Mark 84 bomb


The Mark 84 or BLU-117 is an American general-purpose bomb. It is the largest of the Mark 80 series of weapons. Entering service during the Vietnam War, it became a commonly used US heavy unguided bomb to be dropped. At the time, it was the third largest bomb by weight in the US inventory behind the BLU-82 "Daisy Cutter" and the M118 "demolition" bomb. It is currently sixth in size due to the addition of the GBU-28 in 1991, the GBU-43/B Massive Ordnance Air Blast bomb in 2003, and the Massive Ordnance Penetrator.

Development

The Mark 84 has a nominal weight of, but its actual weight varies depending on its fin, fuze options, and retardation configuration, from. It is a streamlined steel casing filled with of Tritonal high explosive.
The Mark 84 is capable of forming a crater wide and deep. It can penetrate up to of metal or of concrete, depending on the height from which it is dropped, and causes lethal fragmentation to a radius of.
Many Mark 84s have been retrofitted with stabilizing and retarding devices to provide precision guidance capabilities. They serve as the warhead of a variety of precision-guided munitions, including the GBU-10/GBU-24/GBU-27 Paveway laser-guided bombs, GBU-15 electro-optical bomb, GBU-31 JDAM and Quickstrike sea mines. The HGK is a Turkish guidance kit used to convert 2000-lb Mark 84 bombs into GPS/INS guided smart bombs.
According to a test report conducted by the United States Navy's Weapon System Explosives Safety Review Board established in the wake of the 1967 USS Forrestal fire, the cooking off time for a Mk 84 is approximately 8 minutes 40 seconds.