Puretic power block a large part the world total fish catch. Between 1969 and 1979, the Puretic power block was pictured on the reverse side of Canadian five dollar banknote issues. In 1975 Mario Puratić was given the National Inventor of the Year Award by the Intellectual Property Owners Education Foundation for his invention of the power block. Puretic power block The Puretic power block is a special kind of mechanised winch used to haul nets on fishing vessels. The power block is a large powered aluminium pulley with a hard rubber-coated sheave. While many men were needed for the back-breaking work of
Block and tackle blocks. Frictional losses also mean there is a practical point at which the benefit of adding a further sheave is offset by the incremental increase in friction which would require additional force to be applied in order to lift the load. Too much friction may result in the tackle not allowing the load to be released easily, or by the reduction in force needed to move the load being judged insufficient because undue friction has to be overcome as well. A block which is open or can be opened to engage with a bight, without the necessity to thread the