Emergency dewatering Sample Clauses

Emergency dewatering. The emergency dewatering system shall consist of: . Two pumps (operation/standby) for general/emergency safety operation. They shall each discharge 150 m/3//h and shall start automatically when the water level rises. . A 150 mm diameter pipe on the backup. . The valves and accessories necessary for operation of the installation. . A quick connect/disconnect coupling for attachment to the fixed pipe in the tunnel. . Hoses for connection to the tunnel pipe, and storage facilities for the hoses. The pumps shall be installed in the front bottom section of the backup. The characteristics, power ratings, and manometric head of the permanent and emergency dewatering pumps shall be such that no booster station is necessary for pumping out of the tunnel to the TBM launching pit. The pipe in the tunnel shall be 200 mm in diameter. The hoses wound onto reels shall retain their sectional area even when wound under no pressure. The pipework and components comprising the dewatering lines shall be suitable for conveying water containing up to 6% suspended solids with a maximum grain size of 20 mm.