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
Brake shoe Brake shoe A brake shoe is the part of a braking system which carries the brake lining in the drum brakes used on automobiles, or the brake block in train brakes and bicycle brakes. The brake shoe carries the brake lining, which is riveted or glued to the shoe. When the brake is applied, the shoe moves and presses the lining against the inside of the drum. The friction between lining and drum provides the braking effort. Energy is dissipated as heat. Modern cars have disc brakes all round, or discs at the front and drums at the rear. An