Book Recommendation

Reg White, the British Tornado champ wrote a book about sailing Ts back in the 1970's I believe. If you can find a copy read it. I have a copy locked up safe in a storage vault where I can't find it.

thom

Frank is certainly an intelligent man although I have to say that he is very one eyed in his views on performance. His constant references to the 18's and their superior performance is baffling.
I have sailed Cats since i was a little tacker and have also sailed on 18's quite a lot. There is no way an 18, even in the glory days of the Grand Prix boats (much bigger rigs and wings than today and by the way much more fun) are a patch on a Tornado. Now that the T has the big rig and kite, the difference is even more noticable. In Sydney we have the chance every now and then to compare speeds and it always ends with the T romping away, even in conditions where Frank says the 18 is in its superior envelope. His points on the Cats hull speeds are way out of line with actual experience. Also sustained speeds from the skiff are not as good as he would have you believe. I sailed an 18 last weekend (mainsheet) and i was again reminded of how inefficent these things are (although i really likes the new carbon mast, super light and very well made). there is a lot of leeway upwind, the sails are very full (in order to pull the heavy and inefficent hull upwind)The other point is that there is no acceleration upwind, the boat always feels bound up and no easing of sheet or bearing away seems to work. then when you look at the control systems i shake my head... the kite is all manual, ie there is a bag behind the mast, seperate tack and halyard lines and the retrieval is a complete nightmare. You need two guys the take the kite down and if you make one tiny mistake you will be swimming.... the take down has to take place well before the mark. When you look at the current Cat systems where the take down is left until you are at or past the bottom mark it is amazing. Also the Kites are very full which i find interesting considering the current sail shapes in the Tornado. The speeds are quite modest downwind in the 18 and the main aim seems to be depth. but the Tornado is faster by a considerable margin and actually ends up about the same depth as the apparant builds. I think Frank has the right idea but has applied it with a serious slant.
As a side issue a mate of mine has been testing his 18 with hydrofoils, now that thing has some potential! it has been plagued with problems including snapping a foil off at 25kts.... but when it gets going well it is wild sight to see an 18 flying 2 feet of the water with a kite up and three on the wire. Some testing on Monday was aimed at getting the thing to foil upwind, in a light (8-12kts) breeze it was very close to coming up but it was not quite there yet. I think if the skiffs are going to get any faster than they are now this is the only way they will get there.

Frank's books really is a gem for sail trim and understanding the dynamics of sailing fast boats. His weather/wind chapters are the best I have read.

But the man dont like cats' that is for sure.

I think someone on here put it best when they said something to the likes of:

"I'll race berthewaite anyday on my cat. He can quote all the paragraphs he wants about how cats are slower than skiffs while he's hugging his centerboard."

Or something like that

Yes, I realize the skiffs are his main "squeeze" and so a bias comes through in his book...but he does makea good point that our cats do bury bows as speeds get up there and this does become limiting. The skiffs, once they are up & planing do not have any such limits. So far I've come across several comments in the book specifically about the Tornado...while not glowing, he does mention the quailty of the rig.

Anyway, it's easy to see past these biases (afterall, I know I'm biased on the Tornado ) and get to the meat of the book...how winds work, how sails work (particularly at higher speeds) and how hull/blades work.

I also like the fact that Frank constantly reminds us that we are still a long way off having efficient sailboats...Glider wings are an order of magnitude better at flying than a sail is at sailing. There's still lots of room to improve sailboats.

Sure a Cat will bury the bows at speed, but the speed at which a Cat will do this is actually faster then the pace the skiffs get to. and with the evoloution of Kites this is even more so. If Franks views on efficent sail shapes etc are so crash hot, then he should have another look at his beloved skiffs. The rigs are very full and in reality quite unresponsive compared to a good rotating wing mast with a square top sail. The foils on Skiffs are nothing too exciting and the skiff guys certainly freak out when we show them the Marstrom Tornado rudders, particularly the hollow in the rear of the blade.
I do like his weather section though, there is a lot to be said for many years watching and taking notes on weather patterns.

Macca,
I'm just getting into the know about Marstrom boats...will be owning my first very shortly. Can you explain what you mean by the hollow in the rear of the blades?

I have a RONSTAN AUSSIE 18 FOOT skiff video were you can see how these boats do not nose dive. They actually have a special name for such footage; they call it the Ripper Replay. Let me put it this way, I rather pitchpole on a cat.

However I think that Bethwaite has written a killer book filled with gems.

