89er

[sheeting yarns]

Mate, I'm not a sailmaker, but I know what I want.

I have watched Maka, on countless occasions, possibly the WING, C-Rigs and the C2Byte rig where the most challenging, because they were free standing, but even the XX and 29erC rigs, the boat would be on it's side, we weren't getting what we wanted, so addition of a bit of Carbon tape here or there altered the whole dynamics of the sail and it's response.
He would then go away and re do the top of the sail by altering the rocking of the panels to achieve the same response.

As it has been explained to be, it's about keeping the elongation of the Mylar within it's elastic limits (the Carbon tubes are no were near their Elastic limits) so it can react many many millions of cycles the same way. In any given race any sail many react 200-300 times per windward leg, so to ratchet up 100,000 is not that hard. In a year you will hit 1m easily.

Again, as mentioned before, back in the 1990's, we measured the fall off of very hi end alloy in 3-4 months of sailing 18teen 4 times per week (with 3 rigs) so in-effect if you had one rig sailing once a week you would expect some alteration (may not all be bad) in 3-4 months.

If you are going to hang a spinnaker of the top of a mast, then the strength and the rigging of that mast is such that you can't mast the tip flexible enough to make a Pin (ellipse) head work properly and if your sailing a single-hander, and if you want "sparkling" performance down-hill then the extra area up hi, working well up-wind, that will kick in down-wind and make it so much more enticing.

So your right, but you need such small movements in the Mylar to achieve great gains.

Chris Carin's did it with Dacron, Norths are now doing it with 3Di just a different order.

Sail structure has changed dramatically lately with the availability of HM carbon for both rigs and sails. Doyle Sails was the first of the large sailmaking groups to figure out that sail structures have been built back-to-front for the past 50 years and decided to do something about it. Now their structured luff technology is leading edge in dynamic response. Having the most stable and lowest stretch fibre paths and strength in the front rather than the back means that the luff area remains stable along with the built-in shape there. With the luff area remaining stable, the leech becomes more dynamic and can flatten and twist under increasing load. If we look at any wing structure in nature from birds to insects, they also have the same structure. You'd think sail designers would have paid more attention to this over the past 20 years when the science was there to allow us to see how wings on these creatures of nature manage to fly in the most remarkable ways with barely any effort.

 

[JulianB]

Needed Alex to post this, very short but good starting point, a short video, we are doing between 7 and 14 knts during this 2 sail run.



So got the foil out in about 10mins, Nicky helped, got it back here, some structural tears through 3 x 320gm Basalt so there was some load happening with the 2 Hz womping.

This was not a hum, it was repeated womps that move the whole boat.

I think in my haste in hand fairing the foil, that I left a string of imperfections maybe 2-6mm aft, virtually all on the stb side of the LE, so I am thinking that I was going from attached flow to separated flow and it just oscillated.

So after I post this I am going to design a LE fairing mould and get it 3D printed and then detail the LE. I also "necked" the last 75mm of the board as it went into the Bulb. Well that is going to be 5 x 320gm layers of Basalt, lots of HD bog with lots of fingers/wedges into the foam, and tied onto the spar. Twist wise, there are plenty of off-axis unies in the construction and even with a lever, it seem pretty twist adverse so I don't think I can blame the laminate/Basalt.

But I am going to completely re-laminate the last 75mm of the fin and carry that across onto the shoe, as I commented above, I necked it, so that necking will all but disappear.

Plan is to go sailing again, Tuesday or Wednesday. Last night was big, and Whitty was in fine form, with Gilly and Stack, and the Mesiha, and Imlay, Jimmy Beck was up to no good and all want to come sailing so no shortage of crash test dummies.

If it still womps, then I will go cut the tip of one of the 20 odd surfboards under my back deck fins, and put it right at the back of the Bulb to dampen the oscillations.

Pretty obvious the rudder can be 100mm shorter at least. Actual tiller can be 300mm shorter and tiller extension another 300mm, so that will make tacking the boat a whole lot easier.

New M5 dynema halyard will get made tomorrow, probably Monday fit-out and Tuesday sail.

Need to get into details and cutting the length of the ropes down, but I hope we can get this thing going, no issue we will go past 20knts pretty easily.

