Air mine

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A Lancaster dropped an air mine and 30-pound incendiary bombs over Duisburg during Operation Hurricane in 1944

An aerial mine (sometimes referred to as a mine bomb , blockbuster, or blockbuster ) is a large, heavier explosive bomb that was primarily dropped from aircraft in the aerial warfare during World War II . Air mines are used against unarmored area targets and are particularly aimed at a strong detonation wave that devastates the surrounding area.

functionality

Structure of a "cookie" Mk I

Air mines during the Second World War in the air war against cities from both the German and the British and US air forces used. Air mines did not detonate - as the name would suggest - in the air, but mostly on the ground, triggered by an impact fuse . An air mine ignited directly in the air has an even greater destructive effect because the shielding by neighboring buildings is minimized and the pressure wave is reinforced by the oblique reflection (see also air explosions in nuclear weapons ). The distance fuses required for this were not yet used at that time.

Air mines weighed from several hundred kilograms up to several tons and were filled with high explosives up to 80 percent of their total weight . Compared to normal multi-purpose bombs, they were usually considerably larger: several meters long and up to a meter thick in diameter, but were relatively thin-walled, which is why only a relatively small proportion of the weight was accounted for by the steel shell. Due to this weak sheathing and the high weight, however, there was a risk that the air mine would burst on the ground before the percussion fuse responded. For this reason, they always had several detonators. In rare cases, air mines were even dropped on parachutes . Then they could theoretically be equipped with a time fuse .

British 1.8-ton air mine, which in defusing 4 December 2011 for evacuation in Koblenz led

Because of the thin steel casing, air mines could not penetrate deep into buildings or into the ground, which was what was intended. The explosion craters (bomb craters ) were therefore relatively flat or even completely absent, and the fragmentation effect of these bombs was relatively low.

The pressure wave, which is many times stronger than conventional high-explosive bombs, was devastating. It destroyed all conventional buildings within a radius of 100 meters, tore out doors and window frames up to a kilometer away in the open, and caused window panes to splinter at a distance of two kilometers. When such bombs exploded over residential areas, they covered the roofs within a radius of several hundred meters. For this reason, air mines were also used to give incendiary bombs good access to easily flammable attics and chairs and thus start large fires; Even where only window panes were destroyed at a greater distance, there was still a better way for the fire to spread, as sparks could now get into living rooms and ignite textiles or paper. The goal was the self-reinforcing firestorms . The resulting rubble made roads impassable for rescue workers. Direct victims of aerial mines died as a result of the enormous pressure wave at lung cracks .

Terminology

The technically correct term mine bomb can be traced back to the so-called mine effect in specialist circles, i.e. to the particularly large pressure wave in relation to the size of the bomb. They are not barrages like land mines or sea ​​mines that are dumped and explode when touched.

The German Air Force named sea ​​mines that could be relocated by air drop as air mines ( LM A, B, C and F ). In fact, at the beginning of the war, the German Air Force also used sea mines as a makeshift, because few heavy bombs were available, which were dropped by airplanes over land as explosive mines. Possibly this circumstance led to the fact that the German-language program of the BBC adopted this term, and this was established by listening to the enemy station in the German language.

The German Air Force used the term mine bomb for the high-explosive bomb Cylindrical , which, however, did not correspond to the definition of the air mine described here, but a multi-purpose explosive bomb . The German Air Force developed its own mine bombs late and was officially called large-charge bombs . In popular parlance , the air mines were often referred to as bath stoves or advertising pillars because of their large dimensions or as apartment block crackers because of their effect . The English term blockbuster also comes from the enormous destructive power that could destroy entire blocks of houses. The British Air Force officially designated their mine bomb models with the abbreviation HC for high capacity . The American Air Force, on the other hand, used the designation light case .

World War II models

Great Britain

The bombs used by the RAF on a loading bay during the war: in front two 1,000 or 500 lb high explosive bombs, behind a mine bomb HC 2,000 Mk.I, then a HC 4,000 Mk.III or Mk.IV "Cookie". On the back of the large transport trolley a “blockbuster” (HC 12,000 LB) consisting of three 4000 “cookies”.
HC-4000 dud (1790 kg), painted over

The first mine bomb used by the British was the HC 2000 LB Mk I, a mine bomb of the weight class 2000 pounds (actual weight around 790 kg, that is 1733 lb ) with an explosive charge of 625 kg Amatol . It had a conical tip with a head fuse and was slowed down and stabilized by a parachute. The HC 2000 LB Mk III finally had a flat, rounded face with three head fuses and a sheet metal tail unit. The HC 2000 LB had a diameter of 470 mm and a length of the bomb body of 2655 mm; the total length with sheet metal tail unit (Mk.III) was 3327 mm.

The next larger mine bomb, the HC 4000 LB ("Cookie"), had a similar structure; initially with a conical tip and a detonator and two to four side detonator receptacles, a weight of 1789 kg with 1350 kg Amatol (HC 4000 LB Mk.I), later also with a flat rounded face, three head detonators and two side detonator sockets and up to 1500 kg Torpex (HC 4000 LB Mk.II to Mk.VI). The HC 4000 LB had a diameter of 760 mm (Mk.I) or 750 mm (Mk.II - VI) and a length of 2960 mm (Mk.I) or 2730 m (Mk.II - VI). It was first dropped on April 1, 1941 during an attack on Emden ; by the end of the war, the Royal Air Force dropped a total of 68,000 air mines of this type. The prerequisite for dropping such heavy bombs were bombers with a high payload. The Royal Air Force received the Avro Lancaster from late 1941 .

