Tunnel escape system for smoke or fumes - has temperature responsive escape flaps and water supply system

摘要

The ventilation duct is to be fitted with an extraction fan, capable of evacuating the toxic fumes or smoke. The toxic fumes could come from road traffic for example. A number of inlet ports feed the ventilation duct at a number of points along the tunnel. These ports are covered with a lid (7) hinged in a horizontal position at (8) and kept in position by a bolt (10) which holds the lid fixed onto a vertical side plate. The plate is slotted so that then the bolt is loosened due to the heating of a fusible washer (14) the lid may move open. A temperature sensor in the duct controls the supply of cooling water to the duct.