Hashash explains that the immersed-tube design requires largeportions of the tunnel to be built on a dry dock that is floated outinto the water and sunk.

哈沙什解释说，沉管式的设计要求大部分的隧道建筑在干坞上，干坞漂浮并沉没在水里。

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When the ship was in dock, the dock gates shut to keep the water in.

轮船进入船坞时船坞门就关上以阻止水出去。

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But they need deeper water to dock, and bigger cranes to be unloaded than are needed for the current biggest ships.

BBC: Felixstowe opens new berths for giant container ships

Strathclyde Police said his body had been recovered from the water at King George V Dock, near Braehead shopping centre, at about 11:30 on Monday.

BBC: Body of Ross Ramsay, 30, found in River Clyde, Glasgow

Even that would involve filling the hull up to the lower deck with electrolyte and, to balance the pressure, probably flooding the bottom part of the dry dock with Thames water.

BBC: NEWS | Science/Nature | Landmark ship 'faces collapse'