Anonymous wrote:

Hi Jim,

We converted our ANNIE in 2018 (a 30' Cornish Crabber, now for sale with her gaff rig soon to be re-fitted). She was transformed and we loved the confidence that the rig gave us. However 50sqm plus is quite a thing to handle even in JR form, so I would encourage anyone thinking of this size of rig to try to find a similar one to sail first. Like you, we wanted to keep the accommodation and deck hatches as much in place as poss, but ended up moving the mast forward nearly 4 feet which made her a real cat-boat though the balance turned out to be perfect to my eternal relief and joy. Thanks to Arne in that respect - I followed his instructions for finding the right place for the mast to the letter! So her mast was in the eyes of the ship, wrecking the spacious head compartment - which was an excessive luxury!

I made the solid D fir mast myself (I'm a sawmiller) and, on a 6ton boat the (estimated) 190kg stick gave her a lovely slow roll, so my advice would be you don't necessarily want to make a super-light mast on such a vessel. Too light a mast may give her a sharp motion? Incidentally, our 5.9m battens were ali tube, as was the yard. The whole bundle was a big lift for 2.

She sailed like a dream!

It's a great thing you're planning. Good luck!

Pol.

Hi Pol, thank you for that reply, very informative! Your Annie does look good in the photo. 

I agree with having a heavy mast. Her present one is and she has a lovely motion. The construction method I am thinking about is not for lightness but strength. I intend to keep building up the layers of glass and carbon untill it is a similar weight or a bit more than my current mast. I imagine the finished mast will be very stiff, is that a problem do you think? I was thinking of carbon battons like Ming Ming 2. He described his sail as being virtually flat at the top and then each lower panel has gradually increased  camber which sounds interesting. Does anyone have any views on his lower two panels being removable. Seems sensible as easier to make at home and they could be removed in areas with strong wind.

What are your mast dimensions and sail area please. 

Thanks, Jim 

Anonymous wrote:

Jim,

now I tried my hand on it, using a standard Johanna style sail with the yard angle lowered to 60°.  The resulting sail in yellow lines is the result.
My guess is that the original JR (retraced in black) should work just as well as the one I drew up, so all I can say is good luck!

Cheers,
Arne

PS: The full size drawing is in my album, Arne’s sketches Section 7, photo 13.

Thank you Arne for spending the time to draw this, I like it! Possibly I should place the mast more towards the bow but for structural and access reasons I have placed it aft of the fore hatch, which is why I've drawn a taller and narrower sail that projects in front of the mast a bit more than normal to compensate.

I've explored using a suitabley strong existing aluminium pole for a mast but drawn a blank. I am now nearly decided on building a thin walled (22mm) Douglas fir mast, then wrapping glass tape around and and around to the truck. Then carbon tape layed side by side all the way up longitudinally which should give good torsional strength, then repeat glass then carbon. Perhaps 5 glass and 4 carbon plus glass taping the inside. Perhaps aiming for a walk thickness of 18 mm. If it's convenient maybe vacuum bagging each layer. The above is a not very educated guess but I think the principle should work. I was thinking to carry on taping till too strong people could only just lift the spar. My current rig is heavy and she is slightly down at the stern since fitting a 36 hp buhk so a heavyish mast will be ok. I would very much appreciate your and any one else's thoughts on the prospective construction.

At the moment the planets are aligned as I have someone who is interested in buying my entire rig, I can use space in a mates workshop this summer and a boatbuilding friend is going to give me a hand with the build. All the best Jim

Jim,

now I tried my hand on it, using a standard Johanna style sail with the yard angle lowered to 60°.  The resulting sail in yellow lines is the result.
My guess is that the original JR (retraced in black) should work just as well as the one I drew up, so all I can say is good luck!

Cheers,
Arne

PS: The full size drawing is in my album, Arne’s sketches Section 7, photo 13.

I hope this is the right area to post some initial questions. I designed and built Atlas as a gaff cutter 25 years ago in Tasmania and she is of traditional timber construction. I am now getting older and am seriously considering converting her to a single masted Junk for simplicity. I've drawn an initial rig that has a 43 foot mast (6 foot bury) with a flat sail about 550 square feet (please see attached photo). I would like to sail back to Australia so would like a bullet proof mast with some reserve. I would rather not a wooden mast but perhaps an aluminium one if possible. I imagine this rig might be at the outer limits as regards weight. I look forward to hearing member's thoughts. Thanks, Jim