geronimo
Active Member
It would seem to me that unsinkability, like the ETAP yachts, is a very desirable property of boats.
However there are very few around. Why is that?
However there are very few around. Why is that?
unsinkability
- Thread starter geronimo
- Start date
Koeketiene
Well-Known Member
Cost
And, the double hull makes the big, huge, caravan down below impossible.
And, the double hull makes the big, huge, caravan down below impossible.
Boomshanka
Well-Known Member
They cost more than an equivalent size 'sinkable' (double skin and all that foam to pay for). There are a few etaps about (over 500 21i models afloat somewhere). I'm of course completely biased though and think etap are great boats /forums/images/graemlins/grin.gif All joking part, the unsinkability factor was high on the list when we were looking what to go for.
Stoaty
Well-Known Member
Unsinkable does not mean it will be upright when swamped.
Boomshanka
Well-Known Member
Just to contradict my previous post... fire overcomes all notion of unsinkability too /forums/images/graemlins/blush.gif Here's hoping we never test that one.
PeterGibbs
Well-Known Member
? becasue the risk of sinking is almost infinitely small, whereas the incumbrance of all that buoyancy material is a 100% major loss to the boat?
Could be wrong...
PWG
Could be wrong...
PWG
Noddy
Well-Known Member
Because they have a huge lead mine attached to the bottom.
Que the multihull argument!
Que the multihull argument!
achwilan
Well-Known Member
Part wrong... you don't loose that much as buoyancy is distributed in the whole hull (or nearly) between the two skins. Cost is the major issue, and fire of course (just buy ad hoc fire extinguishers...). Repairability is another one as you have almost no direct access to the hull from inside. Comfort is a good point as the resultant insulation suppress condensation and allows for a warm boat in the cold season. A quiet mind when sailing by night or in dirty weather is another point: you don't ask yourself philosophical questions as you know you will stay afloat... (I have been sailing a Challenger Horizon - 23' unsinkable from Jullien yard, a great little boat- for a good while, 20 years ago). Unfortunately, as far as unsinkable sailboats are concerned, the supply is a bit sparse...
Sans Bateau
Well-Known Member
[ QUOTE ]
Unsinkable does not mean it will be upright when swamped.
[/ QUOTE ]
You are making an uniformed guess that is totally wrong.
For Etaps to achieve the French Merchant Maritime certification (the only marine authority in the world to have such a certification) for unsinkable, the boat has to not only be able to float upright, but be able to recover from (I think) a 90deg knockdown. Etaps can sail when fully flooded.
It is true that the average boat buyer will be less interested in the safety of a boat to the extent that Etap seeks to achieve, than he will be in the number of berths and the size of the saloon. But as for space, just compare the likes of the excellent Jeanneu 32 with an Etap 32S. The Jenny has a huge cabin but little in the way of storage as the eye level is left open to help the feeling of space. Also check the size of the cockpit lockers and decide where the dinghy, liferaft, fenders and other junk will live, it wont. Now compare the Etap, yes it does feel more 'snug' below, but high level lockers give loads of storage space and there is a huge cockpit locker.
But I, like others, like Etaps not just because the unsinkability, although it helps. The double skin and foam makes the boat stiff, better insulated and quieter. Add to that the fact that size for size if you chose another make, you are more likely to see Etaps sail past you than you will sail past Etaps, that is unless the Etap is at anchor of course!
Unsinkable does not mean it will be upright when swamped.
[/ QUOTE ]
You are making an uniformed guess that is totally wrong.
For Etaps to achieve the French Merchant Maritime certification (the only marine authority in the world to have such a certification) for unsinkable, the boat has to not only be able to float upright, but be able to recover from (I think) a 90deg knockdown. Etaps can sail when fully flooded.
It is true that the average boat buyer will be less interested in the safety of a boat to the extent that Etap seeks to achieve, than he will be in the number of berths and the size of the saloon. But as for space, just compare the likes of the excellent Jeanneu 32 with an Etap 32S. The Jenny has a huge cabin but little in the way of storage as the eye level is left open to help the feeling of space. Also check the size of the cockpit lockers and decide where the dinghy, liferaft, fenders and other junk will live, it wont. Now compare the Etap, yes it does feel more 'snug' below, but high level lockers give loads of storage space and there is a huge cockpit locker.
But I, like others, like Etaps not just because the unsinkability, although it helps. The double skin and foam makes the boat stiff, better insulated and quieter. Add to that the fact that size for size if you chose another make, you are more likely to see Etaps sail past you than you will sail past Etaps, that is unless the Etap is at anchor of course!
AngusMcDoon
Well-Known Member
[ QUOTE ]
[ QUOTE ]
Unsinkable does not mean it will be upright when swamped.
[/ QUOTE ]
You are making an uniformed guess that is totally wrong.
[/ QUOTE ]
What you say may be true for Etaps, but there are other unsinkable boats out there too. Dragonfly trimarans cannot sink. Flood all compartments of all 3 hulls, and they will stay afloat because they are foam-cored double-skinned and have no keel. But they won't necessarily be upright!
A DF800 was a while ago in a catastrophic high speed collision which crumpled the bows of the hulls so much that the watertight bulkheads lost integrity. All DFs have a watertight section in the bows of each hull in front of a bulkhead in case of collision, but they have their limits!
The hulls flooded from the front, and the boat slowly pitchpoled. It remained afloat, all the crew survived, but it did not remain upright.
Before the 'trimarans are dangerous' brigade leap on this incident as demonstrating how dangerous tris are...
...This has only ever happened once
...Only the smallest DF (the 800) is prone to this
...It requires all 3 watertight bulkheads to be broken to happen
...You got to be really unlucky to prang all 3 hulls
...Most other boats that broke their bows like that would sink in seconds
[ QUOTE ]
Unsinkable does not mean it will be upright when swamped.
[/ QUOTE ]
You are making an uniformed guess that is totally wrong.
[/ QUOTE ]
What you say may be true for Etaps, but there are other unsinkable boats out there too. Dragonfly trimarans cannot sink. Flood all compartments of all 3 hulls, and they will stay afloat because they are foam-cored double-skinned and have no keel. But they won't necessarily be upright!
A DF800 was a while ago in a catastrophic high speed collision which crumpled the bows of the hulls so much that the watertight bulkheads lost integrity. All DFs have a watertight section in the bows of each hull in front of a bulkhead in case of collision, but they have their limits!
The hulls flooded from the front, and the boat slowly pitchpoled. It remained afloat, all the crew survived, but it did not remain upright.
Before the 'trimarans are dangerous' brigade leap on this incident as demonstrating how dangerous tris are...
...This has only ever happened once
...Only the smallest DF (the 800) is prone to this
...It requires all 3 watertight bulkheads to be broken to happen
...You got to be really unlucky to prang all 3 hulls
...Most other boats that broke their bows like that would sink in seconds
Sans Bateau
Well-Known Member
Fair comment, I thought I covered that in my first paragraph.
