Fastest dinghy?
Printed From: Yachts and Yachting Online
Category: Dinghy classes
Forum Name: Dinghy development
Forum Discription: The latest moves in the dinghy market
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=237
Printed Date: 15 Aug 25 at 11:51pm
Software Version: Web Wiz Forums 9.665y - http://www.webwizforums.com
Topic: Fastest dinghy?
Posted By: AlanWT
Subject: Fastest dinghy?
Date Posted: 30 Sep 04 at 9:05am
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Just been reading an old book about dinghy racing, and it refers to a Jollyboat being timed at over 17 knots at (I think) Edgbaston Reservoir in the '50s or '60s. Timed outright speed isn't something that appears in modern boat reviews, but I'm sure that the modern style of lightweight dinghies with their high power to weight ratios must be able to beat that figure. Anyone know for sure? - what is the fastest current or recent production monohull dinghy? Could be a bit of fun to be had finding out! Alan |
Replies:
Posted By: JimC
Date Posted: 30 Sep 04 at 10:09am
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I know of no boats that have been timed properly over a 500m course, which is what counts. Lots of people make lots of noise, mostly based around rough estimates or maybe peak speeds under GPS.
The very fastest boats are going to be those that combine modern hull shapes and very light weight with moderate sail area, because dinghies are not efficient enough to achieve high wind speed/boat speed ratios, so its going to take a fair bit of wind. If you've got very big rags you just aren't going to be able to carry anough apparent to get a decent speed in 25knots plus. That could mean that the boats capable of the highest top speed are not what you might expect. My guess would be that Cherubs and 29ers have got to be in the frame. I reckon that the sails on the 14s and 49er are just too big for really high speed in a lot of wind, no matter how fast they are in the moderate stuff. My guesstimate is that a 500m average figure in the low 20s ought to be achievable fairly readily, but I don't know how much higher. Its so dependant on wind and wave condtions though. |
Posted By: Phil eltringham
Date Posted: 30 Sep 04 at 10:38am
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I think you are right, its the same reason why windsurfers held a lot of speed records not that long ago. It was simply because they could go out in far windier conditions than a dinghy and so despite being less efficient could reach higher speeds. Also on the plane with the asymmetric up the speed differences will not be too large, suffice to say that all of the classes you mentioned have probably hit the better side of 25 knots but keeping that held over a 500m course is unlikely. It would be quite cool to have in a boat test, problem is you cant draw a comparrison unless every test is done in the same conditions and I doubt that people like RS and Laser will have done full speed polar plots for their designs, let alone make them public. ------------- FLAT IS FAST! Shifts Happen |
Posted By: Matt Jackson
Date Posted: 30 Sep 04 at 12:21pm
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Not that you're biased at all Jim ------------- Laser 203001, Harrier (H+) 36 |
Posted By: Granite
Date Posted: 30 Sep 04 at 1:30pm
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The foiling Moths could probably have a good go at it |
Posted By: Doctor Clifford
Date Posted: 30 Sep 04 at 3:13pm
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two hulls good, one hull bad !!!!! ------------- regards Dr. Clifford take two tablets twice daily |
Posted By: Lucy Lee
Date Posted: 30 Sep 04 at 3:16pm
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Well now, Weymouth Speed Week is coming up very soon. Apparently it costs about £50 to enter for the day so if anyone can get the day off... ------------- Fly Cherub! |
Posted By: redback
Date Posted: 30 Sep 04 at 4:47pm
| The Laser 4000 loves a lot of wind, mainly because it doesn't have a huge sail area - on the other hand its a bit heavy - but an excess of 20knots is claimed. The 49er has too much sail area to cope with really strong winds unless its sailed by olympians! I wouldn't mind betting a RS 800 would be fastest in about 30knots at somewhere just under wind speed. Surely the 18 foot skiff is the answer? However all these boats are assymetrics and they are optimised for upwind/downwind sailing and they handle badly when 2 sail reaching. |
Posted By: Phil eltringham
Date Posted: 30 Sep 04 at 6:55pm
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I have heard a story about some guys trying something like this in an 18. It involved the biggest wind they could find and blasting accross a harbour with the big rig with a rib following them. The basic Idea was to launch, pop the kite, go as fast as possible to the other side and drop the kite, land the boat with the trailer brought round by car. Don't know where, when, and who by so could be a bit spun, but the story comes from a mate of mine in the 18 fleet so i trust the authenticity. Anyway the chase RIB clocked them at 47 knots which is not far off world record speed and probably a fair bit faster than most of us have ever been. ------------- FLAT IS FAST! Shifts Happen |
Posted By: Bruce Starbuck
Date Posted: 30 Sep 04 at 7:08pm
| hmm, i reckon a 420 2 sail reaching with a 15 stone crew in 50 knots of breeze would be right up there!!! |
Posted By: Bob Ashby
Date Posted: 01 Oct 04 at 8:16am
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I am sure nothing goes as fast it felt the first time I got planing as a middle aged beginer back in the 1980s in an Albacore with clubmate Graham Parker giving me a few tips off of Teignmouth beach. That felt supersonic! My jaw nearly fell off from the width of the grin! I shall remember it till I die! Fast is when its all on the edge of control! |
Posted By: hurricane
Date Posted: 01 Oct 04 at 4:51pm
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the fastest production boat has to be a tornado sport see the page on http://www.catamaran.co.uk - www.catamaran.co.uk showing how fast it was in the round the island race!!!! |
Posted By: JimC
Date Posted: 02 Oct 04 at 12:15pm
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Blasting dead downwind in 50knots won't do it. You've got to have apparent wind. Think about it, if you're doing 30 knots dead downwind in 50knts of wind, then you only have 20knots across the deck. Then also if you gat a 10 knot gust followed by a 10 knot lull - and 20% variation in gusts seems to be reasonably common according to Bethwaite - you'll suddenly have variation between 10 knots and 30knots. Unless you've got the apparent wind forward of the beam then the faster you go the less wind you have across the deck.
