Military Review

Electronic warfare. Battle of the Atlantic. Part of 1

Since the beginning of the war, the British ASDIC (the acronym for the Anti-Submarine Detection Investigation Committee, Submarine Detection Research Committee) was actually the only means of finding and detecting submarines. It was a prototype of a modern sonar, it worked on the principle of echolocation. The use of ASDIC created certain problems for the wolfs of Doenitz, and in the summer of 1940, he suggested changing the tactics of attacks on the convoys of the allied forces.

Electronic warfare. Battle of the Atlantic. Part of 1

ASDIC display

According to the observations of Grand Admiral, the escort escort of the British often consisted of not the newest ships, distinguished by weak protection and not the most advanced sonar. Therefore, the Germans decided to attack escort ships at night and from a surface position, in which the ASDIC could not locate submarines at a sufficient distance. And the night well hid the Germans sticking out the felling from observers both from the air and from ships. And the tactics of Doenitz gave abundant fruits - boats of the U series with impunity sent more and more new ships to the bottom with enviable regularity.

One of the episodes of the Battle of the Atlantic

Any war is very similar to a chess game - every move of the enemy forces the opposing side to look for reciprocal steps. And the UK responded by installing Mark I-type special anti-submarine radars on ships and planes of the Coast Guard. In particular, the Bristol Beaufighter Mk IF two-seater heavy fighter aircraft was the first aircraft in the world to be equipped with the 270 kg locator version. But this radar was not entirely suitable for detecting a submarine on the surface, and at the beginning of 1941, it was replaced by the Mark II. This equipment has already allowed to “look out” for the protruding wheelhouse at a distance of 13 km, but there were difficulties with it too. The fact is that at night the plane could not go on the bombing of a German submarine, since the interference from the sea surface masked the location of the submarine. The plane had to fly at altitudes that did not exceed 850 meters, otherwise radar signals reflected from the water lit up the screens. But such a technique did play its part - the Germans diminished their speed in the attacks, and the losses of the British Navy decreased, especially within the range of the Coast Command.

Bristol Beaufighter Mk IF - the world's first winged radar carrier

From that moment on, the German submariners receive a response - a massive attack on convoys of the "wolf pack" from all sides. Moreover, the Germans began to do this far from the coast of Britain, which excluded the detection of aircraft with their ubiquitous locators. Then the Americans got it too - in May and June, the Nazis sank 1942 of the Yankee merchant ships around 200.

The answer was not long in coming. On the heavy and long-range aircraft of the Consolidated B-24 Liberator type, the allies installed new radars operating at 1-2 GHz frequencies, as well as powerful searchlights Leigh Light.

Leigh Light under the wing of the B-24 Liberator

The latter made it possible to illuminate a German submarine that surfaced for attack with a beam from a distance of 1,5 km, which greatly simplified the attack on it. As a result, the German U-boats went down much faster and more fun. In the fight against such British tricks on German submarines, locator detectors of the FuMB1942 Methox model appeared in mid-1, later FuMB9 Wanze and FuMB10 Borkum, developed too late by FuMB7 Naxos, and so on until the very end of the war. The Germans only changed the operating range of the received radio emission and sensitivity. It is noteworthy that the Germans borrowed the receivers for Metox ready-made from the warehouses of the French company. The only thing that had to be invented was the receiving antennas, which were built in haste around the wooden cross, for which they received the nickname "Cross of Biscay." Early detection of radiation was the key advantage of such receivers. aviation locators of British forces. As soon as the submarine commander received a signal from Metox (or later versions), he immediately urgently submerged the boat under water. And all this happened before the detection of boats by aircraft radars.

