ANNOUNCING THE MORRELLI & MELVIN A2 A-CLASS CATAMARAN

Newport Beach, CA - Designed by Pete Melvin of Morrelli & Melvin and Jeremy Laundergan of Askeland Engineering, the new Morrelli & Melvin A2 A-Class Catamaran builds on their success with the Waterat A-Cat they designed in 1996. Pete Melvin won the A-Cat World Championship with the Waterat in 1997 and the design went on to win five consecutive North American Championships.

The International A-Class Catamaran is a high-performance “box rule” International Sailing Federation design specification dictating an 18-foot long, 7½-foot wide catamaran with 150 square feet of sail area and a minimum weight of 165 pounds. The class has been steadily gaining popularity in the US since the World Championship was hosted in Long Beach, CA in 1997.

The new Morrelli & Melvin A2 A-Cat design features low wetted surface area hulls with a high longitudinal righting moment to resist pitching. The low profile bows reduce windage and provide a clean entry for both light air and hull flying conditions.

Morrelli & Melvin, known for their race winning multihull sailboat designs such as PlayStation, Stars & Stripes, Formula 40s, Alinghi and the Inter 18, will build the A2 in their new Development and Prototype facility and are now accepting deposits for the A2.

The ready-to-race (less sail) Morrelli & Melvin A2 A-Cat includes:
• Lightweight Carbon hulls
• Strikerless Carbon Beams
• Carbon mast from Hall Spars
• Carbon tiller and rudder head
• High aspect daggerboards and rudders
• Standing and running rigging with associated hardware

Only $15,500 FOB Newport Beach, CA.

Contact Morrelli & Melvin for terms and conditions or visit http://www.morrellimelvin.com/a2/ for more information including lines drawings and other details

>>The ready-to-race (less sail) Morrelli & Melvin A2 A-Cat Only $15,500 FOB Newport Beach, CA.

Do I understand this correctly, the boat without its mainsail is US$15500,- ?

Wouter

I wonder why there are no photographs of this boat. Have any actually been built yet or is it just a design on paper?

Rob.

You have to crawl before you can walk. The first prototype will be built soon for Pete Melvin. Since this will be the designer's boat, you can be sure that it will be sea-trialed extensively before more boats are built (and others have already put down deposits).

This is exciting news for the US A-Class. If the boat can be produced with enough profit to the builder, this could initiate another growth spurt in the US class as people either buy the new boat and or sell their 1-2 year old Flyers and Mk. V's and buy the new boat to build the fleets.

Its got to be pretty hard to put a price on a new boat, as a large part of that cost has to be on the tooling, so the amount you sell the boat for is closely related to how many you expect to sell, how many $15,000 A class cats will you sell a year?

In a previous post Bob Roberts indicated that tooling was about $50,000, thats alot of money to recover on what is a very labour intensive, low volume, product to build.

I work in the Automotive industry and with parts that are made from Aluminium and plastic, you can usually get them made for not much more than the raw material costs, so if we could find another 500,000 people like us every year our cats would probably only cost a few hundred dollars .

Hey Rick,

That's great news. I'm so glad the US is going to put a rod in the fire. It's very cool for M&M to step up and take the risk. It sounds like it will be a very stiff boat with all the carbon stuff.

Very Very Cool!!!
Mike Hill

Why does this cat have strikerless Carbon Beams, surely strikerless is heavier, do other any other big cats have strikerless beams?

Maybe they can weigh the boat in under the minimum so the extra weight, resulting in drag reduced wave stradling, are no problem.

An A-cat only has 7 1/2 foot beam and 150 sf of sail. This combined with the low weight means there is very little load on the cross bar relative to many other designs. By adding a little shape to it, it will easily be stiff enough to handle the loads. Pete did this on the Water rat with sucess. The problem with it was the way they shapped the beam made it very expensive to build.

Matt

Hello grob,
The A cat can be strickerless because the loads on the main beam are so small. The loads come from the max righting moment and the A cat is a one person boat trapezing on a 7.5ft beam and the platform itself is very light weight, 165pounds, so the loads are small, about half, relative to a two person boat for example.
The Supercat product line was the first boat to go strickerless, 1980. The SC15 and SC17 are both strickerless two person boats with the aluminum main beam being 4.5inches in diameter.
Good Sailing,
Bill

I have seen the solid model on the computer and the plug at the factory. It will be a winner. A lot of work using all the best ideas. They also have some really cool tools for designing it.

Seen the photos of the A2, but can't find any explanation for the "upside down" hull bows design.

I Know it showed its worth with round-the-world cats. But still, what is the explanation?

My guess is reduced windage.

Hello Bill, Grob,
I'm still a wee bit curious about the loads on the main beam. The tension in the sheet must "go" somewhere. Isn't a.m. tension rather large 6-7* (what you can pull by hand) of maybe 100-200N?
Is this a force so small that it's negligible? I get it to be in the magnitude of 3KN would this be about correct?
Or am I just sailing?

rgds
Patrik Elfving

Hi Sparky,
The upsidedown forward hull shape does three things.
1. Reduced windage.
2. Reduced forward stability, less pitchpole margin.
3. Less drag when pushed underwater, verge of pitchpole.
Conclusion: A light to medium air hull design; just the opposite of the Playstation modification.
Bill
Bill

The "upside down" shape of the hull is to reduce the greatest detrimental drag factor of a "small" hull's forward movement, ie with "tumble home" (narrower at the deck than at the bottom of the hull), when the bow is depressed by a wind gust, and before it responds to the gust with forward motion, by reducing the "rough water drag factor" of the hull, (rough water factor is simply in lay mans terms, the distance that the water is parted at the surface) the greatest impedence to the hulls forward motion is actually reduced instead of dramatically increased, (the reverse is known by all sailors who have droped the bow of a hull that gets wider at the deckline deep in the water in a gust and the resistence has increased at a rapid rate and caused the "tripping effect" ie the stern wants to catch up to the bow , or as some would say "pitch pole") By reducing the rough water drag effect at the bow , as the hull is depressed, the hull actually becomes more efficient through the water instead of the reverse, and will drive down, through, and out with speed, instead of slowing and, at the least "bucking".
darryl J Barrett.

Hi Darryl,
Thanks for your comments. What you just described is that the tumble home hull shape has its highest "fineness ratio", lowest wave making shape, up near the deck or at the top of the hull. This is the same hull design logic that went into the Super Cat family of beach cats back in the late 1970s. Look at the picture of the SC20 on the first page of this forum. The leeward hull has just gone underwater at the bow and "no problem". The boat keeps right on ripping; no abrupt slow down, no pitchpole, the sailors are obvisously not concerned. Speed and safety characteristics combine in the same hull shape.
Thanks again for your comments.
Bill

G'day Bill,
If sailors REALLY want to know the hows and whys of the performances of hulls through the water and of the sails through the air together with their interaction at the boundary layer of the two, they should get a copy of one (or more) C.A.Marghaj's "sailing theory and practice", There is not a great deal more (unless they want to get really high tech') that a designer of performance boats really needs to successfully design by.
Darryl J Barrett.

Right on Darryl! It is an excellent book and I use it often.
Bill

Patrik,

In the texts that I have read no one seems to take account of main sheet loads when looking at mast compression and main beam loads. I think the reason for this is that to a greater extent the main sheet acts just like another stay. If you put tension on the main sheet it is just like pretensioning the stays, and that does not affect the maximum compression loads in the mast.

I think that the main sheet loads are not additional loads on the rig just loads that are necassary to react the wind loads.

Does anyone else have a better explanation?

Gareth