Military Review

Jumping bomb

Jumping bomb

The idea of ​​a bomb jumping over water, like a pebble, came up with the English engineer and aircraft designer Sir Barnes Wallis during the Second World War, in 1942-1943. To crush the military power of Germany, the Allies needed to destroy its heavy industry, which worked mainly for the army. The main armory The Nazi workshop was the Ruhr Industrial District. Military plants were supplied with water and electricity from several reservoirs. And if their dams are destroyed, the plants will stand up, because, for example, to produce tons of steel it is necessary to spend seven tons of water. In addition, floods caused by the breakthrough of dams will flood settlements downstream, wash out roads and bridges, damage communication lines and cause significant damage to agriculture.

The dams were earthen mounds reinforced with concrete and more than 10 meters thick. To destroy such a structure, it is necessary to expend 30 tons of explosives. No bomber of that time could not lift a bomb of such weight. However, the calculations showed that if the charge is placed from the pressure side of the dam at a certain depth, its value can be reduced to 5 tons (a shock wave in the water will increase the effect of the explosion several times). But how to deliver the charge to the right place? Ordinary bombs were not suitable because of the low accuracy of bombing, and dams are well protected from torpedoes by anti-torpedo networks.

It was here that Wallis came up with: it was necessary to force the bomb to get to the desired point of the dam on the surface of the water under its own power, that is, at the expense of a ricochet. Perhaps this idea occurred to him during the launching of "pancakes" - they say he often amused himself with this with his grandchildren. Whether he studied the phenomenon of "pancakes" from a scientific point of view, we do not know - his work is still kept secret by the British military department. The Wallis project consisted of the following: to hang a cylindrical bomb under the plane across the fuselage, unwind the cylinder around its axis to a certain speed, and then drop the bomb from a low altitude at some distance from the target, so that the bomb independently “jumps” to it. Hitting the dam, the bomb had to roll down its wall under the water to the required depth, where the hydrostatic fuse would work. The rotation of the bomb provided it with stability after discharge due to the gyroscopic effect. The direction of rotation was chosen so that, firstly, to reduce the friction of the bomb on the water, and secondly, so that in the event of a bomb dropping onto the parapet of the dam, it would slide back to its pressure side.

At first, the Wallis project did not arouse enthusiasm among the British leadership, but after a series of experiments, the attitude towards it changed dramatically, and by the spring of 1943, the rotational bomb entered service with the 617 st squadron. It was a cylinder with a diameter of 124 centimeter, a length of about one and a half meters and a total weight of 4200 kilograms (explosives weighed about 3 tons). The cylinder spun up to about 500 revolutions per minute. The hit of two such bombs should have been enough to break the dam.

Preliminary calculations showed that the bomb must be dropped at a speed of 345 km / h from a height of 18,5 meters at a distance of 390 meters to the target. Complying with such harsh conditions seemed almost impossible. Conventional means - barometric or radio altimeters, as well as bomb sights - were unsuitable: the flight altitude was too low. However, the solution was still found, with a simple and witty. To control the height of the aircraft installed two searchlights. The first searchlight, mounted on the nose of the aircraft, shone vertically downwards, the second, on its tail, at an angle to the vertical. Rays of searchlights intersected at a distance 18,5 meter. The pilot had to lead the aircraft so that the spots from the spotlights on the surface of the water merged. The distance to the dam was determined using the simplest range finder, and two towers located on the dam crest just in the middle were used as a reference point (the distance between them was measured by aerial photographs). The range finder was a plywood triangle, in one of the peaks of which an eye was installed, and in the other two there were studs hammered in such a way that when looking through the eye of the turret and the studs coincided exactly in the place where the bomb had to be dropped.

The attack was carried out at night 16 May 1943. As a result of the bombing, two large dams were broken through, two more were seriously damaged. As a result of the devastation of reservoirs and devastating floods, industrial production in the Ruhr fell by a third for several months, normalized water consumption was introduced. The German economy suffered serious damage, which affected the results of the Wehrmacht hostilities. True, the British’s losses during the bombing were enormous: 19 did not return from the 9 aircraft, and 133 pilots died from the 56 crew. But in general, the operation was recognized successful.

