US Patent 7823338 Modular access control system

An access control system includes first and second portable containers. The first portable container comprises a first sidewall opening and the second portable container comprises a second sidewall opening. The portable containers are arranged such that the first sidewall opening in the first portable container communicates with the second sidewall opening in the second portable container. The first portable container comprises a passing room disposed in the first portable container. The passing room includes a barrier device located in the walkway defining a first space between a first passing room opening and the barrier device, and a second space between the barrier device and a second passing room opening. The access control system is constructed such that when the access control system is disposed between a first area and an enclosed second area ingress and egress from and to the second area is controlled by the access control system.