Differential pulley load, and an endless rope looped around the pulleys. To avoid slippage, the rope is usually replaced by a chain, and the connected pulleys by sprockets. The two sections of chain carrying the single pulley exert opposing and unequal torques on the connected pulleys, such that only the "difference" of these torques has to be compensated manually by pulling the loose part of the chain. This leads to a mechanical advantage: the force needed to lift a load is only a fraction of the load's weight. At the same time, the distance the load is lifted is smaller than the
Hook Estate and Kennels and grassland (c.1931), purchased by the Greyhound Racing Association (GRA), soon after the first oval track racing arrived in the United Kingdom. The kennels were located on what was formerly Hook Farm, south of Hook Wood. The mansion 'Hook House' or 'The Hook' served as a base for some of the senior staff including the kennel manager and veterinary surgeon and the Hook Cottages and newly built Hook villas were divided among the trainers and their families attached to the GRA's racetracks. The kennels opened with 150 employees and there was a separate kennel block for each of the original