That sort of instance would be easy to police and protect, but thorough examination of every container moving through every port in the world would be a much taller, time-consuming order, calling for equipment with a degree of sophistication. That’s because not everything exhibiting radiation is necessarily a threat, since some cargoes have it naturally – and that’s a broad church, including such diverse items as bananas, roof tiles and cat litter, to mention but a few.

Quite apart from concerns about what’s contained in within a cargo, and its potential to be a problem at its destination, dangerous cargoes pose threats to ships themselves. The Hyundai Fortune and Hanjin Pennsylvania were both victims of explosions; the former carrying a cargo valued at $140m, and the latter of $50m, which fell victim to an explosion involving fireworks.