So you have two choices for speed, one is very high efficiency with the wind forward of the beam - Yellow Pages Endeavour with 48 knots of speed in 20something knots of wind - and the other is more moderate apprent wind and very high wind speeds coupled with guite amazing control in gusts and lulls - the top board sailors. And again http://www.sailspeedrecords.com/500.html - look at the sail size they carry - http://www.sailspeedrecords.com/500.html . The boards have all hit their records with under 10sq m of rag. YPE was damn near as quick with their class B (150-235sqft) rig as with their Class C (235-300 sq ft) rig. I bet that big rig was nowhere near 300sqft, and they didn't even have a over 300 sq ft rig and the record for that class is even slower. Even a Cherub or 29er rig is damn near the top of class C, let alond a 49er or a 14. Then you also have to think just how difficult it is to get a high average speed. http://www.devboats.co.uk/turbo.wmv - Take a look at this bit of video . Its of a Cherub with a development rig going quite reasonably quickly in a fair breeze. Now look closely. See how much the speed varies? Look at the bit where they run out of the gust and have to point up and so on. Chances are to average 25 knots over 500m travelling like that you've got to be peaking out at over 30. Also shows how much apparent they were carrying when they have to head up that much when it evaporates. WHy are there no measured speed records for modern dinghies. Two reasons I reckon, one its a lot of hassle to organise, and two, too many "big fish stories" would die with the results. I think a 14 did speed week recently and got a best result in the mid teens. I've considered doing it, but its quite a lot of cash and holiday to sit on the beach all week hoping that one day the wind will get up enough to make some runs worthwhile, and probably even then finish with something ike 16knots as your best time. |
Posted By: Scooby_simon
Date Posted: 02 Oct 04 at 5:51pm
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That cherub is not going very fast at all....Low teens I would say.... ------------- Wanna learn to Ski - PM me.. |
Posted By: JimC
Date Posted: 02 Oct 04 at 8:54pm
The variation in speed is the point I was trying to make. Its why GPS spot speeds are very different from timed 500m runs. Because I only got that as a WMV file I can't do any analysis of how fast its going by frame counts, but I don't think its anything very dramatic. |
Posted By: fizzicist
Date Posted: 04 Oct 04 at 8:19am
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Whilst we're on the subject (kinda) I've heard various figures regarding the sensation of speed on water being 3/4 and even 5 times greater than you get over land. Obviously the sensation of speed you get in a dinghy is greater because we all pretty much begin to require a clean wetsuit once the speed gets up around the 10 knot mark in a 14 foot dinghy, but does anyone know why this is?
------------- Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in beer. |
Posted By: Hagar
Date Posted: 04 Oct 04 at 9:24am
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As the question was about the fastest dinghy sailboards and catamarans get disqualified immediately. Sailboards are fast because they are very light and the sail control is far easier with a tilting rig. Catamarans are fast because they have enhanced stability making sail control less critical. (though I suspect that in a speed trial the stability vanishes as they will work to stay on one hull). Although I agree some smaller dinghies can go out in bigger winds than their bigger cousins I doubt they would go absolutely faster. I think the secret is to make hay while the sun shines. With lots of efficient sail on a light, easily driven hull you can get up to a respectable speed before the natural turbulence in the wind gets too much to handle. In the summer I watched a 49er on flat open water in just a force 4 outpace a powerboat over about a mile, while looking like "just another day at the office". I think that a smaller dinghy is unlikely to achieve as much in a bigger wind. However, what counts for the everyday sailor is the excitement and the perception of speed. For me, the peaks were a Laser 1 reaching across the bay at Abersoch in a force 6 gust with the hull chattering over the chop and a Laser 2 two-sail reaching at a world championship in force 6-7 with the crew trapezing behind me. I'm sure every other sailor has similar perceived highs, none of which would make the speed record books. Hagar PS - Fizzicist should calculate the rate of rotation of the eyeball as it watches the nearest stationary point, multiply by the wind speed across the face and throw in a factor of the generated noise. Big wind * close to the water + (shrieking wind * spray) = exciting. 125mph in modern train = nothing. |
Posted By: Granite
Date Posted: 04 Oct 04 at 1:41pm
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For The sensation of speed the closer you are to loosing control the better. Take a Short, Light, Well Powerd up boat out in some waves and the grin will be nailed on. White Sail reaching in a Cherub were you can barely see the boat for the ball of spray and you know that you will be very lucky if you can avoid a pitch pole. Now that feels fast. |
Posted By: Phil eltringham
Date Posted: 04 Oct 04 at 3:37pm
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Its the go-kart effect, 10 knots+ on a topper with your bum on the surface feels a lot faster than in something with a lot of freeboard like a 200 or bigger still a yacht (having said that 10-15 knots feels pretty quick in most yachts beacuse you only get that surfing in a big breeze). The way I see it is if you survive a day on the water then you've played mother nature and won!! If you win a race, even better, and if it feels fast than it is!! ------------- FLAT IS FAST! Shifts Happen |
Posted By: Brian
Date Posted: 04 Oct 04 at 4:57pm
i think its something to do with how close you are to the water/ ground. this is the reason why you feel so much faster in a porsche at 60mph than a bus at 60mph. could also be the engine noises aswell though  . This is also why planes in the air look really slow but are actually going about 500mph etc.------------- |
Posted By: jeffers
Date Posted: 04 Oct 04 at 9:51pm
Having race karts (not gokarts) I can happily say that doing 80mph with your 'seat' about 2 inches off the floor does feel very very fast but not a huge amount more then 80mph in my car... Now look at the formula karts (basically motorbike engines on a kart chassis) which are easily capable of 130mph plus (probably faster if pushed) and then you get speed sensation.. Also have to add that round a course (not just reaching) in an F6+ I can sail a Laser radial much faster than a full rig Laser (power an control I guess...) For thos who have had the good fortune to have had some time with Adam Bowers just remember to arbitray 20 Unit theory, basically once you hit those 20 units it doesn't matter how much more wind you have you aint going to go any faster on a given point of sail..... Just my 2p.. Paul |
Posted By: fizzicist
Date Posted: 04 Oct 04 at 10:30pm
If your eyeballs are rotating, then you're going very fast in a heavy chop!!! ------------- Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in beer. |
Posted By: Matt Lingley
Date Posted: 05 Oct 04 at 12:07am
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I think the feeling of speed in any sailboat is very relative to the conditions. I've seen 20 knots on a gps sailing a J-80 in 30knots+, theres just so much water flying around in those conditions that it feels like your going way faster, but then I've seen 15 on a gps sailing a tornado in somthing around 7knots true and been amazed that the boat was going that quick. If the boat feels like its really being pushed in waves and high winds it will feel like its going fast, even though in flat water and a bit less wind the boat will feel slower but quite possibly going faster. ------------- If it dosn't blow it sucks! |
Posted By: fizzicist
Date Posted: 05 Oct 04 at 7:12pm
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But equally 20 knots or 25mph feels like you're crawling in a car. Even on a bike it doesn't have the same sensation of speed as on water. ------------- Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in beer. |
Posted By: Matt Lingley
Date Posted: 06 Oct 04 at 1:44am
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Exactly, at 25mph your not pushing the car, say at 120 (depending on the car) you are pushing it and it feels really fast! ------------- If it dosn't blow it sucks! |
