to the Rhaetian Railway Ge 6/6 II.

The other two prototypes (11603, 11604) got a softer secondary suspension instead of the joint, which proved to be so reliable in everyday use that all other locomotives of the series were built this way. Nevertheless, the two prototypes with a split body are still in regular operation. The exterior design is similar to the Re 4/4II (Re 420), as are the driver's controls and the conventional transformer technology with fixed running notches, which was applied for the last time for this locomotive. In contrast to the Re 4/4II, the Re 6/6 has two transformers (one power and one control transformer), which are mounted on the frame between the bogies. Due to the higher roof, the Re 6/6 looks more brawny than the Re 4/4II, especially when seen from the front side.

Operations The Re 6/6 is equipped with multiple unit train control together with Re 4/4II, Re 4/4III (Re 430), Re 4/4IV and RBe 540. In passenger traffic they pull heavy passenger trains over the Gotthard route (as an alternative to a double heading of Re 4/4). In freight traffic they are used all over Switzerland for heavy trains, on the Gotthard route very often together with an Re 4/4II or Re 4/4III. Such a couple, often referred to as "Re 10/10" (both locomotives are Re class, so the couple is Re class; 10/10 means that they overall have 10 driven axles out of 10), is capable of pulling the maximum train weight of on 2.6% gradients of the Gotthard line. For heavier trains, up to 1600 tons are operationally feasible, an additional bank engine has to help push the train in order to not overload the couplers.

Locomotive 11638 was retired and scrapped in 1990 due to an accident. For the renumbering to the UIC-conforming new numbering scheme in 1992, only the still existing locomotives were considered, thus the 11638 did not get a new number. But the renumbering was never done consistently. During 2005, the UIC numbering scheme was reworked, and 620 001 (instead of 000) was defined to be the smallest number. To make things easy, the scrapped 11638 also got a new number, 620 038. About half a dozen locomotives bore the new numbers at the beginning of 2006.

After two locomotives were tentatively equipped with radio remote control for pushing trains on the Gotthard line (such that the locomotive pushing at the end of the train may be controlled by the engineer at the front), about 30 locomotives were equipped with it in 2000. To make them administratively distinguishable, they got the new designation Ref 6/6.

When SBB was divided into passenger services and freight, the first thirteen locomotives (11601–11613) remained in the passenger division. On 1 January 2003 they were exchanged against the Re 460, meaning that now all remaining 88 locomotives were assigned to SBB Cargo. Due to the reassignment of the Re 460 to the passenger division, the Re 6/6 again dominated freight traffic on the Gotthard line.

The locomotives are assigned to the workshops in Erstfeld, Bellinzona and Lausanne (Lausanne: 2000, today unknown). Revisions are done at the main workshop at Bellinzona.

Naming and numbering Since the () Ae 6/6, naming of locomotives and EMUs (e.g., SBB RABDe 500, RABe 501) is common practice in Switzerland. Re 620 locomotives are numbered 11601–11689 and named after Swiss communes (except Bad Säckingen). In addition to the communes' names, also their coat of arms is indicated on the side of each engine.

The following table lists Re 620 locomotives with their number, commune names and respective coat of arms (COA). Crossed out numbers indicate scrapped locomotives. № COA Name   № COA Name   № COA Name 11601 Wolhusen 11631 Dulliken 11661 Gampel-Steg 11602 Morges 11632 Däniken 11662 Reuchenette-Péry 11603 Wädenswil 11633 Muri AG 11663 Eglisau 11604 Faido 11634 Aarburg-Oftringen 11664 Köniz 11605 Uster 11635 Muttenz 11665 Ziegelbrücke 11606 Turgi 11636 Vernier-Meyrin 11666 Stein am Rhein 11607 Wattwil 11637 Sonceboz-Sombeval 11667 Bodio 11608 Wetzikon 11638 St-Triphon 11668 Stein-Säckingen 11609 Uzwil 11639 Murten 11669 Hägendorf 11610 Spreitenbach 11640 Münchenstein 11670 Affoltern am Albis 11611 Rüti ZH 11641 Moutier 11671 Othmarsingen 11612 Regensdorf 11642 Monthey 11672 Balerna 11613 Rapperswil 11643 Laufen 11673 Cham  11614 Meilen 11644 Cornaux 11674 Murgenthal 11615 Kloten 11645 Colombier 11675 Gelterkinden 11616 Illnau-Effretikon 11646 Bussigny 11676 Zurzach 11617 Heerbrugg 11647 Bex 11677 Neuhausen am Rheinfall 11618 Dübendorf 11648 Aigle 11678 Bassersdorf 11619 Arbon 11649 Aarberg 11679 Cadenazzo 11620 Wangen bei Olten 11650 Schönenwerd 11680 Möhlin 11621 Taverne-Torricella 11651 Dornach-Arlesheim 11681 Immensee 11622 Suhr 11652 Kerzers 11682 Pfäffikon SZ 11623 Rupperswil 11653 Gümligen 11683 Amsteg-Silenen 11624 Rothrist 11654 Villeneuve 11684 Uznach 11625 Oensingen 11655 Cossonay 11685 Sulgen 11626 Zollikofen 11656 Travers 11686 Hochdorf 11627 Luterbach-Attisholz 11657 Estavayer-le-Lac 11687 Bischofszell 11628 Konolfingen 11658 Auvernier 11688 Linthal 11629 Interlaken 11659 Chavornay 11689 Gerra-Gambarogno 11630 Herzogenbuchsee 11660 Tavannes

Gallery

See also List of stock used by Swiss Federal Railways Swiss locomotive and railcar classification

References

This article was mostly translated from the German language version of August 2006.