Chapel inclined plane the tower. In spite of the large mechanical advantage provided by the brake lever, the brakeman was unable to apply the brake unaided. To further increase the mechanical advantage, a pulley block was fitted to the lever and the brakeman used this to apply the brake. When the tramway opened in 1796, a hemp rope was used on the incline but it was found that this was too weak and a wrought-iron chain soon replaced it. This also proved not to be strong enough and in 1809 it was replaced. The new chain had links 5 inches (127 mm) long
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