Sheave pulley out of several pieces. The two main "halves" of the pulley can be moved closer together or farther apart, thus altering the operational diameter. The usual construction is some sort of locking collar or set screws to secure the components, one half with a threaded central shaft and one half with a threaded center. By rotating the components one can "screw" the parts closer together or further apart, thus changing the distance between the two halves and allowing the belt to ride higher or lower in the groove. The adjustments are constrained to a specific range of size and
Miztec (schooner barge) the State of Michigan after they were seized in a 1992 Michigan Department of Natural Resources and Environment (DNRE) raid on the Great Lakes Shipwreck Museum. The State allows the museum to hold a triple sheave block and hook and a double sheave block and hook from the "Miztec" as a loan. Her wreck is now protected by the Whitefish Point Underwater Preserve as part of an underwater museum. The 194 foot wooden "Miztec" was built as a 3-masted schooner in 1890 in Marine City, Michigan. She was enrolled at Port Huron, Michigan on 8 April 1890. On 3 May