Posted By: Rupert
Date Posted: 06 Oct 04 at 8:28pm
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My old Lada felt fast at about 30. Same reasons as dinghies do, I expect - steering all over the place, and, if raining, somewhat damp, as it came through the rust holes. I think dinghies where it becomes difficult to see where one is going feel the fastest - a Fireball where spray from the crew's far too big feet hit me smack in the face springs to mind from years gone by. I'd see a lobster pot in the distance, think "where's it gone now" and realize it was behind us, and that I'd been sailing blind for a few hundred yards. That felt fast! |
Posted By: Contender443
Date Posted: 06 Oct 04 at 11:00pm
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You managed to push your Lada to 30 - you must have a good pair of running shoes!! ------------- Bonnie Lass Contender 1764 |
Posted By: Barty
Date Posted: 07 Oct 04 at 7:53am
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Check out these bad boys http://www.i14.ch/foils/album01 - http://www.i14.ch/foils/album01 How fast do you think this would feel???? ------------- http://www.highlandtopper.com - For Topper boats & spares in Scotland-highlandtopper.com |
:Posted By: Contender443
Date Posted: 07 Oct 04 at 11:22am
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What's with the helmets?? ------------- Bonnie Lass Contender 1764 |
Posted By: Barty
Date Posted: 07 Oct 04 at 12:36pm
Twin wiring at altitude!!!!.............I think I'd be wearing more than just a helmet. If your on the wire six feet out the water and wipe out its gonna hurt  and at the speed that you could be going at, its gonna hurt even more!!!------------- http://www.highlandtopper.com - For Topper boats & spares in Scotland-highlandtopper.com |
Posted By: Scooby_simon
Date Posted: 07 Oct 04 at 12:55pm
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We cat sailors spend a fair bit of time wiring out of the water ------------- Wanna learn to Ski - PM me.. |
Posted By: Phil eltringham
Date Posted: 07 Oct 04 at 1:09pm
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Maybe you can help me out, I know the whole "wild thing" business of flying a hull to reduce friction, and thats fine. But why by so much?, surely if the hull is just out of the water the rig will be more upright and so it presents a larger projected area to the wind thus producing more thrust. Also the more you heel the less time you have before a possible wipeout!! ------------- FLAT IS FAST! Shifts Happen |
Posted By: Scooby_simon
Date Posted: 07 Oct 04 at 1:58pm
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You say "wild thing" this is the term we use for flying a hull down wind, but, fastest is with the hull just out of the water. But when sailing up wind in big waves, you need to lift the hull to be on top of the approaching waves, so at times it looks like an outrageous hull fly when in fact the lee hull is on a 6 foot wave and the windward hull is not. ------------- Wanna learn to Ski - PM me.. |
Posted By: AndrewP
Date Posted: 08 Oct 04 at 1:17am
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By way of objective data on the speeds of I14's, our data measured 17-18 knots as the speed over one gybe of a two gybe downwind leg with a comfortable two strings in about 13-14 knots. This would easily be in excess of 500 m. The gps had only one data point between the sheeting on of the kite and coming in for the gybe so the speed was consistent. Upwind speeds varied from 8.2 hard on the breeze to 9.9 knots with the sheets just sprung. When in bermuda for the i14 worlds some sailors ran speed trials in the hurricane using the local policeman with a radar gun as a measuring device. The I14.org web site will have a report on the archives somewhere. Andrew P |
Posted By: jimmywalsh2
Date Posted: 08 Oct 04 at 5:31am
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Info from Emmett Lazich, top 18, 49er and Moth sailor.
Sailing the 12ft skiff in 20-25knot wind against tide breeze Best speed Richard and I did today was 22kts. Shortly afterwards Richard sat in because I was struggling to keep the boat under the rig, then Bocko blasted over the top of us! That's quicker that I ever recorded on 49er to date. Normally today in the 12 doing about 19kts downwind with two on wire, and 16kts with Richard sitting in for me. Avg 8.5 kts upwind on lap2 tacking through about 100 deg - due to chop In a GP18 (Collex) the best I recorded (in early 2001) was 28.6kts in between the heads in a strong westerly and confused sea. It felt like 35kts so 28.6 was an anti-climax. In 25kts NE like today, a 1996 rules/formula GP18 (Collex) does 13kts upwind average and 15kts peak upwind tacking through 90 deg. GP18s do about 19-24kts downwind in that stuff gybing through about 45 deg. I'd estimate 2003 League 18s are still a knot or three slower than the 1996 18s. 49er not too bad upwind in 20kts and flat water doing about 11kts tacking through 90. 49er rarely exceeds 20kts downwind, but easily does 15kts in 15kts of wind, so feels very nice downwind in medium stuff. |
Posted By: Scooby_simon
Date Posted: 08 Oct 04 at 12:26pm
Got some exact no's at home, but my 17 will do about 12-13 kts upwind in about 16 knots true (flat water) and about 19kts down wind in about the same. I've not had the gps on board in more wind that than 16kts yet.... (Left the gps at home last weekend  )------------- Wanna learn to Ski - PM me.. |
Posted By: Chris 249
Date Posted: 08 Oct 04 at 10:14pm
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Yeh, but with respect trapping from the cat (and our cat is similar in
length to yours but lighter and has a taller mast IIRC) is like
trapping from the side of a house, compared to trapping from a skiff. The skiff is so much livelier and keeping it right way up downwind requires much faster helm alterations, AND on a big skiff you're a long way further from centreline (14 to 18 foot wingtip span) so the centrifigual force on those sudden bearaways and luffs is much more severe. In the cat, in a lull you can just veg out on the wire (i'm catching that bad habit myself now I'm catting) whereas that's not an option on a skiff. You have to move in, instantly, or you're swimming. Or at least that's what it seems from the cats I sail, against guys like the world A Class champs, the world F18 champ, and several other guys who got top 10 in the F 18 worlds (not bad considering they're actually Taipan 4.9 sailors!)
|
Posted By: hurricane
Date Posted: 08 Oct 04 at 10:34pm
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what those moths are nothing compared to a tornado sport u get alot higher than 6 foot and are going alot quicker than any dinghy could ever go!!! so if you stuff it in then it is bound to hurt and how a helmet can protect u i dont know!!! wimp |
and at the speed that you could be going at, its gonna hurt even more!!!Posted By: sailor girl
Date Posted: 09 Oct 04 at 2:56pm
| hahaha!!! be nice!! |
Posted By: Doctor Clifford
Date Posted: 11 Oct 04 at 1:13pm
i don't think this is strictly true. a big skiff may be 18 foot wide, but you are nine feet from turning point. On a Tornado you are ten feet away, and on most cats 8 feet. they are livelier due to the short waterline length when hammering along (usually foil to foil with bow out) whereas a cat has the whole hull length in the water making it less responsive ------------- regards Dr. Clifford take two tablets twice daily |
Posted By: redback
Date Posted: 11 Oct 04 at 1:46pm
| I find the inertia of a aluminium mast significant compared with carbon, and I'm talking of masts of only 7.5m, but the weight of the mast is significant and limits the rapidity with which I can round up onto a beat from a fast reach. However it also works in my favour when bearing away in a sudden gust since by driving the hull under the mast it counters the heeling force of the gust. Does that make sense I could explain in more depth but it would take time? |
Posted By: Granite
Date Posted: 11 Oct 04 at 1:48pm
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Most of the Cats I have sailed generaly feel bit less lively than skiff type boats thanks to the phenominal weight of most Cats. put that together with the good directional stability giving slow direction changes and while they may go faster than dinghys they feel slower. But the same goes for Skiffs a Cherub feels livelier than a I14 which feels livelier than a 18 footer.
