US Bomb, 2000 lb Penetrator, BLU-109A/B
These are high explosive, hard target penetrator bombs designed to provide penetration capabilities of 48.00 to 72.00 inches (1.22 to 1.83 meters) in reinforced concrete. The bombs are also designed to be fitted with a laser-seeking guidance unit and an airfoil group. The BLU-109A/B differs from the BLU-109/B in the type of explosive filler, the addition of an externally installed hardback, and the application of an ablative (heat dissipating) thermal insulation coating to the exterior of the bomb body.
A conduit (plumbing tube) connects the tail fuze well to the charging well and provides the necessary access for component interface of the fuze and the initiator. During storage and transit, both wells are closed with a plastic or steel plug. Removal of the nose cap provides access to a 3.00-inch (76-millimeter)-diameter (16 threads per inch) threaded boss for installation of a computer control group for use with a guided bomb unit (GBU). During storage and transit, anticorrosion spacers are positioned under the protective nose and tail end caps.
The heavy-wall bomb case is a minimum of 1.06 inches (27mms) thick. The internal cavity is closed off at the tail with a heavy steel closure plate retained by a threaded steel closure ring. Two pipe plugs, located 180 degrees apart, are installed in the closure plate. A V-groove, around the circumference of the bomb base, is provided for tail fin attachment. A protective tail cap and a protective nose cap, installed in the bomb during storage and transit, contain spanner holes for removal and installation. On the BLU-109/B, two suspension lugs, spaced 30.00 inches (762mms) apart, are bolted to the bomb body, forming part of the bomb assembly. Also, on the BLU-109/B, a charging well and a stores-away switch pad are located between the two suspension lugs. The BLU-109A/B has an externally installed hardback, which is secured by eight securing bolts, and provides for installation of NATO Mk 3 screw-in type suspension lugs. The BLU-109A/B is externally covered with an ablative thermal insulation coating (AVCOFM26(NA)) to delay fast cook-off, high temperature reaction time.
The BLU-109/B is painted olive drab. The BLU-109A/B bomb is initially painted with a blue primer. A gray ablative coating is applied over the blue primer. The BLU-109/B has one 3.00-inch (76-millimeter)-wide yellow band painted around the forward end of the bomb body; the BLU-109A/B has three yellow bands painted around the forward end of the bomb body. The national stock number (NSN), nomenclature, serial number, lot number, and loading data are stenciled in 0.50-inch (13-millimeter)-wide yellow characters at various locations on the bomb body.
Collaborative Ordnance Data Repository