SK99 was faultless BTW, no stretch to speak of! M3 caps more than up to the very brief task of hanging onto the spinnaker.

It will be really fun the get to the point were we can push this hard, before Lincoln.

BTW Stu was at Drummoyne last night also and Skeeter is definitely doing Lincoln also!

~~~~~~~~~~~~~~~~~

So Mr Clark, wouldn't it be crushing boring if we all thought that same way!
I really respect what you and your son have done and possibly the single biggest thing I really respect you for is you had every opportunity to screw me back in 1997-8 and you didn't!!!!

You and Chip look at the long term picture and we still have (I hope) a good love-hate relationship. In fact, you hear all this about Indians, Chinese and Asian screwing you. My longest and best collaboration if with Takao (JPN), my HK partners are impecable, my Chinese arrangements are all about what is best for the sport. And Chris Turner (Ovington) struggles to see as far ahead as me, but he atleast tries, and is willing to take a long term position.

WRT Mericans, and business, You (and George Yurios (WCS)) are the only Mericans who have not either screwed me or tried to screw me. Plenty have tired or are trying, I have walked away from some, and when I walk, I never go back! There are just so many better things to do.
Need to hastily add, I am talking about business deals here. I have lots and lots of great dear Merican friends, Dina, the McKee's, Hienikens and the list goes on!

So mate, really appreciate that and I hope to hear your counter POV when ever you feel the need, but if you bite, then you have to expect me to bite back.

May see you in March, if not June, or come "down under" and meet you in some obscure place for a 89er sail and some Aussie red wine! jB

 

[JulianB]

Sail structure has changed dramatically lately with the availability of HM carbon for both rigs and sails. Doyle Sails was the first of the large sailmaking groups to figure out that sail structures have been built back-to-front for the past 50 years and decided to do something about it. Now their structured luff technology is leading edge in dynamic response. Having the most stable and lowest stretch fibre paths and strength in the front rather than the back means that the luff area remains stable along with the built-in shape there. With the luff area remaining stable, the leech becomes more dynamic and can flatten and twist under increasing load. If we look at any wing structure in nature from birds to insects, they also have the same structure. You'd think sail designers would have paid more attention to this over the past 20 years when the science was there to allow us to see how wings on these creatures of nature manage to fly in the most remarkable ways with barely any effort.

Your going to have to tell me how this relates to Square Heads?
Can't see the connection.

 

[pqbon]

View attachment 561365
View attachment 561366

That is one sexy beast!
I've always been a bit jelous of the sport boat scene down south.

 

[JulianB]

That is one sexy beast!
I've always been a bit jelous of the sport boat scene down south.

Ta, jB

 

[sailhmb]

Inspiring update. The heart of a new machine in real time.
Would you describe how you will evaluate the main battens performance and your process for tuning them?

 

[sheeting yarns]

Your going to have to tell me how this relates to Square Heads?
Can't see the connection.

Square head sails can become more dynamic with the aid of the gaff batten compared to a pin-head but if you have a good sail structure and profiling matched to a carbon rig, you can get the same dynamics regardless of the batten arrangement or head width. The beauty of the latest masts and sails is that you don't need as much rig movement as in the past to get dynamic twist and flattening. The result means that even downwind, the mainsail is not going to be too different in bend to upwind so the performance contribution improves all around the course.

 

[gazasmith]

Julian
great to see the 89er sailing. she looks slippery. hope you get the little problems sorted easily.
be passing trough Sydney late January hope we can catch up. would love to have a sail and see how much i like the deeper cockpit. even a day on Skeeter.
meery chrisssy Gasa

 

[JulianB]

Inspiring update. The heart of a new machine in real time.
Would you describe how you will evaluate the main battens performance and your process for tuning them?

I actually know where Half Moon Bay (CAL) is, I'm pretty sure I stayed there some time back.

I went looking for my father's books, because there was a perfect photo in it, but the wife has parked them in the attic, then she started throwing out my SeaHorse mags, and showed me this one.

