Got this from the link posted to the A cat worlds. Correct me if I am wrong, but this is Glenn Ashby? Is this what is involved with mid boom sheeting? I like this setup very much. Seems like a 8:1 in the rear to a block, to a ratchet block on the tramp.
Also seems like he has his outhaul at mid boom as well?
My friends Auz Flyer uses this system to good effect. However , It could cause hassle with our spi halyard and sheets and I'm not convinced my tramp would take the strain as their mains are over 2m smaller than ours. If anybody suffers from back problems this would certainly stop the twisting effect of our rear sheeting, and if someone does convert or is already using this system then I'm sure we would be interested in the results.
MP*MULTIHULLS
Re: Mid boom sheeting, interesting photo
[Re: Mark P]
#81941 08/07/0611:37 AM08/07/0611:37 AM
I was thinking about this the other day, what if you just put a block on the boom, like he has for the out haul, only the next larger size, instead of running the mainsheet all the way down to the tramp? I know the boom would have to be beefy enough to handle the load there but it might be stronger than the tramp, and that would keep the mainsheet up out of the way of the spinaker stuff on the tramp. Has anyone seen it done like that?
In that first picture you can see he has a larger ratchet block on the tramp but it has no clete with it, why not just run that right off the boom instead of the tramp?
Tim, What you are describing is implemented on A cats regularly, Ronstan makes a block that works well for this puropse. Part # RF 62175 low lead ratchet with cam
Alternatively you can buy it witout a cam.
These blocks have awesome holding power much better then the harken ones, but they do chew up line quickly so you will need to replace your mainsheet more often
Thanks Eric, has anyone tried it yet? I recall Wouter had put up some info about a 2-1 mainsheet on the boom some time back, I could see where you could rig it for use either way just by changing where you tie it off. Any F18's using that?
It strikes me that the disadvantage of putting it on the tramp is that it doesn't leave much room for the crew when you tack, if you're sailing two-up. On the other hand, it gives the crew a better sheeting angle if they're doing the main.
Thanks Eric, has anyone tried it yet? I recall Wouter had put up some info about a 2-1 mainsheet on the boom some time back, I could see where you could rig it for use either way just by changing where you tie it off. Any F18's using that?
Paul (#300) has used center sheeting for some time. The difference between he and Ashby is that Paul uses a cleat (look at the Photo of Glenn--no cleat). Photo attached of Paul--blow up photo to see mainsheet set up. Note that his boom is larger in diameter than the standard Taipan boom. I've sailed on Paul's boat and didn't find the setup helpful for me. He likes it because he used to sail a Musto Skiff.
Glenn sent me a parts list needed to set up your sheet like his and I could dig it up if someone is interested.
Eric Poulsen A-class USA 203 Ultimate 20 Central California
Either way, you still have to get the hiking stick around the back of the blocks (traveler)on every tack, that's the part I don't like. If we could figure out a way to just cross under the boom while looking forward and not have to go to the back of the boat, that would be great!
I think Glen's system there is 8:1 i.e., 7:1 at the rear and the lead forward I think qualifies as another purchase. I also think he has a wire under the tramp to take the block loading. I'd like to know how those straps/strops are attached to the boom. Probably epoxy. Definitely NOT drilled and riveted I'll bet. <img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" />
I asked about this system and sheeting directly from the boom in and earlier post but got no satisfactory answers <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" /> but I think it would work. I can't see any more load on the boom doing it that way than there already is. I doubt I'd use the system now though because of the kite sheet and halyard presence on the trampoline. Too congested.
Don't you just love 'A's. I hope I get to own one before I die.
Berny, Here's the email he sent me--sounds like there is no wire and just rivets.
Quote
Hi Eric,
hope you had a good Easter and a good sail with the new rag...
...The centersheeting could be a tricky one but I will try and explain.
I think it is better to sail with centre sheeting as I have grown up sailing dinghys like Lasers and optimists so prefer the mainsheet to come fro the middle of the boat.
I think it is also better for my back to pull the mainsheet straight up the line of my body and not across like you have to do with the rear sheeting.
The Blocks you will need to have it the same as mine is
2 RF40101 (Single Blocks) One of these gets attached to the middle of the boom. Your boom must be at least 40mm Alloy or strong carbon. Use webbing and rivets for the boom.
1 RF40312 (Triple Block with becket) This block goes on the traveller car and has the end of the mainsheet attached to it. 1 RF40302 (Triple Block) Attach one of the single blocks to this and this attaches to the sail and boom. 1 RF1720 ( Ratchet Block for the tramp)
The Trampoline will need to have some heavy sailcloth reinforcing where the Ratchet block goes. Usually 3 layers of heave cruising cloth will be good. (your sailmaker will know) Use a saddle to attach the block there with 2 nuts and bolts and put Large washers under the nuts so they dont pull through the cloth.
It takes a while to get used to using the new system but i think it is worth it. See how you go!!
Regards Glenn.
Eric Poulsen A-class USA 203 Ultimate 20 Central California
"Altered" has always had mid boom sheeting, I carried it in from my Mosquito's and the A that "Altered" came from. By the way the first Mossie I had was sloop rigged with mid boom sheeting and was OK. Mossie has less tramp space than a F16. <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />
My boom is a carbon sailboard mast top section. Is smaller in diameter than most A booms and doesn't bend or break. Currently my boom hangers are Kevlar rope with the ends teased out and epoxied on. Previously I used seat belt webbing wrapped around with one rivet to stop it slipping, but the rivet still got loose, epoxied on is best.
I use a swivelling cleat RF7, initialy this was mounted on tramp alone with a Large thin aluminium plate underneath this worked OK, but after some changes I put a pole up centre of my tramp and cleat is now fixed to it. In both instances it is very important to get cleat angle right. I find I need to cleat regularly to rest arms for downwind work with spin.
Mossie Tim has sheet dropping straight from middle of boom, many skiffs do it this way. But when I sail his boat I get tangled in it. Like so many things in set ups no right or wrong just what you are used to.
My friends Auz Flyer uses this system to good effect. However , It could cause hassle with our spi halyard and sheets and I'm not convinced my tramp would take the strain as their mains are over 2m smaller than ours. If anybody suffers from back problems this would certainly stop the twisting effect of our rear sheeting, and if someone does convert or is already using this system then I'm sure we would be interested in the results.
Goodall runs a very similar system on his personal Capricorns. IMHO it is not worth the effort but the normal rear beam system is what I'm used to. There is a slightly better sheeting angle if the crew takes the main however I find it more difficult to control the sheet during a tack/gybe.
It is still in planning phase on my side. I'm looking at having a block at 40 % of the boom as others describe. However, I'm out of (boat) money for the moment so it'll probably by next season at the earliest. By the way, the A-cat setup will be in the way of doublehanded sailing and not having a cleat is bad news for spinnaker sailing. Personally I'm finding that the rear setup is pretty acceptable when singlehanding and that the boom setup has other downsides when doublehanding which makes application less appealing that on the A-cat. Alsp the way I run my spi lines will directly conflict with any trampoline based mainsheet block.
An A-cat sailor once told me that when the switched from rear sheeting to centre sheeting that doing the wildthing on downwind legs was much improved. Sadly on an F16 this is not an important consideration as the addition of the spinnaker makes the F16 behave totally different on the downwind leg. Doing the wildthing is almost near done on a F16.
The two boats are really diverging both in design and the fitting out. The addition of the spinnaker really does change the total concept of the boat.
Wouter
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
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