Big windows - dangerous in an ocean-going yacht ?

[tunnels]

Originally Posted by Boo2

Hi,

I'm interested to know what people here think about the current fashion for big windows in yachts with eg pilothouses ? Most cats like eg Fusion 40 and Schionning designs seem to have huge areas of glasswork as do monohulls with big pilot houses. I just wondered what opinions are about the seaworthiness of these types of designs in terms of withstanding extreme weather conditions in ocean passages ? Could green water smash large windows and swamp the boats as a result ? Anyone heard of this ever actually happening to such a yacht design ? (I've heard of big ships having glass broken by green water but am specifically interested in the situation wrt small (40-50 ft ) yachts).

What do people here think of acrylic or perspex domes/hemispheres as an alternative to pilothouses ? Anyone tried one and care to relate their experiences ?

Thanks,

Boo

During the cruising season there would be small cruise ships came into Tahiti for the tourist trade , they had shutters made of alminium that covered the big low down close to the water windows when doing open ocean passages and once in civilization and sheltered water the shutters were removed and put away till the end of the season then replaced for the return ocean voyage back to Canada or where ever they came from . So maybe a shutter for ocean passages could add security .
Remember the window wants to bend and pop inwards so a wide flang and windows fitter into its opening from the outside with a securing ring frame Bolted not just screwed , Also flexable sealers and adhesives to take shock and bending and flex and possabilities of lots of movement .

[Boston]

bingo
also consideration must be made for the racking movements
the amount of rack is directly related to the size of the window so a larger window must have an accompanying larger area left open for this movement
IE free of bolts screws or other edge damaging obstructions.

[sabahcat]

Originally Posted by u4ea32

Has anyone investigated frameless hatches?

These seem to be gaining popularity in many custom yachts, as they are easily made and flush to decks or other surfaces. The builder makes a mould the size of the hatch that is essentially a scupper with a C cross section, with the inner edge being covered by a rubber gasket, the outer edge glassed to the deck, trunk, or topsides. Drains of course for horizontal deck hatches.

Seems like it would win at sea:

a) no frame, so the "glass" can move, avoiding the pressure point due to a frame.

b) Hinges and dogs through bolted with holes about 50% larger than the fasteners, again prevent high pressure points.

c) The rubber gasket spreads the load nicely

d) Very easy to fabricate

e) Very easy to replace panes.

yes
I have done this on my last cat and am planning on doing the same on the current build

Hinges and struts are always the issue and how to attach directly to the acrylic/lexan/whatever used.