Size (ie length) of boom

[Jabamusic]

I'm aware of having very limited outhaul possibility on my main owing to the length of boom compared to length of foot of sail.

Upon closer inspection, it would appear that at some stage the boom has been replaced.

What i was wondering is whether there are recommended dimensions for boom versus mast ratios which will obviously have to take into account sail sizes as well?

Thoughts?

Thnaks

 

[Tranona]

Boom length is determined by the length of the foot of the mainsail, not the height of the mast. The ratio boom/mast varies according to the aspect ratio of the mainsail. clearly there needs to be extra boom length compared with sail foot to provide adjustment of the foot and possibly sheeting point for mainsheet.

 

[Cloven]

Can you identify the make of the mast. If so then you may be able to contact the makers with model of the boat and find out what the original spec was.

For example Z-spars do a very comprehensive on-line list of the boats they have supplied:

http://www.zsparsuk.com/crawler.htm

 

[charles_reed]

I'm aware of having very limited outhaul possibility on my main owing to the length of boom compared to length of foot of sail.

Upon closer inspection, it would appear that at some stage the boom has been replaced.

What i was wondering is whether there are recommended dimensions for boom versus mast ratios which will obviously have to take into account sail sizes as well?

Thoughts?

Thnaks

I'd suspect it's more likely to be the wrong length foot - on my first 3 boats the boom was between 4-8% longer than the foot of the sail.
As regards the boom/mast ratios that is highly variable.

 

[lw395]

How much too short is it?
There have been many cunning arrangements of outhauls to get the leach of the main right out to the end of the boom or even a little beyond it.
The very ends of the boom are not under huge bending loads, it may be possible to gain an inch or so at each end.

 

[merlin3688]

If we knew the type of boat you had we could tell you what the length needs to, this is a good site for finding out the I, J, P and E (E being the sail foot measurement.
http://sailboatdata.com/

 

[William_H]

Boom length

Clearly the boom is too short or the sail foot is too long.
There are a few trick that may give you a centimetre or two more outhaul. Every bit helps on a smaller boat especially.
Do you have a shackle on the clew of the sail? This can be eliminated. I use a piece of rope (spectra) running through the clew eyelet from a fixed point on the end of the boom that then goes through a pulley set in the boom eventually down to the halyard winches.
If you just use a lanyard lashing the clew to a saddle at the end of the boom is the saddle attachment actually at the end?
Is the tack of the sail right forward against the mast? The attachment should give a straight line up the luff with no strain on the bolt rope or slugs.
Can the gooseneck fitting be pulled out of the boom a little to make the boom longer?
If all the above fail then you can fit a piece of Ali tubing of suitable size inside the boom to extend at the end. Remember there will be significant load on the end of the extension pulling upward taking the strain of the clew and ultimately the load of the main sheet. good luck olewill

 

[PhillM]

Might be cheaper and easier to get the sail recut to be a better fit?