To communicate between the batteries and from the defence line to the staff and observation stands, telephones, radio and flash-signals
(The flash-signals in German are Blink-signal, the posts Blink-stations and the operator is a Blinker.) In the following referred to as Blink-
stations. We know not much about the telephone system, because nothing is left, we can assume a standard military field telephone
system. We know more about the Blink stations. We can assume that is has been some kind of a coded Morse system. A number of
blinkstations were constructed in the area, both as towers and placed into barrows high in the terrain. In the last case, holes were made in
the side, so the flash signals could be send.
Blink-stations were placed at Knivsbjerg, Venbjerg, between Venbjerg and Hoptrup, Stenhøj, Björnskov, Gestrup, Toftlund, Vongshøj,
Gasse Höje, Bredebro, Ballum, Juvre, Havneby and List on the island of Sylt. Furthermode there were placed two blink-stations in front of
the defence line at Höjrup and Fjellumhöj.
The lamp was driven by acetylene gas, and had an opening of 50 cm. Beside this an acetylene gas tank was needed and an oxygen
battery were needed. The flashes (blink) were made by pushing a disk between the flame and the mirror in the lamp.
It has been told, that the flashes in clear sunshine without field glasses easily could be seen at a distance of 15 km.
Several reports from the battlefield confirmed, that the flash signals were the most effective and stabile field communication at the time.
Signal flares could not be seen under shelling, telephone cables were vulnerable and the radios were not stabile.
In Jena, 1921, a memorial for the fallen Blinker (Die Deutchen Blinker) was raised in recognition of their great importance. The memorial
was restored a few years ago.