Abstract: A container crane assembly is operable to lift shipping containers for transfer between a dock and a ship transporting the containers. Typically, the container crane includes a hoist attachment which engages the shipping container. A fissile or radioactive material detection device may be mounted to the hoist attachment such that as the shipping container is being engaged, the detection device is brought into proximity to the container so that the presence of fissile or radioactive material, or shielding materials to conceal the presence of such fissile or radioactive materials, may be detected prior to the shipping container being loaded onto or unloaded from a shipping vessel. A comparison may then be made of the output of the detector to a threshold to determine subsequent action regarding the shipping container.