Replacing the GP Medium

A GP Medium is the standard canvas tent the U.S. armed forces have used since World War II. GP stands for "general purpose," although wags say it really stands for "great pain." If an initiative at the Army's Space and Strategic Defense Command, Huntsville, Ala., works out, service members will enter the 21st century with a new space-age tent.

"Imagine a pyramid with the top and bottom cut off," said engineer Rick Berg, who designed the tent. "That's what this is."

The basis for the tent is like Tinker Toys. The tent has struts and nodes that snap together. There are no center poles, so the walls are weight-bearing. There is no set size. If the unit needs an "L-shaped" tent, all service members have to do is snap on more struts and cover it. The basic tent uses 15-foot struts and is 30 feet wide, 45 feet wide and 13 feet high. It can also have a floor.

Another plus is once the tent is erected, service members can move it without taking it down. "Right now, the struts and nodes are made from aluminum," Berg said. "So each strut weighs 38 pounds and each node about three to five pounds. A standard wrecker with a crane can move it. But when the struts and nodes are made from plastic, it will be much lighter. Or the tent can be built in one place and 'choppered' in."

Berg estimates six men can set up the new tent in two to four hours. "It takes less time to take down," he said. "And it is lighter. There are no ropes and tent pegs; there is a base plate that will stake into the ground."

What goes over the tent can change, too. Berg, a general engineer with the Missile Defense Battle Integration Center, designed the tent to provide blast and fragmentation protection for theater missile defense systems. Service members can place Kevlar armor panels onto the tent.

"The choice of fabric is whatever technical specifications you want," he said. "In a chemical environment, you can put on chemical-resistant fabric. You can put nylon camouflage over the tent. Again you might want to put on Kevlar if there's a danger from ground or air attack."

The tent is based on the premise "minimum inventory, maximum diversity." Service members can make many different shapes of tent using one-sized strut and node. With its sloping sides, the tent makes it harder for an enemy radar to detect it.

Berg worked closely with Teledyne Brown Engineering, Essex Corp. and Booz, Allen, Hamilton Inc. in designing the tent. The tent should cost under $5,000, Berg said. The command is sending a prototype to the Army's Research, Development and Engineering Center in Natick, Mass., for evaluation.