Because I know better than the designer... right...

jbarros · #1 (**permalink**) 10-02-2003

ok kids... So....

I''ve found a great design, but I disagree with the sailplan. (IOR High aspect, small main, huge headsails) How incredibly ignorant of me would it be to try to move the mast forward, increase the size of the main, and decrease the size of the headsail?

What tomes would I need to read to do this properly?

Or is it just a REALY bad idea?

-- James

tsenator · #2 (**permalink**) 10-02-2003

How would you move the mast forward? What if its keel stepped? What if its deck stepped? You''d still have to move the pedestal and reinforce heavily below. What about all the side shround chainplates they would have to move to?

Of course I haven''t even mentioned the differnce in the balance of the boat, because a good sailboat design is predicated on the Sailplan and its relationship to the keel, you might be introducing a huge ammount of weather helm and the boat would not be as nice to sail and every helmsman would not like to steer the boat. It might work ok, but the dynamics, especially with a breeze might not be desirable. I think before I did all that major change I would first try and get a very large roach put on the main and (maybe) even consider a longer boom to see how it would handle first. I know the mainsail would probably be bigger than the backstay would dictate, but there are inventive ways a rigger can help with that.

I understand what you are trying to do, I too would like a larger main and perhaps a 7/8 fractional rig. But my sailboat is so well balanced as it is and has such a nice feel, I''d be screwing things up. I think it would be better to find the sailplan you want on another boat.

Jeff_H · #3 (**permalink**) 10-02-2003

Boats are designed as systems. You can''t simply change just one part. If you move the mast forward there may not be adequate displacement forward to prevent the boat from sitting bow down without changing some other aspect of the design. You might be able to move the ballast aft a little, but if the boat is to remain ballanced the keel foil would by necessity move forward because the mast moved forward.

As has been mentioned, the structure and chainplates will need to be moved when the mast is moved and that will result in a different interior layout and so on and so forth, so that quickly this becomes a very different boat than the one that you started with.

Jeff

sailingfool · #4 (**permalink**) 10-02-2003

To do this properly you need only pay a boat designer a suitable fee to alter the design to provide the rig that you want. I would think $5-10K might get the task done properly.
If this charge seems rich, you may not be a good candidate for building a custom boat, because this amount would be barely a deposit.

fourknots · #5 (**permalink**) 10-03-2003

When I first met Nigel Calder, he had moved the mast a few inches forward in his Ingred 38 to try to get her to balance better. He''s one of the few people I know that could put the energy into a project like that with all the details it involves. When he was done (it was a HUGE amount of work), he still wasn''t happy.

There seems to be as much art as science in something like that and unless you really know what you''re doing, you''re likely to be dissapointed by the results.

aflanigan · #6 (**permalink**) 10-03-2003

IF you have sailed this boat and found that she is unbalanced (lee helm),
try a smaller jib and finds this reduces lee helm, you could possibly
consider tweaking the boat towards your goal of bigger main smaller
headsail without radical alteration such as restepping the mast by adding a
high roach main and small working jib, and if that doesn''t give you too
much weather helm, perhaps consider converting a masthead rig to
fractional to further reduce the relative area of the headsail. Even this will
involve some major work (like recutting or replacing the jib, finding or
making a battened main to make use of the full roach, learning to do
without a topping lift which would get in the way of your new main, etc.).
As other posters have pointed out, if the boat was properly designed, these
modest changes would likely disturb the balance of the boat for the worse.

Famed sailor Joshua Slocum, if I remember correctly, took a boat down to
the bare hull and rebuilt it from there to change the rig, a job which took him many months, and that''s probably
what you would have to do with almost any design to do the job right. You
might as well just build a boat from scratch.

Allen Flanigan
Alexandria, V

Sailmc · #7 (**permalink**) 10-03-2003

Have you even sailed this boat? How do you know just from the sail plan that it was designed inncorrectly and will not be balanced. There are many non structural things that affect balance. Mast rake and tune and sail trim will have dramatic results. Jeff_H is absolutely right that the boat was designed as a system.I doubt this boat is that badly designed that a few tweaks as well as some savy sailing wouldn''t get her to behave. Personally I have never seen or sailed a boat with lee helm. Weather helm is by far the more common problem.

sailingfool · #8 (**permalink**) 10-03-2003

Sailmc,

If you have missed the tread of this discussion, it involves armchair sailing where the only thing likely to get wet is the dream.

Jeff_H · #9 (**permalink**) 10-03-2003

I don''t think that is a fair statement. Over the period of time that James has been on this board, he has been asking questions that seemed aimed atlearning about sailing and has been trying to sort through the various design approaches for a small cruising boat. He has kicked around a number of low cost options including possibly building a boat from scratch which seemed to be the genesis of this line of discussion.

Jeff

jbarros · #10 (**permalink**) 10-05-2003

I appologize for the confusion. I was looking at this from the basis of building a boat, and possibly talking to the designer about a diffrent sail plan which would allow for more sailng in a variety of (rough) weather to happen without leaving the cocpit. If in deed it involves completley redesigning the boat, then it would be cost prohibitave, as off the shelf plans + the materials etc are about what I can afford (given the obligatory 20% over that is assumed) however, if it just involved moving the mast, then that would be completley feasable on a new project. However, this doesnt apear to be the case.

Thanks for all the answers

-- James