Highfield lever Highfield lever A Highfield lever is a lever device which allows tension to be rapidly set up in a wire and equally rapidly released to the required extent. It is frequently used in sailing boats where tension in some part of the rigging needs to be adjusted to a pre-set amount as the wind impinges on one side of the sails or the other. It is typically used in running backstays (runners). To make it work, the backstay is led through a block or fairlead along the deck to a two-legged, second order lever mounted with its fulcrum above deck
Lever rule Lever rule The lever rule is a tool used to determine the mole fraction ("x") or the mass fraction ("w") of each phase of a binary equilibrium phase diagram. It can be used to determine the fraction of liquid and solid phases for a given binary composition and temperature that is between the liquidus and solidus line. In an alloy or a mixture with two phases, α and β, which themselves contain two elements, A and B, the lever rule states that the mass fraction of the α phase is where all at some fixed temperature or pressure. Suppose an