The mag is Nov 2020, the shot was taken 1995, from memory it was Rottenest Island (WA) Dave (Gilly) Ewings in the beak, I'm floundering in the middle and Scott Ramsden is steering, 17ft wide wings, looks like a #2 rig.

The point about the shot, which is similar to the one in Dad's #2 book (which was taken in the factory with the boat on it's side, same-same but different) is the consistency of the battens, so coming off the luff they fan or flair out and ever increasing angles off the mast, as you go higher and higher , at a greater and greater angle of attack, that has to do with washout a) as you go up the rig and b) slot effect from the jib. (& in this case the spinnaker)

And again the leach exit is near perfect. In those days we would have started with a quiver of batten material, and we had this big disk sander (fortunately with vacuum extraction) and we would start with a set of what we thought was right and then go up and down the sail, sometimes 3-4 times, to get it just so. Each rig could take a day to get right, and often we went through a few battens. When finished we would do a light final sand and then heat-shrink the battens so the small fibers did not cut the sail.

Also notice how close the main is sheet-ed, also notice that all the leach ribbons are streaming so it's not over sheet-ed.

AWA would be 44-45° TWA would be 145-150°, SOG would be up around 20knts.

 

[JulianB]

OK, Christmas corrections, the photo on the cover of SeaHorse was Hayman Island, FNQ [Far Nth Queensland] date and people are correct.

WRT the womping, one of my crew is Shane who is high up in the Aust Air-force, test pilot, so we have confired and we agree that there is a line of imperfections down one side of the LE, about 3-5mm back from the LE and that is causing the flow to go from attached (Laminar) to detached (Turbulent) and then re-attaching causing the oscillation. This is happening on one tack (Stb) and if we got the LE better it would be less likely. So the board is well (3/4's) of its way through a re-build and re-fair. Mark (Paul) has given me one of his thurster fins and we are going to glue that on the back of the bulb.
Dave (Lambourne, he is the one building DP's sister ship) also had that a long time ago, he 1/2ve the weight of the bulb and it went away. Hew also went away from a fin with a steel spar and went to a all carbon one. In my looking around for materials re the fin re-build I came across a significant amount of Carbon cloth and a lot of Carbon Sock, so we haver decided to build a new fin mid Jan

So 3 pronged attached.
a) increased the laminate substantially at the tip, up 500mm
b) detailed the LE far more, getting rid of imperfections &
c) aft end of the bulb fin.

Can't see us getting on the water until Thursday, but lots of keen people want to push her, so baptism of fire is close at hand.

Working bee tomorrow morning.
There are about 10 things on the list.

One is a new main halyard. I have to date use Marlow, so I decided to give Liros a try. I'm using M5 and needed 11.2.5 - 11.5m eye to eye, so I made up a halyard at 11m assuming some stretch/settling/seasoning. (My shrouds are M5, so I had the Marlow data on that)

So this is at 1 tonne.

About 2.5% settling.

It did take about 5 mins for the "creep" to settle down, you can't measure it, the only way you know its happening is the tension on the scale rolls down, initially a kg/sec, after 4.5-5mins is was 0.1kg/sec and after about 20mins it stopped rolling for well over 1 min.
Took it back down to 400-450kgs which is what I expect the halyard tension to be (it's 2:1, so 900kgs is max) and it shrunk 20mm, but was then very stable.

Now it gets interesting, I did all this, 30mins under tension, put it in the back of the car for tomorrow. I have a "mouse" in the back of the car, so this is a G6 or 1/4" bit of 1:19 SS wire with eye one end and fork the other, 13.35m LOA. It's 20+ years old, been on a yacht for 15 years full tension, yad yad yad, no damage, still in good nick, I could not help myself.

Max extension on the wire 13460mm

Load that happened at.

Starting point 13355mm so a tad over 100mm of stretch on a well aged bit of 1:19 wire at a tonne of load.

Who says wire dose not stretch! And that's at 1/4 of the BS.

Happy new year everyone, let you know how the boat goes on our next outing and the mods to the fin.

jB

 

[JulianB]

We are not sailing today, I'm driving up to Newcastle (2 hrs nth) for 2 days with the family, plus no crew and lots of wind (and rain) so "pulled the pin".

We did lower the mast, and something pulled the cover off the rope, not sure the constrictor is at fault but not enough time to play around so the whole new halyard is in, re-tuned the mast heel and mast is back up. And within 2 mins (of the mast up) we where back up to 1/2 tone on the shrouds.

