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BruceH-NZ

Laser carbon rigs

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Someone called Pete Conway (on FB)  made the following statement:

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Interestingly the benefits of a carbon rig are very minimal, if at all noticeable just because its carbon. One of the major benefits to designers of planing boats (this is intentionally oversimplified) is that there is a certain amount of automatic sheeting in the head of the sail, because apparent wind is so critical to a planing boat. In essence the Aero hull is a planing boat, so the rig design is justified. Part of the skill of sailing Laser is to be super responsive and sheet and steer in a narrow channel. Its a skill on its own, and something that the top guys nail incredibly well. To have a development rig with a different design philosophy (and united to the skill sets of the classic Laser sailor for the reason mentioned), is, in my view, ill thought through and ill judged as a development. Its more like a prettying up, once again at the expense of the sailors developed skill sets IMHO. I am with you all the way, for this reason and more!

The aboves speaks against having the carbon rig, which in the form of the C5, is facing some resistance in Europe by those who sail the 4.7.

It would be interesting to hear @JulianB thoughts.

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1 hour ago, Gantt said:

Someone called Pete Conway (on FB)  made the following statement:

Interestingly the benefits of a carbon rig are very minimal, if at all noticeable just because its carbon. One of the major benefits to designers of planing boats (this is intentionally oversimplified) is that there is a certain amount of automatic sheeting in the head of the sail, because apparent wind is so critical to a planing boat. In essence the Aero hull is a planing boat, so the rig design is justified. Part of the skill of sailing Laser is to be super responsive and sheet and steer in a narrow channel. Its a skill on its own, and something that the top guys nail incredibly well. To have a development rig with a different design philosophy (and united to the skill sets of the classic Laser sailor for the reason mentioned), is, in my view, ill thought through and ill judged as a development. Its more like a prettying up, once again at the expense of the sailors developed skill sets IMHO. I am with you all the way, for this reason and more!

The aboves speaks against having the carbon rig, which in the form of the C5, is facing some resistance in Europe by those who sail the 4.7.

It would be interesting to hear @JulianB thoughts.

 This misses the point. The C5 rig is the one that matters, as it provides an effective rig for smaller, lighter sailors, particularly for the East, where there are many of them.  The 4.7 doesn't really work for this demographic, as articulated earlier in this thread and elsewhere.

 The other carbon rigs complete the set, making a scaled package and addressing a couple of the concerns people are  with the current rigs but it's the C5 that underpins the idea... just not for the current Laser sailing demographic (which is, after all, the point...!).

Cheers,

              W.

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The Aero is just 2.5% quicker than the Laser, and some claim that most of that advantage is in light winds. A 2.5% speed increase is not going to change a 14 footer from a "displacement boat" or whatever Conway (someone who slings lots of shit at the Laser for some reason of his own) reckons it is, into a "planing boat".  It's a odd thing to say - the Laser is very clearly a planing hull anyway. 

In an apparent wind of 15 knots as felt by a Laser, the Aero would having an apparent of 15.375 knots. Even allowing for the squaring effect it is strange to claim the Aero is going to experience different conditions.

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I think there has been a political stance to support the Laser 4.7 just how it is, and then a search for technical information to justify that position.

There are quite a few steps for it to take before any of the carbon rigs are introduced, including a vote by the ILCA membership.

The C5 is meant to support a slightly broader range of crew weights, plus be more durable - both of which are good.
 

 

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7 hours ago, Gantt said:

Someone called Pete Conway (on FB)  made the following statement:

The aboves speaks against having the carbon rig, which in the form of the C5, is facing some resistance in Europe by those who sail the 4.7.

It would be interesting to hear @JulianB thoughts.

Isn't he just talking about the available carbon upper section?  That was developed to not sail any different than the aluminum section but to be more resistant to bending and breaking.

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13 minutes ago, WCB said:

Isn't he just talking about the available carbon upper section?  That was developed to not sail any different than the aluminum section but to be more resistant to bending and breaking.

Don't think so, the comment was made in a FB feed below the video I shared above. I think what is going to be proposed is what is shown in the video. I'm unclear whether or not development is complete. The idea came from Japan, from Takoa Otani (Who is on the ILCA World Council), who asked Julian Bethwaite to design it. Julian sometimes comments here, so hopefully we may get comments from a true expert who is involved.

