AC swamping

[tonyelgar]

Having just got my baggy going I took her for a quick test sail but also did a bit of a swamp test recently (not the cert. one - not many bodies about, any suggestions on alternatives there by the way?!!?) for piece of mind etc etc.
I know that they should sit low in the water when swamped, and the transom is under etc, but I wonder about the CB casing allowing water in whilst swamped, as it is below the water, and how will that affect the drainage of the boat once righted? Is it a problem? I found an excellent thread from 06 which gave a good account of the method for AC boats but some extra pearls of wisdom would be appreciated!
Also the Boat I have, 3255, looks to have once had an aft tank like many baggy trousers, but was removed in favour of bags. The ones that came with the boat were so big i would have had to join the crew in the front! So I have a pair now which match what I had in my last 12. The way I have fitted the bags means they sit quite high towards the gunwale, is this a problem? Or because they sit so low when swamped anyway it makes little difference?
Many thanks!
 
Tony

[MikeDay]

Should be no problem with the boat floating below the level of the c/b case though you might want to look at fitting your rear bags lower in the hull.  The technique is simple once you have the boat upright - bear away onto a reach, flaps open, weight back and you'll soon lose enough water to have the top of the case above the waterline.
 
Mike D
N3496

[Derek]

If you have no tank at the back, the rear bags must be at least 150lb rating. The back bags serve to keep the rear level with the water until you get enough dynamic lift from the hull to start moving back. If you are having to sit further forward than you would normally when sailing up-wind in a breeze, the rear bags may be too small.
The benefit of a small flat rear tank is that it gets the buoyancy low down where it does most good - buoyancy bags only work when they are under the water Achimedes! As an add-on benefit, it also puts a structural box a long way from the neutral axis in torsion. This makes the back of the boat much stiffer which is very useful if you don't have a double floor to do this for you.
Hope this is of some help.
cheers
Derek 3510

[Jerry G]

Our Design 8 (now for sale) has 2 x 150lb stern bags held down by those covers sold by P&B (which have a useful transparent pocket for course cards).  This keeps them more secure than webbing straps with no tendency to bulge up when immersed.  Yes, with our 22 stone the top of the cb case is just submerged when static.  As soon as the boat is moving we move aft and a lot of the water goes out over the stern or through the flaps.  We then trim her so that the top of the transom is above water and as she gathers speed the flaps and bailers soon get rid of the rest.  We have the flaps held by "stretchy" elastic which we don't release, so they act like non-return valves.
Jerry G

[tonyelgar]

I checked today and the bags are 100lbs each, thats 45 kgs. This is what was in the old cheshire cat if i remember rightly, and that was wood not foam sandwich - which should provide some additional bouyancy?? Not sure i want to go to the extreme of rebuilding the tanks back in right now, a lack of indoor faculities at the mo is really making working on her awkward! she seemed to float ok, with me in her but point taken about bag positioning, think I ll make them a little lower when i can. I also got out the bags that came with it and they were 200lbs, and when i inflated them before there really was no room!
If I did eventually go down the route of modifying back to a rear tank would it be as easy just to put a double floor in? as a curiosity point?
tony

[Ian Stables]

Should be no problem with the boat floating below the level of the c/b case though you might want to look at fitting your rear bags lower in the hull.  The technique is simple once you have the boat upright - bear away onto a reach, flaps open, weight back and you'll soon lose enough water to have the top of the case above the waterline.
 
Mike D
N3496

Our AC boat sits with the side decks awash and the transom underwater post capsize. The technique needs a bit of practice, but once mastered is really simple - provided there is enough breeze (if not find a slipway!). Open the bailers before you start so that you do not need to grovel in the bilge once underway, keep the weight well back and the boat flat as you bear away. I find it also helps to raise the board a bit, it closes off the slot and means the boat will accelerate faster as the weight reduces.

[Alistair Edwards]

I followed some good advice from an earlier thread on this subject and fitted a small buoyancy bag between the other two bags adjacent to the transom. Even with two people on board this keeps the top of the transom above water making bailing possible. The extra bag needs to be fitted as low as possible.

