Trailerable Multihulls

[JCD]

Hello RWatson,

Thanks for the chime...

Originally Posted by rwatson

Re mast raising - have you tried using another spar to act as a lever.
example at
http://www.macgregor26.com/mast_rais...st_raising.htm
they use 'baby stays' to keep the mast in alignment during raising

I have looked at many different kinds of folding systems. Probably not all. The reason I'm trying to figure out the geometry for the fold and swing is because it takes the person away from being close to the mast or beneath it when it is being deployed and folded. If I decided to go to this type of set up because I couldn't get the other to work, then I would just use the boom which might be the longest lever I can use without storing it.

Thanks again,

J

[Meanz Beanz]

The Seawind 24 drops the mast forward with the boom as a lever, using the main sheet, in its normal position.

[rwatson]

I think the mast may be a nice surprise.
30ft of aluminium mast, even on a big cat is not all that amazing.
I bet one person could quite easily lift one end of it to head height with 2 arms.

A 30 ft Nacra mast is only around 160 kilos.

With a bit of creativity, the boom could douple as a lever, and you can attach baby stays that are fastened along the rotating axis of the mast, to about half way up the mast to stop it slipping sideways.

Good luck with it all.

[Meanz Beanz]

The SW24 has 10.67m or 35' of mast. Its heavy for one person, two can do it with ease, one person, well setup, can handle it but you would not want a situation that could become uncontrollable i.e on the water, wakes, waves etc.

[JCD]

Originally Posted by Meanz Beanz

The Seawind 24 drops the mast forward with the boom as a lever, using the main sheet, in its normal position.

Hello Meanz,

I agree. Very simple and effective. I might try to set it up as a redundant.

J

[JCD]

Hawdy RWatson,

Originally Posted by rwatson

I think the mast may be a nice surprise.
30ft of aluminium mast, even on a big cat is not all that amazing.
I bet one person could quite easily lift one end of it to head height with 2 arms.
A 30 ft Nacra mast is only around 160 kilos.
With a bit of creativity, the boom could douple as a lever, and you can attach baby stays that are fastened along the rotating axis of the mast, to about half way up the mast to stop it slipping sideways.
Good luck with it all.

Yes, one person could lift it and with enough forethought and time, probably execute the entire knockdown. They would have to be fit, heavier than most, and also beneath it. I also suspect that the "every weekend" sailor will be significantly discouraged if it is too complex or difficult and doing it every weekend requires significant mental will.

The baby stays are a must. There is noooo way that the mast must be allowed to gather any kind of momentum. I was thinking that the shrouds leading aft will lose tension as the mast is shipped, so there has to be something else to hold her there. A set of outboard lowers and in line with the mast is also an option dependent on my paranoia, well, on my resolve to make it exceed a true Category B or as close as possible to Category A as I can get it without hurting her performance.

Thanks for the wishes mate...a little luck right now would be a good thing.

Update: Reworking the mast/beam scantling and the hull scantlings. It doesn't look like much weight reduction will be possible. It all comes out pretty close. Also, I am considering making it a 3 beam'r.

Thanks
J

[JCD]

Originally Posted by Meanz Beanz

The SW24 has 10.67m or 35' of mast. Its heavy for one person, two can do it with ease, one person, well setup, can handle it but you would not want a situation that could become uncontrollable i.e on the water, wakes, waves etc.

Ahemm... The Operating Manual will clearly state that shipping the mast is to be done on the hard. A crane is also an option, but it's cheaper on your own trailer.

Pull up, tie her off, pull out, drop the mast, fold and drive away. Thirty minutes...maybe an hour if you take a couple of "let me have a cold one" brakes.

J

[Meanz Beanz]

I don't have baby stays but the 8mm spectra halyards serve the purpose well, very little weight is taken on them in the whole process. It takes 30 mins to setup and closer to 30 seconds to drop. The setup time could be reduced with dedicated clip on lines to stabilize the boom and mast spanner. A dedicated strong point to take the main sheet (loading up the traveller is a risk!) would also speed things up removing the need to tie around the rear beam. At a guess being well setup could see it being a 15 to 20 min operation.

