It is amazing how many commonplace items are related to ships and the sea. Or perhaps not, given that over 70% of the globe is covered by water and 90% of all trade is moved by sea. Here is one example of an unexpected connection to ships.

Remember the Slinky? The children’s toy has been around for more than 75 years now and is still extremely popular. It was the creation of Richard James, a naval mechanical engineer stationed at the William Cramp & Sons shipyards in Philadelphia. In the early 1940s, he was attempting to use torsion springs to stabilize sensitive instruments aboard ships in rough seas.

James accidentally knocked one of the springs from a shelf, and watched as the spring “stepped” in a series of arcs to a stack of books, to a tabletop, and to the floor, where it re-coiled itself and stood upright. James’s wife Betty later recalled, “He came home and said, ‘I think if I got the right property of steel and the right tension; I could make it walk.'”

James experimented with different types of steel wire over the next year and finally found a spring that would walk. Betty was dubious at first but changed her mind after the toy was fine-tuned and neighborhood children expressed an excited interest in it. She dubbed the toy Slinky (meaning “sleek and graceful”), after finding the word in a dictionary, and deciding that the word aptly described the sound of a metal spring expanding and collapsing.

Over 300 million Slinkys have been sold between 1945 and 2005, and the original Slinky is still a bestseller.

In addition to becoming a toy classic, high school teachers and college professors have used Slinkys to simulate the properties of waves, United States troops in the Vietnam War used them as mobile radio antennas (as have amateur radio operators, and NASA has used them in zero-gravity physics experiments in the Space Shuttle.

August 30th is National Slinky Day.

How the Slinky Was Made

Thanks to Walter Scott for contributing to this post.