The bridge was mined with demolition charges set in five chambers under the
eastern side of the bridge. The charges would have been detonated, and
the bridge demolished, long
before the enemy got near. All the permanent canal bridges
would have been mined.
[Map ref. ST 308298]
In this close-up you can see
four of the patched-over chambers. The water, rising up over them and
encouraging the growth of weed, has made the chambers appear larger than
they really are.