New Technology and its impact on beach cats

[Bill Roberts]

There is an interesting subject on the Catsailor Forum dealing with beach cat new technology. The approach there is to list the new technologies and attempt to relate them to beach cat improvements.

Well, there is another way to skin that cat. Let's look at the performance of beach cats, the US Sailing PN tables, in various boat size catagories and determine the fastest boats and then see if we can explain why the "fastest boats" are the fastest because of new technology.
Let's start off with boardless beach cats. In this catagory we have the H16(PN=76.1), P16(77.5) and P18(74.9), SC17(73.3) or ARC17(70), Dart18(76.9), N500(76) and N570(70.2). This covers boats from 16ft long to 18.8ft long with the N570. What boat has the lowest PN? Why does it have the lowest PN? Does it have the lowest PN because of new technology? Well, according to US Sailing the fastest boat is the ARC17 which is the same platform as the SC17 with square top mainsail and self tacking jib added. Aquarius Sails was the first boat builder to put these items into production in 1992 on the SC17 and their complete product line as well. These new features had been developed in the 1980s on the RC27. If you stretch your defination of "new technology" a little, you could call these two features new technology, at least new to beach cats.
If you use the SC17 PN at 73.3, you see it is still rated faster than all the other beach cats except the 18ft and 8 inch N570. Why is this? The SC17 was the first cat that SC developed with "shared lift". The bow generates about 40% of the side force opposing the sail side force and the oversize rudders generate the remaining 60%. Shared lift is a lower drag method of opposing the sail side force than using a non symmetrical hull shape. You could call shared lift an advanced or new technology in this application.
There is another performance advantage of shared lift that occurrs with the addition of the spinnaker to the boardless beach cat. Since a large portion of the hull generated side force comes from the forward part of the hull, the forward migrating center of effort in the sail plan with spinnaker up can not get in front of the CLR of the hull/bow on the SC/ARC17. Therefore the boat never developes lee helm with spin up. Other underwater designs of beach cat hulls have had severe steerage problems with spins up and some have given up on spinnakers because their hull CLR is just too far aft and the boat always has lee helm with spin up.
I'm out of time; I'll write more later.
Bill

[Bill Roberts]

OK, more on beach cat technology:
Let's move on to the 18ft boats. There has been much activity here in the last few years. Is it due to new technology?
Most of these 18 footers came from Europe and have a unirig with spinnaker sail plan. Why did all of this happen?
A few years ago there was an effort to select a new shaped race course for beach cats that would be more spectator friendly. The rectangle or modifications of the rectangle were tried in the Tornado class. As it turned out the standard Tornado without spinnaker usually beat the Tornado with spin around this race course. Now this was back when beach cat spins were not fully developed and the spin launcher and retractor system was not on the boat. Today that same test would come out in favor of the Tornado with fully developed spinnaker, flat and twisty, and with the spin launching and retreiving system. Anyway, the decision was made to forget the rectangular race course, eliminate the high speed jib reach, and go for the windward/leeward race course which would put more emphasis on the spinnaker leg. This decision led to the unirig with spinnaker sail plan. The jib reach had been eliminated from the race course. The foreign builders were the first to come out with a two person boat with the unirig/spinnaker sail plan tailored to the windward/leeward race course and the F18ht class was born. The 18 foot length boat avioded the multiclass competition of all the 16ft boats and the already existing 20ft boat classes. The F18ht has proven to be fast for its size on the windward/leeward race course, PN = 59.7, but put it on a jib reach and it doesn't do too well against boats with jibs.
So, the new interest in the 18 ft beach cat class did not come about because of breakthroughs in technology but becuase of the politics that changed the shape of the race course. Maybe we should go back and revisit the square/rectangular shaped race course that can parade the boats at high speeds on a leg parallel to the beach 'for the spectators' with a spin take down at one corner and a round up go tight to windward at the other.

