89er

[Erwankerauzen]

Happy New Year Everybody,

Hope the following question is not totally off-topic

Is there any thread comparing the skiff rig vs other rig concept including teardrop rotative masts like beach cats?

Cheers
Erwan

 

[dolphinmaster]

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.

I would say putting a small keel on a blown up 49er ymmv.

 

[JulianB]

Happy New Year Everybody,

Hope the following question is not totally off-topic

Is there any thread comparing the skiff rig vs other rig concept including teardrop rotative masts like beach cats?

Cheers
Erwan

Ohhh, only yesterday I was asked to write exactly that, give me a few day, maybe a week and I will see what I can pen. I was asked to write it for a audience were the 1st language is unlikely to be English, so I need to KISS it, that may take some effort!

jB

 

[JulianB]

A few people have asked to see my fin-let.

Courtesy of Mark Paul

Just glued it on with SpaBond! If it works then we will do the full tart-up, but until then, it's good-nuff to see.

jB

 

[Stanno]

Looks just like a Mark Paul fin off my old Bombara Tri Fin board!! ;-)

That man knows fins ...

 

[DickDastardly]

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.

View attachment 564213
Also have to show you these because they were instrumental in the re-fairing of the LE.
View attachment 564214

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!

Julian you wouldn't happen to have a dxf file for a Tasar board would you? I'd like to try that fairing trick on my leading edge

 

[JulianB]

Julian you wouldn't happen to have a dxf file for a Tasar board would you? I'd like to try that fairing trick on my leading edge

Quick answer is no, the Tasar was late 60's early 70's, not sure 3D files were around then.
And my Tasar Building Manual is probably in the attic.

If you can get me say 4-5 offsets, so 5mm, 10mm, 20mm and 40mm back from the LE, I can draw you what it should be, just set of calipers, overall width that far back, and I can do the rest.

And you probably want a STL file if your going to 3D print.

You will also need some poetic license as you get down towards the tip, because the board tappers as a %, probably 9-10% up toward the keel, down to 6% at the tip.

 

[JulianB]

Looks just like a Mark Paul fin off my old Bombara Tri Fin board!! ;-)

That man knows fins ...

Just FYI, sat down with one Mark Paul this AM for coffee, GT showed him your comments and he was suitably chuffed! Started on about your exploits, NFP!

 

[Stanno]

Just FYI, sat down with one Mark Paul this AM for coffee, GT showed him your comments and he was suitably chuffed! Started on about your exploits, NFP!

Classic!!!! I used to have his posters on my wall as a kid!!

 

[Erwankerauzen]

Thankx for considering the idea, so let me disclose the hidden idea behind the "idea"
I guess there is mould for Tornado carbon mast which are not put at full use at the moment, and I was wondering if a 20 to 21 feet sportboat with "skiffy design" & equiped with such a mast would make a consistant "idea"
Cheers

 

[allweather]

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.

Got distracted by the fin noise, but did you get anything with the notoriously noisy synthetic rigging or is this simply not a concern for this particular boat and how it's used?

 

[JulianB]

Thankx for considering the idea, so let me disclose the hidden idea behind the "idea"
I guess there is mould for Tornado carbon mast which are not put at full use at the moment, and I was wondering if a 20 to 21 feet sportboat with "skiffy design" & equiped with such a mast would make a consistant "idea"
Cheers

So that's a much easier answer!

Given the advances in Square-head technology a good sail-maker should be able to match a sail to virtually any mast (within reason).

Obviously it's so much better if you have one brain doing both the mast and the sail, so what Andrew did for me will net you better results than if I had gone out alone and done the mast and then gone to him (or North or Maka or whom ever) to get the sail done.

So provided you don't over cook the mast, don't make it too big, talk with your sail-maker and get the ei's right then yes there will be benefits to be had.

20-21ft Sports-Boat you probably should look at a Oval mast 90mm-60mm 2.5mm WT, but you need to move the ei's around. Tornado mast would be about that.

Next bit as to the aero dynamic benefits.

