COULD a variable-yield bomb reduce the number of innocent people killed or injured during an air attack targeting enemy soldiers? That’s the thinking behind a US navy plan to develop a “dial-a-blast” bomb.
The navy is seeking proposals from companies to create a bomb weighing 200 kilograms that can either be detonated at full or reduced power. The idea is that the device could be loaded onto planes before a target has been identified, and the explosive power set by the pilot once a target is known. If there is a risk of killing civilians, then the explosive power can be reduced to ensure a small blast radius. In an unpopulated area the bomb, currently known as the Selectable Output Weapon, could be set so that it has the same power as a regular bomb of the same size. Carrying a single bomb would make it easier and cheaper for the navy to arm its planes.
The navy plans to invest $9.9 million over the next five years in developing the bomb once it has accepted a proposal. One company vying for the funding is , a defence manufacturer based in Plymouth, Minnesota, which claims to have technology that could do the job.
Advertisement
ATK’s approach is based on the principle that explosives can burn in two different ways. One is via detonation, in which the flame front moves at supersonic speed and produces a powerful blast. The other is deflagration, or subsonic burning, which causes little or no blast.
“The risk of hitting the wrong target is higher than that of the pilot setting the wrong bomb yield”
In ATK’s design the explosive can be ignited at both ends, one set to produce a detonation, the other deflagration. By varying the timing of these two ignitions, the proportion of explosive consumed by detonation can be altered in a controlled manner.
ATK says it has already demonstrated a 27-kilogram bomb with three different power modes. As well as full-power mode, the bomb has a reduced power mode which reduces the size of the blast area by 40 per cent. There is also a deflagration-only mode, which ATK claims left a mirror located less than 2 metres away unscathed during tests.
While such a device should help minimise civilian casualties, it will place a burden on the pilot to get the setting right, says John Pike, a defence analyst with Washington DC think tank . “There is always the risk of selecting the wrong yield.” However the risk of hitting the wrong target may be greater.
The big advantage for the military is that it would allow aircraft to “take off without knowing what sort of targets will be attacked”, Pike says.