Now let's look at the 20 footers. The Olympic Tornado is still the fastest boat in this size, PN = 59. The I20 came out with many claims about new technology in their boat but it has turned out to be California sales pitch technology. The only boat that has ever been rated faster than the Tornado is the SC20TR. The SC20TR in good shape is still faster that the Tornado but US Sailing chooses to use recent race E T data from old worn out beat up boats that push the PN up to 64.4 w/o spin. The SC20TR is faster that the Tonado because of greater righting moment and greater sail area than the Tornado. The 20TR is a simple 'more horsepower' approach to building a faster boat.
There is a log jam of boats in the 8ft and 8.5ft width range with a PN very near 60. This log jam in performance level will remain until boats become wider. Max boat width sets max righting moment which sets max sail thrust. Boats tend to go the same speed with the same sail thrust. If you want to go faster, you need more sail thrust and more sail thrust requires more righting moment.
There is one other way to go faster, less drag, and that is to go super lightweight like the M20 or CFR20 at about 240 pounds. The M20 in production now costs 35K and by the time you get a trailor under it with beach wheels and protective covers and insurance etc, you have spent the best part of 40K on a 20ft boat that is 9.5ft wide. It is much less expensive to have the same performance on a 12ft wide boat that weighs 400 pounds. The 160 pound weight reduction of the superlight weight boat costs about sixteen thousand dollars more than the 400 pound boat or $100.00 per pound.
That must be really good hamburger! How about that Mike Kelley; have you got anything in your stores that sells for $100.00 per pound?
Bill
PS More coming later.

[Bill Roberts]

Let's look at the ARC22 and see if we can find any new technology. The 22 is simply the 20TR with a new set of hulls slipped under the rig. The new hulls are 22 feet long which increases the pitchpole resistance by (22/20)**2. This 10% increase in hull length amounts to a 21% increase in forward stability, pitchpole resistance or restoring moment built into the platform. Also the 22 built today is about 50 pounds lighter in total weight than the old SC20TR. The increased stability and reduced hull weight are the two differencies between the SC20TR and the ARC22. The ARC22 has a PN of 57; two points faster than the Tornado but the 22 has no new technology. The 22 is an exercise in increased sail area, increased righting moment and increased restoring moment relative to the Tornado and it costs the same as a Tornado. Tom, how do you do it; a bigger and faster boat than the Tornado and no increase in price?

Now let's move on to the RC27/30. These are breakthrough boats! Lets compare the RC27/30 to the Formula 40. The F40 has been declared by many catamaran experts as the ultimate 40 foot long catamaran in performance. Let's look at some numbers.
--------------------------------F40-------------RC30------------RC30/F40%
Boat length------------------40ft-------------30ft-----------------75%
Boat width-------------------20ft-------------16ft-----------------80%
Boat weight-----------------4000lbs---------1000lbs------------25%
Working Sail Area----------1000sqft--------500sqft------------50%
US Sailing PN-----------------54.0------------53.4---------------100%
New boat cost in 2004--$1,500,000.------$70,000.------------5%

So here the RC30 stands at the same performance as the ultimate F40 and only 5% of the new F40 cost. Not only that, it is only 75% as long as the F40 and 80% as wide with half the sail area. This boat design is a technical breakthrough in catamaran performance. If one looks at the parts that make up this boat, you can not find any "new technology". What makes this boat run so fast is the system of "everything operating in concert". There is no new technology, yet the boat is a technical breakthrough in performance relative to the Formula 40. Why don't more sailors buy/sail this boat? Why is this boat not the choice boat for a Professional Racing Circuit? At its present price it is a steal; it is a give away.

Here's another way to look at the RC30 design. Let's assume there is a "New Boat" that compares to the Tornado like the RC30 does to the F40.
-----------------------------Tornado-----RC30/F40%-----New Boat
Boat length------------------20ft-----------75%-------------15ft
Boat width-------------------10ft-----------80%--------------8ft
Working sail area----------257sqft-------50%------------128sqft
US Sailing PN----------------59.0---------100%-------------59.0
New boat cost in 2004--$25000.---------5%------------$1250.

Now the question is,"would this "new boat" sell"? It is 3/4ths as long as the Tornado; it is 80% as wide; it has half the sail area; it has the same performance and costs 5% as much as the Tornado. I ask you again,"would this boat sell"? The answer to this question is a very obvious, "YES"! The builder would not be able to keep up with the demand!
Now the question again, "why aren't there more of these boats, RC27s/30s, sailing/racing in the US? Why are there more of them racing in Europe than in the US? Did you know that an RC27 has won the Bol D Or race in Switzerland beating all the best F40s and other multihulls in the world in this unlimited world championship race? What are we waiting on?
Bill

[Eric2101]

Bill,
it all sounds like goblle de gook to me.

