speed around a course

Discussion in 'Multihulls' started by Bruce Woods, Feb 4, 2008.

  1. Bruce Woods
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    Bruce Woods Senior Member

    The results of a race series where cruiser racer multihulls and monohulls starting together and sailing the same course were recently bought to my attention.

    The three quickest multihulls ( all schionings between 13.5 and 15 meters LOA) are being thrashed by the three quickest momohulls ( 13.7m adams, a northshore 38 and a 10.8 meter as yet unidentified cruiser/racer) In all of the 5 races sailed to date, in varying conditions.

    The courses have a mixture of windward, leeward and reaching legs and are held on a sheltered harbour.

    The average winning margins to the mono's are in excess of 20 minutes over a 2.5 to 3.5 hour race.

    Does anyone else have access to mixed fleet data, and see the same trend.

    I suspect a lot of crap is published about cruiser racer multihull speed. Sure there fast on a reach but carry a lot of windage to windward and aren't that efficient sailing reaching angles down wind except in a blow.

    Any coments?
     
  2. Freenacin
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    Freenacin Junior Member

    Are these results on handicap or elapsed time? Is there anywhere we can see these results? I'm not saying it's impossible, but it seems (very) unlikely that a 10.8 metre monohull would beat a 15 metre Schionning on elapsed time around a course in a mixture of conditions, assuming that both boats were being competently sailed.
     
  3. catsketcher
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    catsketcher Senior Member

    Sailing speeds

    I could understand something like this happening in the confines of Pittwater or Sydney's Middle Harbour - especially on a light shifty day. People in Brisbane or other open waters may not have the same experiences.

    I raced a few times with the twilight fleet where monos and multis raced together - it brought home why monos were so good for what they are usually used for - jaunting around the harbour. They point very high, tack on any shift worth noting and make hardly any leeway. Put a multi in this fleet and it is at a constant disadvantage - always having boats coming up from leeward and having to tack to get clear - you get pushed to the edges of the course. You can't get in close as you tacking speeds are so slow compared to monos that lee bowing and close manouvring get thrown out the window in favour of going behind and overstanding.

    The racing cats and tris (Farriers et al) were faster then the monos but watching cruising cats do a pre start manouvre in light winds was once called "watching dinosaurs mating" by my mono loving brother.

    However most cruiser multis are designed for longer distance sailing. This is probably something that separates them from cruiser racer monos. The advantages of the multi to eat miles up is what makes them a great cruiser.

    The cruiser in me could skew the race around (I know that is a contradiction) and say lets sail 30 miles up and back down the coast and with a husband and wife crew be allowed to put up any extras you like. (and the boat has to be under autopilot most of the time). In most conditions the multis would win by many miles.

    Monos are great boats and will beat multis in certain situations - this is why there are so many of them - they are good boats for their niches. The area where multis are gaining ground is not in the twilight racing area but in the serious cruiser arena. A cats advantages are pretty obvious when out long term cruising.

    cheers

    Phil
     
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  4. Spiv
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    Spiv Ancient Mariner

    Phil,
    I definitely agree with all you said, in 5y chartering my 12.5m Schionning Cosmos in the Swan River, I was many times surrounded by racing fleets while I was on a charter.
    I soon stopped even trying to show off my "cat' speed" and just went my own way admiring the agility of all those monos, sometimes wishing I had a cat like, say, Flat Chat to show them what racing cats can do.

    I have also sailed my cat to Broome three times, nearly always on autopilot, cooking while outside could have been 40kn or more... the only way to go!

    I will never want a mono, and I would not want to go cruising on a racing cat.
    The term 'Cruiser-racer' is an oxymoron, it will do neither well, but if one is able to accept compromises, then... go for one.
     
  5. Guest625101138

    Guest625101138 Previous Member

    I do not have a huge expereience base with it but I found in light air the monohulls could do better than cats on a balanced course. In stronger wind the cats would normally do better.

    If it was a course to a mark with only reaching then the cats usually won easily unless it was ghosting conditions.

    Under ghosting conditions you can do a lot with boat trim on a mono using crew weight to set the sails and reduce wetted surface. Once you get just a touch of apparent wind the boat seems to move magically (if it has a clean bum)

    Rick W.
     
