The B-2 Spirit nuclear bomber will receive the latest 2,300kg GBU-72/B bomb to destroy bunkers at great depths
The US Air Force wants to arm B-2 Spirit nuclear bombers with new anti-bunker bombs. They are called GBU-72/B. The development is expected to be completed by the end of the current fiscal year.
The B-2 Spirit is undergoing modernisation before it is decommissioned in the next decade. As part of this programme, the aircraft will be armed with GBU-72/B bombs, which will displace the GBU-28/B bombs from the arsenal.
The GBU-72/Bs are equipped with a JDAM (Joint Direct Attack Munition) kit with a GPS guidance unit. The GBU-72/B weighs 2,300 kilograms (5,000 pounds). The Pentagon does not disclose details of the new weapon, but notes that it is superior to the 2,300kg (5,000lb) GBU-28 laser-guided bomb, which can penetrate up to 30m of soil or up to 6m of reinforced concrete.
In 2021, the US Air Force successfully conducted a series of GBU-72/B tests, including dropping the bomb from the air. For the tests, the military service used a fourth-generation F-15E Strike Eagle fighter jet. The tests took place over a range associated with Eglin Base, Florida. The necessary target environment was established there. The photo above shows the detonation of the warhead.
Seismic bombs
The GBU-72/B is a development of the Tallboy seismic bomb, which appeared during World War II. It was created by British engineer Barnes Wallis, and the principle of such a weapon was invented by him before the outbreak of the war.
According to open sources, the British Royal Air Force received 854 Tallboy bombs weighing 5443kg from Vickers-Armstrongs. The mass of the explosive is 2358kg.
The Tallboys were used to destroy many fortified installations and launchers. After the Allied landings in Normandy, the Allies struck a railway station near the town of Saumur, an attack considered the most impressive demonstration of the Tallboy seismic bomb's capabilities.
The US became interested in the concept of such a weapon and started production of the T-14. It is a licensed copy of the British Grand Slam seismic bomb weighing 10 tonnes, which were used during the second war to strike submarine bases.
Already after the end of the war, the US created the T-12 Cloudmaker (pictured above) weighing 20 tonnes. However, seismic bombs were then sidelined due to the rapid development of nuclear weapons.
The previously mentioned GBU-28 appeared in the early 1990s during the Iraq war. After 16 years, Boeing created the GBU-57, which was adopted into service in 2011. After four stages of modernisation, the GBU-57 can penetrate up to 60 metres into the ground.
B-2 Spirit modernisation
It was recently reported that Northrop Grumman will receive up to $7bn to expand the capabilities of its fleet of B-2 Spirit aircraft. It is possible that this will be the last large-scale modernisation programme for the bombers before they are decommissioned.
Currently, the B-2 fleet consists of 20 aircraft, two of which are under repair. Northrop Grumman has built a total of 21 bombers for the US Air Force, but in early 2008 one of them crashed in the Pacific Ocean near Andersen military base.
The inflation-adjusted cost of a single B-2 Spirit is more than $2bn. Northrop Grumman is already working on the next-generation B-21 Raider strategic bomber. It was unveiled in December 2022 and made its first flight a year later.
The B-21 is estimated to cost $700 million. However, the US Air Force believes the cost of the next-generation nuclear bomber could be reduced. US Air Force Secretary Frank Kendall said this last month after speaking to Northrop Grumman officials.
The budget for the B-21 Raider programme will be adjusted in FY 2025 to reflect positive negotiations over production prices. At the same time, the U.S. Air Force says the scope of the project will not be cut. The service intends to receive a total of 100 B-21 bombers to replace the B-2 Spirit and B-1 Lancer.