Ball and socket connectors are used to attach conductor stringing blocks to insulators on the arms of 90 foot metal towers of electrical transmission lines. Normally stainless steel cotter keys secure the ball and socket connector in place. In this case, however, black electrical tape was wrapped around the socket to keep the ball in place rather than a cotter key. The tape apparently stretched and the ball came loose, dropping the stringing block approximately 90 feet onto the head of an employee below, one of a four-man erection crew. What should be recommended to prevent this accident from happening again?