Underwater Demolition Team

The Underwater Demolition Teams (UDT) were an elite special-purpose force established by the United States Navy during World War II. They also served during the Korean War and the Vietnam War. Their primary function was to reconnoiter and destroy enemy defensive obstacles on beaches prior to amphibious landings. They also were the frogmen who retrieved astronauts after splashdown in the Mercury through Apollo manned space flight programs.

The UDTs reconnoitered beaches and the waters just offshore, locating reefs, rocks, and shoals that would interfere with landing craft. They also used explosives to demolish underwater obstacles planted by the enemy. As the U.S. Navy's elite combat swimmers, they were employed to breach the cables and nets protecting enemy harbors, plant limpet mines on enemy ships, and locate and mark mines for clearing by minesweepers. They also conducted river surveys and foreign military training.

The UDTs pioneered combat swimming, closed-circuit diving, underwater demolitions, and midget submarine (dry and wet submersible) operations. They were the precursor to the present-day United States Navy SEALs.

Underwater demolition

Underwater demolition refers to the deliberate destruction or neutralization of man-made or natural underwater obstacles, both for military and civilian purposes.

History

John G. Foster

Shortly after the American Civil War, Brevet Maj. Gen. John G. Foster, a West Point trained engineer, became one of the first acknowledged experts in underwater demolition. In 1869, he wrote a definitive treatise on the topic and became widely recognized as the authority on underwater demolition. Many of his theories and techniques were still in practice during the Spanish–American War and World War I.

Christian J. Lambertsen

In 1940, Christian J. Lambertsen demonstrated his semi-closed circuit rebreather, the Lambertsen Amphibious Respiratory Unit (LARU), for the U.S. Navy in connection with his proposal for the formation of military teams of underwater swimmers.

Major Lambertsen served in the U.S. Army Medical Corps from 1944 to 1946 where he did a detached service in underwater operations with the Office of Strategic Services (OSS). After joining OSS, he was vital in establishing the first cadres of U.S. military operational combat swimmers during late World War II.

Demolition Team

The Demolition Team are fictional characters, a team of comic book mercenaries in the DC Comics universe. They first appeared in Green Lantern #176 (May 1984) and were created by Len Wein and Dave Gibbons.

Fictional character history

In their initial appearance, the Demolition Team were hired by Congressman Jason Bloch to destroy the Los Angeles branch of Ferris Aircraft. The Ferris employees were virtually defenseless against the team and their state-of-the-art weaponry provided by the Monitor. Help finally arrived in the form of the mysterious Predator who defeated the entire team unaided. It is assumed the Demolition Team were sent to prison soon after the incident.

The Demolition Team returned several years later with updated technology only to be handily defeated by the Blood Pack after attacking a nuclear power plant in Germany. Hardhat later appeared committing crimes in Opal City.

Rosie, together with several other scientific geniuses and cybernetic beings (Automan, Brainstorm, Doctor Cyber, Ford, and Emil Hamilton), was for a brief period part of the composite cybernetic being known as Enginehead. However (if this story is still canon), the being seems to have been divided into the individual personalities again shortly after the events of the series Enginehead 1–6 (2004).

United States Navy SEALs

The United States Navy's Sea, Air and Land Teams, commonly known as the Navy SEALs, are the U.S. Navy's principal special operations force and a part of the Naval Special Warfare Command and United States Special Operations Command. One of the SEALs' primary functions is to conduct small-unit maritime military operations which originate from, and return to a river, ocean, swamp, delta, or coastline. SEALs can negotiate shallow water areas such as the Persian Gulf coastline, where large ships and submarines are limited due to depth. The Navy SEALs are trained to operate in all environments (Sea, Air, and Land) for which they are named. SEALs are also prepared to operate in a variety of climates, such as desert, arctic, and jungle.

All SEALs are male members of the United States Navy. The CIA's highly secretive Special Activities Division (SAD) and more specifically its elite Special Operations Group (SOG) recruits operators from the SEAL Teams. Joint Navy SEALs and CIA operations go back to the MACV-SOG during the Vietnam War. This cooperation still exists today and is seen in the wars in Iraq and Afghanistan.

Demolition

Demolition is the tearing-down of buildings and other structures. Demolition contrasts with deconstruction, which involves taking a building apart while carefully preserving valuable elements for re-use.

For small buildings, such as houses, that are only two or three stories high, demolition is a rather simple process. The building is pulled down either manually or mechanically using large hydraulic equipment: elevated work platforms, cranes, excavators or bulldozers. Larger buildings may require the use of a wrecking ball, a heavy weight on a cable that is swung by a crane into the side of the buildings. Wrecking balls are especially effective against masonry, but are less easily controlled and often less efficient than other methods. Newer methods may use rotational hydraulic shears and silenced rock-breakers attached to excavators to cut or break through wood, steel, and concrete. The use of shears is especially common when flame cutting would be dangerous.

The tallest planned demolition of a building was the 47-story Singer Building in New York City, which was built in 1908 and torn down in 1967–1968 to be replaced by One Liberty Plaza.