|
Posted By: Phil eltringham
Date Posted: 11 Oct 04 at 2:52pm
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Anyone up for making the 'ultimate' planing cat? Strap a couple of 49er hulls together, rig off that new Jo Richards 30 footer, hey presto!! overpowered in 5 knots, just like the stuff on lake geneva. ------------- FLAT IS FAST! Shifts Happen |
Posted By: Brian
Date Posted: 14 Oct 04 at 5:48pm
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Check these vids out:
http://www.skiff.org.nz/movies.htm - that is fast! New Zealand 12ft skiffs. The speed of them is just sickening ------------- |
Posted By: Phil eltringham
Date Posted: 14 Oct 04 at 6:43pm
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watching that all i could think of was blur's song 2 ------------- FLAT IS FAST! Shifts Happen |
Posted By: Scooby_simon
Date Posted: 14 Oct 04 at 9:21pm
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If you think those skif's are fast, take a look at this : http://www.wallen.se/files/wallen2.mpg - http://www.wallen.se/files/wallen2.mpg (about 2 minutse long so Broadband only) I've also been looking for about 20 seconds of another SWE boat with the kite up that come very close to a chase boat and then just zooms away...Now that IS quick
------------- Wanna learn to Ski - PM me.. |
Posted By: Chris 249
Date Posted: 18 Oct 04 at 12:47am
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Hey Simon, while there's little doubt the cats fly around a course,
don't be so sure they're much faster downwind than a big skiff. It's hard to say without seeing a T up against a big skiff, which I haven't done for a while, but compared to a board they both seem similar in pace. A cat sailor I know (a top skipper in Taipan 4.9s, arguably the fastest 16' cat around, and about 5th in the F 18 worlds as crew) reckons a Cherub can beat a Taipan downwind in a breeze. A couple of times when I've been cat racing I've taken the board out before or during races. It's much easier to stay with the cats than it is to stay with the 16' skiffs down the bay. Of course, the speed of a board v a boat varies enormously depending whether we're powered up or not. In about 10 knots, the 16' skiffs seem similar upwind to the IMCO board, but the IMCO board is slower upwind than a Nacra 14 sq (baby Inter 17) sailed by a world A Class champs runner-up. Downwind, the board is slightly quicker than the Nacra, way slower than the 16' skiff. And the 16 is only about as fast as a 14' skiff. In a good hard breeze, even my old slalom board can blow away a good A Class downwind (and when I say "good", I'm talking about an A fleet that attracts guys like 3 time world A champ and current F18 world champ) yet in the downwind race on the bay, FW boards are similar in pace to an 18' skiff. The FW boards would blow my slalom board off the water on a square run. Many years ago, the Tornadoes (some with kites) raced the 18s and a C Class cat. The first T was just 17 seconds ahead of the first 18. Sure, the Ts have improved since then, but so did the 18s. In fact the top 18's chaseboat (IIRC) measured the 18's speed down the squares as faster than the C C lass (Victoria 150, the world's best at the time). OTOH, I do know T sailors who reckon they kill 18s. Then again, those same T sailors reckon their yardstick with the new rig should only be 3 points faster than the "classic" rig; so either they're exxagerating the speed improvement or they're talking B.S. to the yardstick guys. I'm not saying the cats don't fly upwind, but have you lined up against a good 49er or 18 downwind? You may be surprised. And of course, when it gets to real smallboat speed nothing comes close to a board (apart from YPE which is strictly a flat-water one way machine, which is only fractionally quicker than a board that can sail both ways and in rough water). |
Posted By: Scooby_simon
Date Posted: 18 Oct 04 at 7:39am
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My inter 17 IS faster than a 49er. Simple as that. On UK yardstick I rate at 735 and the 49er at 750. I do struggle against them in the lighter stuff, but as soon as Iam wiring, it's bye bye. Tornado IS MUCH faster than a 18 footer, cannot find the article from the tornado web site, but when they were testing the new big rig a couple of years ago, first time out they went to play with some 18 footers and the author was saying something like, Faster up wind, but not by much and totally swept them away downwind. I'll try and find the piece later.
------------- Wanna learn to Ski - PM me.. |
Posted By: JimC
Date Posted: 18 Oct 04 at 12:44pm
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Simon, as far as top speed is concerned the yardstck means next to nothing. The yardstick represents vmg round the course averaged over all conditions. The Cats are superb moderate wind machines, especially upwind, and they do get round the course very fast. But downwhill when the wind gets up the skiffs just get faster as the multis top out.
Do you know Steve Clark (the owner of Cogito, the top C Class) claims that the maximum speed he's ever got out of Cogito is 23 knots. That's standard skiff territory. But in 8 knots of breeze Cogito will do 19knots, and there's not a skiff in the world that would have a prayer of living with that. I don't often get to race against cats, but the other year I got to race against the top of the Unicorn fleet. They slaughter us round the track because they're so fast upwind, but in a f4 downwind the Cherub is easily quicker. The only spinnaker cat I've ever lined up against is a Spitfire, and I have no idea how good the ones we happened to sail next to were, but the Cherub was the same speed offwind in F3. Upwind again was quite another matter, they're far faster. One of the most impressive sights I know in sailing is something like a big Nacra hurtling upwind in a breeze with a feather of spray from the leeward bow. Ye gods they are quick. But downhill they don't go that much faster in the way that my Cherub, for instance goes more than twice as fast (that's measurable in real numbers) on a flat out reach as on a beat. |
Posted By: Scooby_simon
Date Posted: 18 Oct 04 at 2:09pm
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Jim, were not on the same wave length here. The Tornado I was talking about was just drag racing the 18 footers. C class cats in their latest guise are very fast in light(er) stuff, but the solid sails and hull shapes cannot cope with the big stuff. In the lighter stuff (F3 as you quote) is not that windy, you will be quicker than a few cats down wind. Try it in an F6+
I think you would find that if you started at an up wind mark, even a spitfire (Schrs 104) sould be just a little faster down wind that you. A tornado would be in a different ball park. Once above about F3-4 I have never been overtaken by a Skiff down wind (49er's mainly at grafham) - At our club championship a few weeks ago in a nice F4 I was approx 5 Minutes ahead of the 49ers in a 40 minute race - Not all my gains were upwind Skiffs are fast, but cats are faster (When there is some proper wind around) ------------- Wanna learn to Ski - PM me.. |
Posted By: Chris 249
Date Posted: 20 Oct 04 at 12:23am
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Posted By: rogerd
Date Posted: 20 Oct 04 at 10:41am
| I dont know much about these things but where were the Cats in the two bridges race. That is a drag race between two points and I think the 18ft skiff was just beaten by a board. |
Posted By: Scooby_simon
Date Posted: 20 Oct 04 at 11:33am
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From the Daily sail....
