How do london underground tube travel across the river?

Question

some tube lines go across the river, underground. so where is the line? does it go across the river, in a tunnel beneath the river? or does it travel through tunnel overground, but it seems like underground because we cant see outside?

Answer 1

They are tunnels under the river :)

Answer 2

Under the water line.

Answer 3

Usually tunnel, but the District Line crosses the River Thames at Kew and at Putney over bridges. The District and the Hammersmith & City Lines cross the River Lea at Bromley by Bow over a bridge.

Answer 4

Those tube lines which cross the Thames by tunnel, do so by a tunnel under the river.The first such was the tunnel which takes the East London line. That was originally built as a foot tunnel (before underground railways were built) and the first attempt to dig it had to be abandoned due to the river breaking through the diggings and drowning workmen. At some stations each side of the river, particularly on the Northern Line, you can see massive gates ready to be lifted into position should the same thing happen again, ready to stop the whole system being flooded.

Answer 5

under ther River Thames