Pulley "rove to advantage." Diagram 3 shows that now three rope parts support the load "W" which means the tension in the rope is "W/3". Thus, the mechanical advantage is three. By adding a pulley to the fixed block of a gun tackle the direction of the pulling force is reversed though the mechanical advantage remains the same, Diagram 3a. This is an example of the Luff tackle. The mechanical advantage of a pulley system can be analyzed using free body diagrams which balance the tension force in the rope with the force of gravity on the load. In an ideal
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