Towser's boom end 2

Towser's boom outboard fitting, installed on the boom. The sheave is one-and-a-half inches in diameter and approximately one-quarter inch wide. The thin material is a low-molecular-weight, low-friction polyurethane spacer (aka, a piece of a yogourt tub) to position the sheave and keep it running freely. One-eighth inch 7x19 wire is more than adequate for the load.