wood mast, boom & gaff

[herve]

dear all,
I am building a 4,5m dayboat gaff rigged.

Mast will be 4,3m
Boom will be 3m
Gaff will be 2,75m

I think that mast diameter will be 10cm to 8cm on top.

What about boom diameter and gaff diameter ? What do u suggest ?

thanks,

herve

[Venchka]

What is the area of the main sail and jib? The plans do not include spar dimensions? Is the mast stayed or unstayed? Ok, that's probaly a silly question. Gaff rigs need stays, correct?

Turning to sets of plans I keep in the office, your mast diameter is too large. An 80mm tapering to 60mm mast 5.15 m long with 3 stays will serve for a main sail of 9.29 sq. m and a jib of 3.7 sq. m. The shape and size of the main sail will determine the length and diameter of the boom and gaff. Both spars will be small at the end attached to the mast, swell slightly at the middle and smallest at the aft/upper end. Something like 50-60-40mm for the boom and 40-50-30mm for the gaff. All of these examples are for larger sails on a larger boat. The actual dimensions for your boat might be smaller.

I hope this helps.

Wayne
In the Swamp. :D

[Wayne Jeffers]

Originally posted by Venchka:
. . .Turning to sets of plans I keep in the office, . . .Wayne,

WTF are you doing in the office on a holiday weekend?

You should be out sailing! tongue.gif

Tell the boss I said it was okay.

Wayne

[Venchka]

Bad news. Memorial Day ain't no Hollerday in the earl patch. At least not for small contractors. Besides, we're up to our bums in nasty weather. Seriously nasty weather. Boat breaking nasty weather.

One of these days I will get even. You will be renovating AGAIN or building a boat and I will be sailing. So there! :D

Wayne
In the Swamp. :D

[herve]

Thanks a lot Wayne. In fact, I do not have any design as it a restoration project. The boat, originally, was a marconi sloop with 10,5 sq.m sale area (jibe 3 sq.m and main 7,5 sq.m).

Mast is broken etc ...and I want a small mast to be same size of boat for trailer and storage.

I plan to built a gaff rigged mast, stayed of course. Jib will be 3 sq.m (I have to check with sail manufacturor if the original jib is OK). The new main gaff sail will be 10 sq.m, in order to have more sail area than original marconi design.

Your information and analysis are OK, thanks again.

Hervé (frenchy amateur builder)