2 sail reaching 1000% benefit, huge gains to be had. (nb1)
Up-wind some gains, but you need to consider the downside (nb2)
Under spinnaker, yes gains in that you should be able to make the main more efficient and it therefore should be able to enhance the 3 sails working together (Spi, Jib and Main) as a total wing rather than 3 individual elements. And you are seeing this being exploited a lot in the big maxis and there triple header set-ups, but you need to know what you are doing.

nb1, is you better have a boat that is capable of exploiting the benefit of huge 2 sail reaching potential. It better plane freely!

nb2, is all about the rigging and weight aloft to stay this mast.
If you are wanting to gain the benefits, it needs to rotate!
If it rotates, you can't rely on conventional rigging system, you need to use diamonds etc.

That certainly works, plenty of examples of that, and with a 20-21ft Sports-Boat you can probably get away with it not weighing a lot. Mast head spinnaker, you will probably need a double diamond rig and that's doable without much weight penalty, could be very simple.
You will be relying on pretty significant primary shrouds because one wire is going to take all the side load so it will certainly be M6/G6 rope/wire.

But yes, on the balance of probabilities it will work.

So why did I not do it??
The 89er at 28ft and 11.5m (air draft) I believe that weight will blow out and it would have all gotten to complex. I would have needed M7-G7 shrouds, and probably adjustable upper diamonds, through a rotating step so I decided to KISS.

I will weigh my mast in a few weeks, but I believe it to be well south of 30kgs. 6 Pac's was about 37kgs and approx 10+ kgs aloft on a 1 tonne (all up boat) is a lot of inertia to overcome.
Vivace/Skeeter, under a previous owner did try a rotating mast and it failed, so that was also present in my mind.

But at 20-21ft LOA, so a 8-9m mast (probably 20kgs) on a 2.4m (towing width) stay base it's doable.

 

[DickDastardly]

Quick answer is no, the Tasar was late 60's early 70's, not sure 3D files were around then.
And my Tasar Building Manual is probably in the attic.

If you can get me say 4-5 offsets, so 5mm, 10mm, 20mm and 40mm back from the LE, I can draw you what it should be, just set of calipers, overall width that far back, and I can do the rest.

And you probably want a STL file if your going to 3D print.

You will also need some poetic license as you get down towards the tip, because the board tappers as a %, probably 9-10% up toward the keel, down to 6% at the tip.

Hmm. Indeed that makes sense. I’ll have a look and see whether there’s a simpler way then! Cheers

 

[JulianB]

You weren't at Toronto yesterday?? cooling your heels, at the Tasar Nats. Blowing "oysters off the rocks"! Nice turnout and they have done great things with that club. I was there for few hours chatting, and all classes have issues with supply chains and exploding costs but very enthusiastic group. Good Exc.

Class is in good shape.

 

[DickDastardly]

You weren't at Toronto yesterday?? cooling your heels, at the Tasar Nats. Blowing "oysters off the rocks"! Nice turnout and they have done great things with that club. I was there for few hours chatting, and all classes have issues with supply chains and exploding costs but very enthusiastic group. Good Exc.

Class is in good shape.

Nah, not doing nats this year. Just bought a modest yacht off GT and was planning to go cruising but we have a bit of a fuel tank issue…

Exploding costs a serious issue in Tasars - the supply side economics are obvious but as an economist I can say that sometimes cheaper is more profitable for everyone. I did the 2018 Nationals at Port Stevens. Around 70 boats, gold and silver fleets. This year 33 boats … the data don’t lie. This year we just couldn’t justify the spend on a new set of sails. Next year for the worlds maybe.

 

[JulianB]

Had coffee with GT this morning, helping him with your problem and I believe it's resolved.

McMillan has just brought 800kgs of 29er mast material (2 lots/extrusions of 1/2 tonne press excluding wastage, each, minimum order) and it's up 240% in cost at that quantity. Just getting it pressed was a one year process. Then getting it from NZ to AUS, holly shit.

And it's not just the 29er or Tasar, it's across all parts of the sport and off-course the alloy window industry will feel that acutely!

We as a industry need to look at alloys (if we chose to stay that way) for-instance, the 29er alloy is a military grade alloy that can only be pressed in NZ. The POMs (UK) have tried, the Canadians, the Mericans, in-fact the only other place that I am aware of that can do it is Brazil.
Can get really good extrusions out of Asia and Iceland but not 29er mast alloy, so when Ovington next orders it will be probably NZ extruded, add to that logistics is not going to be pretty. And I stress, this is across the board, no alloy mast-ed boat will escape this fate!