FuMB1 Metox control equipment

The British decided to fight Metox in a simple and proven way - by changing the frequency and length of the radio wave of the locator. At the beginning of the 1943 of the year, the Mark III with a frequency of 3 GHz with a wavelength of 10, appeared. Now the planes could fly to an unsuspecting submarine, which, for example, surfaced to recharge the batteries. Metox was silent in such a situation. And the Germans in this stories at first seriously missed the assumptions about the reasons for the discovery of U-boats. The surviving commanders said that they did not hear the alarm from Metox before the night raid, but for some reason the engineers did not listen to the sailors. Instead, they decided that the British were looking for submarines on ... thermal radiation from diesel engines! As a result, they spent a lot of time and money on the equipment of thermal insulation of the motor compartments of submarines. On the submarines installed special heat shields, which yielded nothing, except for reducing the speed of the underwater vessels. Naturally, nothing sensible came out of this action, and in May-June 1943, the Germans lost about a hundred submarines. The insight to the Germans came after parts of the H2S radar (magnetron lamp) were found on a downed British aircraft in Rotterdam. In the end, all the forces threw on the development of a new radar receiver with a wavelength of 10 cm.

The Germans tried to mislead "flying radar" with the help of balloons, which were left hanging at an altitude of 10 meters above the sea. Such traps under the code name Bold were equipped with steel cables to reflect the signals of the Allied radar and were attached to the drifting buoys. But their effectiveness was expectedly low — the Bold had a significantly lower dispersion area than the submarine, which was easily recorded on the radar screen. Snorkel, which embarked on many German submarines at the end of the 1943 of the year, was an unexpected way out - it could be used to recharge batteries by simply sticking it out of the water. The Germans even covered them with a special radio-absorbing material - here the locators were almost powerless. When the submarines began to be equipped with FuMB7 Naxos, capable of effectively determining the exposure of 10 radar radars, it was too late - the Germans lost the submarines too much.

But not only with the help of locators were hunting for “wolf packs” Dozen. To communicate with large German land, submarines were forced to surface, determine their coordinates and radiate to the command or neighboring vessels. This is where they were directed by forces fleet allies, passed the coordinates to the hunters and drowned the Germans. Typically, a group of hunters included a couple of destroyers or frigates, which left little chance for the enemy. To avoid such losses, the Germans gained know-how - “syringe” transmissions, which were pre-recorded in accelerated form, and then transmitted in just a fraction of a second. At the receiving station, one had only to slow down the recording of the radiogram.

Automatic radio finder Huff-Duff and his antenna on a warship

The answer was the automatic radio finder Huff-Duff, sharpened to intercept and determine the bearing of such "rapid-fire" radio programs. They were put both on the ships and on the coastal posts, which simplified triangulation. This became another modest stud in the coffin cover of the German kriegsmarine.

In general, according to the results of the war, it can be stated that the German command of the Air Force and Navy often neglected electronic intelligence. Meanwhile, regular interception of electromagnetic radiation in the sky of Britain would tell the Germans a lot about the intricacies of war.

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  1. merkava-2bet
    merkava-2bet 1 February 2019 05: 07
    Very interesting, just a request, more schemes and drawings from the photo. Thank you.
    1. tasha
      tasha 1 February 2019 06: 07
      The author in his own words retells almost the entire chapter "Electronic Warfare in the Atlantic" from the interesting book "Electronic Warfare (From Tsushima to Lebanon and the Falkland Islands)" by Mario de Arcanelis.

      We read the second paragraph from the chapter (in the article he is the first):
      "At the start of the war, the only submarine detection tool available was the Asdic (Submarine Detection Research Committee — named after the first letters of that institution), now called sonar (Sonar — Sound Navigation and Ranging). It works on the principle of radiation sound waves in water, which, when they meet a target, are reflected from it in the opposite direction; the distance to the target is calculated by measuring the time from the moment of emission to the moment of receiving a response signal. This is called echo-location. "
      Or about the snorkel: "Towards the end of 1943, some success was achieved by the use of a snorkel - a pipe equipped with a special valve that allowed submarines to recharge their electric batteries while moving in a submerged position. They were covered with a special radio-absorbing material that absorbed, and did not reflect the radiation of enemy radar. "

      For some reason, this paragraph was thrown out: "The commanders of the U-submarines, realizing their advantage, attacked more and more boldly, penetrating the very middle of the slow convoys and causing enormous damage. Also, they were greatly helped by the German service of intercepting radio transmissions Service B, which received and decoded not only radio messages sent to British convoys at sea, but also route instructions from the British Admiralty. "

      The illustrations are interesting, I agree.
      1. Janek Travinski
        Janek Travinski 1 February 2019 10: 21
        Thank you for the source name.
        "Electronic Warfare (From Tsushima to Lebanon and the Falkland Islands)" by Mario de Archangelis.

