Bombs, Gravity

General Description

A typical gravity bomb has a metal casing with a filler, a fin assembly for flight stability, and a fuze to detonate the bomb. The filler can be conventional explosives, nuclear material, incendiary material, propaganda leaflets, or other inert material. Fuzes include a contact fuze that causes detonation on impact, a pressure fuze that uses an altimeter to detonate the bomb at a preset altitude, a time-delay fuze that detonates the bomb after the passage of a preset time period, and a proximity fuze that detonates the bomb when the distance to target becomes smaller than a predetermined value.

Origins and Use in World War I

The Austrians delivered the first aerial bombs from unmanned balloons during the 1849 siege of Venice. On November 1, 1911, Italian pilot Giulio Gavotti threw grenades into an Ottoman army camp in Libya in the first release of an explosive weapon from a powered aircraft. The following year, a Bulgarian pilot dropped bombs on an Ottoman military base during the Balkan Wars. By August 1914, the French, Germans, Russians, and Austro- Hungarians had developed aircraft specifically for aerial bombardment.

Soon after World War I started in August 1914, German zeppelins bombed Liege, Belgium, in the first air raid in history. During the war, tactical aircraft of all belligerents dropped smoke, incendiary, antipersonnel, and explosive bombs on troop concentrations, supply depots, and transportation junctions on or near the battlefield. The first bombs were originally modified grenades and artillery shells with fins attached for stability. By 1918, all countries had bombs, ranging in size from about 2 pounds to 2,205 pounds, with improved effectiveness, specifically designed for aerial bombardment.

Britain, Italy, Russia, and Germany conducted long-range (strategic) bombing with large, multiengined aircraft that dropped the larger high-explosive bombs on rail yards, industrial plants, and urban areas beyond the battlefields. However, these aircraft achieved few significant results because of antiaircraft defenses, lack of an adequate bombsight, and the bombers’ limited range and bomb-carrying capacity.

Interwar Period and World War II

Between the two World Wars, air forces developed bombs with more streamlined casings, better fuzes, and more powerful explosives. By 1939, most air forces had developed their own series of standard bombs with variations in shape and type of casing, fuzes, and filling to attack various types of surface targets and for special uses. For example, bombs for use against warships had hardened and shaped casings and time-delayed fuzes that allowed the bomb to pierce a ship’s armor plating and then explode below the main deck to maximize damage.

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