Underground and auxiliary forces can clandestinely emplace SIGINT and MASINT technical collection devices. These GFM cloches were sometimes used to emplace machine guns or observation periscopes. The six-man crew can emplace or displace the system in three minutes. It then took four days to emplace eight large cannons. Another pintle at the front could be used to emplace the piece. In some early designs, bridge-layers could emplace bridges, but not retract them. Weigle and his crew to emplace their gun on Kettle Hill. The SR team can emplace remotely operated weather instrumentation. It required two to four days to emplace for firing. One of the requirements during development was that the gun be easy to emplace. The size and weight made it difficult to move and emplace. Four spades, carried on the trails, are used to emplace the weapon.