The other bit's like booms and simple "no-bending tubes" (but booms bend) there are plenty of extruder's across the world that can do that and minimises costs, but good hi end masts that last more than a year, ya got a problem!

The 787/A350 possibly very smart decisions, going away from alloy to something which has a significantly longer life span.

49er going to 3Di sails was also driven by that decision process, sails that are 125% (in cost) so more expensive, but if the decisions made by the 2 (49er & FX) Dutch WC (mirrored by others in the fleet) are anything to go by, the Jibs, at-least, are lasting 3+ times as long and we could be down to 1 main a year. Matters not if it's 3di or Stratis or any of another 10 processes, need to think running cost rather than purchase price. The Tasar mast is extraordinary, last 10-15 years easily. But the Tasar mast can only be extruded in Seattle! The sails are multi year.

All classes are going to have to look at costs, that was a major theme of my conversations in Toronto and making early calls to evolve (like 787/A350 process) will save the sailors a lot of money, time and effort.

Lots of money, let me just give you an example. 29er, JC (Kiwi Builder, Ex Norths and Southern) made a statement 6-7 years ago that the jib was now out of spec. So by that, the kids have evolved and are pushing the boats so much harder that the life span of a jib and the number of jibs per year that a boat goes through was starting to become un-acceptable.

And this is not just a 29er problem, most of the other "youth" classes burn through jibs at twice the rate of a 29er, a) because they are dacron, b) because they have light, medium and heavy air jibs so often they end up caught out and destroying a jib in a single outing & c) we (29er) can mandate that a jib is made to a specific weight.

2018 HK worlds, should have been a wake up call. 14 brand new jibs blew out in one day, (it was really fresh, but the kids had evolved and could handle it). It was limited to 14, because we only had 14 new spares ( and I repeat, it was a extraordinary worlds, kids had a huge time).

Getting modifications to the jib, post HK has been like pulling teeth. You often don't get it right the first time, this was one of those cases, it's better, slowed it down, but, for us, not good enough. So a 2nd "prototype" was generated after a conversation between the 3 builders (JC, CT and me) and we were (or I was) pilloried for doing it (it was trialed in Australia, it's now being trialed in Europe). Re-active rather than pro-active, it's now being considered for adoption.

If you do that maths, the money spent on existing technology is mind blowing.
And again I stress, the cost to the 29er parents is far less compared to other classes!

Your exec (Tasar) seem to be taking all that on-board, hence my comment your in good hands. 49er has constantly evolved, in-fact they have been really pro-active on this.

About a year back a committee in WS made a report and the builders and the class (49er) took that on-board, used that report, and made changes to the hull construction to double the life expectancy of a 49er hull in competitive trim. Using the WS report, got it through all the stages. Most importantly worked as a team, all players, CRH, Class, Builders & WS.

We also developed a "retro-fit" kit to enhance existing boats.

We all need to be pro-active rather than re-active, if we want the sport to grow.

I am confient that the Tasar Exc, (and I know that 49er Exc) are pro-active!

 

[JulianB]

2 hrs sail today, only thing we broke was the main-sheet hawse.
Boat preformed well, 9-13knts probably, we saw 14 occasionally mostly up wind.
Seabreeze gives us mostly 9-11's occasionally 14-15knts.
Max hull speed was 14.6 knts, not sure when, probably under kite.
We did do a few 2 sail, "send its" certainly in the 13-14's range
Upwind, very mindful of, low to mid 7's, rarely in the 6's, never in the 8's.
Pretty good tacking angles, 85-90°
Only 5 onboard, Jack, AlexB, Ollie, GT and Me, about 430kgs, and we need the 6th

(did the back of the envelope sum, PL we will be 500-505kgs, perfect!

Anyway, no womping from the bulb or fin, problem now is we don't know which of the 3 things we did fixed it, but it appears goooooone! Very very happy.
Little finlet is very clear on the back of the bulb, you can see it clearly as we are sailing.

Rig also worked far better, started getting into rig tune, main rarely inside out, and when it was it was controlled. Started playing around with the controls, things like jib sheet attitude (vertical angle) and also jib-sheeting angle (horizontal).
New main halyard worked, possibly too well, may have trapped the spinhalyard, few issues getting it down, so a re-mouse of the mast is called for, very likely have to drop the mast tomorrow anyway, WRT measurement.

Also we get to fully weigh the boat tomorrow in "light ship trim".

