Large 'windows' on motorboats

[Adrianwool]

Large \'windows\' on motorboats

There has been a tendency over the last few years to progressively larger areas of glass on motorboats. Whilst this provides a better view out and a lighter interior has anyone experienced any problems with this?. I am thinking here of instances where boats are out in rough seas, eg flexing etc. Also I read recently in 'Custom Yachting' that one of the upmarket builders now glues their windows in rather than placing them in a frame. Volume manufacturers such as Beneteau have been doing this for some time, but with windows of considerably smaller size. Anyone got any views on this?

 

[rafiki_]

Re: Large \'windows\' on motorboats

If you are concerned, check with Robin Thatcher at Trend. They supply most marine glass in the UK.
Cars have been gluing in windscreens for years as they give a better and more resilient finish, and are better for sealing. Downside in cars is that they have to be cut out to replace, but not such an issue ona boat as the chances of getting a stone chip are very small I would think.

 

[Bandit]

Re: Large \'windows\' on motorboats

What scares me is a complete failure of a window on a boat in heavy seas.

Most marine glass is toughened as opposed to toughened and laminated.

Toughned glass is the same as most uk windscreen glass its either in place, strong and impervious or if it fails its sharp gravel.

I have certainly had green ones wash up the saloon windscreen on may occasions.

Sometimes a sharp tap from a hard object will shatter toughned glass, we use it a lot for balconies and ballustrades at work and sometimes just setting it down gently on concrete on edge is enough to shatter it.

I have seen many production boats in the 50 to 60ft range with large " windows" below the deck level rather than portholes or small windows which if they shattered you could bung up in an emergency. If one of these large windows caught the corner of a pontoon or a dinghy with snap davit fittings and shattered you could not leave the harbour untill it is replaced let alone if it failed at sea.

 

[jimmy_the_builder]

Re: Large \'windows\' on motorboats

Yes, but to shatter toughened glass you need a point impact on the thin edge of the glass, which on the boat is always protected in some way. We've broken toughened glass in a similar way to what you described - but always before it was installed, never once it was actually in situ.

Cheers
Jimmy

 

[PowerYachtBlog]

Re: Large \'windows\' on motorboats

Azimut started this trend of glued frame less windows
first on the superstructure in 1991 with the introduction of the Azimut 43 AZ Quarantatre and later on in the shipside with the 68S in 2003
after this everyone in Europe has tried a different version of this
I know of builders who had small leakages from the windows altough this later was fixed
this is something very normal on new boats not today but also yesterday, I know of builder who had full standard portholes removed and sealed after just a delivery trip
another very upmarket builder also decreased the size of its full beam cabin window after some problems with some models
for the rest I never heard of total window failure, but may be I am lucky....

 

[Deleted User YDKXO]

Re: Large \'windows\' on motorboats

Bonded windscreens are very common these days. As poweryacht says, Azimut started the trend some years ago, my present Ferretti has a bonded screen and, for sure, Fairline use bonded screens too. I don't see that the method of fixing, whether it be framed or bonded has any bearing on how resistant the screen is to flexing which probably has more to do with how stiff the structure is to which the window is fixed. Bonded screens are glued onto a flexible seal rather than direct to the structure so there is some scope for movement. FWIW, I have experienced a screen failure on a Broom but that was a framed screen. It doesn't half ruin your day because boat windscreens are not exactly available from Autoglass
I do think that motorboat windscreens are certainly not designed to resist solid water coming over the bow. They are too large and angled upwards rather than downwards. 'Proper' boats have small downangled screens which are far more capable of resisting solid water

 

[Adrianwool]

Re: Large \'windows\' on motorboats

An interesting debate so far, glass I believe can actually provide a lot of stiffness to a structure. I think this has been used within the motor industry (i.e. a windscreen providing stiffness in a saloon car). Bearing in mind the potential vunerability of large screens to heavy weather I suppose its a question of 'sensible use' if you have large screens