Seetakt radar
Encyclopedia
The shipborne Seetakt radar was developed in the 1930s and was used by the German Navy
during World War II
.
In Germany during the late 1920s, Hans Hollmann
began working in the field of microwaves, which were to later become the basis of almost all radar systems. In 1935 he published Physics and Technique of Ultrashort Waves, which was picked up by researchers around the world. At the time he had been most interested in their use for communications, but he and his partner Hans-Karl von Willisen had also worked on radar-like systems.
In 1928 Hollmann, von Willisen and Paul-Günther Erbslöh started a company called GEMA. In the autumn of 1934, GEMA built the first commercial radar system for detecting ships. Operating in the 50 cm range it could detect ships up to 10 km away. This early version of the system only provided a warning that a ship was in the general vicinity of the direction the antenna was pointed, it did not provide accurate direction or any sort of range information. The purpose was to provide an anti-collision system at night, in fog, and other times of limited visibility.
In the summer of 1935 a pulse radar was developed with which they could spot the ship Königsberg
8 km away, with an accuracy of up to 50 m, enough for gun-laying. The same system could also detect an aircraft at 500 m altitude at a distance of 28 km. The military implications were not lost this time around, and construction of land and sea-based versions took place as Freya radar
and Seetakt. The two systems were generally similar, although the early Seetakt systems worked on a 50 cm wavelength (600 MHz), while Freya was designed for much longer ranges and used a 2.5 m wavelength that could be generated at high power using existing electronics.
These early systems proved problematic, and a new version using improved electronics at 60 cm wavelength (500 MHz) was introduced. Four units were ordered and installed on the Königsberg, Admiral Graf Spee and two large torpedo boat
s (which in German service were the size of small destroyers). The Admiral Graf Spee used this unit successfully against shipping in the Atlantic. In Dec. 1939, after heavy fighting during the Battle of the River Plate
, the Admiral Graf Spee was severely damaged and the captain scuttled the ship in the neutral harbor off Montevideo, Uruguay. The ship sank in shallow water such that its radar antenna was still visible.
These early-model Seetakt systems were followed in 1939 by a modified version known as Dete 1, operating between 71 and 81.5 cm wavelength
(368 to 390 MHz) at 8 kW peak and a pulse repetition frequency
of 500 Hz. Maximum range against a ship-sized target at sea was up to 220 kilometres (136.7 mi) on a good day, though more typically half that. Performance was otherwise similar to the earlier system, with a range accuracy of about 50 m. This was considerably more accurate than the guns they ranged for, which typically had spreads of over 100 m. It was also much better than the optical rangefinding equipment of the era, which would typically be accurate to about 200 m at 20,000 m.
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...
during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
In Germany during the late 1920s, Hans Hollmann
Hans Hollmann
Hans Erich Hollmann was a German electronic specialist who made several breakthroughs in the development of radar....
began working in the field of microwaves, which were to later become the basis of almost all radar systems. In 1935 he published Physics and Technique of Ultrashort Waves, which was picked up by researchers around the world. At the time he had been most interested in their use for communications, but he and his partner Hans-Karl von Willisen had also worked on radar-like systems.
In 1928 Hollmann, von Willisen and Paul-Günther Erbslöh started a company called GEMA. In the autumn of 1934, GEMA built the first commercial radar system for detecting ships. Operating in the 50 cm range it could detect ships up to 10 km away. This early version of the system only provided a warning that a ship was in the general vicinity of the direction the antenna was pointed, it did not provide accurate direction or any sort of range information. The purpose was to provide an anti-collision system at night, in fog, and other times of limited visibility.
In the summer of 1935 a pulse radar was developed with which they could spot the ship Königsberg
German cruiser Königsberg
Königsberg was a light cruiser of the in the German Reichsmarine and Kriegsmarine. Her sisterships were Köln and Karlsruhe.After a number of foreign visits in the 1930s, the ship operated along the Spanish coast from November 1936 to January 1937 during the Spanish Civil War...
8 km away, with an accuracy of up to 50 m, enough for gun-laying. The same system could also detect an aircraft at 500 m altitude at a distance of 28 km. The military implications were not lost this time around, and construction of land and sea-based versions took place as Freya radar
Freya radar
Freya was an early warning radar deployed by Germany during World War II, named after the Norse Goddess Freyja. During the war over a thousand stations were built. A naval version operating on a slightly different wavelength was also developed as Seetakt...
and Seetakt. The two systems were generally similar, although the early Seetakt systems worked on a 50 cm wavelength (600 MHz), while Freya was designed for much longer ranges and used a 2.5 m wavelength that could be generated at high power using existing electronics.
These early systems proved problematic, and a new version using improved electronics at 60 cm wavelength (500 MHz) was introduced. Four units were ordered and installed on the Königsberg, Admiral Graf Spee and two large torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...
s (which in German service were the size of small destroyers). The Admiral Graf Spee used this unit successfully against shipping in the Atlantic. In Dec. 1939, after heavy fighting during the Battle of the River Plate
Battle of the River Plate
The Battle of the River Plate was the first naval battle in the Second World War. The German pocket battleship had been commerce raiding since the start of the war in September 1939...
, the Admiral Graf Spee was severely damaged and the captain scuttled the ship in the neutral harbor off Montevideo, Uruguay. The ship sank in shallow water such that its radar antenna was still visible.
These early-model Seetakt systems were followed in 1939 by a modified version known as Dete 1, operating between 71 and 81.5 cm wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
(368 to 390 MHz) at 8 kW peak and a pulse repetition frequency
Pulse repetition frequency
Pulse repetition frequency or Pulse repetition rate is the number of pulses per time unit . It is a measure or specification mostly used within various technical disciplines Pulse repetition frequency (PRF) or Pulse repetition rate (PRR) is the number of pulses per time unit (e.g. Seconds). It...
of 500 Hz. Maximum range against a ship-sized target at sea was up to 220 kilometres (136.7 mi) on a good day, though more typically half that. Performance was otherwise similar to the earlier system, with a range accuracy of about 50 m. This was considerably more accurate than the guns they ranged for, which typically had spreads of over 100 m. It was also much better than the optical rangefinding equipment of the era, which would typically be accurate to about 200 m at 20,000 m.
External links
- ORIGINS OF GERMAN RADAR: SEETAKT, FREYA, WUERZBURG. There is an open source verification for this text on the home page Greg Goebel / In The Public Domain.
- Radar Development in Germany on the Radar World website
- The Radar War (PDF) by Gehard Hepcke, translated into English By Hannah Liebmann on the Radar World website