US Air Force will acquire 15,000 improved 2000 pound bunker busters from 2017 through about 2025

The US Air Force (USAF) has issued a draft request for proposals (RfP) for a new 2000 pound penetrator warhead to replace its current BLU-109/B and BLU-109C/B systems.

The draft RfP for the BLU-137/B Penetrator Warhead, released on 2 December, covers low-rate initial production (LRIP) and four full-rate production (FRP) lots totalling 15,000 bombs.

Intended to be in the same 2,000 lb class of warhead as the BLU-109/B and BLU-109C/B, the BLU-137/B will be procured in an indefinite delivery/indefinite quantity (IDIQ) contract running from fiscal year (FY) 2017 to 2021. LRIP will number 1,000 warheads, with the four follow-on FRP contracts numbering 3,500 each and spanning one year apiece. A second IDIQ award may be granted after FY 2021.

No technical specifications for the BLU-137/B were given in the draft RfP, except to say that it is intended to provide improvements in capability and survivability over the BLU-109/B and BLU-109C/B.

The BLU-109/B is a hardened penetration bomb used by the United States Air Force (BLU is an acronym for Bomb Live Unit).

The BLU-109/B has a steel casing about 1 inch (25.4 mm) thick, filled with 530 lb (240 kg) of Tritonal. It has a delayed-action tail-fuze. The BLU-109 entered service in 1985. This weapon can penetrate 4–6 feet of reinforced concrete, which is greater than the 3 foot capability of the Small Diameter Bomb.