Hi Mike: I am not a designer but do have some comments. The Portuguese
bridge will not protect your forward windows from real heavy seas. Storm plates
are used as a final resort if you were unlucky enough to misjudge a weather
window. You do need the time to put them up so it is a matter of quick
attachments if the need arises. With the weather info available today they  (storm
plates) will be a good thing to carry them but you probably  will not require
them. (Mr. Murphy rules the unwary). The post from one of the  NAR participants
stated that they fitted out before leaving and perhaps more  comments will come
from them. If storm plates mean a complete refit of your  present windows your
decision will be more difficult to make. Regards. Leonard  Stern,
Indifference.

I never understood much about physics (that darned three-legged milking stool) and less about fluid dynamics, but you have asked some great questions. I too would like to know if I placed an aluminum, storm cover with fixed louvers half-open; would they serve to break the force of the waves striking the windshield, or must storm plates be solid? If louvers are OK, that would solve vision problems.

If weight and storage are concerns, there are composite panels that would work. Again, must the plate be a solid monolith? Since water is incompressible, I would think that the plate would have to be solid or, say, three interlocking pieces to make one solid panel.

Ron Rogers
----- Original Message -----
From: Bob R

Hi All,

I wonder if we are looking at the storm plate problem correctly. Wouldn't we want to know first what breaking wave forces would  happen on a particular window and window support configuration? I think so.

Then we could look at materials and dimensions. Polycarbonate (Lexan) can take sharp forces like that of a hammer, but will it take breaking wave forces without overflexing or bending? I am not sure plexiglass is appropriate because I believe it is more brittle than polycarbonate.It would be nice to be able to see through the plates even though we might not like what we see comming at us; therefore that rules out plywood or metal storm plates. After knowing the forces  needed to protect against and the area that needs protection, we would want to engineer the thinnest possible material to do the job. Of course, the thinner it is, the easier it should be to put in place before the storm.

Having a glass surface over plastic sounds nice, but, storm plates are not going to be used much or cleaned much. The layered materials are more expensive and I believe, unnecessarly so.

Storage is a real problem. Do we need to have a contigious piece of storm plate covering a window, or, could the storm plates be broken up into two or three pieces? This would be a design to take the forces away from the window the storm plates protect.

I think we need to look outside the box for effective engineering and designing of storm plates. And I'll admit, I have a strong bias for polycarbonate materials.I envision two or three strips of polycarbonate with L shaped aluminum reinforcing for each window. This configuration should result in a stronger, stiffer, and, lighter storm plate, more than adequate to dissipate the breaking wave forces on the passagemaker windows.