In the Details with Peter Harken: How the First Plastic Balls Got into a Block

Hear Peter Harken tell the tale of how a single detail (the bounce of a plastic ball) launched an entire company. This detail made all the difference. Less mass. Faster acceleration. If you listen to Peter Harken recount the moment he realized the Delrin® ball bearings he spilled on the floor while assembling a prototype he’d designed working at a medical equipment company during his university career, he’ll tell you that when he saw those balls hit the pavement and bounce he was surprised at how quickly they reacted. They appeared to spring off the floor. To him that meant they would react equally quickly inside the sheaves of the first Harken ball-bearing blocks. Peter’s watershed understanding was that to make a responsive block the sheaves needed to be quick. They needed to start moving quickly, with even small amounts of force exerted. In fact, Harken designed his blocks to make it easier to ease sails in the lightest breeze. Accounts of the earliest users of the original Harken blocks all remark on how easily the sails eased: "Beware of the black blocks with the white balls. If you don't duck immediately, the boom's gonna knock your head right off."