Pete Conway has been involved with sailing for years, even coached in Denmark for a while, and is very passionate about Laser sailing. (Though I can't say I know him myself).

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If the C rigs get approved that will entice me to purchase another new laser, to me that would be the most economical way to get a C rig.  If not I'll patiently wait for carbon lower sections to be approved for the classic radial. My current lower section isn't bent yet, but haven't had this one out in a proper breeze :)

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Hi guys, as you know, initially Chris but then Takao, who I respect beyond just about anyone else in the sailing community commissioned me to do a Carbon rig.

Caldecoat is a big boy, 95-100kgs, as am I, but he is 20 years younger and a whole lot fitter.

Otaini is 65kgs wringing wet 10 years older than me, but still a whole lot fitter.    (there's a message here).

Chris's focus was the big rig, for pretty obvious reasons.

Takao's focus is Kids in Asia (and he is a big kid often) and he (Takao) has been on about this for years, and the future of any sport, is the growing middle class in Asia, and that's not China, it's Asia.     For what ever reason the 4.7 has not had anything like the success there as it has in Europe in particular.

Even when we where doing the 29er, 22 years ago, the late great Dave Ovington wanted bigger and more powerful and Takao wanted smaller and easier to sail.

Ya got to remember that a 25 year old Asian woman is 50kgs, at 27 year old guy is maybe 65kgs.      Sure, like any culture there are bigger people and smaller people but as a whole, Asian's are 10-15kgs less than there Oceania counterparts.

Where the C5 rigs are now.

The 3 rigs that where in Valencia are in Tracy Usher garage in San Francisco, I don't believe they have been out of the bags yet.

In Australia, Chris is doing exactly what the ILCA and OLCA have asked and that is get "a few" rigs (C5) out there for at arms length testing and that is happening.    I have one in my roof outside, but it's yet to see the water, but that's not arms length testing [ALT]either.

The C6 rig is in remarkable good shape given it had the least amount of time spent on it.   But it also need ALT, and there is non scheduled at the moment, the whole focus is on the C5.

The C8, probably has had the most amount of testing done on it, because I'm big, Chris is big as is Tom Burton, Gerard West, Bret Perry and just about everyone else who has sailed it.  The issue with it is once we made this decision to make them all "check-in-able" which has significant consequence logistically, that the "stump" needs to be addressed.     Again, there is one in SFO, but there is no plan beyond some fun sails to progress that to ALT at this stage.     Bit on here at the moment on a number of other fronts, but there is a plan to revisit the stump latter this year.

Re single handers.

I have said this a few times, and Dad addressed it in his book, you need "X" amount of RM/kg to plane.    You can't get anywhere near X in a off the gun-whale, body swung single hander.    Those kgs are total kgs, so boat, mast sail, foils and the person, so the weight difference between a Melges and a Aero is real, but it's not enough to affect the sum in a manner that will allow either boat to plane up-wind.      Just about every one of these boats will do maybe 105% of hull speed, if sailed very well.   The difference in weight will be reflected in pointing angle, the lighter boat should point higher, but the conundrum is the lighter boat is more difficult to hold that higher angle because it has less momentum. 

Off wind, different story, because you can generate enough "x" factor to plane.   All boats can, and the more sail you have, the more likely you are to plane so to compare boats you really need to compare say a 7m² sail with another 7m² sail on the lighter boat to get any "real" comparison.    My caveat to that is if you use a Carbon mast you can carry about 8-10% more area, so the Carbon rig boat can argue to carry a 7.5 - 7.7m² sail "legitimately" (provided the mast is 50% lighter). 

Re Carbon.

Single word "inertia".  And its a X² law.   

