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Rhaetian Railway (RhB) – Prototype and H0m Model Railroading

Hipp's turning disc signal

      This rather uncommon type of signal, which is hardly known anymore today, has ensured safe railway operations on the lines of the RhB for many years. As far as I know, there is only one of these signals left today along the tracks of the RhB: On the “Wiesener Viaduct,” direction to Filisur, where I filmed it in September 1997 (and was photographed while doing so, cf. below …)
      (A second Hipp signal is found at the Landquart main depot – as a monument; the one shown here is the only one that's left on the RhB network.)

      Mathias Hipp (the name is often misspelled; there is only one “t” in “Mathias,” and the name was “Hipp,” not “Hypp”) lived from 1813 to 1893. The turning disc signal is only one of his many inventions which made the trained watchmaker from Württemberg/Germany famous; he was given an honorary doctorate by the University of Zurich in 1875, and he was commonly known as the “Swiss Edison.”

      The turning disc signal named after him was developed in 1862; this type of signal was commonly used long before semaphores came into use. The first semaphores in Switzerland were not seen until 1880 in border stations to the Baden Railways.

Hipp's turning disc signal on the Wiesener viaduct (September 1997)
front view: position “open” (track clear)	lateral view: position “closed” (Stop)

      The signals were driven by a weight in the mast which was electro-magnetically triggered; a battery was provided for this. You had to “wind up” the drive after ~ 200 rotations. Rotation of the disc was uni-directional (which is difficult to reproduce in models), i.e., the signal was “opened” by a 90-degree-turn; for “closing,” however, it was not turned back by 90 degrees, but it made a 270-degree-turn in the same direction.
      It is remarkable that Hipp's turning disc signals were equipped from the beginning with an electrical registration of the signal position that was sent back to the controlling station.
      The fact that these electrically controlled signals were in use for a very long time is probably due to their insensitivity against snow and storms compared to the wire-controlled semaphores.

      H0m model railroaders can use the Bemo model of Hipp's turning disc signal on their layout. It can be illuminated and it can be rotated with a semaphore drive. This, however, only allows 90 degree back-and-forth movements instead of the prototypical 90–270 degree turns.
      Ferro-Suisse once had, according to the literature quoted below, a Hipp signal in their program that could also only perform 90-degree movements; this model, however, has long been out of production.

Hipp's turning disc signal (Bemo kit, finished model from “Modellbau-Manufaktur”)   Left: Position “open” (Go) Right: Position “closed” (Stop)

      The most recent picture of Hipp's turning disc signal in my collection was made in autumn 2005. This technical railroad monument would definitely profit from a restoration …

Hipp's turning disc signal at the Wiesen viaduct, October 13, 2005

References:

• Hip Hip, Hurra! Die Hippsche Wendescheibe beim Vorbild. Eisenbahn-Zeitschrift 7/89, p. 24–29
• Hip Hip, Hurra! Die Hippsche Wendescheibe im Modell. Eisenbahn-Zeitschrift 7/89, p. 54–55

Copyright © 1998–2008 and responsible for contents: Christoph Ozdoba.
First version January 11, 1998, last edited February 24, 2008.

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