The U.S. Air Force, like the army and marines, uses ships to preposition heavy equipment in regions where the gear may be needed in a military emergency. One of these ships is a 670 foot long, 41,000 ton (displacement) container ship carrying smart bombs and missiles. The MV Tech. Sgt. John A. Chapman can carry 1,063 20 foot shipping containers containing the weapons. Each of these 20x8x8 foot containers can carry up to 18 tons of cargo (but most carry much less.) The MV Chapman is a ro/ro (roll on/roll off) ship that has a 120 foot long ramp that enables trucks to haul off the containers. Many of the containers are stored in air conditioned spaces, to reduce the heat stress on the munitions. The Chapman has a crew of 19 and moves around the Pacific, so it can race to hot spots like Taiwan, South Korea or the Persian Gulf, as needed. The ship normally carries several thousand smart bombs and missiles, of various types and sizes. The air force pays over a million dollars a month to lease and operate the ship.