Twistlock

A twistlock or twist lock, together with matching corner castings, as defined in norms including ISO 1161:1984, form a standardized (rotating) connector system, for connecting and securing intermodal, and predominantly ISO-standard international shipping containers.

[2][3] The relative obscurity of this invention belies its importance to a more efficient world trade and transport, as the Tantlinger lock made handling and stacking standard containers much easier.

[4] A major advantage of this approach to attachment is that containers, which may be stored or transported without being inspected for months at a time, do not require any maintenance in order to function effectively.

The male part (which is more exposed and susceptible to damage) is placed on vehicles and equipment that are inspected very frequently, and will work with all standard containers.

Double male twistlocks (midlocks) are also used to lock two stacked containers vertically, for example in double-stack rail transport or on well cars.