Water ballast for dinghies?

[Greenheart]

In today's light airs, I sailed a friend's Mirror dinghy. Must be the latest in the year I've ever sailed, north of the equator. She was taking the boat home for the winter and I begged an hour or two's sail on account of the weather. Nice day.

It set me thinking again about which dinghy I want next year. And, about just how much sail a singlehander can manage, in terms of hiking/trapezing to counter the heel of a sporty rig in a breeze. Sportier than a Mirror, anyway!

Even though the little gunter didn't give me any exercise today, I did start to wonder if there's any good reason why the simplest method of water ballasting, isn't more popular. In fact, I don't think I've ever seen or heard or read of the idea...

If one bought a couple of sturdy plastic 20 litre jerrycans...and tied each to a strong central point like the centreboard case, using a cord of a length equal to just over half the overall beam...the filled cans may sit securely on either side of the centreboard, until a tough beat makes the helm wish he was a few stones heavier...at which point, luff for a moment, reach for the first jerrycan and hang it over the windward gunwale!

It'd probably want secure snap shackles on each side-deck, to prevent the cans roaming destructively round the cockpit during an unforeseen broach. And maybe a bit of aluminium sheet so the cord or wire doesn't cut a groove in the side-decks.

But assuming one is prepared to persevere, is it really any less practical than a sliding seat? They look precarious, but reward practise.

And wouldn't it be a fine thing, to be able to gain three or six stone at a moment's notice, then jettison the weight for downwind legs?

And if the boat does roll over, the 'ballast' will become neutral once it's in the water. And at least it'd be cheap.

 

[William_H]

Water ballast

I suspect you will find you are too busy to operate the water ballast especially when tacking.
I really think that a body (yourself) is the best form of movable ballast. I have never seen a movable seat. I thought that was what the gunwhale is for ...sitting on.
What I have never understood is why they don't use reefing on dinghies. I was involved in a junior sailing school at our club for many years. The boats were 10ft with jib and main. However the main sail had reefing points. The reduction of sail area in could turn a gusty horrible sailing day into quite a reasonable day for a lesson. The reef was simply tied in with cord at front and back before departure.
regarding your choice of dighy. would always want one with a jib. It makes sailing to windward so much easier. A jib IMHO does not mean you need a crew. I think gaff rigged boats are really out dated.
Go for one with side bouyancy tanks so you don't have to bail out before you start sailing again after a capsize. good luck olewill

 

[Greenheart]

Quite right about the jib, and reefing generally. I'll want both, whichever class I buy.

Hmm, thinking about having one's hands full during tacking...and those side-buoyancy tanks you mentioned...if I set up a fixed water tank along the dinghy's centreline...and a 12v self-priming bilge pump with 4cm dia pipes to those side tanks...I could push a button and have that helpful water ballast pumping to whichever side I want it. Or, maybe use a pendulum switch, so the water is always automatically pumped to the 'uphill' tank?

Then again...40ah battery for the pump, pump itself, wiring, pipes...starts to sound hefty. Still, you heard it here first!

For the record, the International Canoe uses a sliding seat. So does the 'Toy' class dinghy, I think. I've heard of others, too.

 

[Searush]

Sliding seats are great fun on fllat decked dinks, feeding makes sense too, but the complications of water ballast as described are a step too far for me.

 

[craic]

Modern raid dinghies have central tank on-demand waterballast to make them singlehandable offshore in heavy weather and better rowable inshore. Waterballast is filled and emptied in mid-race through gravity and selfbailers. Waterballast in a dinghy can be used both to stabilize the boat during sail, and to de-stabilize the boat if -ever- turtled. Works fine.

 

[Seajet]

Or combine all these ideas !

Years ago some racing dinghy crews had personal water ballast jackets to add weight; I would think certain safety issues and inability to move around quickly knocked that idea.

International Canoe with sliding seat;

These things often go past my boat, usually one can hear a sort of " aaaaaargh ! " in doppler effect as they approach and disappear; rather tricky beasts.

 

[Billows]

I often though about designing a sailing dinghy that was impossible for the wind to capsize.Some thoughts were a weak link in the main sheet, sails with velcro seam that would blow out or sponsons on a beam which normally would be out of the water but at say 30 degrees of heel would dip in the water, slewing the boat to windward.Proas use a similar scheme, sponsons need not be big if on a longish beam and also could be very lightweight.

 

[Seajet]

But...something digging in on the leeward side will slew a boat downwind, so this would be a strange sponson that dipped when heeled and did the opposite.

Velcro self destruct sails would be a disabling pain; there are plenty of 'dinghies' which are pretty impossible to capsize, but they rely on weight and / or form stability, so are generally a bit unweildy ashore.

 

[alant]

In today's light airs, I sailed a friend's Mirror dinghy. Must be the latest in the year I've ever sailed, north of the equator. She was taking the boat home for the winter and I begged an hour or two's sail on account of the weather. Nice day.

