Question

7. This bridge opens outwards. It is
balanced by a pivot pier which is at
its centre. (2 words)​

Answer 1

Answer:

A swing bridge is a movable bridge that has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravity, about which the turning span can then pivot horizontally as shown in the animated illustration to the right. Small swing bridges as found over canals may be pivoted only at one end, opening as would a gate, but require substantial underground structure to support the pivot.