How a dry dock can also open at both ends

Was the Normandie dock also a passage into another part of the port?

It is described as a lock arrangement that could open at either end, although its detailed layout remains uncertain.

The Normandie dock is identified as a lock arrangement in which a dock can open at either end. This addresses its possible role as a passage into another part of the port. Similar arrangements at British dockyards are recalled, but the detailed engineering remains uncertain. Their vulnerability to damage consequently remains an open question here.