Cat A ocean standard need full revision

[Concerto]

Interesting reply by Tranona as the regulations have been updated in 2020 for hull windows. However the definition of watertightness still fails in respect of the impact of waves or hull flexing. These should require stress testing as a waterproof window is defined as one that can sustain constant immersion, which is far less bonding strength requirement than repeated impact of waves along with hull movement.

 

[potentillaCO32]

Some google trawled evidence to back up Tranona's points. From the insurance arm of BoatU.S.
1. For every boat that sinks under way, four sink on their moorings/berth.
2. Biggest single cause of their reported sinkings under way are through hulls or hoses from through hulls failing.
3. Then comes hitting an enderwater object rocky shoal etc
4. Hitting floating objects such as logs
5. Rough weather knockdown/downflooding comes last.

No mention of windows or keels

 

[lustyd]

The windows, being bonded from the outside, will be better when submerged since the water pressure will press against the window.
The adhesives use have a strength of over 10KG/cm2 when properly applied and maintained. This is more than sufficient for the application. Engineers know that, regulators know that, forumites continue to speculate

 

[Chiara’s slave]

Keels falling off is a good headline maker, like a capsizing multihull. Both extremely rare, but people are irrationally fearful of them.

 

[geem]

The windows, being bonded from the outside, will be better when submerged since the water pressure will press against the window.
The adhesives use have a strength of over 10KG/cm2 when properly applied and maintained. This is more than sufficient for the application. Engineers know that, regulators know that, forumites continue to speculate

The yacht that lost its large over sized pilothouse windows in the New Zealand storm were blown out front the inside by the pressure of hull flexing.
What has the boat building industry or the ISO standard done to implement measures to stop this happening on other boats built with bonded windows?

 

[lustyd]

The yacht that lost its large over sized pilothouse windows in the New Zealand storm were blown out front the inside by the pressure of hull flexing.
What has the boat building industry or the ISO standard done to implement measures to stop this happening on other boats built with bonded windows?

But those aren’t windows below the waterline so an entirely different scenario. If you lump these all together it just sounds like the problem is modern design.
Edit: that Bavaria didn’t even have windows in the hull.

 

[billskip]

were blown out front the inside by the pressure of hull flexing.

What the hull was compressed and the cabin was so airtight the pressure blew out the windows??....somehow I don't see that happening often....

 

[seeSimon]

Keels falling off is a good headline maker, like a capsizing multihull. Both extremely rare, but people are irrationally fearful of them.

Such incidents perhaps also tend to result in spectacular/significant, probably "reportable " accidents. Fatalities not unusual.

Eg Plenty about keel loss in MAIB references.

Little about bonded in window loss, SO FAR... AFAIK!

My UK built, bonded in cabin windows failed at about 10 years old...
No frits, therfore perhaps improperly designed/installed? Not a significant reportable incident.

See Nov 23 posts on here...How Safe are Windows in the Hull

 

[geem]

What the hull was compressed and the cabin was so airtight the pressure blew out the windows??....somehow I don't see that happening often....

I agree. You really wouldn't want it to happen often.

 

[RunAgroundHard]

What the hull was compressed and the cabin was so airtight the pressure blew out the windows??....somehow I don't see that happening often....

Not force from air pressure, force from the stress of the structure deforming applied to the windows.

 

[geem]

But those aren’t windows below the waterline so an entirely different scenario. If you lump these all together it just sounds like the problem is modern design.
Edit: that Bavaria didn’t even have windows in the hull.

There is an order of risk. Bonded in windows in the hull would be perceived as a higher risk than bonded in windows from a deck saloon.
As I pointed out in my earlier post. Friends deck saloon windows fell out. This isn't an isolated case, although the level of failure of our friends was a little alarming. I am sure the high temperatures of leaving such a boat on the hard in Antigua every summer and the UV were instrumental in their failure.
Lagoon catamarans have the curved front windows fail. I know two of them that have had this happen. None of these bonded window failure that I know about first hand were on hulls. Both windows that failed were curved so its possible that the curved aspect contributed to the failure.
The Lagoon 62 had a professional skipper and was maintained to a high standard. The window failed without warning.
My friends Lagoon 38 was old but had been in the Caribbean for a number of years. It popped out whilst sailing.

 

[dansaskip]

My thoughts.
1. Modern boats are clearly safe for ocean crossings. You just have to look at the ARC start line.

Actually one just has to search on internet for problems for ARC boats to see a number of sinking or abandonment's to wonder about this statement

 

[lustyd]

This isn't an isolated case

It’s also very far from common, even less so in boats properly maintained or within the expected life of the adhesive.
How old was your friend’s boat and what maintenance had they or previous owners done to the windows? I’m not saying mechanically fixed windows aren’t better, but I do think bonded windows are adequate. After all, the grid in your friend’s boat is bonded to the hull too with no mechanical fixings.