How can I improve this mainsheet arrangement?

Since we bought Necessity a couple of years ago we have been looking at the mainsheet arrangement and how it can be improved. Currently, the mainsheet has a 3 point boom purchase from a pilothouse traveller. The mainsheet is led forward and down to the deck just aft of the mast, then across the deck to starboard, then aft to the PH. It then goes up and over the pilothouse and through the dodger to a winch next to the companionway. CanvasNecessity0004.JPG In all the friction involved is horrendous. In light to moderate air there is no need to cleat the main at all – friction does it . I have considered several different options but wanted to see if others have addressed this issue with success. Here is what I have considered so far: 1. leave the arrangement as it is but replace current Schaefer blocks with ball bearing ones. 2. reduce the main sheet diameter from 7/16″ to 1/2″ to make existing blocks run better. 3. Leave existing boom purchase but drop down from the boom to the top of the PH then across the top of the PH and aft to the winch. The issue is that the mainsheet will tighten as the traveller is eased. 4. New double ended mainsheet with triple purchase on the boom exiting at the traveller outboard from the car to both ends then back to the companionway winches. I think this is the best arrangement as there are only 2 turning blocks (1 at each end of the traveller) However, I have not seen one so I am concerned about trying the prototype as there is a substantial investment in blocks. I would very much appreciate any advice on this topic as we want to make any changes this spring. sincerely, Brian Hall (#135, Necessity)

a. My first reaction was; why do the lines lead all the way to the main deck and then back over the ports to the cockpit? I installed a dodger recently, which interfered with the mainsheet going directly aft, leading off my three point purchase. I now (temporarily) go around the dodger to make adjustments (the three sheave block has an attached cleat). My solution: I plan to install two (2) turning blocks just beyond the hatch cover on top of the pilot house, then aft thru the traveller support and a hemmed opening in the dodger to a winch and cleat starboard. The winch and cleat are already there to handle the traveler lines. In this regard I would like also to see any helpful feedback from others regarding Necessity’s possible solution. I’m also investing in the Dutchman boom brake to avoid an accidental jibe while heading directly downwind. Tim Oneil (#138, Whaleback)

b. On #102, Bodacious I have the setup you have but it does not come back to the pilot house. It is adjusted from the front of the pilot house. There are no turning blocks or winches. It adjusts easily, However I was thinking of swapping the end blocks and turning the traveler car around. This would bring the traveler controls back directly to the pilot house. You might have to stand in the companionway to adjust it. Gene Byrd, (#102, Bodacious)

c. When constructing our Corbin 39 from a bare hull, I studied a number of mainsheet systems and decided on the one I will describe. My main objective was to have a very strong system which was devoid of the lines running aft from the mast. Friction was a factor in my decision but I was more influenced by my experience with charters that had similar systems. It seems that I was forever rolling the lines underfoot or worse, tripping over them. Therefore: no lines on deck! We had an arched stainless steel bridge constructed that spanned the companionway opening and was thru bolted to the molded risers on either side that were designed for this purpose. It is not bolted to the storm cover since the cover is not strong enough to add any strength. The curvature generally follows the coach roof lines. The traveler track is bolted to the bridge. I used a Harken track that allows for flexible spacing of the bolts. Other manufacturers now make similar units at lower cost. I had Harken bend the track to my bridge curvature. The first design had a strong pad eye on the port forward side of the bridge. The sheet was fixed to this eye and led to a block on the traveler car. From there it went up to a boom block, back to another traveler block, up to another boom block, back to another traveler block, then to a block the starboard deck slightly aft of the bridge. From this block the line was led to a winch. This arrangement, where the terminus of the sheet is at the same spot on one side as the turning block (to the winch) is on the other side allows the traveler to be moved without changing the sheet location…in theory. The theory doesn’t exactly apply here since the bridge is curved while the boom swings in a generally flat arc. I guess that the matter could be solved by using a straight bridge rather than an arched one. However, the small amount of shift in the sheets did not affect things much except when the main was pulled in very hard. In any case, I didn’t mind a little “tweaking” of the mainsheets. However, adjusting the traveler position required some effort. This was due to the usual forces on the system, plus the friction of the mainsheet as it proceeded thru the blocks. I have since modified this system for other reasons. I stopped the mainsheet on a becket on one of the boom blocks rather than on the bridge end. This increased the mechanical advantage from 4:1 to 5:1 which helped my spouse. It also meant that the main had to be adjusted anytime the traveler was moved. This has not turned out to be a significant problem. The original system caused the blocks on the traveler to twist and interfere with each other. This was due to the torque caused by the two ends of the sheet pulling on different sides of the traveler. It caused chafe on the blocks and made the lines tend to twist around each other which caused lots of problems. The new system eliminated those problems and generally runs noticeably freer than the old system. I use Harken blocks throughout and I find that the whole system runs freely. Well, I apologize for all of the words and I hope that you have some notion of what my mainsheet system looks like. If I can be of any further help, please do not hesitate to contact me. For what it’s worth, we also installed a small 4:1 block and tackle inside the boom on the main clew outhaul. This has made adjusting the outhaul while under load much easier. Best regards, Lou Marilyn Lieto (#193, Impresa).

