Sometimes when researching one Hackaday story we as writers stumble upon the one train of thought that leads to another. So it was with a recent look at an unmanned weather station buoy from the 1960s, which took us on a link to a much earlier automated weather station.
Weather Station Kurt was the only successful installation among a bold attempt by the German military during the Second World War to gain automated real-time meteorological data from the Western side of the Atlantic. Behind that simple sentence hides an extremely impressive technical and military achievement for its day. This was the only land-based armed incursion onto the North American continent by the German military during the entire war. Surrounded as it was though by secrecy, and taking place without conflict in an extremely remote part of Northern Labrador, it passed unnoticed by the Canadian authorities and was soon forgotten as an unimportant footnote in the wider conflagration.
Kurt took the form of a series of canisters containing a large quantity of nickel-cadmium batteries, meteorological instruments, a telemetry system, and a 150W high frequency transmitter. In addition there was a mast carrying wind speed and direction instruments, and the transmitting antenna. In use it was to have provided vital advance warning of weather fronts from the Western Atlantic as they proceeded towards the European theatre of war, the establishment of a manned station on enemy territory being too hazardous.
A small number of these automated weather stations were constructed by Siemens in 1943, and it was one of them which was dispatched in the U-boat U537 for installation on the remote Atlantic coast of what is now part of modern-day Canada. In late October 1943 they succeeded in that task after a hazardous trans-Atlantic voyage, leaving the station bearing the markings of the non-existent “Canadian Meteor Service” in an attempt to deceive anybody who might chance upon it. In the event it was not until 1977 that it was spotted by a geologist, and in 1981 it was retrieved and taken to the Canadian War Museum.
There is frustratingly little information to be found on the exact workings on the telemetry system, save that it made a transmission every few hours on 3940kHz. A Google Books result mentions that the transmission was encoded in Morse code using the enigmatic Graw’s Diaphragm, a “sophisticated contact drum” named after a Dr. [Graw], from Berlin. It’s a forgotten piece of technology that defies our Google-fu in 2017, but it must in effect have been something of a mechanical analogue-to-digital converter.
Should you happen to be visiting the Canadian capital, you can see Kurt on display in the Canadian War Museum. It appears to have been extensively restored from the rusty state it appears in the photograph taken during its retrieval, it would be interesting to know whether anything remains of the Graw’s Diaphragm. Do any readers know how this part of the station worked? Please let us know in the comments.
Weather station Kurt retrieval image, Canadian National Archives. (Public domain).
Weather station Kurt in museum image, SimonP (Public domain).