[rwatson]

Yes - all excellent sugestions.

Lowering the mast to the bow means you will have to undo both side stays, which can be a real pain. Might be better to lower the mast to the stern. This also works better when you have a self furling jib, because the furled jib just lays down along the mast as it is lowered. Not so neat a solution when you lower towards the bow.

One trick I found is to run a stretch cord to pull the two main stays together, so that as the mast lowers, the two stays get pulled together as they loosen.

This is to keep the stays from getting snagged on other gear, which would often mean the mast lowering had to be interupted to clear the 'snag'

I assume that as its a smallish cat that the mast is a rotating one. You can build a mini tabernacle that allows normal rotation when sailing, but has the facility for a pin to be inserted for the mast to pivot on when being lowered, and prevent the mast rotating.

The spectra temporary baby stays are a perfect solution.

[waynemarlow]

From experiance of raising and lowering a mast using the side stays as security is a bit risky, as the mast goes up / lower there is sufficient slack in the side stay ( the stay mounting point is behind the mast step and if you move the stays foward there is nothing to stop it over rotating ) to allow the mast to move quite a significant distance sideways particularly at the most vunerable point as the mast goes horizontal.

As you have a cat have you thought about using a winch rope from each bow and thus it would be a triangulated pull, you could have each pulling stay coming back to a common winch.

[Meanz Beanz]

On the SW24 the setup requires the sidestays to be moved to anchor points on the main beam to aviod that issue. Like I said before if you have strong halyards its easier just to use them. I would not try it with sidestays in place unless it was a very light mast, beside the fact that you can't when lowering forward, but still if going backward. By that I mean without some extra support/guide for the mast.

[Richard Atkin]

Hello J,

Why not just copy the SW24?

Do you mind the energy required to concentrate when everything goes right? Or is it the energy required when you lose concentration? Just relax and make sure you are mentally focused before you begin....and it should be fine every time. You don't need a portable fool-proof crane.

Safety is 99% skipper and 1% boat design.

You have been given more profound insight from Lord Richard.
(be warned though - I have never raised or lowered a mast that can't be balanced on my head).

[JCD]

Originally Posted by Meanz Beanz

I don't have baby stays but the 8mm spectra halyards serve the purpose well, very little weight is taken on them in the whole process. It takes 30 mins to setup and closer to 30 seconds to drop. The setup time could be reduced with dedicated clip on lines to stabilize the boom and mast spanner. A dedicated strong point to take the main sheet (loading up the traveller is a risk!) would also speed things up removing the need to tie around the rear beam. At a guess being well setup could see it being a 15 to 20 min operation.

Hello Meanz,

I don't think we can beat the 30 seconds to drop it unless we have a couple of chainsaws, but less than an hour is good. We’re shooting for 1/2.


Thanks for chiming in with all the info. I'm listening.

J

[JCD]

Hello RWatson,

Thanks for sharing this info.

Originally Posted by rwatson

Lowering the mast to the bow means you will have to undo both side stays, which can be a real pain. Might be better to lower the mast to the stern. This also works better when you have a self furling jib, because the furled jib just lays down along the mast as it is lowered. Not so neat a solution when you lower towards the bow.

The self furling is a go and will definitely look at folding the mast aft. I would also like to see a nice roller reef boom for the full slatted main. Working.

Originally Posted by rwatson

I assume that as its a smallish cat that the mast is a rotating one. You can build a mini tabernacle that allows normal rotation when sailing, but has the facility for a pin to be inserted for the mast to pivot on when being lowered, and prevent the mast rotating.

You won’t believe me but I swear that this was just communicated as an idea by my partner. Described a little different but basically the same. It is also practical for a concept rig.

I wanted to thank all of you for all this information. I’m kind of glad to see this thread kicking a little. The rig is just not my strength.

J

[Meanz Beanz]

1/2 hour for the complete process is easily achievable. Don't overlook some form of restraint if the mast rotates, that one can catch first timers out. If you have a pelican striker, and you go with a fwd drop, allowing for some form of cradle to catch or support the mast is a good idea.