Creel room in action. Two spools are needed for each of the endless cords. As fast as a spool runs out, the auxiliary spool is immediately pulled into service. Each time one of the spools is replaced, the new spool is tied to the end of the spool which is unwinding so that there is never an interruption in any cord. Should a cord break, it is immediately replaced from an emergency spool until the break can be repaired. Firestone (General Tires), Akron, Ohio