It set me thinking again about which dinghy I want next year. And, about just how much sail a singlehander can manage, in terms of hiking/trapezing to counter the heel of a sporty rig in a breeze. Sportier than a Mirror, anyway!

Even though the little gunter didn't give me any exercise today, I did start to wonder if there's any good reason why the simplest method of water ballasting, isn't more popular. In fact, I don't think I've ever seen or heard or read of the idea...

If one bought a couple of sturdy plastic 20 litre jerrycans...and tied each to a strong central point like the centreboard case, using a cord of a length equal to just over half the overall beam...the filled cans may sit securely on either side of the centreboard, until a tough beat makes the helm wish he was a few stones heavier...at which point, luff for a moment, reach for the first jerrycan and hang it over the windward gunwale!

It'd probably want secure snap shackles on each side-deck, to prevent the cans roaming destructively round the cockpit during an unforeseen broach. And maybe a bit of aluminium sheet so the cord or wire doesn't cut a groove in the side-decks.

But assuming one is prepared to persevere, is it really any less practical than a sliding seat? They look precarious, but reward practise.

And wouldn't it be a fine thing, to be able to gain three or six stone at a moment's notice, then jettison the weight for downwind legs?

And if the boat does roll over, the 'ballast' will become neutral once it's in the water. And at least it'd be cheap.

I think, that Ian Proctor designed a water ballasted 'dinghy/keel boat.

 

[paddy01]

Or combine all these ideas !

Years ago some racing dinghy crews had personal water ballast jackets to add weight; I would think certain safety issues and inability to move around quickly knocked that idea.

International Canoe with sliding seat;

These things often go past my boat, usually one can hear a sort of " aaaaaargh ! " in doppler effect as they approach and disappear; rather tricky beasts.

Yes similar heard from these

http://www.youtube.com/watch?v=xW_UfYGO3Kg

 

[Bobc]

All depends whether you're talking about racing dinghies or cruising dinghies.

Racing dingies don't have reefs. One of the the 2 classes I race is the 12ft Skiff on which we have different complete rigs for different wind strengths (so we swap the mast out and all 3 sails, which takes about 15 mins). However, some of our maisails have zip reefs in, so you can drop a bit of main off if you're at the top end of the scale for that rig.

Most racing dingies that only have 1 rig, tend to be optimised for 12-16kts, and these rigs can be quite well de-powered by inducing mast bend, flattening, pulling the draft forwads, venting the leech, etc., so most can race in up to about 25kts, at which point the racing is usually postponed/abandoned anyway.

As far as water ballast goes, the best way to do this is to wear a water jacket. They used to wear these in a number of classes, but they have now all but disappeared as it wrecked the backs of the wearers. If you want to get more leverage then you either use trapezes, a sliding seat (as per my other ride, an International Canoe), or widen the boat with racks (wings), or indeed a combination of the three.

If however you're talking about a cruising dinghy, then most of these have reefable mains and roller furling jibs, and are heavy and stable enough not to require any additional leverage.

 

[craic]

On-demand waterballasted,
for instance http://www.multimono.com/ and http://www.swallowboats.co.uk/content/view/181/131/ .

Water ballast makes racers cruisable and suitable for weather when all dinghy racing is long abandoned.

 

[Signed Out]

Those are both really interesting and good looking boats, Craic. Not too sure about those funny little amas on the one pic on the mono site though. Interesting rig on that- appears to be a slightly flexible "gaff/sprit" with a loose ended 2nd- almost a full batten or sprit, but not quite.

As for the water ballast- like we discussed in Zagato's trailer sailor thread, it doesn't have to be dynamic- as you (Craic) mentioned above, they only need to be central and opened/closed when required. No need for pumping, etc. No need for windward/leeward tanks- central will do- yes, water is water, so no heavier than outside the hull, but far heavier than the buoyancy they replace.

And reefing on dinghies is not rare- wayfarers, toppers, lasers. These have the ability. OK, so maybe trendy skiffs don't, but rigs can be changed (depending on class rules if that's your bag).

Keep your mind on these lines, Dan, I always find your threads get me thinking. Jem.

(Thinking of which, going back to your earlier ones, there's a cheap contender mast on ebay at the mo- could be used for a project...).

 

[Bobc]

"Proper" skiffs (like my one here) do have reefs. If you look closely, you'll notice the extra set of tack and clew points and the zip.

Most racing dinghies however these days are "Single Manufacturer One-Design" (or SMODs for short), and it's the rules that stop owners from doing such things as adding reefs.

 

[Greenheart]

Interesting and instructive, thank you gentlemen.

My enduring memory of the reefing on the Topper, was that it explained without words, why over-simplistic solutions to sail reduction are so rotten. The sail's shape is dismal when rolled round the unstayed mast, and progress to windward was made just as difficult as when I was over-powered with the sail full (I was only a skinny little stripling then).

