End Boom Sheeting

Kopite

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Mar 11, 2015
110
Catalina 27 Monroe MI
Hello All, I have an '84 Cat 27 that has mid boom sheeting with the curved traveler. I am racing the boat, and find the current set-up less than ideal - firstly because it's hard to move the traveler upwind to trim, and second as the sheet and traveler are not ideally positioned for use from the tiller helm. The former I could fix with conversion to a straight traveler, but I'm thinking of a more ideal fix by going to boom end sheeting. The difficulty I'm facing is that on the '84 there is no room between the aft lazarette and the tiller head for mounting a track. I am looking at : mounting to the cockpit seats (on plinths to get above the tiller head), mounting to the inner sides of the coaming, or even from the top of the coaming ( all options suitably engineered and braced ) . Has anyone made such a conversion previously, and if so, what route did you take ?
 
Feb 26, 2004
22,782
Catalina 34 224 Maple Bay, BC, Canada
You might consider going to the Catalina Yachts website and looking through their archived borchures to se how they did it on the older boats. The C27s have their own association website and you might even be able to source an older C27 manual to see more details.

I have owned a C22 (1983-87) and a C25 (1987-98) with end boom sheeting and tillers. My C34 (since 1998) of course has a wheel with a cabin mounted traveler - the flat kind and I've upgraded the sheaves to 5 or 6:1 from the original 3:1. I run my boat from in front of the wheel and haven't had any issues with the traveler. When singlehanding, I drop the traveler first before tacking, makes it a lot easier. That difference in purchase makes it easy to pull it up, even though I usually drop it first.

PS - re the next post, you might save some $$ by buying direct from Garhauer rather than going through CD.
 
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Joe

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Jun 1, 2004
8,007
Catalina 27 Mission Bay, San Diego
Hello All, I have an '84 Cat 27 that has mid boom sheeting with the curved traveler. I am racing the boat, and find the current set-up less than ideal - .............etc
Kopite, you're definitely on the right track by moving to end boom sheeting if you're concerned about performance.

If you put the track just aft of the rudder post, like it is on the earlier models, the sheet has an angle to the boom end. To prevent excessive wear on the tang and the boom's end cap attachment, I lashed a couple loops of poly webbing just in case. I got that idea from other race boats after mine broke loose one day (yikes, but it was less dramatic than you might think).

Anyway, my suggestion for a new traveler would simply be to bridge the new track from coaming top to coaming top... pretty much directly above where the older model C27's like mine have theirs. I think the height increase would actually help performance by increasing the traveler's range by allowing the mainsheet more clearance over the lifeline. If I were racing I would disconnect the top lifeline anyway. If you use the "hi bar" style track you may not need to build a complicated bridge with those incredibly expensive SS risers. Rather I think a nice looking, heavy block of hardwood bolted into the coaming's sidewall, would allow you to extend the track right across to the outside edge of the coaming where you can anchor the end caps. So the wide coaming top's surface and the 2 or 3 inch of the block would give solid support. Design wise, the block needs a drain to let water on the bench pass through. Or maybe even not take it all the way down... I don't know, it sounds like you're capable of designing something that makes sense and looks nice.

Regarding the traveler itself... maximizing the range is a priority, that's why I suggested the coaming mount, but it is also why I'm suggestion NOT putting the blocks and cleats on the track ends like a lot of systems you see these days. First of all, because you will have the increased leverage that the boom will provide you only need 2:1 or 3:1 purchase for car control. On my rig I use 5/16 club quality dacron double braid, run continuously from one side to the other, rather than two separate control lines. I really encourage you to set yours up this way. It makes keeping things organized much easier and you can sit on the coaming closer to the bulkhead and still have no trouble uncleating or finding the new end after you turn. If you don't like it that way, then just cut the line in half and use it as two separate lines. The other thing is to route the line forward before mounting the cleats. My boat, because the track is at bench level, has the cleats mounted on the side of the coaming. The cleats have fair lead to keep the lines captive. If you have them mounted on to of the coaming you could put the cleats on a swivel base... that would allow you to set and release from the opposite of the cockpit easily. I envy you if you set yours up that way. I use the tiller pilot arm's peg on the tiller to kind of snag the continous line for easy, quick access, because I use the traveler alot more than the mainsheet when sailing upwind... I'm sure you do also or you wouldn't be making these alterations.