d. Brian, I found this diagram of my original setup. Note the use of a triple block instead of a fiddle on the traveler. The boom-to-traveler distance is short and I think a fiddle will not work well. However, the use of a triple block was responsible for a lot of the twist I observed. As I described, I have made two changes. You can see the eye that terminates the sheet on the forward port side of the bridge. The sheet end has been moved from the eye to a becket on the forward boom block. Also the triple has been replaced by three singles supported by stand up springs on each. These can each find their own angle and the system, which looks cumbersome, works well. Cheers, Lou

e. Lou, Thanks so much for your thoughtful comments. You have obviously had a great deal of experience with this issue. Here are a few of my questions: Do you by chance have a picture of your current arrangement you could send? I sail in the Chesapeake but I live about 350 miles away, so a picture will have to wait until I next make the journey which will be in about a month. I’ll send you some then. Do you have a dodger which is up most of the time? I have a dodger & bimini which I keep up all of the time. Does your mainsheet go through it to the cabin top winch? The sheet leads from the block on the traveller to a stand up block (with a spring on it to prevent it from falling over when not under tension) and from there to a cheek block. The cheek block is on the deck at approximately the location of the starboard traveller blocks just aft of these. The sheet travels straight aft along the pilothouse roof under the dodger to another cheek block where it turns to the winch. The winch is located on the pilothouse deck at the aft corner of just to the starboard side of the companionway opening. Am I right in thinking the main is dead ended at the traveller and adjusts from only one end (starboard)? It is deadended on a becket on one of the boom blocks.

Does the final lead from the boom to the turning block pass through a block at the traveller or come from the boom directly? I am not sure of the question. The final lead of the sheet comes down from the boom block to a block on the traveller. The function of this block is to turn the rope from vertical (from the boom) to horizontal – to the stand up block mentioned above.
We currently have 3 attachment points on the boom. Do I understand that you have two? Does this create any problem with excess loading of the boom? I have two attachment points. A third may be located between these two but does not currently exist. The riggers I have consulted as well as the manufacturer of the mast were quite certain the there would be no problems with the loadings.
Is there any need for a winch to trim the main in heavy air with the 5:1 purchase? Was the 4:1 too difficult? That depends on various things. If you reef early perhaps not. I make it a practice to use the winch when the wind pipes up. My main may be larger than average since I had the mast made 4′ higher than on the original plans. Nonetheless, I do not feel it wise to have the mainsheet secured only by a cleat. The possibility for an unpleasant “surprise” while uncleating the the sheet under load is not worth the savings. My wife and I are in our mid 60’s and we usually sail alone in the Bay and in coastal trips, including overnighters. I can pull the sheet in under most conditions but my spouse cannot. The winch certainly makes fine tuning the main very easy. The move to 5:1 was mostly predicated on the twisting and block chafing problems I mentions earlier. However, as I said, I like this arrangement much better than the previous design. I have enclosed a couple pics of a mock up the arrangement I am considering which would use two blocks on the traveller and a mainsheet which is double ended. What are your thoughts based on your experience? I thought the double ended model would allow the mainsheet to move “through” the blocks as the traveller was adjusted but I am concerned about the twisting problem you encountered. The other alternative which Frank Bryant on #186, Visitant has used is to end his mainsheet with a set of cams on the traveller car itself. This requires him to open the dodger window to adjust the main. We are planning to take the boat transatlantic and I’m not sure this is workable in a high wind situation when you would most likely have the dodger closed in. Although I have not tried it, I share your concerns about the design used on #186, Visitant. I did not use a fiddle block in my design so you may have fewer problems. On the other hand, consider the following. When the main is sheeted in reasonably tight and you wish to ease the traveller, the distance between the traveller and the boom increases as the traveller moves outboard. Net, you have to adjust the sheet anyway, albeit less than you would have to with a single ended mainsheet. You may come to a different decision, but I found that I don’t tweak the main nearly as much as racers do and the convenience of adjusting the traveller without having to touch the mainsheet is just not that big a deal. By the way, hauling on the traveller with my system (which is 4:1) takes some strength. I don’t need a winch but it does require some ooomph.