Stepping backwards 2 steps, there is a weight reduction and it is significant.     A std Laser alloy rig is 10.4kgs.    The Radial is about 10kgs.     The new Carbon rig that is a development as in designed to be very cost efficient but is 100% Carbon and is a similar span to a Radial rig comes in a just over 4kgs.   (4015 gms I think), that's tracked, but needs fittings, and they weight 28gms (mast head fitting) 102gms (goose-neck fitting).    Get into square-heads in a moment but they tend to be full batten, so you carry 500gms more in the sail weight,  bottom line is you'r going to end up 5.25 kgs lighter.    So a Laser/ILCA dinghy, that's 75kgs (dead weight (no crew) is now 70kgs and that's 7% and that's very very real.

Now stepping backwards 1 step, all single handers are sailed up wind at about 6° heel, cut a long story short, the rig hangs out of the boat to leeward, so some of the effort you apply to hold the boat upright (6° heel) is countering the weight of the rig (to leeward) do the maths and its about 5-7% of you right moment.   It is this factor that allows a Carbon rigged boat to carry more area, to counter "more available righting moment, what my father would have called Sail Carrying Power and its a simple calculation.

So now we have 7% lighter and 7% effectively "more available Righting Moment".

Now the biggy, inertia!   Took a while to get this, because there was empirical evidence that was not explained but the 2 above,  it just did not make sense, but a very "enlightening conversation" with Gottfried (Klampfer) from Austria  follow by a fine bottle of red with Paolo (Portiglia) that night In Milan and it all fell into place.

Let me see if I can explain this.     Yes there is a weight reduction, but its a lot more.     The top of this new rig that is about to appear on my door step in 20mm (ID) maybe 25mm OD.     At the joint. 1/2 way down its 46mm ID, 51mm OD and at deck level is 52mm ID and 59.5mm OD.   It's Carbon and FRP laminate weighs about H1800 (1.8 x the density of water), compare that to the std alloy mast, 50mm OD in the topmast section, 1.7mm WT, lower mast is 64mm OD and 2.4mm WT and alloy is H2700.

Yes, one mast weighs about 10kgs, and the other weighs about 4.15kgs, little under 6kgs less, but the CoG, the balance point of the mast is so much lower with the carbon.

So the difference is not just the difference in weight, its also the height of that weight, and inertia is that height sq x the weight.

So without doing the actual sum, its very easy to end up with a mast that has less than 1/2 the inertia, so whats that?  Get a stick, 2.5m long, stick a 10 kg weight on the end of it and walk around holding it upright with one hand, then simulate going over some waves, turning corners (un-expectantly because you did not see that boat coming) or that gust that caught you un-aware's.   Then do exactly the same exercise with a 2m stick and put 4kgs on the top.

Every time you hit a wave and the boat pitches up-wards or downwards your fighting that inertia, every gust that catch's you un-awares you are fighting that inertia as you have to swing hard to stop the boat rolling to leeward (or windward) that's inertia your fighting, and it becomes draining.    Once you sail the lighter rig mast, you never want to go back to the heavier rig.    It in itself is not faster, but what happens is the drop in inertia means that you can sail the boat better for longer, and ts simply more fun, and time and time again, even with the most focused individuals, that simply comes through in the data.    It was the missing "X" factor in the calculations.

If your learning to sail, the rig is far less daunting, it has far less chance to become overwhelming.    The simple fact is a carbon rig is far better for the Punter than the Rock Star.

Final point is square head versus pin-head rig.

Carbon dose not like to bend, because it dose not like to elongate.   It can elongate, about 1% without issue/fatigue.

Aluminium dose fatigue, it cycles, everyone in the aircraft industry knows this which is why here are so many planes parked in Nevada. 

Nothing wrong with a good pin-head rig, all my 18teens where pin-heads, Lasers etc etc, but to be able to manipulate them you need a powerful vang and you need to bend the mast about 4.5-5.5%.    4-5.5% you cycle alloy, end of story!

A square-head rig, and I define a square head as a sail whose head-board length is at-least 25% of foot length (49er is 27%) and it need to be >90° (FX is about 115°) to the mast, held out by 2 top battens, one at approx 45°  and the primary control is downhaul!     They bend 1.5-2%.   

This is getting a bit long so I am going to cut this short, but a Carbon rig is normally a lot smaller than a alloy rig in Dia, and this again is a X² law, and if you couple that with a good square-head sail plan, bending 1/2 as much then there is a very real prospect of developing a mast that will never fatigue.       

