The Mark 84 or BLU-117[7] is a 2,000-pound (900 kg) 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. At the time, it was the third largest bomb by weight in the US inventory behind the 15,000-pound (6,800 kg) BLU-82 "Daisy Cutter" and the 3,000-pound (1,400 kg) M118 "demolition" bomb. It is currently sixth in size due to the addition of the 5,000 lb (2,300 kg) GBU-28 in 1991, the 22,600 lb (10,300 kg) GBU-43/B Massive Ordnance Air Blast bomb (MOAB) in 2003, and the 30,000 lb (14,000 kg) Massive Ordnance Penetrator.
| Mark 84 General Purpose bomb | |
|---|---|
 | |
| Type | Low-drag general-purpose bomb |
| Place of origin | United States |
| Service history | |
| In service | Since 1950s |
| Production history | |
| Manufacturer | General Dynamics Ordnance and Tactical Systems |
| Unit cost | US$16,000 |
| Variants | |
| Specifications | |
| Mass | 2,039 lb (925 kg) |
| Length | 12 ft 7 in (3.84 m) |
| Diameter | 18 in (460 mm) |
| Filling | Tritonal, H6 or PBXN-109 |
| Filling weight | 946 lb (429 kg) |
| References | Janes[1][2][3][4][5] & The War Zone[6] |
Development and use
The Mark 84 has a nominal weight of 2,000 lb (907 kg), but its actual weight varies depending on its fin, fuze options, and retardation configuration, from 1,972 to 2,083 lb (894 to 945 kg). It is a streamlined steel casing filled with 945 lb (429 kg) of Tritonal high explosive.[8]
The Mark 84 is capable of forming a crater 50 feet (15 m) wide and 36 ft (11 m) deep. It can penetrate up to 15 inches (38 cm) of metal or 11 ft (3.4 m) of concrete, depending on the height from which it is dropped, and causes lethal fragmentation to a radius of 400 yards (370 m).[9]
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.[10] The HGK is a Turkish guidance kit used to convert 2000-lb Mark 84 bombs into GPS/INS guided smart bombs.[11]
According to a test report conducted by the United States Navy's Weapon System Explosives Safety Review Board (WSESRB) established in the wake of the 1967 USS Forrestal fire, the cooking off time for a Mk 84 is approximately 8 minutes 40 seconds.
Deployment in wars
MK 84 were used by U.S. forces in the Vietnam War, Iraq War and Afghanistan war and bombing of Yugoslavia in 1999[12] and by Israel in the 2014 Gaza War.[13]
According to a forensic investigation by Human Rights Watch, MK 84 bombs were also in the Saudi-led intervention in the Yemeni civil war.[14]
In 2023 and 2024, the Mark 84 bombs are currently being used extensively in the Israel–Hamas War.[15][16]