Thank you so much for your efforts. It is good to talk about the issues with someone else who has dealt with them. Thanks, I specialize in trying all of the unworkable solutions first! By the way, where are you located? We sail out of Bayfield Ontario on Lake Huron. We sail out of a marina on the northeast side of Kent Island which is across the Chesapeake Bay from Annapolis, MD. I will get you some photos later if you are still interested. All my best Brian Hall, s/v Necessity and Lou Lieto, (s/v Impressa)

f. I don’t believe I can help you too much in arranging the mainsheet for you, what works for me may not work for you etc. However; I can tell you from my experience you do not want to have a load bearing block on the flat deck if it is in tension. That point loading will deflect your deck and cause lamination problems with the plywood coring and lead to failure. Even with good back-up plates. Shear loading I would guess is ok. I had to replace my mainsheet system for the same reasons you mentioned and more. I had to redo the deck coring around the area where the block was fastened through the deck behind the mast and with a good stainless steel backing plate. Good luck, Gene Whitney, (#069, Joint Effort).

g. Brian, Here are a couple of pictures where you might get an understanding of what I did for the new traveler. Originally the traveler was in the cockpit as you know, I constructed a rooftop unit and made it a mid boom system. This works well for me, I do not use a winch for sheeting in all but the most windy days. The mainsheet does not lead to the cockpit in any way. I think the cockpit is too small for this. I like to get up to the traveler on deck where there is room and use my legs to sheet. When the weather pipes up and I need to use a winch I sheet to the winch on the mast, here I can use the mast pulpit and brace myself for the sheeting while standing up. My mainsheet faces forward for sheeting. The vang is nearby also as well as the traveler controls. when I need to put the sheet to a winch I think it is also time to put in the first reef. The boat is so stable I have no problems feeling anxious about doing this. This is not a race boat and there is no reason to put the traveler in the cockpit for speed or safety. Besides in the small cockpit there is no way to put proper effort into sheeting the mainsheet without wrenching your back or putting a elbow in your wife’s or crew’s face when trying to pull in 20 or so feet of loose line. I find I do very little mainsheet trim anyway, I mostly run the traveler up and down to trim on the wind and off the wind it is very easy to trim the sheet on your feet by the pilot house. One good thing with this system is you can hardly over trim the mainsheet and that saves your main from too much distortion as what happens on most race boats. I hope I was some help to you. Gene Whitney, (s/v #069, Joint Effort)

h. My first reaction was; why do the lines lead all the way to the main deck and then back over the ports to the cockpit? Brian – I agree 100% just creates friction. I thiiink the original reason was to allow the traveller to be adjusted without affecting mainsheet tension.I installed a dodger recently, which interfered with the mainsheet going directly aft, leading off my three point purchase. I now (temporarily) go around the dodger to make adjustments (the three sheave block has an attached cleat).

A = Brian – We have a dodger too and want to come aroooound it.

My solution: I plan to install two (2) turning blocks just beyond the hatch cover on top of the pilot house, then aft thru the traveller support and a hemmed opening in the dodger to a winch and cleat starboard. The winch and cleat are already there to handle the traveler lines.

Brian – See my notes and pics to Lou – we thought about a double ended mainsheet which would essentially follow the path of the traveller lines. Probably would cleat it to port and use the existing starboard winch. In this regard I would like also to see any helpful feedback from others regarding Necessity’s possible solution. I’m also investing in the Dutchman boom brake to avoid an accidental jibe while heading directly downwind. Tim Oneil. (s/v Whaleback) and Brian Hall, (s/v Necessity)

A couple of pictures that may help with some of these suggestions.