I did try posting on a previous thread but it was lost so will start again. For those who do not know the Essence was a Bavaria Ocean 47 which was lost off the coast of New Zealand during a storm, 3 of the crew survived, the skipper died. One of the crew has written an account which has been published by YBW. There has also been an official enquiry in New Zealand.
The official finding of the enquiry was that the Essence was lost because windows in the saloon broke under the stress of a broach/knock down and no storm covering had been fitted to these windows.
I have paid a lot of attention to this story but some of the facts remain not fully described and owning a similar vessel wonder about both its structure and how I could have coped in similar circumstances.
I have just overhauled the saloon windows in my boat - they were leaking! They have aluminium frames with acrylic 8mm sheet . The acrylic is framed from 2 aluminium extrusions screwed together. This frame rests against the outside of the coach roof sides and is held in position by a further aluminium extrusion on the inside which is screwed into the outer aluminium frame. The security of the frame to the coach roof sides is created by the pressure of the aluminium frames screwed together. There is no mechanical fixing of the windows to the cochroof sides - that's how the storm windows would be attached. The original fitting of the windows used only tape on the outside rather than a strong mastic . In my case the tape had lost all adhesion.
When the Essence was knocked down - moving at 7 knots with 7m high waves, the force of the crash caused flexing in the boat - hull and deck. because there was just a narrow flange holding the frames in position , the windows popped out it there entirety . We are not informed if the acrylic broke in pieces but when the boat righted the window was gone.
Having stripped the windows out I was shocked to see how thin the fiberglass was to coachroof sides - going from 11 mm at the base to 7mm at the top. Also the screws holding the aluminium frames together are just 4mm with a bite of maybe only 2mm. I would not be surprised if the screws had stripped under the pressure. I don't think this should be taken as a criticism of boats with large windows but I do think more could be done to maintain structural integrity with mechanical fixings. It would not be that difficult to do this on the Ocean 47 - there is space between the window frames for strengthening and integrating the window with the structure. Now all boats leaving New Zealand will have to storm covers fitted to all windows and ports.
With the windows gone The Essence could not recover . I wonder about that. But thankfully I will never be in that position.