In answer to a few questions, surprisingly, no Dymena sing from the shrouds at all yet. I was expecting it, and have plans to damped it, but it has not appear.
Still no sign of creep in the Dymena, have not upped the Main shrouds tension via turnbuckles at all yet, they seem to be completely "seasoned".

GT and I plan on going right over the boat tomorrow, and sail Tuesday, Thursday and possibly do the Super 30 race on Saturday.

I may still make a new fin, mostly because I found a lot of Carbon, and throwing it away is not a option. We will more than likely do a stability test in the next week or so, and we will see the fin in all it's glory then. Rudder is possibly too light, WRT feel, and probably too long!

Boys having fun, GT, Ollie, AlexB and Jack, Spin sheet has some grunt.

Re the rudder fence, pretty clean, very happy.

Deidre's reaction, I married well!

 

[JonRowe]

Looks the goods!

 

[allweather]

Anyway, no womping from the bulb or fin, problem now is we don't know which of the 3 things we did fixed it, but it appears goooooone! Very very happy.

That's a good problem to have compared to changing three things and something undesirable occurring! Very happy that didn't happen and looking forward to further data in that regard if you build another fin entirely as you mentioned.

surprisingly, no Dymena sing from the shrouds at all yet. I was expecting it, and have plans to damped it, but it has not appear.

Nice to hear about how things are after a proper sail in regards to the shrouds. You're dropping tension in between with your hydraulic mast base, right? And that works as you intended regarding getting back to the right tension shortly after pumping it up again. (Going to copy that method, will have to see if local rigger has a setup I can use to season my ropes...)

No singing has my avid interest! Are you willing to share the cliff notes what counter measures you had in mind if it hadn't worked out as nicely as it appears to have?(wonder what sweet spot the 89er hit)

Re the rudder fence, pretty clean, very happy.

That does look way tidier than a lot of skiffs I've seen. By the way, the plate is too small to effect wake otherwise, or is it?

Anyway, congratulation on the champagne run

 

[JulianB]

That's a good problem to have compared to changing three things and something undesirable occurring! Very happy that didn't happen and looking forward to further data in that regard if you build another fin entirely as you mentioned.


Nice to hear about how things are after a proper sail in regards to the shrouds. You're dropping tension in between with your hydraulic mast base, right? And that works as you intended regarding getting back to the right tension shortly after pumping it up again. (Going to copy that method, will have to see if local rigger has a setup I can use to season my ropes...)

No singing has my avid interest! Are you willing to share the cliff notes what counter measures you had in mind if it hadn't worked out as nicely as it appears to have?(wonder what sweet spot the 89er hit)

That does look way tidier than a lot of skiffs I've seen. By the way, the plate is too small to effect wake otherwise, or is it?

Anyway, congratulation on the champagne run

I don't have any hydraulics on the boat, we take the D2's off, because that's were we attach the lifting slings, but other than lowering the mast a few times, I have not backed the tension off.

The plan is to do so, and possibly as soon as this week we will start doing that and we will do it by simply un-winding the turnbuckles, only need 6 turns to de-tension the D2's, my guess is the Primary will take 10 turns. If we do drop the mast tomorrow for measurement, then the plan is to even up all the shrouds and be very anal about it. Once that happens, we will get serious about defining a base setting, and once that happens, tensions can go on and off in a calculated fashion.

WRT dampening humming Dynema, it's all about harmonics, alter the harmonics, ever so slightly and they go away. I don't have any humming, but if it starts, a very small amount of lead flashing, a bit of shock-cord, even just taping a lead sinker mid wire works wonders. Of-course twisting the rope gives you a spiral surface, that kills the Carmen Trail, no Carmen, no harmonics. But twist the rope has so many other things not quite right about it!

Here goes my mind again. I do remember, the year before that shot was taken on the cover of SeaHorse, Scotty Ramsden was the skipper of BNZ, very late in the season, we did a boat against boat trial. BNZ had Dyform wire, AAMI had 1:7. We would hit a wind speed and the wires on BNZ would take-off, as in hum, and BNZ exited backwards. So it's important!

The fence, simply allows me to get the LE of the rudder under the back of the boat so the pressure spike, aligns with the hulls spike, and I think you end up with less resistance, and certainly a cleaner wake. You could do it without a fence, but then you would end up with crap between the hull and the top of the rudder,and that aint good!