Jonny, I agree that steel is a viable option for a heavy-displacement yacht with good ballast ratios, like yours (and mine).  A friend replaced his timber masts on a 28ft steel-hulled Spray in Asia more than a decade ago (Si Hai, junk schooner) and has had no issues.  He sourced them from China.  Paul Thompson in NZ has built a few tapered steel masts with success, including for La Chica, his 32ft Tahitiana design.  If you properly seal the ends, there should be little internal corrosion, and any external rust spots are easy to see and address.  Also, as any old Breton tunny fisherman could tell you (if there are any still alive), a bit of weight aloft eases the motion.  They used to hoist a heavy fisherman anchor up the mast a bit when hove to in a Biscay gale.

Anonymous wrote:

Jonny

That JR is based on a Johanna 65 master sail with AR = 1.10, so was quite quick to draw up.

Mast length.
The shown mast is 13.66m above wl. In addition there is 497mm down from the wl. to the cabin sole, so together that should be about 14.16m. Any more or less length at the bottom end depends on how you build the mast step.

Then there is the boom height.
The clew appears to sit about 76cm above deck. With the 22% mast balance, the clew will hit the guardrail unless you let it pass over it. Maybe you should consider lifting the boom 10-15cm to be on the safe side? Then the mast must be lengthened with the same amount...

Mast thickness.
I find it quite difficult to do a proper calculation of mast scantlings, as the boats grow much bigger than I am used to (Traveller’s disp. = 6441kg). It appears that the Traveller will need an aluminium mast with diameter between 25 and 28cm, and with wall thickness of 5-6mm, depending on the alloy grade available.

Frankly, the best tip I can give is to ask David Tyler. His Tystie was in the same displacement league, so the mast which worked for him, is likely to work for your boat as well.

Good luck.
Arne

(Arne's Sketches section 8-23)

Thanks Arne. Those mast dimensions you mention are very close to what I was sort "guesstimating" Hopefully David will see this and comment as well , or I'll send him a message at some point. First things first with this boat will be:

To get her engine running 

and

To make a few calls and see if the tapered mast that I know about is still available.

fingers and toes crossed on that one!

I'm already living aboard , and she is quite the well built and good looking little ship. She'll be even better with a junk rig.

best.

Jonny

That JR is based on a Johanna 65 master sail with AR = 1.10, so was quite quick to draw up.

Mast length.
The shown mast is 13.66m above wl. In addition there is 497mm down from the wl. to the cabin sole, so together that should be about 14.16m. Any more or less length at the bottom end depends on how you build the mast step.

Then there is the boom height.
The clew appears to sit about 76cm above deck. With the 22% mast balance, the clew will hit the guardrail unless you let it pass over it. Maybe you should consider lifting the boom 10-15cm to be on the safe side? Then the mast must be lengthened with the same amount...

Mast thickness.
I find it quite difficult to do a proper calculation of mast scantlings, as the boats grow much bigger than I am used to (Traveller’s disp. = 6441kg). It appears that the Traveller will need an aluminium mast with diameter between 25 and 28cm, and with wall thickness of 5-6mm, depending on the alloy grade available.

Frankly, the best tip I can give is to ask David Tyler. His Tystie was in the same displacement league, so the mast which worked for him, is likely to work for your boat as well.

Good luck.
Arne

(Arne's Sketches section 8-23)

Arne Kverneland wrote:

The length of the trunk cabin seems to vary a bit between drawings.
Now I have drawn a rig with the mast about 150mm forward of the bulkhead forward of the loo. That mast could even be moved 100mm or so to the port side.
Have a look.
Arne

( See Arne's sketches, section 8 - 22)

The length of the trunk cabin seems to vary a bit between drawings.
Now I have drawn a rig with the mast about 150mm forward of the bulkhead forward of the loo. That mast could even be moved 100mm or so to the port side.
Have a look.
Arne

( See Arne's sketches, section 8 - 22)