And I really do mean a mast that NEVER goes soft, you can use it for years and years and years.  

To prove that point the demand for topmasts in the 49er has drop to 1/10th of what we used to sell and the number of boats has risen in the same period.

With pin-head and alloy/Carbon combination mast, you went through 3-4 masts per year, now you keep your favorite mast for 3-4 years,    Its that dramatic.

     Sorry, I have to go back and do some work, ciao

                           jB

 

 

 

 

 

 

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Brilliant.  Thanks JB!!!

 

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1 hour ago, Stanno said:

Brilliant.  Thanks JB!!!

 

 Hey Stanno... are you going to Kingston this summer?

Cheers,

               W.

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Currently, the primary difference between a carbon Laser rig and an aluminum Laser rig is North American Dealers have not yet paid in advance for Carbon Rigs LP hasn’t yet shipped. 

Otherwise, the rigs are identical to the unobtainable aluminum rigs because all we have are stories about maybe having some someday 

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2 hours ago, Gouvernail said:

unobtainable aluminum rigs

This is at the heart of the World Sailing changes made recently. 

I hope you get better access to your toys fast! I agree with your sentiment of too much politics and not enough sailing expressed elsewhere. In my view, the politics is interfering with progress and in order for progress to be made, the destructive political differences must be dealt with. :(  

I don't think the intention is to have the carbon rigs available until the ILCA membership has approved them. Julian's excellent answer above surprised me when said there is more development needed. 

Also in need of developing is the way it is introduced, to minimize disruption. (That may already have been developed, and I have yet to hear).

Either way, having gear last longer and a slightly expanded crew weight range will be good for the class. Though as we see above (especially with Pete Conway) there are those who don't see it that way.

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18 hours ago, JulianB said:

Sorry, I have to go back and do some work, ciao

First, fantastic reply from Julian. You can't ask for more.

Second, anyone who's sailed a boat with a CF mast and a modern rig -- designed or inspired by the Bethwaite's "automatic" rigs -- can feel it in their bones. When you get back to an aluminium mast, non-tapered, having to crank the vang to have the sail leech try and bend the uncooperative mast at the risk of tearing the sail... it feels like driving the Flintstone's car.

Grew up on Opti and Lasers, even coached kids on them and generally owe them heaps. But modern rigs are better, and you can feel the difference.

Personally I feel it when I am starting to be overpowered. A modern rig "automatically" just gives a bit in the gust, the top of the sail flanges open, and the boat darts forward, aaaah. An oldstyle aluminium rig with a pinhead sail, I'm either hyper-responsive or I'll have to work hard to avoid being overpowered, ah, f***, gust, damnit. 

Maybe that shows my limitations but man I'm not going back :-)

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Gantt, re extra development, it's mechanical development as in making purpose designed mandrels and actually testing the stump (of the C8).

So there is this magic number of 2.77m.    And its not universal, and some airlines and couriers will accept larger and some won't accept 2.77m, some will only accept 1.8m, Aust Post being one.   But in the world of FedEx and DHL and UPS if you ring up and say you have a parcel 2.75m LOA, they will std a std truck and pick it up that day.     And we have checked this, with CX and QF and AA, you give them warning and you front the airport with a "swag" with a entire C6 rig in it, hard bits are 2.7m, soft bits go out to 2.75m they will transport it for you as part of your checked-in-luggage.

(also a Laser boom is 2.7m long, so that became a target)

If you are say 3m, then no std truck with the couriers, Emirates will take it,  but CX wont, BA wont, etc etc.

C5 and C6 both come in at 2.7m LOA (hard bits) and the Swag (soft) is 2.75m and in 99% of cases so far, we have not had a issue.

C8 the tip we can easily make 2.7m, but the lower mast ended up +3m and that was a issue.

Add to that, the C5 and C6 are kinked at deck level, so that dictates ID's of the lower mast.

Where as the C8 is not kinked, so infact the C8 rig is very close to the optimum ID/OD's and taper's across it's entire length.  That has huge implications in the manufacturing process so a C8 rig may end up not costing a whole lot more than a C5/6 because its simpler to make.

Need to stress we are talking about a extra 100gms in the lower mast of a C5/6 to accommodate the kink, and the kink was a game changer. 

