Questions about this type of Enterprise

[Tink]

I think the more modern approach is water ballast, all you need to know here:

http://www.swallowyachtsassociation.org/?page_id=1183

I like the idea of removable lead ballast that would be fixed along the centre board case, look at the forecast and decide if it is needed. The ballast would be in say 5 kg chunks and removed before pulling it up the slippway and transferred to a little trolley. I have both the lead and the trolley.

 

[DownWest]

My Whilly Tern is fine in almost all conditions two up, but I have had a couple of frights on my own. Iain reccomends some ballast if one up and brisk. 40kg held down on the floors amidships would do it, in easily handled lead ingots as you said.
It has the fore and aft decking, but I don't kid myself that it would be easy to recover after a capsize in choppy water and I have a few creaking bones to make it more difficult. Hence building a mini cruiser with a ballasted keel.

 

[Tink]

I have re-red the water ballast article, here is stability curve,



The thing we all worry about is the point where the stability goes from positive to negative and the boat is stable upside down. For you average dinghy this will be at 90 degrees and I think for many people this the critical point, we have all seen the following:
A) Novice crews hanging not wanting to get wet onto the gunwale and actually inverting the boat.
B) Experienced crews nimbly hoping over the gunwale onto the boat, creating positive stability and righting the boat before the mast hits the water.
C) Violent, down wind, capsizes where the moment of the mast drives it underwater without and chance of crew intervention.

This is from the article



The blue line is unballasted and red with ballast. At 90 degrees righting moment can start to go negative depending on the ballast but then in this graph it the goes positive which is due to the buoyancy of the mast. If we have a weighted board we can keep the positive righting moment past 90 degrees, and can do the same to a lesser extent with internal ballast and get self righting. Just thinking of what is actually happening at say 70 to 90 degrees, the sail will be producing so little capsize moment at the time that it will be crew position and moment that have the biggest effect of what happens. Buy adding buoyancy aloft we can produce stability to give the crew time to right the boat annd recover. With well designed righting lines a less agile crew can do this without getting onto the board.

I think what I am saying is how useful mast head buoyancy is, I obviously appreciated this but the graph just reinforces the impact of it.

 

[Daydream believer]

Actually total inversion is not always that bad for a tired crew - - as long as the mast does not touch the bottom.
If tired & the dinghy is on its side it can be almost impossible to get on to the centreboard to put ones weight on to it. But when the boat is upside down & if there is a lip on the gunwale then one can get a foot onto the lip & then get up onto the upturned hull quite easily because the lip is level with the water. Normally one can get a hand to the board to pull on.
From there one needs to decide which way to go by looking at tide & wind then gradually lean on the board, possibly putting a foot on the gunwale until the boat comes to 90 degrees. Being on the hull to start with one can thus find ones self on the centreboard. Then it is easy to reach over, release the kicking strap & main-sheet & possibly the jib sheet, if not on cleated on the wrong side. Then it is a case of applying weight & stepping over the side as the boat comes up.
if you do fall in again then it works better on some dinghies (lighter ones) to reach in & raise the board before rolling in over the side. This is because it allows the dinghy to skid sideways & not sail on the board & tip over. Same for letting off the kicking strap. It allows the leech of the sail to spill the wind so that as the boat comes up the sail does not start sailing.
It is a mistake to tighten the kicking strap then tie loads of half hitches in it so it cannot be released.

 

[Fascadale]

I used to sail an Enterprise
I also used to sail a Gull

Fifty years later I have a Mk1 Gull

And I'm planning on doing a bit of inland cruising next summer in the Gull (as well as some more serious sailing in the R34)

 

[Tink]

Actually total inversion is not always that bad for a tired crew - - as long as the mast does not touch the bottom.
If tired & the dinghy is on its side it can be almost impossible to get on to the centreboard to put ones weight on to it. But when the boat is upside down & if there is a lip on the gunwale then one can get a foot onto the lip & then get up onto the upturned hull quite easily because the lip is level with the water. Normally one can get a hand to the board to pull on.
From there one needs to decide which way to go by looking at tide & wind then gradually lean on the board, possibly putting a foot on the gunwale until the boat comes to 90 degrees. Being on the hull to start with one can thus find ones self on the centreboard. Then it is easy to reach over, release the kicking strap & main-sheet & possibly the jib sheet, if not on cleated on the wrong side. Then it is a case of applying weight & stepping over the side as the boat comes up.
if you do fall in again then it works better on some dinghies (lighter ones) to reach in & raise the board before rolling in over the side. This is because it allows the dinghy to skid sideways & not sail on the board & tip over. Same for letting off the kicking strap. It allows the leech of the sail to spill the wind so that as the boat comes up the sail does not start sailing.
It is a mistake to tighten the kicking strap then tie loads of half hitches in it so it cannot be released.

I have never heard or tried releasing the kicking strap, sounds good. I think whether being inverted is safer will depend on the geometry of the boat. Good righting lines and a good gunwale lip for pushing against can make the whole standing on the board issue, again geometry / buoyancy placement are important.

 

[ShinyShoe]

I have never heard or tried releasing the kicking strap, sounds good. I think whether being inverted is safer will depend on the geometry of the boat. Good righting lines and a good gunwale lip for pushing against can make the whole standing on the board issue, again geometry / buoyancy placement are important.

Pretty sure the racing kiddies who sit perfectly on the line release the kicker too. Then pull it on as part of the acceleration process... So given you will likely want to sit "still" while you sort your self out once back on board... Seems a good idea to have it off

 

[Tink]

Pretty sure the racing kiddies who sit perfectly on the line release the kicker too. Then pull it on as part of the acceleration process... So given you will likely want to sit "still" while you sort your self out once back on board... Seems a good idea to have it off

I fully understand the function of the kicker to control the leach and power in the sail. Until recently I was had no formal sailing training but experience. In the past five or so years I have been an assistant instructor and level 2 race coach. I was somewhat confused when I leant that the RYA way of rigging and launching a dinghy was with no kicker tension. After I was told this I experimented, above a force 4 without kicker tension the flogging of the sail as disconcerting and not good for the boat. With kicker on the sail more docile, I’m talking about head to wing on land on a trolley here.

 

[wombat88]

I have capsized a couple of boats in the last few years. I am not a great sailor and certainly not athletic.

First there was the Merlin which went over on a regular basis even when not racing, particularly on a dead run. It was pig to right and being a 1950s boat could hold an awful lot of water and first time I forgot the bucket. One felt very ginger exerting pressure on the thinnish wooden centreboard and she had a habit of going over the other way once righted. Was towed home knackered on more than one occasion.

Then there was the Prout Swift cat. You'd expect this to be awkward but helpfully she had a nice big line attached at the foot of the mast for just such an occasion. She did not invert. Once on her side and with said rope in hand the trick was to walk forward on the lower hull while leaning out. She would magically flip back up quite abruptly, no water inside (obviously) and off we'd go.

I now go out of my way to avoid falling over.