KEEPING YOUR BOAT AFLOAT

[bornfreee]

While pouring a glass of water from those 10lt water bladders that you can buy from Coles it got me thinking how would those bladders go as floatation in case you were holed or one of those old sea cocks gave up the ghost.
Ripping out one of the old used bladders i blew it up with my mouth and was impressed how large it was, it rolled up very small when deflated so would be easy to store the next question was how many would you need to hold up the boat and that is were you guys come in to it does any one know how to work out the maths? going to sea in a boat that cant sink sure gives you a peaceful mind makes me smile thinking how they say nothing empties a boat of water faster than a scared man with a bucket can you imagine what a scared man blowing up his empty bladders would look like.

[admin]

I reckon you'd be better off saving your breath for the swim back to shore!

But seriously, the amount of time to manually inflate a sufficient amount, let alone restrain them so they dont float away would negate the reward in my opinion.

If anything filling the vberth and under cockpit area with some kind of closed cell foam fixed in place would probably be a better option, if required! you'd want to get the balance right too!!

Without knowing the maths, i reckon it'd take a fair to hold up 3tn of boat (let alone water weight inside!)

dan

[Swift]

258 X 10 litre bladders would be equal to the displacement of a Top Hat. To provide useful freeboard of 6 inches another 160 bladders would be required. Therefore the total is 418 with no allowance for additional weight of the contents of the boat.

Your probably aware that large bladders inflated by compressed air were marketed by a company called Yacht Savers. They may have gone out of business. The objections to using bladders include the lack of room once they are inflated and keeping the boat in trim. However I think that the main reason they have not been more widely used is the increasingly popular view that all you need is an EPIRB, an insured boat and a life raft.

I too have pondered how to make a Top Hat unsinkable. A mark 1 has 2 large cockpit lockers that are totally sealed off from the cabin. The cockpit lids could be sealed with good gaskets. Also, for models with outboards it would be a simple matter to install a water tight door to the area under cockpit. Therefore you would have 3 watertight compartments equal to almost half the displacement of the boat. To keep the nose up is more problematic, There's not a lot of volume under the bunks or the v birth. This would be the ideal situation for large bladders.

Designing an unsinkable boat from the ground up like the excellent French Etap designs is relatively simple. In fact it's so simple I don't know why all new boats under about 25 ft should not be unsinkable. Over 25 Ft you begin too loose too much storage volume. It's much more challenging to make an existing boat unsinkable, particularly if 43% of the weight of the boat is lead in the keel. There's a good practical article on this subject on the Atom Voyages site : In Search Of The Unsinkable Boat: http://www.atomvoyages.com/projects/UnsinkableBoat.htm.

Keith

[Phillip]

Morning bornfree, (sorry you did not post your name)

To my knowledge no Top Hat has ever sunk at sea

But I do know of 2 that have run up on the hard stuff

To counter these 2 right offs you need the following:

A good kitchen timer, so you can be woken up before sailing onto the beach
(This happened to the first Top Hat [a mk 0] to go overseas, never came back of course!).

A sober skipper.
(This happened to a mk 1 that had a professional skipper to take the newly purchased Top Hat [mk 1] from Sydney to Pittwater, he tried to round Barrenjoey at about Long Reef and put her up under the cliffs, it was chain sawed up to remove, that cost more than the yacht was worth! Result a big court case.)

The only other loss I know of was at a mooring near Melbourne where a mk 0 sunk through a lack of maintenance.

So I don't think we need to be worrying about buoyancy in a Top Hat.

Better to make sure you have your required buckets and your bilge pumps, electric and manual are working and well maintained

Phillip
SEAKA

[Tales]

Phillip,

I believe that another wooden TH "Brigadoon" was lost at Mornington (Port Phillip) a couple of years ago on its mooring (with a number of other boats) in a big storm. A pity as she had been brought back from near death a couple of times already in her lifetime.

With no bridge deck the TH is vunerable to being pooped. We keep the lower storm board in the companion way (secured by a lanyard and clip accessable from outside and inside) in rough weather.

Also the cabin sole on Tales (MKIII) is lower than the access hatch to the bilge so a lot of water can't actually drain into the bilge if it went inside. I am thinking of cutting a couple of drain holes to solve the problem.

Just a bit of trivia, the smaller plywood filler in the V berth is an exact copy of the lower storm board and could be used as a replacement in an emergency if the original was lost.

Cheers,
Tom

[storm petrel]

Hi All,

Seems we all have the same thoughts. I made up a reinforced ply, lower storm board which is secured down by a couple of hatch clamps. I keep this board in while at sea and store the 'dress' board down below as a spare. In addition, I have drilled a large drain hole in the timber at the back of the cabin floor to take any water on the cabin floor into the bilge.

I think the best way to keep a Top Hat afloat is to keep water out of it!

Cheers,
Mark
Storm Petrel

[Phillip]

Afternoon All,

Thanks for that info on BRIGADOON Tom as she was probably one of the original 10 built by Mouldcraft .

The Mk1's only have two parts to their cabin main hatch (built in fibreglass), the bottom one being to high too easily get over at sea. I made up a new one that is the same height as the cockpit lockers and this is a lot better.

Of course early Mk1's can remove the stern hatch to allow breaking seas to return where they should be.

Phillip
SEAKA