Cut a long story short, we had the C8, we wanted it to be under 2.7, so it had to be 3 piece, we did some maths and decided that we would have the joint at the Gooseneck, lots of reason why that decision was made, but for Valencia, we simply got the existing C8 rig with a 2.7m tip,  3.15m Lower cut it mid-way between the GN and the Deck, we then jammed a internal sleeve up the inside and it had a huge WT, probably close to 10mm.   What the English would call "Heath Robinson" solution.   Not elegant, and pretty heavy but it worked just fine!      I don't believe that rig is yet to sail, its in Tracy's garage. Maybe we will get it out in SFO and give it a thrashing in the next month or so just as a test and a bit of fun.

So to be more elegant, we will make the tip and mid mast 2.6m LOA, and combine that with a 700mm stump to end up with a 5.7m mast LOA.

It is that, that requires some development, its just a question of milling some mandrels, and doing 2-3 samples to match the existing bend.

We are yet to even look at the milling part, and I can't see it happening till Christmas on present time lines, then we need 6months of ALT, yada yada yada.

      jB

 

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1 hour ago, JulianB said:

So there is this magic number of 2.77m.    And its not universal, and some airlines and couriers will accept larger and some won't accept 2.77m

Ha! I wasn't expecting that Julian! But yes, it makes complete sense.

It overcomes the possibility of getting a dud mast when a charter boat is being used. Mast breakages are one the top causes of gear failures. I've had three in the Laser.

I'm in support of the carbon rig, though there are those who are not. There is uncertainty about the way it will be introduced, though mostly, there are some people who seem to be afraid of the change.

Pete Conway's main objection seems to be:

Quote

Lasers are a supreme physical test, along with being a massive challenge of dealing with conventional methods of sheeting, dealing with sea conditions and velocity changes. 
To an extent, and sometimes completely, the carbon rig being suggested is taking away those challenges. As a development rig it therefore fails, and as an Olympic rig it fails totally. There can be little argument about that IN THE CONTEXT OF SKILL SETS, AND WHAT MAKES LASER RACING SO COMPETIVE. You want to make it easy? Go ahead. The class then loses its challenge that it has thrived upon.

I'm unclear how much influence Pete has, that doesn't really matter. He's been a coach in the past (and i think he still is), and I would expect a lot of sailors look to him for advice. What matters is that he reflects what is very likely being said elsewhere. I happen to not agree with what he's saying, because a reduction of inertia doesn't mean that the challenges he describe go away. In my mind, if the weight range to be competitive increases; so too does the pool of sailors - more sailors means it is hard to win races which is all good.

It is important to hear people who are mad keen Laser sailors who are concerned about changes, and be sure their concerns are heard and addressed. I would hate to find out in 10 years time that Pete was completely right and the carbon rigs were introduced - and it killed off sailing the Laser.

Equally important is that I have not sailed a C5, C6 or C8 rig, so my comments are entirely speculative. I very much doubt that Pete Conway has either.

My question to anyone who has tested these new rigs is how much of a difference does it make? Is it a deal breaker in your view like Pete Conway is suggesting? The feedback I heard has been positive so far, though obviously not much to do with fleet racing.

---

Makes me recall one of several times I have had a mast come down. Three times in a Laser. Once on a Farr 3.7 (a shackle came undone).

In 1985, I was sailing in the NZ Nationals in Plimmerton, Wellington. In race two, I was in second place, just behind Murray Armstrong. I had the best start and Murray had passed me on the first winward beat. I don't know who was third, they were about 50 metres back. In a Laser that was just a few weeks old, I broke my top section at the jybe mark. (I had too much kicker on, so it was partly my fault, partly the well known design issue). Got a DNF, then a DNS for race three in the afternoon. Ripped my sail; my nationals were over. My picture was taken by the media boat that towed me back to shore, and was published in the local Wellington paper. While I raced the rest of the regatta with a replacement mast, my heart wasn't in it and performed without distinction.

At a young age I allowed it to have a big impact on my sailing career. Within a few years, I had decided to not pursue the Olympic dream - but instead to be a weekend sailor only.

