THE SIGNAL BOX

OVERSEAS

ALBORG No3
Danish State Railways (DSB)

by John Hinson & Michiel Rademakers

Alborg No3 signal box
Photograph 7/55, by Dr J W F Scrimgeour

A view looking south through the three-platform junction station at Alborg, with No3 box in the centre of the view. Alborg No3 signal box opened in 1902, and was the supervisory box overseeing operations at all other boxes at the station.

The tall three-arm signal by the box is interesting - in Denmark these were typically located at the signal box and not at the protecting point as typically found in British, Dutch and other practice. Danish semaphores protruded to the right of the post (as the lines were right-hand running), so the signals apply to trains proceeding away from the camera. Ordinary stop signals were provided with the classic Germanic "blob" at the end of the arm. This signal is a so-called togvejsignal, i.e. a route indicator signal. It has the form of a top-left junction signal here, but it could also take the form of three masts placed together in front of the box. Only one of the togvejsignaler could be pulled if the relevant stop signal (the Up Home or indkørselsignal from Nørresundby in this case) was clear. The arms read top to bottom, left to right, in the same way as British signals would. The arms were coloured red, but show a yellow light when on and green when off, in line with their subsidiary nature. The corresponding indkørselsignal is far out in front of this signal, before any pointwork, so the togvejsignaler here indicate diverging routes. When signalling the converging routes out of a station, the togvejsignaler would be grouped in front of the signal box, as seen from the drivers position, while the stop signal, in this case named udkørselsignal would be out in rear of them, a train length past the last point.

Distant signals had red arms with a splayed end not unlike a British distant signal, and showed flashing yellow and green lights by night.

Siemens & Halske block instrument
Photograph 7/55, by Dr J W F Scrimgeour

Amongst the equipment in this box was a Siemens & Halske block instrument for the single line section to Limfjord Bridge on the main line to North Jutland. The provision of this instrument was unusual, and all other single lines in Denmark were signalled by Telephone Block.


Comments about this article should be addressed to John Hinson