So no Cats were sailing but I would fancy a go at that one...
------------- Wanna learn to Ski - PM me.. |
Posted By: rogerd
Date Posted: 20 Oct 04 at 4:48pm
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Which raises the question. Why no cats? Did they feel they had no chance |
Posted By: Scooby_simon
Date Posted: 20 Oct 04 at 7:43pm
Maybe they were not invited ? I would love to have a go at it, but it would be a bit of a treck for me... ------------- Wanna learn to Ski - PM me.. |
Posted By: Harry44981!
Date Posted: 20 Oct 04 at 8:11pm
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make a holiday out of it- i went this summer- its a really nice place, and windy most of the time. ------------- |
Posted By: hurricane
Date Posted: 20 Oct 04 at 9:27pm
|
ok the tornado has cleaned up on handicap so who eva said that doesnt know what they are talking about if u want to win in ca sailing and are any good u will sail a tornado if u cant handle the speed then u best do something clever and buy a silly slow boat like a laser 4000!!!! |
Posted By: Chris 249
Date Posted: 21 Oct 04 at 12:58am
|
"the tornado has cleaned up on handicap so who eva said that doesnt know what they are talking about" Well, it depends where you are. In the UK, the Tornado may be cleaning up. That doesn't mean that they clean up in other places. For a start, we here in Australia sail under a different yardstick. And secondly, it seems that the level of competition out here may be higher than that in the UK. Simply put, in the last year Aussies have won the worlds in Tornadoes, A Class, F 18s, Hobie Tigers and got second and third in Hobie 16s; that's more than half the International cat classes. It's easy to "clean up" against the F 18s, for example, in a country where the best F 18 was about 27th or 38th or something in the worlds..... |
Posted By: Harry44981!
Date Posted: 21 Oct 04 at 7:57am
|
Shame about your dinghy sailors though! ------------- |
Posted By: Scooby_simon
Date Posted: 21 Oct 04 at 8:09am
|
OK, first F18 worlds. First brits were 10th
I posted a question on a CAT sailing forum http://www.catsailor.com/forums - http://www.catsailor.com/forums and got the answer that
thread is here if anyone is interested in reading it all http://www.catsailor.com/forums/showflat.php?Cat=&Board=Test&Number=39443 - http://www.catsailor.com/forums/showflat.php?Cat=&Board= Test&Number=39443
------------- Wanna learn to Ski - PM me.. |
Posted By: Chris 249
Date Posted: 22 Oct 04 at 12:28am
|
Mea culpa about the UK F 18 places. And you're dead right that the Brit
dinghy sailors (and the skiff sailors) are kicking our arses in most
classes at the moment. But when you look at my post, remember that it was written in answer to one which said "the Tornado has cleaned up on handicap so whoever said that doesn't know what he is talking about". The fact remains that Ts don't "clean up" on our handicap against guys like the world champs in As, F18, etc. And Scooby, you posted on Catsailor that "I'm having an 'interesting' 'discussion' with some skiff sailors won't believe that a Tornado is faster than a skiff". That makes it sound a bit like we're being unreasonable. Can I point out that; (1) I for one sail cats- and one with an almost identical yardstick to yours -not skiffs. (2) The only evidence anyone can come up on the T v 18 question is; (a) a reaching race in SF between the 18 "Colour 7" and a C Class. The C allegedly won (and surely everyone would expect it to). The Colour 7 team retired about '82 and the SF series was even earlier IIRC. What a 20 year old reaching race between a C and an 18 has to do with current Ts on a normal course, I'm not sure. (b) there's also the allegations about how Ts blast past 18s, which I've heard about. However, the fact is that the T handicap has only changed 3 points since the days when (as recognised by yardsticks) they were slower all-round than an 18. 18s have also improved since those days in most conditions. However, all anyone's been able to find is big fish stories; n ot hard evidence. (c) in the race (C '88) between the C Class Victoria 150, the 18s and Ts with and without kites, the racing between the best kite T and the best 18s was very close. I was reading an article about it in an old mag the other day. There was 17 seconds between the best kite T and the best 18. The 18 gained downwind on hte C and the Ts. This is information, directly from Rob Brown who was skippering the top 18. Both classes have developed a lot since then of course. The top kiteless Ts were never in the race after the first mark. Given the information; the small change in yardsticks and the race results on one hand, and nothing but unsubstantiated claims on the other; I don't think I'm being unreasonable in saying "I'm still open ont h e question although I tend to favour the skiff."
reaching race between |
Posted By: Doctor Clifford
Date Posted: 22 Oct 04 at 8:19am
|
and a well sailed Spitfire (that means 'not me') gives
a Tornado a run for its money round the cans, too ------------- regards Dr. Clifford take two tablets twice daily |
Posted By: Scooby_simon
Date Posted: 22 Oct 04 at 10:05am
|
intresting comment on Yardstick. Very few t's (or prolly 18's) are sailed on yardstick. The tornado on SCHRS has gone from 1 as a classic to 0.94 (6.3% faster)
http://www.schrs.com/schrsratings.asp?id=newcat - http://www.schrs.com/schrsratings.asp?id=newcat This is why we use measurement handicaps for cats
------------- Wanna learn to Ski - PM me.. |
Posted By: Pierre
Date Posted: 22 Oct 04 at 10:32am
|
Well put Chris 249. A bit of sanity and reasoning, based on knowledge and research. Thankyou. |
Posted By: Phil eltringham
Date Posted: 22 Oct 04 at 10:33am
|
measurement handicaping works well for cats because they essentially all work the same and so a sum based on general dimentions will give a fair reflection af realative speeds. For dinghies I would argue that the vastly different hull forms possible that could still have the same basic dimentions, can produce significantly different speeds round the cans. To this end usuing a purely measurement based system will not work as well, short of trying to quatify things like planing area. The other problem is things like how boats performance changes with windspeed. The most dramatic example must be the flying int. moths, below flight speeds they will be at best as fast as normal ones. Above it though, and they are significantly faster. Now I kow this is going down the american route, and it has been discussed elsewher but I am really warming to that idea. ------------- FLAT IS FAST! Shifts Happen |
Posted By: Contender443
Date Posted: 22 Oct 04 at 11:00am
|
There are 3 factors which affect a the "accurracy" of a boats handicap (outside any skill factor). 1. Is as mentioned previously is windspeed - most trapeze boats lose out on handicap until they can trapeze. Especially something like a Contender which struggles to beat lasers on the water in light weather. 2. Then there is the effect of tide. Basically a slow boat spends more time sailing the course so is affected by the tide for longer. We have had discussions in our club over a tidal correction factor to be used to adjust the handicaps. 3. And finally course design can affect the results. Contenders do well with long beats and close reaches. Particularily where kites cannot be flown.
