F16 One up .

Does anybody know if there is a F16 designed to be sailed one up.Seems to me all that is needed is a shorter A class with slightly fatter hulls.All the F16 designs I have seen have enough volume in the back half to support two adults.Creating more drag than is neccesary or why would A class be so slim. Also do any F16 have canted hulls, I have had problems with my rudder ventilating on a number of occasions when flying a hull and trying to change direction, seems the rudder doesnt like travelling through the water at an angle.
Gary.

Not aware of any designed specifically as single-handers only.

Later model Stealths have canted hulls - these are the "Stealth F16" ones. I do know of one of the earlier boats that has been converted so that it now has canted hulls. I haven't sailed it so I can't compare it to the uncanted hulls on my boat (that particular boat also has had T-foils added to the rudders by the owner).

G

All the F16s around at the moment seem to be very capable single handers. I have sailed a Taipan 4.9 single handed for a couple of years and found it to be excellent. I did not sail it with a spinnaker though.

Rob.

Gary,

As an Australian you are probably very aware of most things I write in this reply however I will put them down anyway.

>>Does anybody know if there is a F16 designed to be sailed one up.

I know that both Blade F16 was designed to function as an optimal compromise between a singlehander and doublehander. Phill, as a regular singlehanded sailor, has put alot of effort in this. The base was a doublehander of course but it had to be and fell like a proper singlehander as well. I don't really understand how Phill went about this but I'm aware that he is very happy with how it sails in both modes. The few test sailors having sailed the Blade in singlehanded mode were no different in their appreciation. I do know it has alot to do with the shape to the keel line. At a time it was feared that the doublehanded setup would suffer as she behaved very well in singlehanded mode, however this was later debunked. The Blade has a very wide range of crew weights easily running all the way up to 165 kg combined crewweight, which is alot for a 16 footer.

I understand that the Taipan 4.9 is a good singlehander with a good doublehanded mode till about 140 kg of combined crew weight. Of course its hulls mirror 90's generation A-cat hulls with a tornado style stern. I think it's singlehanded performance is reflective of this (when sailed without a spi).

The Stealth F16 was designed as a doublehander from the beginning and some sailor prefer to have a special singlehanding mainsail made for the mast. Apparently the doublehander has a quite powerfull main. Having said this, I think about halve of the Stealths sold are almost exclusively sailed as singlehander. The jib kits function there to transfer the boat into a doublehander when occasionally taking somebody along.

I think the boat most designed from a singlehander setup is the Bimare 16 or javelin 16 but we haven't heard much of these lately and even the Bim owner in my area has sold her bim. So now we have no active Bim F16 sailors in our class.
The Bim 16 however fits the same describtion as the Taipan as a 90's generation A-cat hull design. The javelin 16 is too unknown for judgement however its hulls appear to be the same 90's generation A-cat hull shape but with a trimmed foredeck and stern. I'm not sure this is an improvement over the standard hullshape. A wave piercer hull needs to be redesigned from the bottom up and is completely different from any old hull shape.

The Australian yard of Alpha-Omega is looking into the F16 class and I don't know yet the specs of their design although I hear that they are looking to make it full carbon construction without raising the price much. It will be a feat to see that one.


>>Seems to me all that is needed is a shorter A class with slightly fatter hulls.All the F16 designs I have seen have enough volume in the back half to support two adults. Creating more drag than is neccesary or why would A class be so slim.


to this I would like to reply that one doesn't reduce drag much at all by making the back of the hulls more narrow. Problem is that the wetted surface area isn't much impressed by that. To much volume in the hulls can lead to a singlehander that doesn't have a pleasent behaviour in waves and that may degrade performance but I don't think the named boats suffer much if at all from that.


>>Also do any F16 have canted hulls,

Stealth F16 = Yes
Blade F16 - Taipan - Bim = No

Wouter

I sailed against a Mosquito with canted hulls a few years ago, the owner didn't seem to have any control problems as he sailed away from the fleet.

Hi All,
Well I have done it, bought a new boat no longer will I be able to join the mossie fleet. I purchased an A class the first prototype Boyer mark V.[flyer style hulls] carbon mast etc. But before you all tell me to get off the F16 forum the good news is I will be cutting its length to 5m. widening to 2.5m. shortening the mast and fitting a spinnaker. The ultimate single handed F16? We will have to just wait and see have been measuring up all day working out all the new bits I need etc. cant wait to get it in the water it will probably take a few months.Just in case anybody has seen the boat it is purple in colour and was originaly sailed by Glen Ashby. I think it will be called Altered .
Regards Gary.

