I can’t pretend that I was pleased to see this thread re-emerge. However ‘Defiant B’s post was most interesting, and a great first post to the forum.

I am curious as to how the statement in our book can be said to be ‘inaccurate’. I’ve re-read both our author’s statement as quoted and Defiant B’s interesting illumination of the detail but apart from being brief and thus (arguably) not doing justice to the complexity of Boulton Paul’s interrupter gear, I can’t see how it’s actually wrong. (Defiant B’s preamble relating to the nature of interrupter gear types does not mean that the usual uses of the term exclude or define this specific use.)

On the other hand I’m delighted the book is regarded as ‘otherwise excellent’.

Andy, that’s a good shot, another copy of which we used in the book, as well as a couple of companion images showing the structure with cupola off and with the guns removed. I’d add that this image still has part of the turret mounting frame (a sort of lying-down ‘K’) visible in the middle. That is (of course) not part of the turret, and is a remnant of a full frame the side members of which have been retouched out.

Regards,