------------- Bonnie Lass Contender 1764 |
Posted By: hurricane
Date Posted: 22 Oct 04 at 12:07pm
| there isnt a chance in hell in a well sailed spitfire keeping up with a well sailed modern tornado unless it is blowing old boots and the tornado isnt using its kite!!!! |
Posted By: Stefan Lloyd
Date Posted: 24 Oct 04 at 8:44am
RORC tried wind-strength dependent handicapping under IMS for the Commodore's Cup (an international yacht event). It was a complete fiasco ("Comedy Cup"). Protests rumbled on for days. There are issues like different windstrengths at different times in different places on the course. Windstrength-based handicapping is a nice sounding theory but a complete nightmare for race officers in practice. |
Posted By: redback
Date Posted: 24 Oct 04 at 9:06pm
| There is no way round it. Handicap racing is not nearly as good as class racing, but pursuit racing can be fun and its much better for the spectators. |
Posted By: Scooby_simon
Date Posted: 24 Oct 04 at 11:17pm
|
Still have not foujnd what I am actually looking for, but I have found the handicap ratings for various classes used in Aus : http://www.vic.yachting.org.au/default.asp?Page=1352&MenuID=Handicaps/1023/0 - http://www.vic.yachting.org.au/default.asp?Page=1352&Men uID=Handicaps/1023/0
I'll concede that the 18' handicap is for 1999, but that is about the time the big rig was first mooted on the Tornado:
I am still lookning for the article I actually want.....
------------- Wanna learn to Ski - PM me.. |
Posted By: Blobby
Date Posted: 25 Oct 04 at 2:36am
|
Back to the start of all this - the fastest dinghy in a straight(ish) line. Sorry folks, I agree with Jim C - it is a Cherub. Yes he is biased but the numbers stack up so maybe the bias is with reason... Assuming we all believe Frank Bethwaitre when he says that top speed in a breeze is overwhelmingly governed by Sail Carrying Power / Total Weight, then have a look at the numbers below for 49er & CHerub...
Cherubs should be a mite faster than a 49er - assuming you can drive them as hard in a big blow... (Oh - and I have it on good authority that a 29er can outpace a Taipan 4.9 in a straight line downwind in 30 knots of wind... of course on a proper race course the Taipan is massively quicker. |
Posted By: Phil eltringham
Date Posted: 25 Oct 04 at 4:43pm
The numbers for the cherub and 49er are true but they miss one thing, and that is that a cherub is four and a half foot shorter so yes, downwind in a blow the cherub will go faster in a straight line (length not as much of an issue provided you can keep the bow up). Round the cans the 49er will win becasue the extra hull length makes speed upwind far superior. Remember also, the most important factor in all of this are the two monkeys trying to hold the thing down in 30-whatever knots of breeze.  ------------- FLAT IS FAST! Shifts Happen |
Posted By: JimC
Date Posted: 25 Oct 04 at 4:56pm
|
If we're talking about maximum speed in a fair bit of breeze then I'd say there is more to it than that. IME FB is not much interested in top speed, only in speed round a course. This is of course perfectly correct for designing boats to win races.
But for speed in a straight line ignoring the course then modest sail area comes into it. If you watch 49ers and 29ers in the same conditions you'll see the 29ers are sailing much hotter angles. And when all else is equal hotter angles means more straight line speed, if less vmg. So to reprise, the reason why I think that the boats capable of the highest top speeds would be something like Cherubs and 29ers is because these are the boats that have modern hull shapes, light weight, decent SCP to weight and modest sail area. My limited experience (I've never been sure how good 29ers I've lined up with are compared to my boat) tends to be that Cherubs have the legs of 29ers downwind in equal conditions, but I also suspect that the longer, steadier and stabler 29er might be able to be sailed in more wind by an equally talented crew. But you must never underestimate just how important crew ability is. Its probably worth 10-20% on top speed. So to do a comparison against another class in a race you firstly need to be sailing alongside them at the appropriate bit of the race, which doesn't happen very often. It doesn't happen often because if the boats are of similar sorts of speeds the only time you'll actually be alongside another is if you happened to get to the top together, or if someone has capsized after a swim and recovers alongside you (or vv). And secondly you then have to be sure that the boats are being sailed equally well. The only time I really lined up right next to a Spitfire we sailed right through him. But he had his main pinned in far harder than us, yet was going slower, so we reckoned his lack of speed was from crew oversheeting sails, not boat. That's why I've got so few comparison points. All the times I've done the Grafham Grand Prix I can never remember lining up against a multi downwind. I've seen plenty going past upwind though. |
Posted By: Lucy Lee
Date Posted: 25 Oct 04 at 5:02pm
|
Wow, lots of positive vibes out there for my favourite toy I think that the numbers might look even better if you put more realistic crew & helm weights in for the Cherub: most of us sail with an all up crew weight of under 135Kg (not 150Kg as shown above), but my maths might be a bit wonky. If anyone it interested in seeing how fast they REALLY feel, there will be loads of Cherubs at Carsington Water Sailing Club on Saturday November 13th. I can't promise 30 knots of breeze, but anything above 11 knots is usually enough to put a grin on your face for the rest of the day Lucy (Cherub sailor, so very biased)
------------- Fly Cherub! |
!Posted By: Scooby_simon
Date Posted: 25 Oct 04 at 10:12pm
|
This prolly because all the cats are long gone I am planning to do the GGP this year and so we could (try) and get some quick drag races in if there is some good wind
------------- Wanna learn to Ski - PM me.. |
Posted By: Chris 249
Date Posted: 26 Oct 04 at 12:47am
|
For a start, how realistic are FDB's ratios? Consensus among skiffies
seems to be that they are OK apart from the fact that they include the
"lever arm" which is generally thought to be irrelevant or misleading.
