Portsmouth Block Mills in 1808. The machines were of 22 types and totalled 45. They were driven by two 30 hp (22.4 kW) steam engines. The machines included circular saws, pin turning machines and morticing machines. With these machines 10 men could produce as many blocks as 110 skilled craftsmen. A pulley-block has four parts: the shell, the sheave, the pin for locating the latter in the shell and a metal bush, or coak, inserted into the sheave to save wear between it and the pin. Blocks can vary in size and in the number of sheaves. The process of making the shells
Wire rope spooling technology the grooving on the drum. Alternatively, a sheave can be integrated and installed within the housing frame. In this case, the system can be set up anywhere around the drum. Oceanographic installations that spool rope up to 46 layers have demonstrated that level winders give synchronized and controlled spooling in the harshest, most testing conditions. Grooving systems for multilayer spooling can be carved onto steel shells that are mounted onto old drums, by either bolting or welding, as an outer sleeve. Called split sleeves, they can be retrofitted onto old drums or mounted on new drums to allow a future