Cuxhaven wind semaphore

from Wikipedia, the free encyclopedia
Wind semaphore in Cuxhaven on October 6, 2004: South winds at 6 Beaufort each  on Borkum (left) and Helgoland

The wind semaphore at the Alte Liebe in Cuxhaven is a device for the optical transmission of weather information to ships sailing from the mouth of the Elbe towards the North Sea . It indicates the wind speed and direction on the islands of Borkum and Helgoland with pointers and signal arms.

The facility, which was first built in 1883/84, was rebuilt in 1904 after a storm damage. With the introduction of radio technology , it soon lost its importance for seafaring and is now in operation as a technical monument . The Cuxhaven semaphore is the last system of its kind in Europe to have been preserved in its original state.


The technology of the semaphore ( Greek : character carrier) falls back on the optical pointer telegraphy, which was first used in France since 1794 and later also in other European countries . Altona merchant Johann Ludwig Schmidt operated an optical telegraph line with several stations from the Cuxhaven Elbe estuary to Hamburg as a ship reporting service between 1837 and 1850 . Such lines on the mainland were quickly replaced by the reliable and faster electric telegraphy in the second half of the 19th century . Because the new wired technology for messages between ships and the coast could not be used, communication at sea was only optically and acoustically until the introduction of radio technology at the beginning of the twentieth century .

The wind and weather conditions at sea, which were initially unknown for sailing ships, increased the risks for the crew, ship and cargo considerably. Therefore, at the instigation of the Hamburg Nautical Association, the Cuxhaven semaphore was built, from which seafarers could always read the current weather situation in the German Bight . Wind semaphores of a similar design were also built at the mouth of the Weser at the Hoheweg lighthouse, in the East Prussian Memel , as well as in Pillau , Schiewenhorst and on the Hela peninsula .

The Cuxhaven facility was operated by the Seewarte Cuxhaven until 1902. After that, this task was taken over by the naval administration. The semaphore was destroyed in a severe storm on November 21, 1903. A larger and more stable plant was put into operation at the same location on December 1, 1904. In 1968 there were plans to demolish the no longer needed semaphore. After resistance from the population of Cuxhaven, however, the facility was preserved, protected as a technical monument from April 3, 1971 and officially kept in operation. In 1982 the semaphore was finally decommissioned. On a private initiative, however, it is still set to the current weather data from Borkum and Helgoland. Today, the wind semaphore is one of the tourist attractions of Cuxhaven. It has since been provided with an explanatory display from the Cuxhaven City Museum .


Control lever for the indicators for transmitting the wind speed

For the first system from 1883/84, the mast of the ship “Aurora”, which was stranded in the Lower Elbe, was used, presumably for cost reasons. The second plant, which went into operation at the end of 1904, was built as a steel structure and has been preserved to this day.

The semaphore, which faces the mouth of the Elbe, consists of a steel frame that is tied to each other and to the ground with wire ropes . Two massive masts supported at the rear on the left and right side carry the pointers for the wind directions on Borkum (left side) and Helgoland (right side) at a height of about ten meters.

A cross bracing connects these two outer masts at the level of the pointer axes with the higher, braced central mast. This carries six pairs of indicators to display the wind speed on both islands. These pointer arms, like the wind direction displays, are adjusted by means of levers on the ground, the movements of which are transmitted to the indicators by wire ropes.

The capital letters B and H are attached to the middle mast below the indicators as abbreviations for the island names.


Wind semaphore in Bremerhaven

The information about wind speed and direction was received by telegram twice a day from Borkum and Helgoland; just as often the system was adjusted accordingly. The circular displays on the left and right show the wind direction on the two islands with a pointer each, whereby this representation corresponds to a compass rose .

The six indicators for each island either remain in the hanging zero position or stand at right angles to the mast, each for two wind speeds on the Beaufort scale . The wind strengths 2, 4, 6, 8, 10 and 12 can be displayed. This is a comparatively simple coding: The Prussian optical telegraph was able to display 4096 different characters with half of the indicators using different angular positions. However, the simple display of the wind semaphore should have made it easier to read the sea.

The wind semaphore from the Hohe Weg lighthouse, reconstructed using some original parts (the letters “B” and “H” and the two compass roses) has been in the entrance to the New Harbor in Bremerhaven since 2005 . All pointers were equipped with a gear motor in order to display the meteorological data sent online by the German Weather Service every two hours.

Web links

Commons : Windsemaphor Cuxhaven  - Collection of images, videos and audio files

Individual evidence

  1. There is an identical system in Bremerhaven , but it was dismantled in 1976 and only reconstructed in 2005 using some original parts, see here ( Memento from May 22, 2009 in the Internet Archive ).
  2. a b c d Information board of the Cuxhaven City Museum at the wind semaphore.
  3. Hans Pieper: From the history of communications technology from antiquity to the present - with special consideration of optical telegraphy in France and Prussia . In: Rheinisch-Westfälisches Wirtschaftsarchiv zu Cologne: The telegraph station Cologne-Flittard. A little history of communications engineering . Cologne 1973, ISBN 3-933025-19-2 , pp. 43–44.
  4. ^ Joseph Krauss, Heinrich Meldau: Wetter- und Meereskunde für Seefahrer , Edition: 2, published by J. Springer, 1931, p. 102.
  5. and another landmark of Cuxhaven ... the semaphore , website of the Marinekameradschaft Cuxhaven from 1897 - Admiral Ruge - e. V., accessed on October 9, 2012.
  6. ^ Geographical Society in Bremen (ed.): German geographical sheets . Published 1906, Notes: v. 29-30, p. 156.
  7. Reconstruction of the semaphore from the Hohe Weg lighthouse . In: Hinrich Gravert . Maritime History Society e. V .. Archived from the original on May 22, 2009. Retrieved March 31, 2010.

Coordinates: 53 ° 52 ′ 20.1 "  N , 8 ° 42 ′ 35.3"  E