Screw (simple machine) advantage (the ratio of output to input force). Screws are widely used in threaded fasteners to hold objects together, and in devices such as screw tops for containers, vises, screw jacks and screw presses. Other mechanisms that use the same principle, also called screws, don't necessarily have a shaft or threads. For example, a corkscrew is a helix-shaped rod with a sharp point, and an Archimedes' screw is a water pump that uses a rotating helical chamber to move water uphill. The common principle of all screws is that a rotating helix can cause linear motion. The screw was one
SS Archimedes a six-bladed "windmill" propeller designed by himself. Brunel's design was to prove a costly failure for the company. Smith and his fellow investors had originally hoped to sell "Archimedes" to the Royal Navy, but when this did not eventuate, the Ship Propeller Company sold the vessel into commercial service. The company, which is estimated to have lost a total of about £50,000 on the "Archimedes" venture, was subsequently wound up. The later career of "Archimedes" is sketchy. The ship ran aground at Beachy Head in 1840. In 1845, she disappeared from Lloyd's Register, but appeared again in 1847 following an