Invented in the mid-1950s by Keith Tantlinger, the simple device made it possible to stack cargo containers aboard ships and securely attach them to truck trailers and rail cars.
Twist locks are placed into the corner fittings of shipping containers, which can then be locked to others by turning a metal handle. They’re simple to operate and extremely secure.
To be useful, containers had to be standardized, and others had developed rival ways of stacking them. But after Mr. Tantlinger persuaded his former employer to release the patent royalty free, it was adopted as an international standard.
These standardized stackable containers quickly replaced the manual loading and unloading of cargo and the cost of transport plummeted, ushering in the current era of global trade.