  6. deepsix
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    deepsix Senior Member

    Almost all modern monos will plane downwind. Older generation monos that are limited to hullspeed were at a massive disadvantage against cats. This is especially the case if you compare the smaller multis and sportsboats. A Melges 24 is not that much slower than an equivalent sized multi.

    The other major consideration is the caliber of sailors. I do not want to offend anyone here, but it appears that the majority of racing takes place in monos and this is where you find the guys that really know how to drive a boat. I am taking about amateur sailors and I am excluding dinghies and beachcats.

    Moderate wind probably 15-18kts gusting a little over 20 at times. The course was a 5 mile broad reach easing to a run(most boats carried a spinnaker), this was followed by a one mile beat and a 5 mile fetch back home. The race is held on an inland resevoir so the water is flat.

    Seacart 30 tri - 0:55min
    Dragonfly 8m tri - 1:30
    Sportsboats(Melges 24 and Pacer 27) - 1:40
    Larger Racer/Cruiser Monos(Farr 38, Mountgay 30, j105, bene35)1:45-2:00
    Faster Small Keelboats(J22, J27, L26, Bene. F.C.8) 1:50-2:05
    Cruiser-Racer and Cruising Monos>30ft(Stadt 34, Ocean 31, Peterson 33, astove 30, atlantis 36, Impact 33, Sadler 32, Muira 31)2:05-2:45
    Elf 26 cat - 2:45, 3:32
    Wildcat 30 - 3:35, 3:51
    Dean 26 cat - 4:08

    The standard of sailing in the small keelboats is quite high so they are fairly quick. These boats are generally smaller than you are looking for and are not the newest boats around, but it may count for another data point. Keep in mind that the multis started 10min after the monos, and there is some bias because there are so few multis in the race.

    http://www.ldyc.co.za/RTIR 2007/2007 rtir results_2007.htm

    I honestly believe that cats are quicker than similarly sized monos, but the difference is not as large as some make it out to be. The quality of sailor is the largest factor here.
     
    Last edited: Feb 7, 2008
  7. PI Design
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    PI Design Senior Member

    In my experience a very cruiser orientated Prout 34 catmaran is considerably quicker than a similarly cruisy monohull. Upwind they have similar VMG but with the Prout going lower and faster. Reaching the cat is a coupl of knots quicker. I guess a yacht with a dozen bodies hanging off the rail would be quicker still, but that is hardly a fair comparison! My fathers' Dragonfly 920 Extreme (trimaran) is a cruiser/racer and is extremely quick on all points of sail and is surely faster than all but the largest and fastest of monohulls. What a fantastic boat - my parents can cross the Channel to France in three hours!
     
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  8. Pericles
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    Pericles Senior Member

    From what I have seen, catamaran design has had a really big shake up, over the last 5 years, since the arrival of the first Gunboat 62. Such a quantum leap in performance is now the raison d'etre of the latest tranche of designs, leaping off the drawing boards. These 4 are just my favourites. Others will have different choices. There's no prejudice here. :D

    http://www.africancats.com/

    http://www.gunboat.com/

    http://boboramdesign.com.au/

    http://www.pedigreecats.com/js/js52cons.htm

    These new weapons (and don't forget http://www.cammas-groupama.com/en/index.jsp right now) are head and shoulders above the fastest monohulls, in my opinion. Remember, it's only my opinion! When (and if) the latest giant multihulls are permitted to race alongside the latest giant monohulls, I know where my money is.

    There will be those who will cite past race results, but the operative word is "past". When Boeing 707s reaped the benefits of the Comet Mk.1 crashes, 50 years ago, piston engined airliners were outdated almost overnight.

    http://en.wikipedia.org/wiki/Jet_Age

    So it will be with the previously competitive vessels within the boat racing fraternity. Winning is all! Only build or buy catamarans. Sorry chaps. :mad:

    Pericles
     
  9. AC Fan
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    AC Fan New Member

  10. Alan M.
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    Alan M. Senior Member

    The boat in the picture in the Bob Oram Design link is "Just Add Water", a 44C, which is the boat I'm currently about 75% of the way through building.

