The catenary rod comes through the bulhead at a very strange angle and has to be forced to assume the correct shape. It first goes thorugh the screen adn then the bulhead 2" further on. To ese this process Paul rolled a sheet of brass into a tube that ws put through the bulhead to capture the end of the rod and the rod was then 'persuaded' through the bulkhead with the thread damaging the bulkhead which is original timber.