Granted, the Topper is a kids' boat, and simplicity and robustness are its virtues, but I'm very happy to have long since graduated to the freedom and relative complexity of variable rake, shrouds, and twist in the leech, plus the advantages of a jib/genoa.

At the risk of alienating competitive contributors and readers of this thread, I must confess to being completely immune to class racing rules; all my sailing is cruising, but I'd much rather cruise fast - wouldn't we all? As such, I'll be free to make any modification.

Seajet's repeated advocation of the Osprey, remains in my mind; very tempting, but my garage is a yard too short! The design's generous proportions would make it a lovely long-legged cruiser, with a roller genoa, slab reef in the main, and space for whatever I cared to add, in the asymmetric/water-ballast/boom tent/racks/nav lights/cocktail cabinet category.

I like the look of the Kestrel too. Seems to be a decent size, nice high freeboard, and fast without being a handful. But there are so few around! Why is a design that's virtually as big and practical as a Wayfarer, and much quicker, not everywhere?

I don't fancy a disc-slipping water-ballast jacket. But I'm not convinced there's no mileage in liquid kilos. Maybe a couple of those tubular water-tanks, strapped outside each gunwale, and rigged to let the ballast slosh downhill through sections of 4" drain-pipe under gravity, a moment before tacking, after which it'll already be back on the new windward side? Of course, it may risk causing a rather lavatorial soundtrack...flushed with success?

I'll keep thinking...

 

[alant]

Interesting and instructive, thank you gentlemen.

My enduring memory of the reefing on the Topper, was that it explained without words, why over-simplistic solutions to sail reduction are so rotten. The sail's shape is dismal when rolled round the unstayed mast, and progress to windward was made just as difficult as when I was over-powered with the sail full (I was only a skinny little stripling then).

Granted, the Topper is a kids' boat, and simplicity and robustness are its virtues, but I'm very happy to have long since graduated to the freedom and relative complexity of variable rake, shrouds, and twist in the leech, plus the advantages of a jib/genoa.

At the risk of alienating competitive contributors and readers of this thread, I must confess to being completely immune to class racing rules; all my sailing is cruising, but I'd much rather cruise fast - wouldn't we all? As such, I'll be free to make any modification.

Seajet's repeated advocation of the Osprey, remains in my mind; very tempting, but my garage is a yard too short! The design's generous proportions would make it a lovely long-legged cruiser, with a roller genoa, slab reef in the main, and space for whatever I cared to add, in the asymmetric/water-ballast/boom tent/racks/nav lights/cocktail cabinet category.

I like the look of the Kestrel too. Seems to be a decent size, nice high freeboard, and fast without being a handful. But there are so few around! Why is a design that's virtually as big and practical as a Wayfarer, and much quicker, not everywhere?

I don't fancy a disc-slipping water-ballast jacket. But I'm not convinced there's no mileage in liquid kilos. Maybe a couple of those tubular water-tanks, strapped outside each gunwale, and rigged to let the ballast slosh downhill through sections of 4" drain-pipe under gravity, a moment before tacking, after which it'll already be back on the new windward side? Of course, it may risk causing a rather lavatorial soundtrack...flushed with success?

I'll keep thinking...

kestrel was Ian Proctors plastic design - I had a Gmach one.

Wayfarer was a ply design, so hard chines as opposed to round bilge Kestrel.

Used to be a good fleet at Keyhaven for Kestrels, but none left.

 

[Greenheart]

That's what I mean - why didn't such a good, large-ish, practical and rewarding design, sell tens of thousands? Weird.

Thanks for clarifying the hull shape difference.

 

[Seajet]

Dancrane,

there's a council type sailing school near my mooring which operates Kestrels, usually fitted with smaller mains.

They seem Ok, obviously robust, always struck me as relatively likely to roll without actually converting it into any dramatic forward power ( I've seen plenty of full rigged Kestrels too ).

I think my main objection would be that it seems to lack any character, but that's personal taste.

Now if an Osprey really is too long, I'll say " Scorpion ! " again then.

 

[Greenheart]

Cheers, Seajet. I hadn't forgotten the Scorpion, another lovely looking boat. I'm greedy though - I want something at least 15'x5'.

I still fancy the Albacore too - as a sort of 'best all-rounder', being fairly roomy, fairly quick, and ripe for modification - I mean, as standard (PY 1066), it doesn't even have basic kit like spinnaker and trapeze.

I guess if I'm considering any project that may affect structure, I'm better off looking at all-ply or composite construction, ie not a Kestrel. Though I think they built some in wood in the early days.

I lately read some very encouraging stuff about Albacore performance, to the effect that in mixed class racing, the technically faster Tasars - also without trapeze/spinnaker - are routinely beaten by the weighty old Albs. Maybe it's their wily, aged crews?!

 

[Seajet]

Just a thought, how about a Hornet ? Haven't sailed one, don't know how suitable for singlehanding; but as they look like a 16' Scorpion ( not quite as well proportioned looks wise ) they should be seaworthy.