DURING April Dorsey station on the Camden Line in Baltimore was equipped with a 20ft shipping container housing walk-through explosives and metal detectors supplied by Smiths Group.

The USA’s Transportation Security Administration wants to know whether the container can process large numbers of passengers without requiring them to empty their pockets or remove their shoes. Because of the high cost of the equipment, if the tests prove successful the relocatable container could be deployed at a station during an emergency or on a random basis.