On the river there isn't always enough room (or wind!) to head off on a fast draining reach so it is good to have the bailing option. I carry a very large bucket!

[Phil Brown]

I've got hold of 2 kayak buoyancy bags at 25 litres each. They are the same length as the standard bags in our Design 8 but are tapered ( as would fit in the bow of a kayak). I'm planning on fitting them low down at the back and being long and thin, they shouldn't impede the flow of water out of the flaps and should give an additional 50kg of buoyancy without getting in the way of the toestraps either.

[tonyelgar]

Thanks for the great feedback chaps.
Think I ll investigate an extra buoyancy bag for now, and see where time and money take me concerning rebuilding the tank. Come to mention it I did see a merlin rocket with a small bow bag wedged between the usual buoyancy below the tiller once, but they struggled to drain after capsize i think!  A small narrow bag or the kayak bags phil mentioned either side sound just the job.
I am reassured ian that i am not the only one with an occasional sinking feeling!!
 
Tony

[Dave Croft]

Hi Tony,
I used to own 3255 back in the early 90's. It's nice to hear she's still about.
When I had her she had the aft tank, I am surprised it was taken out as it adds to the strenght and stiffness but now it's gone I suggest you take the advice of fitting a small bag in the transom area, the flaps will still work as no matter how tight you tie it down the water will find a way past. One thing also to check is that the main bags are secured low enough. It's all well and good to have 150lb bags but if they are half out of the water after a capsize they are not as efficient.
Where are you sailing the boat? We found she went very well at Salcombe and on open water but was tricky on the river.
Dave C
 

[tonyelgar]

David,
good to hear about some history! She currently resides in weymouth, the chap i bought her off didnt have the time and she was in a sorry state from sitting. Apparently some one before him had put in these huge bags and only tied them to the gunwale .
I'm hoping to get her sorted for some opens next year as the dinghy sailing at WSC is a bit tame when it does show its face, where did u sail her? If there are any old pictures I would be really interested. Currently have a length of carbon for a boom and am considering some options for sails as Im still using the '86 alverbanks which came with her, but for now trying to bring some cosmetics into things as she really has had it hard recently .
Thanks for the advice on the transom, shame about the tank - I thought alot of the other baggy's look really nice with them in.
 
tony

[Evsco]

Our AC boat sits with the side decks awash and the transom underwater post capsize. The technique needs a bit of practice, but once mastered is really simple - provided there is enough breeze (if not find a slipway!). Open the bailers before you start so that you do not need to grovel in the bilge once underway, keep the weight well back and the boat flat as you bear away. I find it also helps to raise the board a bit, it closes off the slot and means the boat will accelerate faster as the weight reduces.

Dear all,
as newbies, my daughter and me had the opportunity (!) to try this out on our first sail in N3237.  We righted easily enough and then set off on the reach.  However, while the water flowed out of the transom flaps easily enough, the level then stayed up to the rear buoyancy tank and didn't want to drain much more.  We had self bailers open, but the wind had died somewhat so they weren't sucking much.  Also, as couldn't get much more water out, the boat was rolling quite alarmingly when half full - how to stop just tipping back over? It wasn't too breezy and the wate was flat, but I can imagine it being easy to capsize / right / capsize in more difficult conditions.  Am I missing something, or am I going to be depending on the rescue boa if we ditch in a blow?!

[tom lee]

Andy (I assume thats who you are)

If there is not enough wind to make the selfbailers work, the only way to empty the remaining  water is to use a hand bailer. you may have spotted on my boat the 5L petrol can with the front cut off for that purpose.
when the wind is stronger, then emptying the water is not a problem: sit back go on a reach and sail fast the water should empty quite quickly.

[Evsco]

Tom,
You're right, its me! Had great fun on first sail, just got caught out by a sudden gust / lull / gust when we turned onto a run.  Anyway, we always intended to capsize, just to try out righting (and I'm sticking to that story)!
I'll invest in a suitable hand-bailer - I think my daughter will quite enjoy using that!  She quite liked capsizing (though when I looked up just after tipping in, she was dangling by both hands from the 'top' gunwhale, until I coaxed her into the water).
Still glad I bought the N12 - its a pocket rocket...