I do agree with Macca however that cat rigs are underplayed in this book. This is a pitty as the cat rigs today are as good as sophisticated as the skiff rigs. Nevertheless the basic aerodynamic principle to apply equally to both designs.

I do sail a bit of 49-er skiff and indeed Macca upwind these boats seem to be bound up upwind. Indeed there is no much acceleration upwind. We are all told that the boat planes at 8 knots but I have only been able to get it to plane consistantly on downwind legs and upwind in noticable stronger winds. I found that the 49-er will only plane upwind when the crew double traps. This is in more wind than 8 knots I can tell you.

We sail the 49-er in an area with alot of cats and it is really humbling to see the cats pass by at times. However the experience of getting the beest in a plane and keeping it there is very exiting. And I like the skiffs for that reason.

Both designs have their strong points and their lesser attractive ones.

Wouter

I think the video you refer to is "Awesome Aussie Skiffs" ?
If I remember this correctly, I think the most inspiring nosedives was when they jumped from a wave and straight INTO the next wave. Buried the bow completely, two crew did the great circle route around the bowsprit on trapeze while the skipper with headcam gave us the 'fish eye view'. Great video

I guess the 18 is nearer to Frank's heart than catamarans, and that would explain some of his bias. After all, he and his son has spent considerable time in 18's and the class is important to them.

But, he also is quite specific about the advantages of cats. Like reaching and medium wind performance.
I find the points he make about the weak points of catamaran to be quite valid. Like slow tacking, large wet surface area, unable to use some kinetics effectively, hard to use gravity to help sail twist in little wind, always in displacement mode (no planing) etc.
Also, it is obvious that he recognizes catamarans as high performance crafts, but points out the differences between monohulls and cats a bit biased perhaps..

After all this ruckus, I guess more people are going to buy his book and make up their own opinion..

Macca: Hollow in the back of Marstrøm rudders ? Do you mean the venting holes, as there are no hollows below the waterline on my Marstrøm rudders ?

The reverse curve on the rudder blade may be similar
in theory to the reverse curve(elliptical planform and reduce
induce drag)used on the Spitfire wing?

http://www.yarchive.net/air/airfoils_riblett.html

It would be interesting to me to compare the Reynolds number
of a Full scale wing to a cat's rudder in the water?

>>I think the video you refer to is "Awesome Aussie Skiffs" ?
If I remember this correctly, I think the most inspiring nosedives was when they jumped from a wave and straight INTO the next wave.

No, no the most impressive footage is when Julain Bethwaite is commenting on the quality of Ronstan fittings by pointing to a little cam cleat on a 49-er while saying " This little cleat here take upwards to a 1000 kilo's, particulary during a nose dive". That is while his father claims that only cat dive and pitchpole. Humm, how can that be.

But really the best "down the mine" in video is the oen made by the all yellow "skilled engineering". They are rounding the top mark (picture these comments with a heavy aussie accent) and just before you can hear the skipper Michael Walsh (?) say to hsi crew " We are going to rip this bear-away Guys ! " > Then you see the boat and he just slamms the rudder over only to launch the complete crew, himself included, into the air. Then the commentator is heard saying "Lovely yellow bottom !"

But then again there are so many dives to choose from.

>>But, he also is quite specific about the advantages of cats. Like reaching and medium wind performance.

Like I said I do a bit of 49-er sailing and cats beat us in all but the right drifters. Teh only advantage of the 49-er is on downwind legs with that huge kite up; some 30 sq. mtr. Being a cat and skiff skipper myself I can honestly say that cats have an advantage on pretty all points of sail and in nearly all conditions.

One thing to remember on skiffs is that no sailboat is as slow as the one that is upside down. This happens quite often. It is not easy controlling that 30 sq. mtr. kite on the overdimensioned surfboard.

But really I love it alot. When it all works out it is absolute thrilling. You're full of adrennaline because you expect to be wipe out any second. It is like when you first started cat sailing.

>>After all this ruckus, I guess more people are going to buy his book and make up their own opinion..

Ohh yes it is an excellent book.

Wouter

BTW, to anyone interested in getting this book, I just found it on this site's on-line store.

Enjoy.

The Hollow in the rear section of a Martsrom rudder is hard to pick but has a distinct function, in the vertical plane (with the rudder in the down position) there is a slight hollow in the chord of the blade, this is about 2/3 from the leading edge. very subtle but important.

and BTW, the commentator on the Ronstan vid and all the 18 vids is actually my business partner