The US Air Force tested a bomb to quickly sink ships

Alexander Sychev

She was thrown onto an old, decommissioned cargo ship. During the explosion, the ship literally tossed up and broke in half.

The GBU-31/B bomb is a guided munition that has been developed over the course of about a year by the Air Force Research Laboratory as part of the Quicksink (Quick Sinking) program. The development is new, but based on the technology already tested on other bombs and the old Mark 84 aerial bomb. It has been in service with the US Air Force since the Vietnam War.

The largest of the bombs in the entire series. Its actual weight may differ slightly from the nominal, varying depending on the modification, in the range from 896 to 947 kilograms. The combat charge weighs approximately 430 kilograms of tritonal, a mixture of trinitrotoluene and aluminum powder. The bomb penetrates 380 millimeters of metal or about three meters of concrete.

The US Air Force used these munitions in a number of armed conflicts organized by Washington and after Vietnam. But during Operation Desert Storm in Iraq, the bomb turned out to be useless due to strong dust storms - they missed often and badly.

Research, development, testing to modernize the bomb and make it highly accurate even in adverse weather conditions began in 1992. Then they decided to attach a navigation novelty to a simply falling ammunition - a global positioning system (GPS) receiver and sets of "universal direct strike equipment" (JDAM) - attachments. In fact, these are additional planes and a new tail section with controlled aerodynamic surfaces, which is replaced by a standard stabilizer.

JDAM-equipped bombs are controlled by an integrated inertial guidance system connected to a GPS receiver. Dropped from a great height, such a modernized bomb is capable of gliding, taxiing up, at a distance of up to 28 kilometers. This is how the GBU-15 was born. A series of tests showed that in various weather conditions, the hit accuracy reaches 95%, and the maximum miss was no more than 11 meters.

In December 2001, a modified bomb was field-tested in Afghanistan, nearly killing Hamid Karzai, then the country's acting president. Unfortunately, he led an Afghan armed detachment, supported by a group of American special forces, during one of the clashes with the Taliban.

Finding themselves in a difficult position in a clash with a detachment of the Taliban, the Americans requested fire support. Aircraft dropped bombs from JDAM. As a result, three people were killed, 20 people, including Americans, were injured. The investigation showed that a member of the US Air Force Tactical Control Group, who was part of the special forces, changed the battery in the GPS receiver during the battle, but did not check the settings. But they went astray, gave out the coordinates of a mixed Afghan-American detachment instead of the Taliban.

During Operation Allied Force in 2002, GBU guided bombs were used in Yugoslavia. In total, American strategic bombers then dropped more than 650 Boeing-attached bombs, hitting 87% of their intended targets.

After such success, JDAM systems began to equip bombs weighing 230 (Mark 82) and 500 (Mark 83) kilograms. Since 1998, Boeing has produced over 400,000 JDAM kits.

And finally, the turn came to the Mark 84 weighing almost a ton. By equipping these heavy munitions with a planning and spatial orientation system, the Pentagon sought to obtain a reliable means of destroying enemy ships, cheaper than torpedoes and missiles, but with the same destructive effect. “Heavy torpedoes are effective at sinking large ships, but they are expensive and used by a small part of the navy. Quicksink gives us a low cost solution that can potentially be used by most Air Force combat aircraft”, - said Maj. Andrew Swanson, Head of Advanced Programs, 85th Air Force Division.

Indeed, it turns out cheaper. A Mark 80 bomb, for example, with a new set of plumage and guidance, a fuse and a proximity sensor, costs about $30,000. Cruise missile Tomahawk - almost 730 thousand units.

In addition to the already standard set, consisting of an inertial navigation system, a GPS receiver and a tailor-made tail, a new radar target finder was also placed in the bow of the GBU-31 / B.

The fuse was set up so that the detonation took place as close to the keel as possible. As conceived by the designers, this makes it possible to achieve guaranteed destruction of the conditional enemy watercraft. However, the test was carried out on a dry cargo ship. The design features of warships, the presence of multiple decks, can weaken the penetrating effect of the bomb.

The bombs of the GBU series also have one more weak point. Due to the short range, these ammunition can only be used if the enemy air defense system is suppressed. If it was not possible to achieve air supremacy, then the carrier aircraft simply would not be able to fly up to the drop distance, and the bombs themselves are an excellent target.