Since it was the prototype what were the hulls made of? Whereabouts are you going to remove the length from? It seems like more work then starting from scratch, you must have got a smokin deal.

Hi Gary,
Sad to see you leave the Mozzie fleet, I`m sure they will miss you.
Good luck with what sounds like a very exciting project. One question : If you`re shortening an A-class, I`d assume you`d be reducing it`s weight. I`d then assume the boat, all-up incl spinnaker kit, would weigh no more than 80-85kg at most. How are you going to find an extra 20kg to make F16 min. weight ?
Maybe get concrete daggerboards ?

Cheers
Steve

Hi Steve,
Gee Wizz I hadn't thought of concrete dagger boards thanks for the suggestion. Seriously part of the reason the boat was for sale is that it is a bit heavy for A-class. It has been sailing A-class at around 80kg. Also by the time I cut and shut the hulls and reinforce the outside of the front half of the hulls and the beam mounts, reinforce the mast to take the spinnaker etc. I think the boat will be hopefully OK. Actualy speaking of weight I think I still owe you a reply about how OZ mossies get so light. I don't know of anything specific, everything is made light but strong hulls are generaly 55kg some needing lead. Masts are fairly light and so are most of the fittings, booms are mostly small sections with the track cut off they do bend a bit but are strong enough. Centre boards and rudders are lite mostly fibre glass moulded with a foam core, rudder boxes and arms are tube aluminium. No big secrets I can think of, you just need to start with light hulls and keep everything to a minimum after that.Don't worry I will still be around the mossies. I just couldn't pass up this opportunity to have a go at taking on all other cats upwind and downwind before I get to old and look back thinking if only I had given it a go.
Regards Gary.

Hi Gary,
Sounds like a big undertaking, if you`re cutting the transoms shorter, you might have to move the centreboard cases & front beam to balance the boat. I`m sure you`ll work out the best way to do it. Keep us posted on the progress, ie take pics!!
On the Mozzie weight subject, I weighed my boom, main & jib in it`s sailbag & was horrified to find it`s 15kg, the bag can`t weigh 1kg, so just the sails are quite heavy, bloody mylar !! At least it lasts a while though. I`ll have to look elsewhere for a weight reduction. My blades & boards are very light, blades are obeche timber (like balsa) with 1 layer cloth & epoxy, the rudders are obeche with carbon skin. Stocks are as per the Auzzie stocks, with a fibreglass rod as connector arm.
Don`t know if I can reduce weight by much. I think if Tim weighed his boat in sloop configuration with spinnaker kit he`d find much the same as us, within 5kg or so. I could be wrong, maybe he can enlighten me (no pun intended !)
Cheers
Steve

Hi Steve,
Surprisingly it would appear that the centreboards beams etc. are in aprox. the right positions.As I am taking about 8" of the back of the boat and about 11" of the front, [overall F16 length 5m. is actualy almost 16'5"]this takes the least volume out of the hulls, the bows will be fuller than A-class and have a round rather than a knife edge stem. This leaves the boat with the front beam further back than a mossie [more bow has to be good?]then the centre boards are further back than a mossie to. Currently as a A-class the mast has quite a bit of rake so even if I have to put a longer boom on to fit F16 sail area. I have room to stand the mast more upright to balance up the weatherhelm. In theory it all looks good. In fact I have worked out a formula, I am sure some math brain can give me the values for. Aclass-L+W-M/H+Sm2=F16 As for pictures I will have to wait till Tim gets back from holidays to use his digital camera.
Regards
Gary.

Here are some photos of Gary's new F16.

These are some bits he doesn't need -



and here is the man himself shaping a new bow -




Tim

Excellent Gary

Just what the doctor ordered. Another F16 on the water soon.

By the looks of what your doing you may be forced to eat that bag of corn pellets before we meet up again.

I fly out for the Dutch Coast Challange tomorrow, I'm very much looking forward to meeting the other starters and enjoying the hospitality.

