Building Shesha, a Hunter Valley GIS, Australia

[SimonLew]

That's a slick throat attachment idea, Ian. What happens at the peak? I assume you want some tension preset adjustment there.

As to leaning planks, I love it, wanna see video of the carnage.

[woodeneye]

Hi Ian,
Yes, I think your block with grooves will work. Good idea!. As long as the luff tension is prevented from affecting the tension along the yard, that is the aim. Otherwise it's very hard to set the sail correctly. By the way, great drawing!

Are you thinking that a single sheet of 6mm ply with the Paulownia edge strips (capped with hardwood) will provide enough stiffening for the plank? Wow, that would be a radical and light solution if it works! Much easier to make as well.

Simon,
I just have a clam cleat so the peak can be tensioned. If conditions change during a race, there isn't much you can do to adjust it though, unless you have your halliard running back to the cockpit so you can drop the sail. However, where I sail, if we still have light conditions after lunch at this time of year we can usually be assured that a sea breeze will fill in at about 3pm, so I take a punt on this before heading out to the start line. So far it's worked!

[woodeneye]

As to leaning planks, I love it, wanna see video of the carnage.

I trialled a small waterproof "helmet video cam" last w/e. It's a cheapie bought off eVilBay. The end result was not very good as my head was in constant motion and the movement was too fast. Watching the video made me seasick!

I then tried mounting on the gunwale. This was much better in terms of the video quality, but the curve of the gunwale meant that the video was a lot of gunwale and sky, with the odd Nacra or A Class Cat slashing by! The camera doesn't have a screen to compose the shot, so it's a bit of trial and error. For this w/e I'll mount it on a short vertical piece of timber or dowell fixed above the gunwale. This will allow me to move the camera around a bit as well. Finding a place for it that will not get caught up with tillers and sheets isn't easy.

Anyway, I'll see if I can edit out a chunk of the vid and post it here (it's 2gb!). There is a part where I nearly capsize while gybing that is interesting, and another where I'm calling for mark room on a 470 and the 470 gets out of shape and very nearly capsizes on top of me.

[Boatmik]

hmmm .... sounds like you need a video of highlights!

MIK

[IanHowick]

Hi Ian,

Are you thinking that a single sheet of 6mm ply with the Paulownia edge strips (capped with hardwood) will provide enough stiffening for the plank? Wow, that would be a radical and light solution if it works! Much easier to make as well.

Yes, I'm thinking a single sheet of 6mm ply, stiffened up along either edge by a structure similar to the GIS gunwale.

Say a strip of 8x50mm hardwood laid flat along the top of each edge of the ply, 50x50x50 mm paulownia blocks as spacers along the bottom of the edges with a 12x50 mm strip of hardwood (tassie oak/vic ash) below that.

Easy to set it in a curve when you're laminating it up, though if you left it flat it could go in the boat lengthways down the middle and double as two rowing seats if you were raiding and wanted to row two up. Something for Joost for his next Raid Caledonia!

I just had a play in the garden with a couple of 100x50mm pieces of pine, my feeling was a beam of one piece of 100x50 pine cantilevered out one metre from the edge wouldn't be quite strong enough, two side by side would be plenty, so I'll work out the structure to be about the same stiffness as a 200x50 piece of pine but as light as possible. (Try yourself if you get the chance, see if you agree that you'd be happy hiking out on a plank made of two 100x50 mm pieces of pine laid side by side)

Will try to draw a picture of what I'm thinking when I get a chance.

Ian

[IanHowick]

That's a slick throat attachment idea, Ian. What happens at the peak? I assume you want some tension preset adjustment there.

As to leaning planks, I love it, wanna see video of the carnage.

Peak end attachment will he a 'sock' made out of nylon (or polyester) climbing tape or similar that fits over the end of the yard, 3mm spectra attached to that that loops down through the eyelet in the peak of the sail. I'll also have a think about using tape and a friction buckle / some velcro to give quick and easy adjustment of head tension.

Ian

[woodeneye]

Hi Ian

Back online! Have just changed internet provider and phone company.