Why are you not offering a "new" 20' boat that can compete with the I20. Sailing the ARC21 I am always in the open class, never will I have head to head competition. (not that I really care but others do care, that might explain your lack of sales))

[Bill Roberts]

Eric,
I did the 20ft thing back in 1978. There were two versions of the boat, the standard 20 and the 'tall rig'. The standard was rated with the same PN as the Tornado (64 w/o spin) for several years. The tall rig (PN = 61 w/o spin) has always been faster than the Tornado, the chinning bar for all 20 footers. The tall rig 20 won the Miami to key Largo Race 5 years in a row; was never beaten by a Tornado. I have moved on. But, an ARC20 can be built in the ARC22 mold by simply moving the transom forward 2ft; no other changes. This boat would blow the doors off any existing 20ft boat today especially in the ocean. This capability was built into the 22 tooling for distance racing, Worrell etc, where 20ft length was the rule. The boat would sail to the same PN as the ARC22 (USS PN = 57) in all conditions except very heavy weather. How about ordering one from Tom H. today.
The situation is not that Tom and Bill are avoiding head on competition; the situation is that sailors do not order the boat.
Bill

[samevans]

Eric,
I posed that question to Bill when the ARC 21 was first released.
I specifically asked why he didn't design a Formula 20 compliant boat so that he could prove/disprove the worth of his design in head to head competition.
He fed me the same garbage about modifying molds "if somebody aked them to".
Of course that wouldn't make it class compliant though
Who in their right mind would ever go to a mfg., who advertises a 17', 21', 22', 27', and 30' boat and expect them to build a one-off 20' for them?

Bill and Aquarius are quite happy with their "gift" handicap ratings and don't want to take a chance on changing anything.

COWARDICE that is the reason.

P.S.
Eric, you didn't actually think that there would be other ARC 21s to race against did you?
Aren't you the ONLY ONE racing?

[Bill Roberts]

Hi Sam,
There was a time when 'one of a kind' 20 footers raced in the Worrell 1000. The ARC22 plug/mold was designed so that it could produce either a 22ft boat or a 20ft boat for that race. That is where the ARC20 comes from.
As far as building a 20ft boat/class again, that has no appeal to Tom or me. Why build a 20ft boat that is slower than the one you built 25 years ago. The SC20TR had a PN of 61 when it was raced regularily back in the 1980s. Put a spinnaker on that PN and you have a PN w/spin of 58.6.

I have an ongoing disagreement with Darline Hobock about letting a given one design boat/class' PN slip upward from a demonstrated lower level as the class gets older and the better sailors move out of the class and the sails etc get old and worn out.
Put new sails, ropes,blocks, tramp, etc as needed on an old boat and the PN is right back where it was 25 years ago. The H16 PN at 76 is proof that the PN of a given boat design does not go up as the years pass as long as the boat is kept in like new condition. The H16 PN has been 76 since back in the 1960s.
Smile, Sam
PS The PN advantage of the SC20TR in this year's Steeplechase Race came from the fact that the boat did not use the spinnaker. That is a 0.96 factor. When we looked at the race course and the weather forecast/wind direction, it looked like we might be able to carry the spinnaker for about 5 miles out of a 110 mile race. A 4% hit on total ET for being able to use the spinnaker for 0.5% of the race course distance did not look like a winning game to me and my crew so we elected to register without spinnaker. We were the only boat to do so. If we had registered with spinnaker and taken the 0.96 hit, we would not have won the race on corrected time.
PPS Sam, I'm designing a 50 footer now. Is that OK?

[thommerrill]

Hello Sam-

I think you are the COWARD in this thread!

Awhile back I saw another one of your self absorbed opinions on the Catsailor site stating that "ARC22 owners were trying to buy a win". When I asked you which ARC22 owners you had spoken too??? you disappered just like the COWARD you are.

Now I have another question:

WHEN DID YOU EVER DESIGN, SAIL, WIN, MANUFACTURE, PUT YOUR MONEY UP TO BUILD A BOAT OF YOUR OWN??? IF YOU HAVE POST THE PROOF HERE ON THIS SITE!!!

Have you ever sailed an ARC22, SC20TR, SC20??? It doesn't sound like it!
Is your baot rated below 64???? or do you have a boat???

I look forward to seeing your accomplishments posted...

Post them soon OK!