Be safe

Tony Jenkins

Pretty "bow"! ugly "glasser"!! (he he he)

Hi everyone,
Some time ago, I got tired of seeing the cats fly by my 20ft monohull and rented school cat to check it out.
In spite it was just an old newcat14, I really got bitten by this cat thing and I now NEED to buy one.
I've looked arroud and, as I am by nature a solo sailor, I've narrowed the choice to F16HPuni or A Cat.
As I haven't sailed either yet, can someone drop me a line comparing these two cats?
What really puzzles me is that guy cutting the flyer into F16...
I know this is a F16 forum but eventhough I'd like to hear your side of the story .
Thanks in advance.

The best winds to you all.

Hi Pete,

why don't you check out the F16HP website at http://www.geocities.com/F16HPclass/ then go to the articles section and select Comparative F16 HP 1-up performance analysis.

I did the same checksum and ordered a T49 las year. No regrets whatsoever.

Good luck and wishdom

Hi Pete

It's the spinnaker that makes the difference! In the Mosquito's we have discovered how a spinnaker transforms a cat, and that's why Gary wants a chopped-up A-class with a spinnaker rather than a pure A-class without. Time will tell, but he is gambling that the converted A-class will be faster around the course than the original (not to mention a lot more fun downwind ).

Tim

Hi Pete,
your not the first person to think I am crazy.
But on the subject of cutting a A class into a F16, it realy came back to my need for a spinnaker, I can no longer imagine sailing without one. Sailing the mossie with spin. gave me a look at the front of the fleet, but I needed more upwind speed the A classes strongest point. In OZ their are no A's sailing with spin. around the reggattas that I have seen, but there is the start of a F16 fleet.
I couldn't find a F16 in OZ at a suitable price to fit my purpose [one up incorporating flyer type hull shape.] so a second hand A class seemed like a viable option as I have done alot of fibreglass work on my boats over the years.

You probably still think I am crazy cutting up a perfectly good boat but my need to test my theory's and new callenges were to strong.
Regards Gary.http://www.catsailor.com/forums/images/icons/crazy.gif
http://www.catsailor.com/forums/images/icons/crazy.gif

Thanks for hints guys,
"by the numbers" the comparison is very close, I guess the spi really makes the diference bringing that extra rush.
I'll have to try and test-drive them both to get the feel.
And Gary, don't get me wrong... I'm 100% with you.
A man has to do what a man has to do,right?! That´s also what I'm doing...
Keep us posted on your advances.

Pete

It will never work while it's "PURPLE" Get your priorities right lad! If it don't look right it aint right!
Change it to something nice like purple with nice broad vertical stripes of pale green and pink????? (I think I have to be sick now)

Hi all,
The modification of the A to F16 is structualy complete, I am happy with the bow shape very full down low but narrow at the deck. The stem came up narrower than I expected with a radius from pencil thin at the top to finger thick at the bottom.
I have just finished glassing in the transoms. I have also layed 300mm. wide unidirectional carbon from the bow to past the sidestays, hoping this will stiffen up the hulls and take the side loads of the forestay bridle and spinnaker pole support ropes.

Also have taken delivery of new Irwin mainsail built to rules looks like a real weapon. Similar square top to A-class but more roach all the way down to a 60mm. longer boom than the A, slightly shorter than a Taipan boom.

Hoping Tim will be around soon to take more photos to put on the forum. If you Carbon fanciers are lucky it will be before I put the filler on, so the Carbon will be exposed although I may have to put a R rating on it. After the comments on the rules thread I don't know if some of you will cope and don't worry Darryl it won't end up Purple although the stripes sound nice.

Regards Gary.

Here are some photos I sneaked while Gary was out!

Cool bow shape.


And a good look at those exciting fibres....


Rather mundane looking transom. As long as it holds the rudder on it's done it's job.


Tim

Some designers who are paid a fortune to come up with "the best shape possible" have produced many cats over the years and still haven't even approached the potentual of those hulls. I am not sure if your "design" work has been accidental or by intent! but which ever, the finished resulting "shape" shows an enormous performance potentual, (from what I can see with the limitations of the photo's)
the only area (possibly an illusion from the angles of the photo's) that may be a slight drag inducer is the rate at which the bottom of the bow opens out to its bouancy so "bluntly". Although if the first 2 to 3 inches (in depth) of the entry is kept under water when driving it should make very little difference to its driving resistance (or lack there of).
Darryl

Hi Darryl,
Thanks for the positive comments on the hull shape. I had a picture in my mind of the shape I wanted to end up with and am happy with the end result. The hulls had the kind of shape I was looking for which is why I bought them, shortening them has just made it more pronounced not to blunt I hope. The hulls have a more rounded bottom and turn in the rocker line further forward than the Flyer hulls but hopefully will still be fast the proof will be in the sailing. At least they wont slap like the latest A hulls do, I stopped sailing Arafuras and Arrows that were always picked on for slapping years ago.
Actualy I have always been a fan of the bulb bows and canted hulls on Crowthers big cats which have been around for years , especialy after sailing a few of them.