    I doubt if this design was in any way influenced by the Gunboat, since it is at least 5 years old itself, and Bob really wouldn't have been much interested in Gunboats back then, they are in some ways opposite to his philosophy, which is simple, light, long boats which represent excellent value for money.

    For example, you could build and nicely equip one of his 60C's or 62C's for less than a fifth of the price of a Gunboat.

    Other than that though, I agree with you. I would love to see how something like this http://au.youtube.com/watch?v=HZ53CxBUj68 would do up against the motor-sailors in the Sydney-Hobart.
     
  11. brian eiland
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    brian eiland Senior Member

    I believe you answered a lot of your own questions. Yes, in many instances the performance attributes of multihulls have been over-rated. And this is particularly true in the case of production cruising builders hyping their products to similar limits that more performance multis can achive.

    In light to moderate winds with 'holes' in it the mono will almost aways beat the multi. The mono's weight carries it thru these lulls in the breeze where the multi tends to stop and start. Likewise shifty conditions (likely in the 'sheltered harbor' quoted) will act similarly on the momentum of the multi.

    A lot of the cruising multi designs carry excessive windage in their rigging and their deckhouse shapes. These extra drag forces can result in less speed to windward and excessive drag angles (less pointing capability).
     
  12. Pericles
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    Pericles Senior Member

    Alan,

    "I doubt if this design was in any way influenced by the Gunboat, since it is at least 5 years old itself, and Bob really wouldn't have been much interested in Gunboats back then, they are in some ways opposite to his philosophy, which is simple, light, long boats which represent excellent value for money."

    Agreed. The Gunboat 62 and its successors are light for their size though. Simple? Perhaps not! Value for money? Yes!. Few of us could afford one, but I'd bet there are a significant number who post here, who would be knocking on the door, if they won the Lotto. A lot of bang for the buck!

    The overall success of the package seems to be greater than the components alone. Each innovation seems to potentiate the whole or in other words, increase or augment the effect of, or act synergistically. That's almost like saying "I've no idea what makes the boat so fast, it just is!" :D That said. I'll bet Brian Eiland does.

    However, Kach22i has posted an excellent summation from Malcolm Tennant.

    http://boatdesign.net/forums/showthread.php?t=21267

    As usual, horses for courses and may good fortune attend your build.

    Pericles
     
  13. Bill Gibbs
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    Bill Gibbs Bill Gibbs

    I race Afterburner, a 52' coastal offshore catamaran. My 20 races a year since 2001 are primarily in a multi class, w/a multi start, inside a primarily mono race. In the US multis represent about 5% of racing boats. We usually do not usually compete directly against monos for trophies, but usually share the same course with the top monos.
    I sort-of agree with many of the "general" comparison statements between mono and multi performance made here, but they seem to gloss over the huge range of multi performance, as well as the similar huge range of mono performance. We had a race where the multi PHRFs ranged from -185 to +350. All of the general statements are wrong, if you select the right comparison. In fact I'd question how useful such general comparisons are? Some multis tack faster and point higher than many monos, etc. You can build a mono that reaches faster than many multis. So to stamp a generic comparison, you have to equivalence the mono and multi being compared, and this is not easy as they have such difference performance characteristics. Same length? Same cost? Same accommodation? Same purpose?

    Nothing especially simple about this.
     
  14. Pericles
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    Pericles Senior Member

    Hello Bill,

    Welcome.

    "Nothing especially simple about this."

    Very true, if it were, we'd all be doing it! :D

    Pericles
     

  15. Kerry Thomas
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    Kerry Thomas Junior Member

    Monos vs Multis

    When my racer/cruiser 25 year old design cat was in the water we always beat the monos in the weekly Sunday evening beat up the harbour from Motuihe to Westhaven in Auckland. Including 50 footers with a railfull of monkeys. Some were so embarrassed they would sneak behind Browns Island and motor. We would still be ahead! The multis mentioned are not cruiser/ racer , but cruisers that have racer added to their title to speed them up.
    Any cat with a full bridgedeck or under 40 foot with 6 ft of headroom in the bridgedeck is not a racer in my book.
    I will conceed that in very light airs the monos were faster. However as soon as the wind picked up at all we were up to 6 knots+.
    So speed for dollars the cat definately wins hands down.
     
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