        "Authors" of articles, write where they "took" knowledge.
  2. Galleon
    Galleon 1 February 2019 09: 49
    Thanks for the article and thanks to the respected Tashe for the suggestive comment. To me, as a Rebovarian, the article reads as fascinatingly as a good detective. Mario has already downloaded the book, ahead of the weekend ... Life is beautiful!
  3. Decimam
    Decimam 1 February 2019 12: 02
    ASDIC (Acronym for Anti-Submarine Detection Investigation Committee, Submarine Detection Research Committee)
    Such a committee did not exist. The Admiralty had an Anti-Submarine Division. The ASDIC abbreviation is for privacy purposes.
  4. Operator
    Operator 1 February 2019 13: 20
    With pleasure, plus to the author - to the fans of Mario de Arkangelis, please do not read the continuation laughing
  5. tasha
    tasha 1 February 2019 14: 27
    In particular, the Bristol Beaufighter Mk IF double heavy fighter became the first aircraft in the world with an on-board locator, on which a version of the AI ​​Mark I locator weighing 270 kg was mounted.
    The first experiments on the installation of a full set of radars in an airplane, the British conducted in March 1937 of the year. In August, the 1939 Mk I locator was installed on six Bristol Blenheim aircraft ...
    On the night of July 23, 1940, Blenheim shot down a German Do 17. This was the world's first confirmed radar fighter attack.
  6. tasha
    tasha 1 February 2019 15: 01
    An interesting paragraph about FuMB1 "Metox" from a book about German submariners

    “This radar detector has been installed on submarines since August 1942. It was supposed to detect the operation of a search radar with a wavelength of 1,5 m at a safe distance for the boat. The device got its name from the name of the company (French!) That produced it. 1941 in North Africa, a Wellington bomber with a working radar fell into the hands of the Germans, which allowed them to design the Metox.

    However, it quickly became clear that Metox produced too many detections. Then the fleet turned to Dr. Runge, an expert of Telefunken, with a request to understand this problem. Runge quickly found out that Metox does not distinguish between signals. For example, he took the work of the Luftwaffe transmitter, located 80 km from Bordeaux, for the operation of an aircraft radar. A number of changes have been made to the design of the detector.

    But even after that, the troubles did not end. The Germans discovered that Methox itself emits weak electromagnetic radiation, which is typical for many radios, especially superheterodyne ones. In the spring of 1943, the boats suffered heavy losses because the British began using a new 10cm radar that Methox could not detect. However, a captured British officer said during interrogation that the Methox radiation was the cause of the trouble. Coastal Command aircraft allegedly received a special receiver to detect this radiation. Since it was technically possible, the Germans believed. Doenitz banned the use of Methox. At the same time, it slowed down the installation of the more advanced Naxos detector on submarines by several months. "
  7. NF68
    NF68 1 February 2019 16: 36
    Interesting article.
  8. Decimam
    Decimam 1 February 2019 17: 11
    It seems that it is worth to thank the author for covering an interesting topic, but the level of "illumination" is extremely low. The author is clearly far from understanding the topic, therefore, the presentation is sometimes completely fantastic in nature, having nothing with reality, for example, "a trap under the code name" Bold ".
    Bold (from Kobold-goblin) - a container about 10 cm in diameter, filled with calcium hydride CaH2. being a solid source of hydrogen. When ejected through a torpedo tube in contact with water, intense release of hydrogen bubbles began, forming a cloud, which is perceived on the sonar screen as a submarine.
    Where the author got his description from is a mystery.
    1. Alf
      Alf 1 February 2019 20: 13
      Quote: Decimam
      Bold (from Kobold-goblin) - a container about 10 cm in diameter, filled with calcium hydride CaH2. being a solid source of hydrogen. When ejected through a torpedo tube in contact with water, intense release of hydrogen bubbles began, forming a cloud, which is perceived on the sonar screen as a submarine.