Just for interest I must agree with you about Carbon getting cheaper in OZ, materials at least the 150gm m2 uni cloth I used whilst possibly not being the ideal cloth or the best quality, I used it because it was incredibly cheap at $20. Aus a metre 600mm wide which I cut in half job done for $60. and a lot of sanding to fair it up.
Regards Gary.

Do you feel you have gotten your anwers?

Pretty much the way I see it.

A-cat ;

-1- good international fleet.
-2- Striking upwind performance
-3- extremely lightweight
-4- only for solo sailing


F16

-1- The biggest rush you can ever get while solo sailing. Downwind under spi in the trapeze is it !
-2- More robust than an A-cat. It will take 2 adult in 20 knots of breeze without a care. So near impossibel to break singlehanded
-3- For solo sailing and double handed sailing. Taking somebody along
-4- More of a Open class regatta boat + distance races. A-cats stick more to themselfs as they get hammered by spins
-5- Cheaper than an A-cat when featuring more stuff

Name? - altered reality - Just a thought
Darryl

Hi Daryl,
A few weeks ago I had gone off the name of Altered and had decided to call it Cut Cat, describing exactly what it is and hopefuly also going like one.

But since painting the final coats last weekend in a vivid blue similar to the font colour. (Hopefully Tim will have pictures for you soon.)I have swung back to Altered sounding a bit classier. I had thought of Altered State, Altered Class, but I hadn't thought of Altered Reality thanks for the thought. [color:"blue"] [/color]

Regards Gary.

Gary,
My vote is with Daryl's suggestion , "Altered Reality".
That is a top name all things considered.
Good luck, I hope she smokes them.
Phill

Hi All

The final gloss coat is now on and wow!

Tim

Latest view of "Altered" complete with mast, pole and chute.

Tim

Looks terrible !! .....

Terribly well-built, and terribly fast.
Can`t wait to read (& see pics) of her first outing in a combat situation. Keep the pics coming, and put the damn sails up so we can see !!

Well done Gary, Thanks Tim for the photo`s.

Cheers
Steve

Again I think that the extra width makes the F16's look impressive. Okay I'm biased but still. The width makes it look like a whole lot of boat even when it is only 5 mtr long.

The recessed mainbeam looks effective, I trust it will shed water like a dream.

Would pictures of this boat by something for the F16 video that the Californian guys are making ?

Wouter

Two words:
Just beautifull!

cant wait to see some pics of her under full sails on the water.

Holy....Looks faster than hell and asthetically among the best looking boats i've seen - any chance of some video for the F16 promo video ...?

Congrats !

PK

Okay, I'm going to try to attach stills from video so far...

#2

#3

And my favorite, #4

It's good to see someone trapeze correctly with a straight back and bent knees rather that "squatting" on the side of the boat with their back upright and looking like they are relieving their bowels whilst sailing
Darryl

Well the cat is a third of the way there with a really good looking platform. The next third will be the sail plan and if that is as good as the platform we will then, as they say, "know what the horse can do - it's the jockey that is the unknown quantity"
Its all looking great so far
Darryl

Hi all,
thanks for the positive thoughts, It's getting realy hard to not get to excited about the prospect of getting Altered in the water. But it is still some weeks away, work has been keeping me away from home limiting my time to work on it.

This photo was taken when I was measuring for the kite so it is not as complete as it might look. Still no fittings on pole or top of mast no rudder fittings etc. Don't worry you will see it first here Tim is as keen to take photo's of it as I am to show it to you. Must go, Altered awaits.

Regards Gary.

Great paint job, what type of paint did you use for that?

Regarding boat names, if she does go like a shower of [censored]......maybe "All-Turd". Sorry, just had to say it!

All the best

Hi all,
well today was the day Altered finaly hit the water. minus the kite. But after sailing I was glad I didn't have the kite ready as with a fresh breeze gusting to 15kts. I was busy just trying to sort out little problems with sheeting etc.

