Munroe effect

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The Munroe effect (sometimes incorrectly called the Monroe effect or Misznay-Schardin effect , which describes a similar phenomenon, see below) describes the partial focusing of explosion energy caused by a cavity molded into the explosive. This focusing can greatly increase the effectiveness of an explosive charge; it is used, for example, in weapons based on the shaped charge principle . Also projectile-forming charges based on the Munroe effect. The effect is named after Charles Edward Munroe (1849–1938), who discovered it in 1888.

functionality

Drawing of a shaped charge

The explosion energy is normally released in all spatial directions. By forming the explosive, however, part of the explosion energy is now concentrated in the hollow body or, ideally, in its axis of symmetry. In practice, this focus is strongest when the cavity has the shape of a cone (see illustration). In this case, a directed high-speed plasma is created , which cuts through steel comparatively easily.

In the case of projectiles or missiles, the explosive charge is usually not encapsulated , so that a large part of the explosion energy does not contribute to the formation of the plasma jet. This loss is accepted, however, since the additional explosive has less additional mass than a possible encapsulation.

Technical use

This effect is exploited in terms of weapon technology by additionally lining the surface of the cone with a metal - the so-called liner . This is centered by the explosion with extremely high pressure on the symmetry axis of the cone and thus cold-formed, creating a metal spike several kilometers per second that penetrates even thick armor plates when it hits (see hollow charge , bazooka ). There are also other areas of application, such as cutting charges for demolishing buildings.

development

While working at the Naval Torpedo Station in Newport in the United States , Munroe noticed in 1888 that when a block of gun cotton with the manufacturer's name was stamped detonated next to a metal plate , the letters cut into the plate. If the letters were raised in relief above the rest of the gun cotton, the letters also stood out from the surface of the metal plate. In 1910, the German Egon Neumann discovered that TNT cut with a conical indentation through a metal plate that would normally only be dented by the same amount of explosive.

This effect was used for the first time in World War II during the battle of Fort Eben-Emael on May 10, 1940, when German paratroopers and airborne pioneers captured the fortress, which was considered impregnable.

Misznay-Schardin effect

During World War II, the German ballistician Hubert Schardin and the Hungarian József Misznay researched a more effective anti-tank mine, for which they investigated the directional effect of explosives arranged in a plate-like manner. The bundling of the explosion energy achieved is less than with the Munroe effect and is known as the Misznay-Schardin effect. The German bank manager Alfred Herrhausen was murdered in 1989 with a bomb that worked according to this effect (see projectile-forming charge ).

Today's meaning

In current military applications, a Munroe effect shaped charge warhead can penetrate solid steel armor equivalent to 1.5 to 2.5 times the diameter of the warhead. The modern composite armor or reactive armor developed as a countermeasure to shaped charge weapons , in turn, reduces the effect. Against this a tandem shaped charge is used.

In civilian use, shaped charge bodies are used as cutting charges , for example to cut steel beam girders when demolishing old high-rise buildings or industrial ruins.

See also

Individual evidence

  1. WP Walters, YES Zukas: Fundamentals of Shaped Charges . John Wiley & Sons inc., New York 1989, ISBN 0-471-62172-2 , pp. 12-13.
  2. Egmont R. Koch : The trace of the bomb - New findings in the Herrhausen murder case , ARD 2014, 45 min.
  3. Misznay – Schardin Effekt at unterm.un.org ( Memento from March 4, 2016 in the Internet Archive ), viewed on April 30, 2018
  4. The construction sites: Use of linear shaped charges , September 2008 edition, pages 42–44 (PDF, 1.01 MB) ( Memento from April 22, 2018 in the Internet Archive ), viewed on April 22, 2018
  5. The construction sites: AES: AES Linear Shaped Charge (LSC) data sheet of cutting charges (PDF, 988 kB) ( Memento from January 22, 2017 in the Internet Archive ), viewed on April 28, 2018