      A similar moment is shown in the film of the 57th year. The Enemy is below, only there the emission goes directly from the torpedo tube.
      By the way, the film looks very lively and interesting, unlike the U-571.
      1. Decimam
        Decimam 1 February 2019 21: 14

        Since 1942, the submarines were equipped with special devices.
  9. bone1
    bone1 1 February 2019 21: 15
    Electronic warfare is considered completely one-sided, from the point of view of only fighting the submarine, but what did the Germans use to fight the convoys? belay
    1. bubalik
      bubalik 2 February 2019 12: 10
      Electronic warfare is considered completely one-sided, from the point of view of only fighting the submarine, but what did the Germans use to fight the convoys?
      ,,, in one article, everything will not fit, you need to create a whole cycle.
      1. bone1
        bone1 2 February 2019 19: 33
        It was clear that the topic was voluminous, but it was more logical to evaluate, for a specific period, both the means of the Germans and the means of the Allies, and not to consider only the use of the means of the Allies and the attempts of the Germans to react.
  10. Avior
    Avior 1 February 2019 22: 21
    To preserve the antenna of our radar, I covered it under the skin of a light body on the bridge. One of the sailors constantly rotated the antenna, which was a massive wooden cross with fixed cables. We called this design “Biscay Cross” by the name of the place where our submarines first applied it.

    When we left Bergen's fjord behind the stern, the ocean subjected the boat to a severe test. But only the “Biscay cross” was seriously damaged. I lowered the broken wooden structure into the wheelhouse and ordered an urgent repair. For several hours we walked without warning of danger, the enemy could easily detect us before we knew about his appearance .... When the U-230 entered the danger zone, the stormy sea was enveloped in darkness. The "Biscay Cross" was restored, which has become a powerful tool for preventing attacks from the air. [146]

    At 2.20 a radar operator detected a target. This was signaled by the radar. The radio operator reported:

    - Radar contact, volume two, quickly amplified.

    Sigman jumped down from the bunk and rushed into the central post. From there he ordered a bridge:

    - Remove the cross! Anxiety!

    Engines increased speed. The cross fell into the room of the central post, the watchmen fell on it one after another, finally destroying the structure.

    But then the situation has changed

    tuning the Metox radar to detect the threat of an air attack. That night, the radar three times signaled the danger and we made an urgent dive. The enemy aircraft dropped deep bombs after us.

    On the morning of 10.12, the big-eyed Borchert extended his hands up and shouted:

    - Plane!

    Seeing a tiny black moth diving at us from behind a cloud, I threw the Biscay Cross into the wheelhouse. Everyone on the bridge rushed down after him. When the deck had already gone under the water, I looked again at the plane and realized that you had no more than thirty seconds to go before the next bombardment. Then I ducked into the hatchway and slammed the lid behind me at the very moment that a giant wave had covered us. The U-230 hid under the water after 18 seconds, keeping at least 10 seconds in reserve to save it from the bombing. When the boat dived into the depths with a trim of 50 degrees, the pilot took a foamy track at the point of our dive for the landmark for bombing. ....

    Being under water, we were surprised that our radar did not give any danger signals. We spent in the submerged position for more than half an hour. Then they surfaced, but only for a very short period of time.

    12.25. Urgent immersion when a twin-engine aircraft appears. No sign of a pilot using the radar.

    12.50. U-230 surfaced.

    13.32. Anxiety. Plane. No radar search. Four bombs exploded near the boat. Stuck horizontal steering wheels.

    Werner Herbert. "Steel coffins"
  11. brom
    brom 3 February 2019 03: 05
    And Doenitz’s tactics bore fruit - U series boats with impunity they sent to the bottom more and more ships with enviable regularity.

    Write U series boats - this is how to write submarine type boats. fool
  12. bone1
    bone1 19 March 2019 21: 12
    A very interesting topic, it’s only a pity that the author went too quickly on it.
  13. Alexei
    Alexei 26 March 2019 06: 21
    Article is super! Author, I demand continuation !!!