Heel-tune, had this recently on 49ers. In the 18teen days, we worked on 40-50:1 that the mast heel "tune" so this is the angle mast sit on the step and how it affects the tube above, in my case mast is 112mm (f-n-a) so 112 x 50 = 5.2m. The mast was very straight before, you could see it bearing on the front of the heel, so angle grinder, sand paper, then mast back up and it now has a much nicer even curve well past the lower spreaders. We also went right over the mast, not that 1 x 1 hr sail is that defining, but it all looks great, no issue with anything.

Also added the fin to the back of the bulb, I was going to go over today, but that's looking too hard at present, we did about 5 other things, and it was really hot, so that sapped our enthusiasm.

Few people have commented on the wire stretch, calling it re-coil and the alike.
Firstly it was G5, (not G6) so 5/32" (M4), BS is 2.3 tonne and 1:7 and even 304/1:7 would be less stretchy. (did this test 12 years ago, the report is in the public domain)
I am not interested in the stretch of wire to be honest, I did it because I had everything there and a opportunity to do it.
But Wire dose stretch and it "recoils" a lot.


The SK99 DM20 is proving everything I thought it would be, I have great confidence in it, but time will tell.

The Liros is now up inside my mast, it "settling" is similar to Marlow, there is only a few % between them.

Watch this space for up-dates!

jB

 

[Bill E Goat]

Have you thought of carbon rod rigging as the 12 footers use, obviously larger diameter

 

[allweather]

Watch this space for up-dates!

I am. Busy over Christmas though, with the family as you said...
I liked to see the comparison with steel wire. It is one thing to know the data, of course wire stretches, but having a fairly direct comparison like that is still nice!

Heel tune was interesting to hear about. Especially since I have a mast that stands only on the aft edge and didn't have anyone that could explain to me why they claim it is an issue.(as long as the mast base can handle it)
Also helps with bending as you just enhanced by grinding off the front/at an angle if I got that right? Very nice to know how easily such adjustments can be done.

 

[longy]

Compression loads on the mast base will impart bend if the base is not flat on the step. In your case, with the mast only bearing on the aft edge, the middle of the mast will bend forwards. This happens as the compression loads seek to push the mast down - the leading edge of the mast has room to sink and the tube bends to allow this. If the aft edge of the mast is floating, the tube will bend aft in the middle.
Having a slight angle to the mast base has long been used as a tuning method, esp if there are no partners

 

[JulianB]

Re Carbon rod rigging, one of the crew is Jimmy Beck, he has a 12ve and has the 3mm Carbon rod, plus somewhere on my travels, probably Southern Spars in Sri Lanka or Valencia, I saw them doing those really serious Carbon shrouds and the way they terminated them, very impressive.

I did think about Carbon shrouds but at the end of the day, this boat is going to get un-rigged in Syd and then driven to Port Lincoln, so having 2.4m hoops to wrap carbon rod around for the transit is not practical. The DM20 appears so idiot proof. I am seriously thinking of taking back-up material on my travels so that in the event of damage to the rigging you just do another splice, attach it to the back of the car and give it a decent tug. Good to go, and yes it would appear to be that simple, no expensive terminal swages, do it while waiting for dinner.

Heel tune, it's critically important, it affects the whole lower mast. The 29ert is a classic where you are allowed to wedge the front of the mast, so you can alter the whole lower mast with 0.5mm shim and take crew weight from say 120kgs to 135kgs combined. (so you wedge the front of the lower mast for heavier crews, you don't wedge as hard for lighter crews) 29er has no D1's so it's even more pronounced, but it sets up the lower mast and therefore that affects the mid-mast. Probably far more important that Spreader angles to be honest.

D1's on a 49er do mask possibly 50% of the affect of poor heel tune, but not completely.
With the 89er, the D1's are almost redundant. Never expecting them to exceed 500kgs (per side). They are really only there to counteract the Vang.

49er, SS had the mast sitting at or behind the aft edge, especially the FX rig, so much so that you have replacement plugs when the back of the mast failed. This is all well and good in places like Europe or Australia were there is lots of support but in places in Asia and Sth America, what some people sail with is extraordinary. Lack of maintenance dose not help.
