|Heliograph team in Southwest Africa|
At the very outset of the German-Herero War in 1904, the Southwest Africa protectorate's single telegraph line along the train tracks from Swakopmund to Windhuk was cut in several places. Protecting these vital links from further sabotage tied down considerable resources, including heavy automatic weapons that could otherwise have been deployed against the Hereros.
Communication between isolated commands over vast distances and across varied topography in this region would require portable, wireless technologies. The Germans came to rely on two different systems during the war with the Herero: one with its roots in the armies of antiquity and the other a product of the modern age. Neither offered a perfect solution, and both would later be supplanted by subsequent advances in radio development, but together they had advantages that the Germans came to appreciate and which ultimately influenced the course of the decisive action at the Waterburg in August 1904.
The heliograph was a simple concept that used mirrors to direct the rays of the sun and communicate between observers using Morse Code. It required no other power source and was mounted on a simple surveyor's tripod. While reliance on the sun restricted heliography to daylight conditions with clear skies, it was well suited to the highveld and arid conditions of southern Africa.
The British had uses heliographs during the Zulu War in 1879 and in the Sudan in the 1880s, while the American General Nelson Miles employed them during his campaign against Geronimo. Both the British and the Boers employed heliography during the 2nd Boer War (1899-1902), and it may have been this conflict that caused Imperial Germany to reconsider investing in this technology. They adapted the British Mark V heliograph with additional refinements in 1900, and initially used them in Southwest Africa at fixed stations to communicate with distant outposts that were not yet served by telegraph lines.
As long as the receiver's location remained fixed or could be identified by the sender, sending messages this way was a reliable means of communication, bu there were disadvantages for its use in the field. Heliography required a clear line of sight between sender and receiver, ideally transmitted from high elevation, but the dense thornfeld along the Swakop River and its drainages to the North and East of Okahandja offered few natural eminences, forcing troops in the field to improvise signal stations atop termite hills and thorn trees. Von Glasenapp's Ostabteilung spent over a month maneuvering in pursuit of the Herero and was seldom in one place long enough to establish heliograph contact with the station atop Kaiser Wilhelmberg at Okahandja or with Winhuk via a heliograph station at Seeis, requiring riders to carry messages part of the way. Intermittent heliograph communication delayed reporting the defeat of von Glasenapp's section back to headquarters, and it was impossible at this stage for mobile sections to coordinate their efforts, even when separated by as little as 50 miles, because the low topography and dense thorns prevented signalers for fixing the position of their counterparts.
During the build up of troops under Lothar von Trotha in May and June, 1904, the Germans added wireless radio communications capacity in the form of three (some sources say four) funkentelegraph equipped carts and wagons, each able deploy either a 12 ft2 kite or a 350 ft3 hydrogen-filled balloon to extend its antenna in the field. Four commissioned officers, four NCOs and 27 men assigned to these wireless sections departed Hamburg on April 30th in the transport "Herzog", arriving at Swakopmund on May 24th, 1904.
The portable wireless stations or funkenstationen were first used against the Herero during the Waterburg campaign that August, where their relative strengths and weaknesses soon became apparent.
Each wireless station required at least three two wheeled support vehicles, which together transported a broad array of equipment, including gasoline powered generating plant, cable drum for hauling the balloon, the receiving apparatus, and the hydrogen tanks and balloon. The Germans found two wheeled cars less stable and prone to tipping than four wheeled wagons, and each weighted nearly a ton when loaded. High winds tore kites and prevented the balloons from reaching an ideal elevation, and the balloons themselves, soaring well above the thorn trees, clearly marked the location of the units they served and made them attractive targets for Herero rifles.
The converging German sections that fought below the Waterburg included several that were wireless equipped, including the headquarters section (von Muhlenfels), von Heyde's and von Estorff's sections. While these allowed sporadic communication among these separate German elements, it was the simpler heliograph technology that played the divisive part in establishing communication between them, for Oberleutnant Richard Volkmann who was stationed to the North of the plateau wisely dispatched Lt. Auer. with a heliograph to the top of the Waterberg where he was able to communication with the various sections far below.
After the battle the wireless units were soon taken offline for servicing as the campaign against the Herero was winding down and war with the Nama shifted German attention to the south. While these initial funkenstationen were down for repairs, an additional three units arrived from Germany and were deployed in the field. The heliograph was a necessary supplement, and unlike the original wireless units remained in use by signal corps in many armies well after World War II.