A jumping bomb was created to solve a specific problem - the destruction of dams, it was simply not suitable for anything else. That is why in literature it is most often called Dam Buster (dam destroyer). In addition, Wallis actually created a “disposable” weapon, the re-use of which was very problematic: knowing about the threat, the enemy could reduce its effectiveness to zero by simple measures (for example, put barrage balloons or add anti-aircraft machine guns). Nevertheless, the destruction of dams with bombs entered into history as one of the most original and witty operations conducted by the British army during the Second World War.
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  1. kind
    kind 13 July 2013 07: 40
    A jumping bomb was created to solve a specific problem - the destruction of dams, it was simply not suitable for anything else.

    This is exactly the case when the end justified the means.
  2. erg
    erg 13 July 2013 08: 04
    The idea of ​​bouncing water bombs was also used by ours. When attacking German ships, pilots dropped bombs while walking at low altitude at some distance from the ship. The bomb ricocheted from the water and hit the side of the ship. This method is captured on the footage of a military newsreel. But how the guidance was carried out, what instruments our pilots used, I do not know. Can anyone have relevant materials on this topic?
    1. Lankov Victor
      Lankov Victor 13 July 2013 11: 10
      Dear erg, type in the search engine "masthead" or "masthead bombing"
      1. erg
        erg 13 July 2013 18: 49
        Thanks for the help, I already used it. I’m interested in specific things: bombing instructions, technical documents, etc. Maybe something is laid out somewhere?
    2. The comment was deleted.
    3. Alex 241
      Alex 241 5 September 2013 17: 31
  3. Stas57
    Stas57 13 July 2013 08: 21
    both the idea itself and the history of its application are very interesting.
    here are animated usage patterns
  4. vanya
    vanya 13 July 2013 10: 34
    the factories were mainly owned by Americans - it was impossible to destroy them, I had to look for other methods.
  5. il grand casino
    il grand casino 13 July 2013 12: 10
    I was at Möhnensee, where platinum was blown up. Good platinum, beautiful. And most importantly, how much water. for 60 km. four-meter wave was after the collapse
  6. igordok
    igordok 13 July 2013 14: 09
    All ingenious is simple. Both the principle of bombing and the "altimeter".
  7. knn54
    knn54 13 July 2013 18: 00
    Not quite on the topic.
    The "rubber / jumping" Yankees bomb is ... a solid hollow ball filled with solid rocket fuel and having one exhaust hole. In case of fuel ignition, hot gases escape through this hole and the ball starts to rush around the room with terrible force, bouncing off the walls and crushing the enemy’s manpower, furniture ... It is officially called the “Kinetic fireball incendiary munition”. And if briefly and informally, then, probably, “kinetic fireball“ - United States Patent 7278356.
    It is assumed that this weapon will be used against bunkers and underground storages with weapons of mass destruction. A conventional bomb with explosives can lead to the release and contamination of the area with the remnants of weapons of mass destruction (biological, chemical or nuclear). While a pack of “rubber bombs”, lowered into the ventilation shaft, can effectively neutralize both manpower and equipment, without devastating consequences outside the bunker. Moving randomly, the bomb quickly sweeps the entire room with its impact, and a flaming combustible substance, in a matter of seconds, glows and burns everything around ...
    1. Aryan
      Aryan 13 July 2013 23: 12
      it's like farting into the chimney ... wassat
  8. Partizanov
    Partizanov 26 July 2013 13: 18
    Or an explosive packet in the stove pipe in a field camp. I with a friend Igor in ZabVO in winter at the field exit to the boss’s trailer sent a surprise through the pipe. And he, a goat, climbed on the coals of the stove at that time to light ... I still see the flash and the boss , which rolls with a bun, and yells like Mowgli ... This is unforgettable !!!
  9. Black Colonel
    Black Colonel 5 September 2013 17: 24
    I liked the witty decisions on the altimeter and the range finder on the target. It seems that this guy (Wallis) in Russia has grown. yes
    1. Alex 241
      Alex 241 5 September 2013 17: 35
      bouncing bomb
  10. magirus2000
    magirus2000 20 November 2014 08: 46
    Somehow a film on this topic came across at Discovery. An experiment was carried out - a model of a rotating bomb was dropped from a rare "Lancaster". Very impressed.
    And the Germans conducted experiments with a jumping disk-shaped bomb. But things didn’t go further than experiments.