Downhaul: The attachment point on the boom is 40mm aft of the tack.

Vang: The attachment point on the boom is 800mm aft of the tack.

[IanHowick]

Thank for the measurements on the boom, Bruce.

I have a couple of ideas as to how to do a lightweight leaning plank,but I think the best thing initially would be just to get a couple of three and a bit metre long 100x50 s and lash them across the gunwales (or try a single 150 or 200x50 plank) and get out on the water and see if the concept works first. You'd needs to sort out bevelled spacers on the gunwale so the force is distributed and doesn't all end up on the inwale side, get someone to bounce on it with the boat tied on the trailer first while you watch to see it's not causing excessive strain on the gunwale structure or ply sides.

I'm likewise looking forward to a video of the carnage!

Ian

[woodeneye]

Well, I had carnage today! We had 20, gusting 30 kts, and huge waves. Have just verified the windspeed from the RAAF base alongside the dam, as there was a lot of conjecture about the accuracy of the club's wind meter which seemed to me to be understating the wind speed and wasn't recording the big gusts at all. Sailors are very good at estimating wind speeds!

I had the GIS out this morning and had the whole dam to myself due to the blustery North Wester which brings with it really big waves. At times it was raining too, not that it mattered due to all the spray. All I could do was reach up and down as it was way too rough to try beating or running. As it was, it was a very wet ride with plenty of spray coming into the boat, and a lot of creaking and groaning going on with the rigging. I had the video camera strapped on but disappointingly there is nothing on the card, so it didn't work. Too bad, because I would have had some hairy rides on record and even took a swim close to the shore on the run home! (Capsized to windward)

My bendy boom has finally broken completely in two, so I had to load the boat back up on it's trailer. After much deliberation the race committee decided a race would be sailed, so I rigged up a club Laser Radial, which is an older boat but with a brand new sail. Even though mid summer here, I needed my wetsuit, booties and heavy spray jacket. As most of you will know the Laser is a very wet boat to sail in big waves, and it was quite chilly with the wind factor. With some of the fleet swimming before the race had even started, they wisely abandoned the race, so some of us just stayed out for a bit and had a blat. I reckon I would have done OK in a race as the other Lasers had full rigs. That's if my abs could have lasted the distance, which was probably unlikely! The radial rig seemed to be the best choice in those conditions, and I was keeping up with the full rigs on some awesome screaming reaches. It was huge fun. However, if we had raced I was not relishing the runs, and almost certainly I think I would have dunked it, as Lasers have a bit of notoriety on that point of sailing and this was my first sail in a Laser!

Oh well, with two weeks off due to the holidays, I have plenty of time to make that new boom.

[robhosailor]

We had 20, gusting 30 kts, and huge waves./.../
My bendy boom has finally broken completely in two

Sorry for it, but 20-30 knots is really big wind for small flat bottomed boats...

Taken reef on your mainsail were?

[woodeneye]

Sorry for it, but 20-30 knots is really big wind for small flat bottomed boats...

Taken reef on your mainsail were?

No Robert, I don't like to reef my sail

[robhosailor]

No Robert, I don't like to reef my sail

And it is a cause of demage I think (in 30 knots capsize or... broken mast or boom is normal).

[woodeneye]

And it is a cause of demage I think (in 30 knots capsize or... broken mast or boom is normal).

Yes Rob, you are right. Today I should have tucked in a reef. But the first reef on my sail is too big and too slow.

[robhosailor]

But the first reef on my sail is too big and too slow.

I see this problem, but I have quite different character - I'm reefing my sails earlier than other sailors. Than not demages and capsizes I've had.

[IanHowick]

Hi Bruce, have you considered a second hand windsurfer mast for your yard and or boom?

It's a while since I held a windsurfer mast in my hand so I don't have a good feel for whether they're in the ballpark for stiffness, and haven't figured out how their International Mast Check System relates to a stiffness value I can understand.

I suspect they're too flexible for a boom, but it might be worth grabbing one next time you're at the beach and seeing if it's in the ballpark for a yard.

Ian