So in my 2:1 system, the line is anchored at an eyestrap on the coaming wall near the track. It goes up to a small block on the car (the car has a pivoting shackle, because the mainsheet tackle is angled to the boom as mentioned earlier) the back to a halyard style block (some people call the up and over)...but you could just install a bullet block with a padeye.... then it goes forward about a foot or so to the cam cleat mounted vertically, and angled up a bit for easier operation. You could easily increase to 3:1 by replacing the car's block with one that has a becket, and adding the old car block to the track end side.

Okay.... that's pretty chatty of me, so I'll just say yes, do it and PM me if you have questions. The transition shouldn't be too costly ... just remember that you'll need less purchase , meaning smoother operation, meaning you'll use it more. Good Luck.
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Kopite

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Mar 11, 2015
110
Catalina 27 Monroe MI
Stu, Thanks for the comment. I have looked at improving the cabin top, such a s a flat traveler, better cars and sheaves, and I do as you suggest to pre-set the traveler on a tack - but it's too hard to actively trim in heavier air. I also like the purity of a boom end set-up as regards the control over sail shape. From my research, it seems the older boats did have the traveler in a similar location to my plan, but a lower tiller head, and a camber track, simplified the execution.
 
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Kopite

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Mar 11, 2015
110
Catalina 27 Monroe MI
Joe,
Thank you very much for the guidance - it all makes perfect sense and addresses the issues I have been working with.
The sheet angle toward the boom has been a concern for me. I have it calculated at about 15 degrees at seat level, and although this could be accommodated by a Nicro track (the angled contact surfaces will accept 20 degrees), it would create a moment into seat mounted riser blocks needed to lift the track enough to clear my tiller head motion.
Hence I am considering an aluminum seat back mount plate, something like Barton Marine do on their removeable traveler mount as in picture below. I'm doing some stress calcs to see it Nicro track could handle that span with simple end loading. An advantage is that in this case I could easily angle the track to match exactly the boom attachment point, and I could also bolt on a section below the track to increase strength if needed.
1674574324418.png

Coaming top to coaming top is nice as the mount can be compact to reduce moments. A block like you describe could be used to make the track mount more of a cantilever than a pin, hence increasing track load capacity as might be needed.
In either of the latter cases the area behind the intended mount has good access from the aft lazarette, so it will be easy to throw in some 1708 to add strength.

I had already decided I would like a traveler with the clam cleats on the car so I can easily lock the new windward traveler control line ahead of a tack, but I don't see such a thing available for the Nicro track, so would have to look at modifying the current car. It looks to be possible if I can use 2:1 instead of the 3:1 of the current set-up. (I should have mentioned that this is a low budget project - I plan to redeploy the existing car set up so all I need is a $400 dollar piece of track and some garage work). Otherwise I may stick with track mounted cleats i have now - as with a set-up on the coaming side (or top) it will fall easily to hand.
More thinking to do there, and will review your advice in the process.

On the boom, how is your sheet attachment point set up ? I was thinking to run a bolt through the boom near the end so that it goes through the end cap to allow clamping. What mechanical advantage do you run on the mainsheet ?
BTW I'd love to take down my lifelines as I do when playing - sailing with a tiller extension and sitting on the outer edge of the coaming - but for racing our rules insist they be closed.

I'll update as I investigate further - currently I'm working on the Nicro track "Iy" so I can put some stress data behind the options. Nice thing is I can continue to run the current set up until I'm ready..

Thanks again for the input..

Andrew
 
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