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 output force), formula_5 is the ideal mechanical advantage of the system (which is the same as the number of segments of line extending from the moving block), and formula_6 is the mechanical efficiency of the system (equal to one for an ideal frictionless system; a fraction less than one for real-world systems with energy losses due to friction and other causes). If formula_7 is the number of sheaves in the purchase, and there is a roughly formula_8% loss of efficiency at each sheave due to friction, then: This approximation is more accurate for smaller values of formula_7 and formula_8. A