It is ancient history now.

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The thing that is evolving the fastest is the sailor!

And that is the problem.

Just try and tell a sailor he has to sail the boat the way they did 20 years ago and see what reaction you get!      Just imagine the reaction of the coaches, and in some cases the parents.

But it is these people that then bitch because the boat that was design without even contemplating the sailor of today, who is being driven by the coach/parent, breaks, or fails, or simply can handle the new load, who then get all thingy because it can't, but get even more upset when you actually do something to overcome the problem.

Its so short sighted and so 2-3 year event horizon.    

Evolution is inevitable, if you fight it, you get Revolution, and that ain't pretty!

Meet Pete once in Mumbai, as the head hi performance coach, but it was brief, so I really con't comment on him.

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

On another note, got a really interesting PM about inertia and 49ers!   I know the answer, I just don't know how to explain it, give me a few hours to "refine my thoughts".

                  Gantt, as always, jB

      

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On 6/14/2019 at 5:56 PM, WGWarburton said:

 Hey Stanno... are you going to Kingston this summer?

Cheers,

               W.

Heya W - not this year ... Miss S is head down juggling school and a ton of training ahead of Aus nats / Oceana / Worlds next Oz summer ... looks to be a cracker of an event and many of her buds are heading over!!!

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I have always been an advocate for constantly modernizing the Laser Sailboat. 

My expertise is more in the area of the construction of the hull and deck and I have been an advocate fir improving that construction since my earliest involvement with Lasers

We also could radically improve the durability of the sails and spars without changing to plastic tubes.

I have not been convinced carbon can do the job of creating sufficient durability and consistency less expensively than aluminum. . 

1. Sail shape and design can be used to adjust the stress on the poles. 

2. Lowering the weight of the hull and deck would help SOME to remove some stresses in the rig. 

***+

Materials and process have been known to this advocate since the 1970s which could be used to create 100 pound laser like hulls and decks which would be more durable than the current 130 pound boat.

If we were to slightly modify the deck shape and incorporate some simple molded interior reinforcements, it may be possible to build an 80 pound Laser for less expense  than the current design.

The old heavy boats could still be used for most racing and sailing camps. 

If such  changes are ever made it will only take a short time to adjust our game . 

Summary: if we are going to even CONSIDER entirely new rigs, we should certainly modernize the entire toy

 

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Agreed Gouv. 

Everyone wants what it best for the class. 

For me, expanding the range of competitive crew weight is a big deal. I see that as a very healthy step forward for the class.

There is so much uncharted territory with the carbon rigs, and with improvements to alloy rigs which is a good idea - and there used to be discussion about it before carbon rigs were considered by anyone. Maybe the higher production numbers will have an impact not seen before by other classes.

---

Possible changes to the hull are good to consider too. Maybe that is where the future is for the Laser. I'm wondering how saving 30 pounds on the hull would affect the competitive crew weight range. A more durable hull is good.

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On 6/14/2019 at 6:09 AM, BruceH-NZ said:

Someone called Pete Conway (on FB)  made the following statement:

The aboves speaks against having the carbon rig, which in the form of the C5, is facing some resistance in Europe by those who sail the 4.7.

I think the referenced quote misses the point. A carbon mast can make the boat slightly easier to sail due to being lighter and maybe it will have better bend characteristics. But it should be possible to make a carbon mast that is almost identical in weight and bend characteristics to an aluminium mast if that is required. So while it might be a good idea to make use of carbon's potential for a lighter mast, it's not an unavoidable outcome and the characteristics of an aluminium mast can be retained if that is desired.

The biggest benefit is that a carbon mast will last much, much longer and so make ownership cheaper in the long run. If a single manufacturer was to make all carbon masts at say 2,000 per year for new boats and maybe another 2,000 per year as masts for the existing 200,000 boat fleet are replaced, they might even be cheaper than aluminium masts.

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On 6/15/2019 at 10:59 AM, JulianB said:

Gantt, re extra development, it's mechanical development as in making purpose designed mandrels and actually testing the stump (of the C8).