So we are now standardising on a set mast talon which will get measured so that everyone has the same set-up and that in turn leads to std rig tensions.
AS I may have commented before, and this was forced on us by SS withdrawing (and they have every right to do that) and bringing across existing tech (because the sailors demand it), you end up having to do interesting engineering that in a perfect world you would never design.
Also, we are pretty anal about insulating the Carbon from the Alloy (via POM). SS did not do that, and that was 1/2 the problem.

 

[Liquid]

@JulianB thanks for the ongoing Masterclass in all things Sport Boaty and Skiffy, which I struggle to keep up with! But I love it!

Heel tune... Took some time to get my head around it, to realize it's like mast blocks stacked in the deck slot or mast rams - on dinghies.

Right....

 

[JulianB]

@JulianB thanks for the ongoing Masterclass in all things Sport Boaty and Skiffy, which I struggle to keep up with! But I love it!

Heel tune... Took some time to get my head around it, to realize it's like mast blocks stacked in the deck slot or mast rams - on dinghies.

Right....

Yes but NO. If that was the case then the D1's on a 49er/18teen would negate any mis-alignment of the heel tune, but as commented above, it's probably negates 50% but not all.

I have never done this so I can't speak with absolution, but I would guess if you sat your mast on a ball (like some cat people do) and that ball was on the neutral axis of the mast tube, so right in the middle of the structural elements of the mast then a chock/ram/D1 would have a constant effect on your lower mast as you alter it.

The evidence from both the 18teen (1991-6) and the 49er (now) is that if you load up the back of the mast it's softer even through the D1's than a mast which is loaded up neutral of fwd.

I'm trying to work out what would happen in a ILCA if you loaded up the front of the tube, but the reality is the down load on the ILCA mast is not a lot (because it's encastored) so possibly it would be trivial effect. Download on the 89er is going to be probably 1.5-1.8 tonne on a 112mm base, so mis-alignment is a major, 49er it can be quite small, only 1/2 tonne on a 64mm base and the D1's carry very hi loads because the boat is heavily vang sheeted, but it's still very real (mis-alignment). ILCA it's likely to never exceed downhaul load, bit of outhaul and your only carrying a factor of the full load.

Sorry, (re ILCA) my mind goes weird places!

 

[Martin T]

I remember years ago there was a fashion on the Laser, to put a loop of rope (end of painter normally) between the back of the mast & mast socket, to keep the mast more upright in lighter winds. Not sure it did anything really.

 

[JulianB]

Exceedingly pleasant time in Newy, just vegging with in-laws.

The extra 5 layers of material in the tip, going up about 500mm, they are all 320gm, 4 layer of cloth, at 45-45° plus 2 at 0-90°, there are also layers of unie (0° x 300gm) under the very lower layer of cloth (45-45°), and multiple fingers of unie, 10 layers deep at random angles.

We have decided to just get sailing and make a decision re a new Carbon board or persevere with this. Need to stress this is very very good and persevere is the wrong word, but unlikely to get sailing before 5th (Thursday) for a myriad of reasons. So not anal about the finish!

GT and I did do 3 hrs on it today and expect to do another 3 tomorrow.
New M5 Lirso halyard is near perfect length (got that right) and GT installed the tension system, plus he cleaned up a bunch of other systems. New 2nd ratchet block positions (I got that wrong) took for-ever with my arm up inside tight places. But it's done.

And is was 28C, bloody hot.

Also have to show you these because they were instrumental in the re-fairing of the LE.

Both about 100mm long, the FRP 1/2 one was great to get the bulk down, the tape is approx the thickness of the sandpaper, so it did not dig in. Started with 120g, ended with 240 - 280g.

But the 3d Printed complete LE, Game Changer

So simple and so effective, started with 400g, went threw to 1200g, (went-n-dry) perfect!

So simple, so quick and so cheap!

 

[allweather]

But the 3d Printed complete LE, Game Changer

That's awesome to hear! I love those machines.
Still not looking forward to faring, but the bit about the sandpaper thickness is a good reminder and the method may help with my lack of practice...

The vibration issue stemming from uneven faring is something I have to keep in mind, last year I had that issue with a different rudder after it was totally redone. Going to have to keep an eye on that... Neat to learn loads of stuff just from reading your posts!

And the project is just exciting. To see what can be done between a more traditional keel boat and a 49er.