I-14 B6

[Phil Alderson]

What do you think of this new design 14 from Paul Bieker
http://www.biekerboats.com/Bieker_Boats/I-14_B6.html

The shape of the bow is interesting, and getting rid of the top spreaders would mean a move away from prebent rigs

[Neil C.]

I thought this was an interesting comment. It's a bit different from the current ethos in our class:

"Over the years, I have had a lot of experience watching fuller bows outperform finer bows in boats that have a lot of power for their length, the most obvious example being the IACC yachts.  It may be startling, but a 14 has approximately the same displacement to length ratio as an IACC yacht, so I think it is a fair guess to think that they would benefit from a fuller entry."

[john_hamilton]

The rig will break. If it doesn't then the mid mast will look horrendous anyway with reversed bend :/

[JimC]

The rig will break. If it doesn't then the mid mast will look horrendous anyway with reversed bend

Paul is pretty smart, I wouldn't bet he's wrong even if if its not something I'd try. Halo's original tin stick (which was something of a treetrunk I admit) had the kite hoist equidistant between hounds and mast tip and with forward angled spreaders the rigid prod to the gooseneck was the only thing stopping it inverting, yet it never showed any signs of doing so... He says he's got aft raked spreaders so it should be possible to keep the mast bending the right way. I've just had a quick look through old pics of 18s and Qs and can't spot what the staying arrangements were, but they certainly had masthead kites before prebent topmasts. The key will be not to dump the main too far. I loathe all the knitting round two spreader rigs, but I'm not smart enough to think of an alternative.

[Ben Howett]

I was very amused when this appeared on SA... the direction of the bow design fits very closely with some of the thoughts ive been having since seeing the new crop of boats in the flesh at largo for the first time. I don't thing its a huge departure from the current class thinking but its something that makes a lot of sense to me. Think of it a little like a dreadnought bow without compromising on waterline length.

Im more interested in the rig design - I don't agree with the above comment at all though. If its been engineered correctly (and there's no reason to think someone of Biekers stature would get this too far off) theres no reason to think it will fall apart or that the bend characteristic's will be any worse that the many other single spreader rigs on the water. The interesting thing will be whether the tradeoffs required to make it work will be too much of a compromise. Im not convinced but hes not the only new 14 to be taking this route.

[Phil Alderson]

There are a few interesting things about the rig change.

In tha ali mast days there were a few 14's with masthead kites and no top spreaders.

One of the arguments towards using the prebent rigs is that the topmast is supported sideways keeping the power in the rig, and also when you bend the mast enough with the cunningham, it all flattens off, and you loose the side suport, and dump power.

With the un-supported rig you do not get the side support, and potentially less overall bend in the mast if you have a shorter stronger top section. How is this going to change the sail design and responce over the wind range, how will it affect the fat top rigs.

[john_hamilton]

I hadn't thought of using The main as a kind of backstay.

[Will_Lee]

It is all very interesting.

The bow thing: People have been round the houses with this before. What happens at the cutwater is unknown to me, but I do know that  bows faired in to a point beyond the bow and then rounded off has been common (on and off) in Marblehead and 36 rater models for a long time. Additional drag on pitch down is down to the entry angle, and if the cutwater is really draggy anyway then you could get a finer angle by doing this. Certainly our 26 foot Wharram catamaran would throw water several metres forwards from the cutwater when travelling at speed. More prosaically, it is probably easier to make something really strong and light with the bow rounded off a bit.

The rig thing: I really like it when things change a bit and suddenly the pressures are there to reverse several design cycles. T foils and other things make the boats go faster upwind, high modulus carbon means the staying does not need to be so thorough. This means having no uppers gains you more, and loses you less. Is it below maximum height?

[pratn0]

Using the main as a backstay is the norm on the F18 cats like the tiger.

At the worlds in Cape Town in 2008,  one boat broke his rig buy dumping the main sheet instead of the traveller in a big gust....  

bit harder to set up and control on a skiff.

[phil_kirk]

I would think that the no uppers developement would leead to a stiffer to section with more weight i the mast tube.

I would expect the load path from the top of the mast would go along the top of the sail and down the leach.  All other parts of the sail are curved.   Also on a broad reach even with the boom over the quarter the head of the main will be off the centreline. Couple this with the head of the kite pulling forwards and to leeward only the mast tube stifnes is resisting the sideways component of both forces.

[Stuberry]

I understand that the trap wires are going to be attached at the top of the mast downwinf to help support the kite.

[phil_kirk]

that's a sensible idea. In the same way that the 505's do I suppose.

It would also reduce the forward pull of the trapeeze wire that trys to use the helm as a swing ball.

[Stuberry]

I wonder if the helm will get a feel for the power in the kite through his trapeze???

[Neil C.]

I wonder if the helm will get a feel for the power in the kite through his trapeze???

Big gust = catapult? Could be fun!

[pratn0]

more fiddly ropes to changed the Trap position upwind or down wind.

Don't want the mast top trap up wind. as would bend the top the wrong way.  I know the 505 had a system that when the kite was up it would release the tweakers so the trap position moved hight up the mast then up wind they are pulled in to the hounds.

Sounds like lots of adjusting of trap hight.. when changing legs.