A counter to airpower has always been to dig. Old enemies like Saddam Hussein and new ones like the Taliban have literally “gone to ground” trying to escape US air supremacy. Other nations like North Korea are legendary for their extensive underground facilities. They shelter troops and weapons, house command facilities, and possibly conceal chemical or nuclear weapons laboratories. Precision-guided munitions (PGMs) can attack cave mouths or tunnel entrances. If you’re good (and we are) you can even skip-bomb a PGM through a tunnel door. Equipped with a delay fuze, it can detonate a short distance inside the tunnel. But some tunnel complexes are extensive. Blowing up the foyer may not bother anyone in the rec room. Thermobaric weapons were developed by the US after 9/11 to deny an enemy the ability to hide underground. First, the weapon uses the same body as the BLU-109 penetrating munition. This is filled with an explosive powder and fitted with a delay fuze. After the weapon hits, the delay fuze allows it to penetrate deeply into the fortification. The BLU-109 can penetrate six feet of reinforced concrete, and much more earth. A small burster charge scatters the explosive dust inside the chamber, where it mixes with the air. The powder is an aluminum compound and the particles are so small they are measured in nanometers. A second larger charge then triggers the deadly air-explosive mix, creating incredible blast and searing temperatures. All oxygen in the area is consumed, and anything that can break, will. Not only is this deadly to personnel and equipment over a large area, but if there are any chemical or biological agents present, they will be incinerated by the 3000-plus degree temperatures - more than twice that generated by a conventional explosive. Also, unlike a conventional explosion, a thermobaric explosion lasts a relatively long time. One expert says, “Instead of boom, this bomb goes BOOOOOOOM.” This extended detonation greatly increases its effects. In Harpoon, thermobaric weapons will have a different damage divisor: 2.0. In other words, it is two and a half times as powerful as conventional high explosives. The BLU-118 thermobaric warhead is a 2000-lb class weapon. It can be fitted as the payload in a GBU-15, GBU-24, or AGM-130. It is likely other weapons will be backfitted with thermobaric warheads. While not designed to attack naval vessels, a penetrating warhead designed to explode in confined spaces will work just fine against a warship. While only Russia and the US have manufactured thermobaric weapons (Russia’s was two hand-held rockets similar to an RPG and the air-delivered ODAB-500PM bomb) other nations will certainly develop their own and field them in the coming years. BT Back to The Naval Sitrep #22 Table of Contents Back to Naval Sitrep List of Issues Back to MagWeb Master Magazine List © Copyright 2002 by Larry Bond and Clash of Arms. This article appears in MagWeb (Magazine Web) on the Internet World Wide Web. Other military history and related articles are available at http://www.magweb.com