September 18, 2005: British firm BAE Systems is offering the lightest 155mm self-propelled gun ever. BAE combined its very successful M777 lightweight (4 tons) 155mm howitzer, with its Supacat all-terrain wheeled vehicle. The "Portee 155mm Gun" weighs about 14 tons, and has lightweight armor added to the passenger cab (protecting the crew from shell fragments). The Portee carries the modified M777, 20 rounds of ammo, and some additional mechanical gear to enable the howitzer to fire from the vehicle. A 155mm howitzer cannot effectively be fired from a 14 ton vehicle (without doing a lot of damage to the suspension), so the Portee partially unloads the howitzer before firing, so that the ground absorbs the recoil, not the vehicle. When it's time to move again, the howitzer is hauled back on to the vehicle, and off it goes. The U.S. Marine Corps and U.S. Army are buying several hundred M777s, which will be towed by a truck. The advantage of the Supacat is that it is more mobile, and go over ground that would trap a truck.