CHARLESTON, South Carolina (Reuters Life!) - Workers at a Google data center combined 12 century know how and space age technology to trigger a medieval weapon that was used to hurl rocks, balls of fire and dead animals over castle walls.

They used an Android cellphone, a computer the size of a credit card and a Blue Tooth receiver to trigger the wooden weapon, known as a trebuchet, during the first Storm the Citadel Trebuchet Competition in Charleston over the weekend.

The trebuchet was used during medieval times to break down fortifications.

They also threw dead people, said Dennis Fallon, dean of engineering at The Citadel, a military college with about 2,100 male and female cadets. What we have done in military history is not always something to be proud of.

More powerful than the ballistas and catapults of ancient empires, the trebuchet used a long swing arm, triggered by the pull of gravity on a counterweight placed at the other end, to slingshot its payload into the air.

The brutal weapon played a large part in the medieval Crusades. According to histories of the time, Richard the Lionheart called his best weapon Malvoisine. Edward I supposedly brought about the surrender of Scotland's Sterling Castle in 1304 with a giant trebuchet named Warwolf.

The trebuchet made a comeback in the late 20th century among medievalists, college professors and fans of the movie Monty Python and the Holy Grail in which a cow is hurled over a castle wall.

In the 1990s in Britain, armament enthusiast Hew Kennedy built a massive machine on his Shropshire estate and used it to throw compact cars and flaming pianos across his field.

Saturday's competition was sponsored by Google during The Citadel's National Engineering Week to support science, technology, engineering and mathematics (STEM) programs in the schools, local employees said.

In November 2009, President Barack Obama announced a major initiative to support STEM education over the next decade to keep Americans globally competitive in innovation and technology.

South Carolina high school students competed along with engineering majors and corporate teams in designing, building and firing the trebuchets.

There's a lot of engineering principles involved. There's a lot of math principles involved. And it's just fun, said Jeff Stevenson, a manager at the Google Data Center in nearby Berkeley County.

Competing teams launched oranges and colored balls at a target, and with a larger machine Google built for demonstration purposes, squashes, melons and bags of flour.

We're playing real-life Angry Birds, said Eric Wages, data center operations manager, referring to the iPhone and Android game in which angry birds are flung at pigs.

The Citadel Cadet Chapter of the American Society of Civil Engineers won the trophy for the best of the college and professional teams.

(Editing by Jerry Norton and Patricia Reaney)