Bjørnar Magnussen Oct 21, 2006:

Yes, it seems like you have found the perfect solution yourself. You don't have to wait for someone else to enter it though. Just close the question (e.g. by picking the answer that was most helpful) and then enter "cannon emplacement" into the glossary.

brigidm (asker) Oct 21, 2006:

In the course of checking out all your proposals, I'm now 99% sure I've found the right answer: "cannon emplacement". Can also be referred to as "gun/artillery emplacement". Some very good photos can be seen here: http://www.palmerstonforts.org.uk/art/empl/emp2.htm . Will wait until Monday before closing question. If anyone cares to check this out and confirm by entering as an answer, please do so. Many thanks for all the help so far - this has been a hard nut to crack....