Author Topic: heavy weather sailing and the Essence  (Read 719 times)

blue-max

  • Able Seaman
  • ****
  • Posts: 152
  • Karma: +0/-1
  • Boat Model: ocean 47
  • Boat Year: 2000
heavy weather sailing and the Essence
« on: October 31 2021, 19:30 »
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.     

Yngmar

  • Administrator
  • *****
  • Posts: 1228
  • Karma: +8/-0
  • Boat Model: 40 Ocean
  • Boat Year: 2001
Sailing Songbird  ⛵️ Bavaria 40 Ocean (2001)