After all, the Cb is easy to pull up and tall rigs tend to be more
sophisticated so they can be twisted off and depowered more easily -
this makes up for the supposedly higher C of E. Just compare a Laser
rig to a taller sailboard rig, the C of E on the sophisticated board
rig is way lower in reality but higher under Frank's measurements. And surely neither Cherub or 29er are fastest under any calcs. The R Class has no minimum weight limit and has hull significantly lighter than a Cherub (32-35 kg). It also allows wings (but doesn't use them) and it almost certainly has heavier sailors than the Cherub so therefore more power. In practise, of course, in all conditions the 12' skiff beats the Rs despite the fact that many Rs are built on 12' hulls. Even when the 12 is down to its number 3 rig, the extra weight of the 12 hull (45kg??) is more than compensated for by the fact that it has a very flat, efficient rig designed just for heavy air. So the 12 is lighter (IIRC) than the Cherub, carries a heavier crew (more power) because it has a bigger light-air rig, and it has a much more effective heavy-air rig. Finally, it would be a hell of a brave person who'd say a Cherub would blast past an 18. Or even the Skate, an Australian 14 footer with twin sliding seats (the forward hand's on an 11 footer which makes an IC plank look small) and a skinny flat lightweight hull. Re hotter angles at same VMG equalling a faster boat - doesn't that ignore the question of what happens when the deeper but slower boat heats up? A boat could be better of running deeper but slower to get better downwind VMG, but still capable out a better ultimate top speed. For example, before they went to assys I think Skates sailed fairly low downwind so assy boats would go higher and faster - but when it actually came to a top-speed contest the Skates could wipe just about everything, reaching with the power of a 7' (?) and 11' sliding seat. |
Posted By: Chris 249
Date Posted: 26 Oct 04 at 12:50am
| Oh yeah, I wouldn't be too surprised if a 29er could drive past a Taipan downwind in 30 knots - for a start Taipans (and most other cats) stop racing at a steady 22.5. Secondly a Taipan is normally capsized or on the beach in a real (not bar talk) 30 knots - as is just about every 29er! Thirdly, yeah the cats are throttling back so heavily for survival and their dash speeds just aren't that fast AFAIK. |
Posted By: Blobby
Date Posted: 26 Oct 04 at 1:56am
|
On FDBs ratios - the numbers above are my calculations not his - but I can't see fundamentally where they could be wrong. If the lever arm wasn't important why do the skiffs change to shorter, smaller rigs in stronger winds... A key thing though in my mind is the use of his threshold ratio of SCP/total wt of 30% for windward planing. As far as I can tell this was determined back in the late 60's & early 70's based on the NS14 development and other classes at the time. These days the rigs have improved dramatically on the development boats and the new SMODs. Better rigs tend to have lower drag and drag causes heeling. If you look at the ratios for a 420 and a 29er, they are designed for the same weight crew, they are the same width and virtually the same all up sailing weight. However, the 420 has a shorter mast and therefore supposedly a higher sail carrying power - the fact that a 29er is faster inspite of this is due to the better hull design and rig design. The better rig gives the 29er a better drive force for the same heeling force The message from this, surely, is that the critical thing is still to generate the maximum drive force. A modern rig, with lower drag, generates less heeling force for the same drvie force so FDB's threshold of 30% in the 70s should surely be lower now - maybe as low as 25%... (Taipans only stop racing at 22.5 knts when they have a choice - when 30kts comes at you because of a tropical thunderstorm just upwind with no warning then you have no choice but to hang on until it blows itself out...) |
Posted By: Scooby_simon
Date Posted: 26 Oct 04 at 7:39am
|
we don't stop racing in the UK just because it's getting a little breasy Ask anyone who came to that grafham cat open (or even opens, it usualyy seams to blow old boots) Except this year ! ------------- Wanna learn to Ski - PM me.. |
Posted By: JimC
Date Posted: 26 Oct 04 at 10:07am
I suspect not Chris. I'm taking the position that this discussion is about which boat can hit the highest sustained burst speed over say 500m in whatever direction suits it in whatever wind suits it. So I'd be suprised if the Twelves and Rs were in the frame because they are carrying very large kites which are optimised for VMG rather than straight speed theough the water. After all from a winning races point of view zig-zagging to and fro without actually getting very far downwind doesn't help much. If you sit down and draw a graph you'll find that the highest theoretical speeds are achieved when you are sailing at 90 degrees plus the apparent wind angle to the true wind, and the closer apparent wind angle the faster you go. This excludes drag of course! And when you look at the graphs for the different angles the benefit from getting a bit more apparent wind angle is huge. Of course you also have to be able to hold it up... Again, taking the position that all monohulls are pretty inefficient beasts and can't achieve much over wind speed, then for ultimate speed you have to be able to manage a lot of wind, which again points you to small sails, unlike the 12s and Rs. Even with the small rigs they have very big VMG optimised kites. But I must stress again that the speed I'm talking about is almost completely irrelevant for race track performance. Kinda fun though! Of course what would settle this is a whole lot of timing data. But by and large this doesn't happen. I suspect the fact that all sorts of "big fish" stories would get exploded is part of this - we've seen that on another forum recently haven't we:-) |
Posted By: redback
Date Posted: 26 Oct 04 at 3:55pm
|
You're certainly right about needing small sails. I've always thought the potential speed of a Laser4000 was faster than say a 49er, since it would be easier to hold it upright at the wind speeds we would be talking about. Not that I'd claim the 4000 is necessarily the fastest (its a bit heavy). Similarly ice yachts (which hold the sailing speed record) have sails of only about 7m - so small that at low speeds they have to be pushed to get up a bit of speed, then the apparent wind effect takes them on to higher speeds. Their sails are also very flat which means low powered but they have to be, to cope with the very narrow angle of the apparent wind at speed. I believe the record speed is in the region of 150mph and at about 3 times wind speed. I think I may have approached 15 knots on occasion and can tell you that steering a dinghy at that speed is extremely difficult. The slightest play in the rudder pintles sends the boat haring off at an angle. The rudders of boats are much too large for those speeds and the boat is extemely twitchy inclined to head up or bear away so rapidly that you are wrestling with the centrifugal forces of the rig rather more than the power. |
Posted By: Scooby_simon
Date Posted: 26 Oct 04 at 8:55pm
|