Tim was racing on the Mossie but I wasn't ready in time so I joined in behind the fleet as they raced around Raymond Island. The boat accelerated realy well in the protected water between the island and the mainland and I quickly passed the monos and large cats, Tim was off in the distance beating to windward, Altered hit the more consistent breeze and started to realy show some speed gradualy pegging the mossie back as we tacked around the end of the island. Then came a tight reach with Tim sailing higher to allow him to set the spinnaker early, Altered loved this angle flat trapping with the leeward bow pressing under but not slowing, spray everywhere to leeward me high and dry on trap it was a blast. I had almost drawn level but well to leeward when Tim set the kite and off he went, leaving me vainly tacking downwind in his wake as he dissapeared around the corner. I needed no further reminder of why I sail F16, the kite will be on next week!!!!!!!!!!!!

In conclusion the boat sailed realy well, the helm balanced and all the big things worked, (the mast didn't fall down and the boat floated) but seriously it does appear to have enough bouyancy despite all the extra weight as compared to the A class it came from. It seems very happy to trim bow up or down upwind, definetly bow down downwind but it didn't seem to slow it down much. Not until a wave hit the main beam but it did that upwind to. Incredible amount of water comes up the leeward hull and turns into spray but I guess this is normal for a plumb stem with a narrow deck, from my big cat experience with hulls of this shape this is how they act. Certainly makes it look like it's going fast.

Hopefully Tim will post photo's soon and I had some video taken to, so I will get him to work on that as well. I am afraid it is all in flat water though, off the jetty at the club but as you will hopefully see the gusts were strong enough to get a hull up and throw some spray around.

can,t stop grinning Gary.

P.S. I nearly forgot in reply to the question the paint is Northane two pack in Botany Blue.

Here's the photos.

Hi all,
another club member took some photo's to here they are.
regards Gary.

Okay, WOW ! and you win.

Some time back you mentioned that you didn't know wether this would be the ultimate F16 or not. When looking at your Carbon stick and boom and the Irwin mainsails I just I just have to declare your boat the winner of the singlehander F16 fleet.

Been laying a ruler along side your hulls in the pictures and she just looks to be absolutely perfect in all proportions. Mainbeam right there in the middle, 4.5 aspect ration mainsail. Sail very close to the top of the mast. The hull shape looks good from what shows on the pics. As if the boat was designed to be a F16 from scratch.

And now that the first real life sailing reports are coming in : Wow ! Signs are that she is all that and more.

My hat off to you for attempting this project and making it work so well.

Wouter

Hi all,
I've been away form this forum as I finally bought my cat (not an F16 I'm afraid...)and now spend my time trying to tame it.
But today I've remembered, what about that guy, the class A cutter?
I've check it out and I was delighted.
It sails already, and very well it seems.
And the finishing... that's professional artwork.
Congratulations, Gary!
Excelent job.

A hobie FX-one I wager. At least that is what your tag pic is showing.

Wouter

Hi all,
Glad you like the look of the boat.
Still don't have pictures with the spinnaker up. I have only sailed it with spinnaker up once. It handled pretty much like the mossie, wasn't much of a day for it though very gusty 10 to 20 kts. was very cautious at first but it didn't do anything unusual stretched a lot of new rope though. Can't wait to get it back out, if this wind would stop blowing so hard, gusted to 40kts. all last weekend, will hopefully have pictures soon.
Regards Gary.

Hi Wouter,
That’s true, I got the FXone.
Balancing all the aspects, I think this was my “best buy” for a first cat. I get support and fleets in the neighbourhood and I managed to get all the stuff within budget.(Yesss, i got the spi... )
It’s a pity it’s not an F16 but, who knows the future.
Thanks once again for your insightful and enthusiastic advice.

Best winds,

Gary finally had some nice light to moderate breeze for Sunday's race. Ideal for the spinnaker. Neil Joiner also had his new Mosquito on the water for it's first race. He will have the spinnaker gear on soon.

Tim

Just Blue-tiful !!

Well done Gary, she looks amazing. You must hate the 5 days you have to endure between weekends that keep you away from her !!

Love to hear how she goes in a mixed fleet, (just be kind to the Mozzies !!)

Cheers
Steve

Really a beautiful boat, and fast as well I hope?

It's a bit hard to see how much the mast is rotated on the lower picture, but is the mast bending sideways, or is it just bending along the major axis?

Also, it looks like the driver is not taking any chances, and drives the boat a bit aft-heavy?