So there is this magic number of 2.77m.    ........................ If you are say 3m, then no std truck with the couriers, Emirates will take it,  but CX wont, BA wont, etc etc.

jB

 

So whilst the magic number may be 2.7 its dictated by the size of the lower hold container, which varies by plane type..

The pilots amongst us could probably add value here, but you can see from the table below, that its physically impossible to fit 2.7 into some plane types. Not withstanding that some planes also have one hold or so that doesn't take a container, but "loose" luggage.

 

Lower hold containers[2] volume in cu.ft (m3), dimensions in inches (cm)

type internal
volume height depth base
width overall
width width contour IATA Suitability LD3-45[3] 131 (3.7) 45 (114.3) 60.4 (153.4) 61.5 (156.2) 96 (243.8) Full double AKH A320 LD2 124 (3.5) 64 (162.6) 47 (119.4) 61.5 (156.2) Half single APE Boeing WB LD3 159 (4.5) 61.5 (156.2) 79 (200.7) AKE Airbus WB, Boeing WB, DC-10/MD-11, L-1011 LD1 175 (5.0) 92 (233.7) AKC Boeing WB, MD-11 LD4 195 (5.5) 96 (243.8) 96 (243.8) Full none AQP 767, 777, 787 LD8 (2×LD2) 245 (6.9) 125 (317.5) double AQF 767/787 LD11 256 (7.2) 125 (317.5) none ALP 747, 777, 787, DC-10/MD-11 PLA pallet[a] 250 (7.1) PLA 747, 777, 787 LD6 (2×LD3) 316 (8.9) 160 (406.4) double ALF 747/777/787, DC-10/MD-11 LD26 (P1P base) 470 (13.3) 88 (223.5) AAF 747/777/787, DC-10/MD-11 LD7 winged pallet 495 (14.0) P1P 747, 777, 787, DC-10/MD-11 LD7/P1P pallet[a] 379 (10.7) 125 (317.5) none P1P All Widebodies LD9 (P1P base) 381 (10.8) AAP Boeing WB, DC-10/MD-11 LD29 (P1P base) 510 (14.4) 186 (472.4) double AAU 747 LD39 (P6P base) 560 (15.9) 96 (243.8) AMU 747 P6P pallet[a] 407 (11.5)[c] 125 (317.5) none P6P 747, 767, 777, 787, DC-10, MD-11
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On 6/16/2019 at 2:09 AM, BruceH-NZ said:

 

Possible changes to the hull are good to consider too. Maybe that is where the future is for the Laser. I'm wondering how saving 30 pounds on the hull would affect the competitive crew weight range. A more durable hull is good.

Great ideas Gantt.

Hell, why not save 60 pounds on the hull? 

Perhaps have an open transom and center sheeting too?

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16 minutes ago, tillerman said:

Hell, why not save 60 pounds on the hull? 

Perhaps have an open transom and center sheeting too?

Pounds sterling? I'd definitely be into that. With a lighter hull, I'm not sure. So long as it increases the weight range of competitive sailor; resulted in a more durable hull - AND was introduced in a way that didn't negatively impact the class, then sure. (I'm not convinced it can. Maybe phased in with 2 lbs less each year for 30 years?).

I moved from a boat designed in the 1960s that had an open transom and centre sheeting (which in certain conditions planed upwind) - into the Laser. (I like the open transom).

For me, my preference is to be very conservative when making change. The original statement about what the Laser is - a one design which supports close racing - still holds true today. Change that puts the class at risk is only acceptable in my view if there is a gain for the sailors. The whole point of my creating this thread was to share Pete Conway's point which challenges the introduction of carbon. That I didn't agree with his points didn't matter. In my mind, there was a possibility that there was something to what he said that I had either missed or didn't understand.

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how is the C series boom with getting the mainsheet caught on the transom? Sure you learn to avoid that anyway, but its still a complication!

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On ‎6‎/‎17‎/‎2019 at 1:23 PM, mustang__1 said:

how is the C series boom with getting the mainsheet caught on the transom? Sure you learn to avoid that anyway, but its still a complication!

It seems to sit much higher so I bet the sheet doesn't snag.