Which is exactly why I still contend that a Tornado is going to the the quickest over 500m 10 feet wide and easier to control than other mono's at those sorts of speeds and when flying a hull you are using all the boat except the lee hull as extra righting moment. Are 18' skiffs approx 18 feet wide ? and so giving slightly less that 9 feet of leverage (lee wing acts against the righting moment)
------------- Wanna learn to Ski - PM me.. |
Posted By: hurricane
Date Posted: 26 Oct 04 at 10:05pm
|
tornado wins in all conditions the sail area and leverage as well as less wetted surface area make it the most powerful boat!!! |
Posted By: Phil eltringham
Date Posted: 27 Oct 04 at 12:15am
The righting moment is created by multiplying the horizontal distance between the centre of bouyancy and centre of all up sailing mass by the total mass. Hence (assuming the skiff is upright, and the rigged boat minus crew has it's centre of mass on the centreline of the hull) the moments of the wing masses and indeed entire hull cancel out. This leaves the righting moment counteracting the heeling force of the sails as only the distance between the centre of the hull and the centre of the crew's mass (horizontally) multiplyed by the crew's mass. If the wingtip beam of the skiff is 18 feet than the leaver arm for the crew will be 9 feet plus the height up the crews body to their centre of mass (about 1-2 to 2/3 height). Hope this helps. P.S. heeling moment is lateral side force from sails plus side force from hull and foils all multiplyed by vertical distance between centre of effort of sails and centre of lateral resistance of underwater hull profile, thus explaing why lifting the plate when its windy makes going upwind easier (reduces force from underwater profile and also leaver arm) ------------- FLAT IS FAST! Shifts Happen |
Posted By: Chris 249
Date Posted: 27 Oct 04 at 1:53am
|
Posted By: Chris 249
Date Posted: 27 Oct 04 at 2:05am
Ahhh yes, you're much better and more macho cat sailors than we are - NOT. Can I remind you of the British v Australian results in the world titles in most of the International cat classes (As, F 18s, Ts, Hobie 16s, etc) and the Little America's Cup? I don't particularly agree with the way cat sailors stop racing in a breeze, myself. But if we look at the boats we sail v the boats you sail, we can see a clue. You guys often sail boats that are normally 25-50% heavier and shorter rigged. Compare a modern A with a Unicorn or Dart 15 or whatever, or a 180kg Dart 18 with a 120kg (IIRC) Taipan 5.7, or a 104kg Taipan 4.9 with a 130 kg (IIRC) Spitfire. Our boats tend to have much bigger wingmasts as well. I'm DEFINITELY not saying we are better sailors per se. You've cleaned us up even in 18 foot skiffs, never mind the Olympics. But currently the cat sailing record is pretty one sided. Look again at the F 18 worlds for example - something like 8 Aussies or expatriate Aussie skippers in the top 10, and the best Pom in 10th. |
Posted By: Scooby_simon
Date Posted: 27 Oct 04 at 7:54am
I'm not actually dis-agreeing with you (we have some work t6o do on the international stage re F18 etc), but you will find in the UK that we do sail when it's windy (+25kts). It is a myth we don't sail when itr is windy. Were there really 8 Ausies / expats in the F18 worlds top 10 ?
I see first, second, fifth and sixth......
------------- Wanna learn to Ski - PM me.. |
Posted By: Pierre
Date Posted: 27 Oct 04 at 9:26am
|
Seems that the cat sailors don't seem to have any empirical data to back their arguements up with whereas Chris and Phil seem to have somewhat more experience and knowledge, and back it up. I thought this was all about all up straight line speed. And it looks to me that there is nothing in it at all at the moment, but with the monohulls winning the debate. |
Posted By: Phil eltringham
Date Posted: 27 Oct 04 at 10:18am
|
The 'sums' I outlined apply equally to cats as to monohulls, Indeed because the righting moment leaver arm is measured between centre of mass and centre of bouyancy, cats have the potential to create huge moments once you start flying one hull. The trick to maximise this is to have the windward hull just out of the water so as to maximise the leaver arm. Hence the reason why nearly every holder of speed sailing records has been either a cat or proa. ------------- FLAT IS FAST! Shifts Happen |
Posted By: Brian
Date Posted: 27 Oct 04 at 10:38am
|
how bout two foiling moths with a single trapeze? would need a bigger rig though wouldnt it? on the topic of foilers, would it be possible to use actual wings like plane to create lift aswell or would the weight of them cancel out the lift? just a thought.... ------------- |
Posted By: Scooby_simon
Date Posted: 27 Oct 04 at 11:24am
|
'nuff said.... Except when it's a windsurfer........
------------- Wanna learn to Ski - PM me.. |
Posted By: JimC
Date Posted: 27 Oct 04 at 12:36pm
I think you'll find the 500m record has never been held by a catamaran, always proas and boards. Catamaran based attempts at 500m speed records seem to have been consistently unsuccessful. But we're off topic, this was about fastest dinghy in a straight line burst. |
Posted By: Brian
Date Posted: 27 Oct 04 at 12:50pm
|
http://www.hobiecat.com/sailing/models_trifoiler.html - http://www.hobiecat.com/sailing/models_trifoiler.html um thats quite fast isnt it? ------------- |
Posted By: hurricane
Date Posted: 27 Oct 04 at 12:50pm
|
this is a yachts and yachting article so there ya go id like to see a dinghy beat that record!!!!! Records were set on Loch Ness on Saturday (August 28) when the crew of a Tornado Sport catamaran turned in the fastest time ever set for a non-stop race from the northern end of the 24-mile long loch to the southern end and back again. Minnis Bay SC crew Chris Fields and Mike Spelling stormed to victory in their Tornado Sport to finish the Caley Marina Loch Ness Monster Race in under four hours and they set a blistering return leg covering 24 miles in just 1hour 19 minutes and 53 seconds. The top-rated pair from Kent completed both legs in 3 hours 47 minutes 49 seconds. |
Posted By: hurricane
Date Posted: 27 Oct 04 at 12:51pm
| oh and the waves were huge in that race so slowing them down!!! |
Posted By: JimC
Date Posted: 27 Oct 04 at 12:56pm
| 16 knots I make that. Very impressive feat of endurance to sail that fast for so long, I'm sure I couldn't. |
Posted By: Scooby_simon
Date Posted: 27 Oct 04 at 2:28pm
|
I think 16 kts VMG on a dead run is not too bad. Take a gybing angle of 90 degrees and it works out at..... Now where is my calculator and trig tables.... Anyone....
Sure ?
I make that just a few for cross bow/II From http://www.speedsailing.com/Background_records.htm - http://www.speedsailing.com/Background_records.htm ------------- Wanna learn to Ski - PM me.. |
Posted By: Phil eltringham
Date Posted: 27 Oct 04 at 3:46pm
|
Jim, please don't miss quote me, I did say "nearly every" Brian, the problem with foiling is that at about 40 knots foils begin to cavitate, its very complex but suffice to say that its an upper limit which there is little point in trying to push as there are better ways of heading towards the magic 50 knot figure. ------------- FLAT IS FAST! Shifts Happen |
Posted By: rogerd
Date Posted: 27 Oct 04 at 4:19pm
| I am sure crossbow was a proa. |
Posted By: redback
Date Posted: 27 Oct 04 at 6:15pm
|
90 degree gybing angle, just multiply by 1.4 and you've got speed through the water - 22.5 for 16 VMG |