Any idea of how much $$$ has gone into the platform (sans sails)?

Blue-tiful indeed.

I think the mast tip is bending away to lee Rolf. The spreader suggest that the mast rotation is just a little in front of the mainbeam. So you almost looking to the mast parallel to the main axis.

Gary, maybe we should give you a few more weeks to get to know you boat and than **** a date of the NSW or VIC states. I'll bet you'll be the combi to beat.

Wouter

Hi all,
yes I do hate the days in between sails. Especialy as I am madly trying to weld up trailer etc to travel to Colac reggatta and yes there are A class and usualy Taipans and hopefully F18's there.
I have been told Glen Ashby and Greg Goodall will be attending, not that I need that sort of competition at this stage. Colac is a inland lake nice flat water so should make it easier to sort Altered out amongst the mixed fleet I hope, Colac is also Tony McKenzies home base maker of carbon rudders etc. as used on Blade F16 and other cats.

Last year we had 10 mossies there, 5 with spinnakers, so hopefuly they will get a good turn out again and yes Steve I will take it easy on them, I am sure they will beat me on handicap.

As far as the cost of Altered it is very hard to compare to costs elsewhere because the platform cost realy just depends on what you can pick up second hand. The modification costs were minimal just time as I did it all myself. I hope this doesn't get anybody too excited but the complete boat on trailer as seen in final pictures cost around $10,000. AUS. but this relies on picking up a cheap ruff A and knowing where to source cheap parts and materials and heaps of labour hours. By comparison in AUS a new Mosquito was going to cost a bit more and Taipans sell second hand from around $8,000 good ones $10,000 plus.

Regards Gary.

Hi all,
having trouble writing this post. Have to just blurt it out.

Altered has failed structualy!!!! The starboard hull has collapsed forward of the main beam, on the inside it has completly broken through the skin and the core. The only thing holding the hull together is the carbon I layed up on the outside of the hull.

It collapsed sailing upwind with me on trap and it was the leeward hull, in about 15kts. breeze and fairly flat water I had everything pulled on hard flying a hull. I had no warning just felt the rig come back and I fell into the water came up expecting the forestay or shrouds to have failed took a while to realise the leeward hull was flapping back and forth. Got the sail and rig down alright all that is intact. Don't worry I think I know why it failed, the bridle loads were something the boat was never designed for. It was my experiment and I have to live with the consequences of not engineering the alterations well enough. Makes the price of the boat (previous post) look alot more expensive now.

Don't know what I am going to do now???????????????????????
maybe cry some Altered has become part of me!

Actualy it's all Wouters fault he jinxed me with the post backing Altered to win titles, I almost said in my return post don't jump to that sort of conclusion to quick. I thought I had alot of sorting out to do yet, but nothing this big.

I'm feeling a bit better now, hope you guy's don't mind a sad post.

Regard Gary.

disaster, feel for you.

Rebuild over the winter ?

Oh man, that is just so sad!

Is a repair feasible, or is the hull beyond hope? Pictures?

If it is beyond repair, you do have all the hardware for an F-16, sans hulls. There are plans for nice 16 foot hulls out there.. (A wild tough, you might use the remaining hull as a plug for a set of new, stronger, hulls. But all this is quite laborsome)

Sorry about your loss, but I hope you and Altered will bounce back!

If you transformed a "A" cat into an F16, repairing this should be a cake walk. Although it may sound easy enough, and even easier for me to say so, but I think you can do it. No need to give up now, just a roadblock that needs to be overcome.

We all followed Altered, you got yourself a group of fans, she is a beautifull work of art. Get the engineering settled over winter, and get that bad boy back on the water!

You can do it.
No need to be sad! you have accomplished a lot already.

So sorry - she was so beautiful.

I think that sentence shows that you are already bouncing back - and I am sure by now that you already have ideas for "Altered Too" As Rolf says, all you need are two hulls, which should be no problem to you after the wonderful job you have already done.
I am sure that we all look forward to hearing (and seeing) how you get on.

I'm trully sorry if I caused all this, Gary.

Would I be correct if I assume you reinforced the outside of the hulls but not the insides ?

Bloody bad luck, Gary.

A real pitty.

>>hope you guy's don't mind a sad post.