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I’m gonna get shot down in flames here, don’t even sail Lasers, buy cheap laser, reinforce mast step, buy full rig setup Melges14 boom! Done. Call it a Haser! Hacked Laser hahahaha

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On 6/20/2019 at 1:32 AM, RobbieB said:

It seems to sit much higher so I bet the sheet doesn't snag.

No more block to block sailing uphill?

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On ‎6‎/‎22‎/‎2019 at 5:35 AM, BruceH-NZ said:

No more block to block sailing uphill?

Based on what I've seen I don't think so.  

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12 hours ago, RobbieB said:

Based on what I've seen I don't think so.  

Which got me wondering if the new rigs point as high if they don't pull the sheet in block to block?

Looking at the video footage there were no shots going upwind, though some were close. Maybe there are some other images? Any comment @JulianB ?

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So there is this un-written rule that luff-length = power.

There is no such rule WRT leach length, and my father used to say that 80% of the power [generated] happens in the from 10-20%, the back 3/4's of the wing is there to ensure the front 1/4 is doing the right thing.

The other issue with the std laser rig(s) is the CoE only gets to the right spot is you go block to block, so its more about balance that anything else.

Re pointing higher, I was not there when the C8 was sailed by the likes of Perry and Co, against other std Lasers, it was up on Port Stephen's year or 2 back, but the feed back "was not negative".   That was the flame rig.

 

What I have seen is the C5, being sailed by kids out of RSYS, and the C5 girl (12-13) simple sailed higher and did not slow down.

The 2 shots are 10 secs apart.   If you want more from the same day, got them, but same story.

It was late May 2018.

It's about 8 knt's what happen in 20 knt's is another story which I don't know.

 

IMG_6867.JPG

IMG_6871.JPG

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6 minutes ago, JulianB said:

The other issue with the std laser rig(s) is the CoE only gets to the right spot is you go block to block, so its more about balance that anything else.

Understood.

The lighter the conditions, the less relevant. 

In a moderate breeze, around the point of being overpowered (around 12-15 knots), I would expect the greatest difference (if there is one to be had). What were the conditions at Port Stephens?

Mostly it is the angle of the boom that has me perplexed. Each degree of angle the boom gets closer to the centreline translates into about a degree of highest pointing achieved, right? Less about VMG and more about pointing higher.

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2 hours ago, BruceH-NZ said:

. Each degree of angle the boom gets closer to the centreline translates into about a degree of highest pointing achieved, 

Only, I submit, if the sails are identical in every other respect. And every degree closer to the centreline also reduces power and increases drag. Pretty much every boat can be sailed higher than optimal vmg.

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The distance between the 2 grommets on a laser are almost exactly 1m apart. a Laser boom is 2.7m

So that equals, 10.49° which is very interesting.

99% of the best sheeting angle of most jibs and most up mains are set at 10°, sure more modern yachts may come into 7 or 8°.

But for a Cat rigged boat, 10° +/- 2° would seem to be about optimum.

A Laser probably operates at a AWA of mid to high 20°, say 27° (49er is 22°) so if you kick the boom out at 11° you have a operating AoA of 16° and that sounds about right.

You need a pretty full lower sail, mostly to steer to, where as a 49er jib which is operating at about 13° is much flatter entry

This 10-12° / Cat rigged boom angle is exactly what the Laser is with the C-Rig or the Std rig(s) use, so empirically, it's what has been found to work.

One would expect a A-class to be a whole lot finer 

Jim, BTW the more you pull the main closer to the CL the more power you have, but quite rightly the higher drag, there seems to be a optimum and that appears to be this 10-11° with the std rig.    What it will be with the C-Rig which should have lower drag only time will tell, but what is evident in the first picture, where the mainsheet is sprung is the the C-Rig can still power up at 13-14° and still out point a std rig.

Whole bunch of qualifications on this, and again, as I said, only time will tell, the biggest is the C-Rig is at-least 6kgs lighter and for these girls that's possible 10%.

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

Re Port Stephens, I simply don't know, but I believe they where all fully powered up.

Initially, with the Mk1 & 2 [C] rigs and Tom [Burton] and Gerard [West] the old rig out performed the C-Rig and yes, first thing they did was pull it down to the deck.

By the time we got to the Flame rig, the tables had turned, and downwind its another game.

 

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