Funicular turnout with Abt Switch first installed at

Funicular turnout with Abt Switch, first installed at Giessbach 1879, Switzerland ASME Landmark of Mechanical Engineering 07 October 2020 The Abt Switch, Giessbach 1

Standseilbahnen vor der Erfindung der Abt’schen Weiche Funiculars before the invention of the Abt switch Source: Wikipedia 2015 07 October 2020 The Abt Switch, Giessbach 2

Situation before the invention of the Abt Switch Funiculars needed two tracks from bottom to top. This is Budavári Sikló in Budapest. It was opened 1870. It is the oldest Funicular in Europa, which is still in operation. Source: Wikipedia, 2014 -10 -19 Vor der Erfindung der Abt’schen Weiche Standseilbahnen brauchten zwei Spuren von unten bis oben Das ist Budavári Sikló in Budapest. Eröffnet 1870. Das ist die älteste Standseilbahn Europas, welche noch in Betrieb ist. 07 October 2020 The Abt Switch, Giessbach 3

The principle of the Abt switch 1879 (1886, 1891) Das Prinzip der Abt’schen Weiche 1879 (1886, 1891) Source: Wikipedia 2015 07 October 2020 The Abt Switch, Giessbach 4

The Inventor Der Erfinder Carl Roman Abt (1850… 1933) Source: Wikipedia 2015, initial source unknown, copyright expired 07 October 2020 The Abt Switch, Giessbach 5

Giessbach, first turnout with Abt Switch 1879 (1889) Improved version since 1889. Picture Hans E. Wettstein during Descente, 2014 -07 -07 The cog rail system Riggenbach was initially used for speed control with a brake. Now it is used for the emergency brake for the case of a cable failure. In later funiculars it is replaced by clasp brake acting on the rails The inner rails need interruptions for the cable and for the cog rail. Cylindrical wheel shape allows a continuous support. Cable passage to the car below between the rails. No rubbing to rail is allowed. The outer (guidance) rail is uninterrupted. The corresponding wheels have two flanges each. 07 October 2020 The Abt Switch, Giessbach 6

Giessbach Funicular on the turnout 1880 Giessbachbahn auf der Ausweiche 1880 Source: "Schweizerische Kunstführer" Grandhotel Giessbach 'Gesellschaft für Schweizerische Kunstgeschichte GSK’. Serie 76, Nr. 751 07 October 2020 The Abt Switch, Giessbach 7

The same turnout 2015 -02 -19 Gleiche Ausweiche 2015 -02 -19 Picture Hans Wettstein 07 October 2020 The Abt Switch, Giessbach 8

Arrangement of the top station in 1879: A cable wheel with 3 meter diameter and a water tank for fast filling the car tank. The initial top station had no roof. Anordnung der Bergstation in 1879: Eine Seilumlenkscheibe mit 3 Meter Durchmesser und ein Wassertank zum schnellen Füllen des Wagentanks. Die erste Bergstation hatte kein Dach. Drawing: Article Carl Roman Abt : «Die Seilbahn am Giessbach» , Zeitschrift Die Eisenbahn (later renamed into: «Schweizerische Bauzeitung» ), Volume 11, 1879, Heft 20. This is from the third part out of a sequence of 6 parts. On line available at ETH Zürich library. Photo: Schweizer/Rieker : Grandhotel Giessbach, Schweizer Kunstführer GSK Serie 76, Nr. 751. 07 October 2020 The Abt Switch, Giessbach 9

Cable arrangement in the top engine room after introduction of the water turbine drive in 1912. In 1948 the water turbine was replaced by an electric motor but drive wheel and disks remained unchanged. Source: Schweizer/Rieker : Grandhotel Giessbach, Schweizer Kunstführer GSK Serie 76, Nr. 751; initial source: Firma TH Bell & Co. Kriens. 07 October 2020 The Abt Switch, Giessbach 10

Cable Drive now Wooden cable guidance grooves Yellow: Service brake disk Green: Interface gear Seilantrieb heute Hölzerne Seilführungsrillen Gelb: Betriebsbremsscheibe Grün: Zwischengetriebe Pictures: Peter Werren 07 October 2020 The Abt Switch, Giessbach 11

The first cars in 1879. Three axles with the lower two in a bogie. Two water tanks in the chassis. This car does not exist anymore. Die ersten Wagen 1879. Drei Achsen mit den unteren beiden in einem Drehgestell. Zwei Wassertanks im Untergestell. Dieser Wagen existiert nicht mehr. Source: Article Carl Roman Abt : «Die Seilbahn am Giessbach» , Zeitschrift Die Eisenbahn (later renamed into: «Schweizerische Bauzeitung» ), Volume 11, 1879, Heft 20. This is from the fourth part out of a sequence of 6 parts. On line available at ETH Zürich library. 07 October 2020 The Abt Switch, Giessbach 12

Today: Car with 3 axles. The middle axle has cylindrical wheels. The guidance wheels with two flanges are at the outer axles on the rear side of this picture. Heute: Wagen mit 3 Achsen. Die mittlere Achse hat zylindrische Räder. Die Führungsräder mit zwei Spurkränzen sind an den äusseren Achsen hinten im Bild. (Picture Peter Werren) 07 October 2020 The Abt Switch, Giessbach 13

Left: The cable fixation at the car is on a lever allowing automatic action of the emergency brake in case the cable tension decreases below a limit. Right: The emergency break of each car acts to the teeth wheel engaged in the cog rail. Pictures: Peter Werren 07 October 2020 The Abt Switch, Giessbach 14

Hotel Giessbach Project drawing 1874 Hotel Giessbach, Projektzeichnung 1874 Source: Schweizer/ Rieker : Grandhotel Giessbach, Schweizer Kunstführer GSK Serie 76, Nr. 751; Denkmalpflege des Kantons Bern (Gerhard Howald) 07 October 2020 The Abt Switch, Giessbach 15

Giessbach Hotel from south in hibernation February 2015 Giessbachhotel von Süden im Winterschlaf Februar 2015 Picture Hans Wettstein, 2015 -02 -19 07 October 2020 The Abt Switch, Giessbach 16