Surely not, this is drama. There wouldn't be any exitement if there is no risk of failure. This time, the risk won out over good fortune. But I for one have heaps of respect for you for starting on an adventure like that. You're my hero. I remember running heaps of numbers on the basic Taipan platform to determine the right modifications. I remember the feeling during the first times out on the water. I understand the greatness of the project you choose to undertake.

Together with the others I hope she is salvageable. This project has trully won the hearts of the sailors on this particular forum.

If I may; I've you choose to repair it and the failure was on the unreinforced inside of the hulls than I would advice you use the same cloths for the reinforcements as was used to build the hulls. Using a different cloth can still lead to problems as, for example, glass and carbon have different properties leading to staged failure. Meaning first the stiffer carbon will fail as the more flexible glass will not take any load at that time. Then all the load on the glass again, which will fail in sequence. Using the same material for the reinforcements is a good way to prevent that. I'm sure you know this yourself but I just wanted to make sure.

But again Gary, bloody shame this happened.

Hope you will rise from the flames and get altered back, with you in the saddle.

Wouter

Oh NOOOOO !!!

Sorry to hear the news Gary.
I saved all the pics of her on my pc, and look at them often. You just HAVE TO FIX her ! (I know it`s easy for me to say that when you have to put all the money & hard work in, but I really hope you get her back out there soon.)

Good luck,
Steve

Whoa. I know you Australians have quite the sense of humor, and I've had my leg pulled more than once by you guys. So, I'm just wondering if this is really true--did Altered really meet demise?

It sounds as if you need to open the hulls and glass in a relatively light "sub deck" approx' a third of the hull depth down from the deck extending from approx' the shroud mounting point through to the main bulk head under the front beam and then continue it on in front of that bulk head for approx' 600mm forward. This wiil allow the loads generated by the bridle "pulling" the bows together and upwards, and the similar loads caused by the sides way water pressure on the lee ward bow.
As an "A" class these loads would have been minimalised by having a "high" bridle and only one very high aspect mainsail creating only a minor amount of the loads that you are now experiencing, but what you have done when converting to an F16 is to dramatically increase the collective "inward and upwards" loadings on the inside of the hulls forward of the front beam. The front beam/bulk head act as the privit point for those forces and just the "skin" of the hulls with out any structural disipation of those loads will result in this type of failure.
The sub floor does not have to be of any great strength or weight, as it "assumes" much more strength than its own construction would sugggest by its engineering in place.
I know its a set back BUT the man who never made a mistake never made anything, and this problem is relatively easily surrmountable

Gary,

My sympathies. Thanks for taking us along for the ride. Beautiful work! Hope you find a way to revive her.

In any case, thank you so much for sharing with the world.

GARY

Gary,
I'm very sorry to hear about your minor setback.
But unless the failure is catastrophic this is just a minor set back and a good opportunity to make those hulls bullet proof.
I agree with Darryl's post entirely.

However you eventually decide to affect the repair consider the two main problems would be column failure on the inside hull side between the bridle and the main beam and ripping the bridle fitting out because there is either no bulkhead at the bridle or a bulkhead that is not designed to take the bridle type loading.

If you have not already formulated a repair plan I would like to make the following suggestions to get you thinking.

Given the hulls cross sectional shape I would cut the hull open from the bottom near its widest point. This will give you good working room.

I would cut a section out between a little forward of the centre case (200mm) and main beam bulkhead leaving a good section in place around the main bulkhead.
This will save having to disturb the bulkhead and will allow the remaining section of hull to keep the sides true.

If possible I would leave another section in place half way between the main beam and bridle. The cut would stop a little short of the bridle but close enough to put in a bulkhead and secure the bridle fitting to it. if one isn't already there.

If the hull has just delaminated repair would be quite simple. Inject resin and through bolt or screw with slightly flexable plates either side to apply pressure.

Personally I would then dril the inside skin at intervalls and inject resin around where the sub deck was about to be fitted.
To securely tie the two laminates together.
Glass in the sub deck from near the bridle to back past the main beam.
Relacing the panels that have been cut out is quite simple.
You can make up a fibreglass plates to form a lap bond on the inside and once the panel is bonded in place grind a taper into the outside laminate and glass that back together.

Even with now stronger hulls you might like to consider the height of your bridle.
The lower the bridle the higher the loading on the inside hull wall between the bridle and main beam and inwards loading on the bridle fitting.

You could even go to a system similar to marstrom are using on the M18 and M20 but without the carbon tubes. Instead use a line from the mast to the pole around 1.5m up from the mast base to behind the shuffer.
This line can also help give positive rotation to your mast.

