Eglin engineers test bombs with brains
By Doris Johnson, Air Armament Center Public Affairs
/ Published February 05, 2003
EGLIN AIR FORCE BASE, Fla. (AFPN) -- Determining if warheads can penetrate underground targets and detonate after counting floor levels or measuring depth was the focus of recent sled testing on a Hard Target Smart Fuze here.
HTSF engineering team members placed the fuze in an inert warhead on a 2,000-foot test track and sent it through walls at a speeds of 1,300-feet per second, said DeAllen Hobbs, Air Armament Center HTSF engineer.
He said the HTSF features a device that measures impact and depth of burial. When a bomb hits a floor or ceiling of the intended target, the device measures a high impact that looks similar to a seismographic recording of an earthquake; when a bomb passes through an open space or void, the device measurements are shorter, and it records a void.
The HTSF can be programmed to trigger detonation after a certain number of voids or impacts are counted, Hobbs said.
"If intelligence reported an adversary's biological or chemical weapons storage in an underground facility, say, four floors down, then the fuze could be programmed to detonate the warhead at the fourth void it counts and limit collateral damage," Hobbs said. "If we only know how deep it is underground, then we could program it to detonate at the depth required to hit the target."
Team members conducted seven successful HTSF tests on the sled test range here to validate the fuze's design capabilities to detect layers and voids, Hobbs said. During many of the tests, the fuze was also temperature conditioned along with the warhead; two warheads were soaked at 160 F for 12 hours, while two were conditioned at 65 F for 12 hours.
In one test, engineers sent an HTSF-equipped warhead through two feet of concrete, 15 feet of air, six feet of concrete, 12 feet of air and then six feet of concrete, Hobbs said. During the entire test series, engineers only encountered one failure which was directly related to the fuze at a low temperature. Hobbs said experts fixed the problem and retests of the fuze under the same low-temperature conditions verified it.
According to Hobbs, fuzes have been used in warheads since aerial weapons were first delivered in World War I. He said designs were simple then, serving mainly as safety devices for the airmen who worked with the munitions. Later models added time delays.
"This development is a quantum leap in a fuze's ability to function," said Hobbs.
The new fuze will enter flight-testing in April, with four tests scheduled, Hobbs said. Testing is targeted for penetrator warheads such as the BLU-109 and the BLU-113. He said the fuze is projected to enter production in January.
"No one has the capability this fuze provides," Hobbs said. "What's more is that we are doing this all in the same size and volume as the fuzes that were used in Vietnam, and we're having excellent results." (Courtesy of Air Force Materiel Command News Service)