The next category was developed according to the modular principle : initially the HC 8000 LB, consisting of two segments with a diameter of 965 mm and a length of the bomb body of 2410 mm, the total length was 3340 or 4040 mm depending on the tail unit type. With a total weight of 3590 kg, this mine bomb had a 2450 kg explosive charge made of Amatex 9 (51% ammonium nitrate , 40% TNT , 9% RDX (Torpex)), later even 2670 kg Torpex 2.

In September 1943, the fears of the German experts who had had them after the discovery of the first HC 8000 LB were confirmed: It was possible to assemble an HC 12000 LB from a head section and two rear sections of the HC 8000. This now had a 3620 mm long bomb body; it was - depending on the tail unit - 4722 or 5420 mm long, of the total weight of 5450 kg, 3670 kg accounted for the explosive Amatex (or 4000 kg Torpex 2).

Germany

SB 1000, 1000 kg

In the German Air Force, thin-walled explosive bombs were called mine bombs during World War II . These bombs were given the usual designation, which is composed of the letters SC ( high-explosive bomb, cylindrical ) and the weight class in kg.

The definition of high-explosive explosives listed above corresponds to the "large charge bombs" introduced by the Air Force:

  • SB-1000, 735 kg explosives Amatol 60/40 (60% TNT, 40% ammonium nitrate)
  • SB-2500, around 1640 kg Amatol 60/40 - an experimental version made of aluminum with 2000 kg mp 60/40 could only be produced until 1942.
  • SA-4000, about 2700 kg Amatol 50/50 (with a total weight of 3360 kg; was only built as a test sample)

The German Air Force initially only had two-engine bombers available for the bombing war ( Heinkel He 111 , Junkers Ju 88 , Dornier Do 217 ), which could only carry a bomb load of up to 2500 kg to the target. In the course of the war, the performance was increased to 5600 kg ( Heinkel He 177 , albeit with a reduced range), but the performance never came close to that of the four-engine American and British bombers.

United States

AN-M56, 1920 kg

In addition to the GP bombs (General Purpose = multi-purpose bombs with an explosive content of around 50%), the American Air Force only used one corresponding mine bomb: "Bomb, light-case, 4,000-lb M56".

Technical data: total length with tail unit around 2980 mm, length of bomb body 2430 mm, diameter of bomb body 870 mm, total weight 1905 kg, of which 1470 kg (77%) explosives Amatol.

The LC 4000 lb was mentioned for the first time in the instruction sheet on the disposal of enemy dropping ammunition No. 8 of February 15, 1943, but only as a photo with the (incorrect) designation “bomb DEMO 4000 LB”.

Development after the Second World War

A BLU-82B in a US Air Force exhibit

The main role of the mine bombs during World War II was to cover roofs to give incendiary bombs better access to combustible material. The introduction of the atomic bomb at the end of World War II completely changed air warfare. The area bombing became obsolete, because now the destructive power came from a single bomb. That is why the large mine bombs disappeared from the arsenals.

However, the American Air Force has developed two models for special tasks : The BLU-82B (Daisy Cutter) was primarily developed to create clearings for helipads in the jungles of Vietnam. The successor, GBU-43 / B Massive Ordnance Air Blast (MOAB, colloquially called Mother of all bombs ), was considered the largest conventional bomb until September 2007 and is GPS- controlled detonated before it hits the surface. Both bombs are so big that they do not have to be dropped by bombers but by converted cargo planes.

The aerosol bomb was developed as a weapon with a similar purpose . This achieves a comparable effect with less mass. The Russian aerosol bomb, the father of all bombs, is considered to be the most powerful conventional bomb in the world.

Defuses and evacuations

In Germany, when air mines were defused, extensive evacuations were carried out several times, for example in Koblenz in 2011 , in Augsburg in 2016 and in Frankfurt in 2017 , the latter with 65,000 evacuated people, the largest such measure in the history of the Federal Republic, and on April 8, 2018 in Paderborn with 26,400 evacuated people.

Web links

Wiktionary: Luftmine  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Wolfgang Fleischer : German dropping ammunition until 1945: High explosive bombs, incendiary bombs, special dropping ammunition, dropping containers, detonators , Verlag Motorbuch, 2003 ISBN 9783613022867 [1]
  2. HC 4.000 "Cookie": This is how the Augsburg monster bomb works | BR.de. Bayerischer Rundfunk, December 23, 2016, archived from the original on September 4, 2017 ; accessed on September 11, 2017 .
  3. Jump up ↑ Oliver Teutsch: Bomb in Frankfurt - bomb disposal: "Experience and a little gut feeling" . In: Frankfurter Rundschau . 2nd September 2017.
  4. ^ Bomb disposal on April 8, 2018 in Paderborn. Retrieved April 5, 2018 .
  5. This is how the bomb disposal in Paderborn went. In: New Westphalian . April 9, 2018, accessed April 10, 2018 .