Having said all that most problems have more than one sollution. In many cases it just gets down to personal preference.I have done nothing more than express my preference in the hope that it gets you thinking if you have not already started.

Once again I would like to stress the importance of looking at this as an opportunity to make the hulls bullet proof.

This experience will make every win in the future all that much sweeter.

Good luck.
Regards,
Phill

Hi all,
you guys are unreal thanks for the support. This realy does feel like a community of sailors, certainly makes me feel better.

Still don't know what I am going to do with Altered will be getting it looked at by others this weekend, I am still going to take it to Colac, am sure I will get lots of expert? opinions but there will be at least one boatbuilder there with experience of this kind of repair. I hope to get it fixed by a boatbuilder, as I just don't have time available now. If I can't get it fixed by boatbuilder I will be in further touch with Darryl and Phil there expertise is much appreciated.

Regards Gary.

Gary,

Phill has some great techniques for the laminate and core repair. The break sounds typical of a catamaran hull failure though. A compression failure in the hull just forward of the front cross bar. A-cats are very light and not designed for the loads that would come from a sloop bridal forestay set up. Composites are very poor in compression. Carbon is one of the worst fibers for this as well, mainly because you use carbon to go light, giving very thin skins to your hull laminate. Thickness is the key to good compression resistance.

Given that the A cat probably was able to get away with not having to have a false floor as described earlier, you could most likely add the additional reinforcement needed to comensate for the added compression loads on the deck alone. Bonding an additional layer of core to the existing deck, then laminating and fairing the new top surface would drastically improve the comression taking ability and if done with the same skill shown in your other work, you would not be able to tell anything was done. This would be a lot easier than opening up the unbroken hull to place a sub floor.

Just a thought, Good luck in getting back on the water soon.

Matt

Maybe I missed something here...

The photos show you sailing uni-rig...no jib. So why did you lower the bridle union from the original high-bridle of the A? Is it to allow stabilizing the spin pole and mounting your cool blue triangular snuffer mouth? The F18HT uses a high-bridle and is snuffed mid-pole. And remind me whether F16 is uni with spin or sloop-spin (jib and spin)?

Did you ever run it with a jib?

David, Matt

The same thoughts occurred to me as well.

First the Bridle seems a little low to me as well considering the hulls were modified A-cat hulls. Personally (as I didn with my own boat) I would have raised the bridle intersection and used a extra 3rd line to keep up the blue snuffer mouth. In altereds case I would have placed the bridle strop some 2 mtr's up from the decks and have it then continue as a single stay.

Having double forestays is not what you want to have on a spi boat as the spi tends to get blown between the stays to often. A single forestay with a high bridle strop seems to be the best compromise.

David. F16 is both sloop and uni-rig. We sail sloop when doublehanding and uni-rig when singlehanding. Gary only sails singlehanded as far as I know and has no jib as a result.

I agree with Matt that the most simple reinforcement against the most likely cause of the failure would be to just laminate an extra skin to the outside of hull that is just inside and in front/below the mainbeam. The failure seems to me to be a compression buckling failure caused by the increased bending stresses due to the bridle strop. You probably have added 400 kg sideways load to the hulls = ALOT.

The fibres can probaly take the laods but not if they become unstable when the hull starts to get out of colom (rimples along the hull) and moves sideways inward and/or outward. Thickening the wall will prevent this rimpling effect and thus induce more strength than would be expect by just adding the cloth.

But we need to be sure that this failure under compression buckling was the case of this. A sub deck is the most effective solutions as that would completely stabilize the walls.

Get up back there on that horse Gary !

Wouter

Hi all,

thought I would give you an update on Altered. All has finaly been sorted out and boat is being fixed and strengthened by McKenzie Composites as we speak, hope to be back on the water in a few weeks. Bigger better stronger etc. Can't wait to get back on the horse Wouter.

Hope to be racing end of January long weekend in OZ lots of sailing on, maybe even in South Australia, Phil what to you think of Milang Goolwa?

Febuary is looking very busy possibly travelling interstate for reggattas every weekend. Still working on trailer to make sure it is up to scratch.

Anyway hope you all have a good christmas and a happy new year, thanks for your support through the good and bad times with Altered.

Regards Gary.

From you I expect nothing less !

Happy X-mas and best wishes for 2005 to you too

Wouter