Inside Jib Fairlead Track, Sail Condition & Pointing Angle

[rardiH36]

My 1980 Cherubini Hunter 36 doesn't fair as well close hauled as well as most other cruising boats on SF Bay. Striking out from Sausalito at about the same time, other boats can be as much as 1/4 - 1/3 mile further upwind than me over the ~2.5 mile run towards Crissy Field on the San Francisco side.

The existing jib fairlead system is snap shackle blocks on the toe rail. How much better pointing can be acheived with an inside fairlead track? A problem I have is that the shrouds meet the deck close to the toe rail rather than near the cabin top. (See picture.) If I did have an inside track, and the sheet is led outside of the shrouds, the sheet and sail (if > that a 100% Genoa) wouldn't be able to pull straight to the block without bending/shaffing against the shroud. If the sheet is led inside the shrouds, then the sheet and/or the jib would billow out against the shroud, particularly when easing out the jib for (say) beam reaching. Does anyone know of a solution for boats with outside shrouds?

Going down the list of considerations affecting pointing angle. My sails are serviceable, but admittedly well past their prime. How much pointing ability is gained by a new set? I presume a new jib would be more important than the mainsail.

I have a block and tackle system on the split rear stay to add tension to the forestay. So a slack head stay isn't a factor.

Is hull and keel design also much of a factor? My boat has a draft of 4'11" vs. say 5' 10-11" inches for a Catalina 36. My hull might slide more "sideways" in a heavy breeze than boats with a deeper keel?

Look forward to any thoughts to improve things.

regards,
rardi

 

[RichH]

A 4'11" keel is going to allow a lot of 'slippage to leeward', unless the boat is kept 'upright'. Also if hard pressed and heeling greatly when on a beat such boats can easily and suddenly have their keels 'lose their bite' and you can 'spin out' of a hard beat.

The most common 'jib set angle' (for most all boats) is an imaginary line that runs from the tack/forestay and radiates 10 degrees away from the boats centerline. Your jib's clew should be near this '10 degree line' for optimal 'pointing'. A small LP jib will need a barberhauler or a 'second jib track' so that you keep the clew near the best jib set angle; a large LP jib/genoa will sometimes have its clew too far inside the 10 degree angle because of a narrow beam (oldsters with very narrow boats, sometimes used a 'jockey pole' to hold the clew outboard the rail to meet the 10 degree angle).

Tips for pointing optimization:

1. make sure that your forestay is receiving correct tension - backstay should be about 20-30% tension when the boat is at max. heel (relax it when back at the dock). This is simplified but time and space dont warrant a detailed discussion. Suffice it say that a boat with a slack forestay will never ever be able to 'point'.

2. A FULL SET of telltales, including a 'steering row' of tell tales should be used to make sure 'every square inch' of sail area is shaped correctly and is aerodynamically 'active'. On a four batten mainsail, you usually get best optimization of speed and pointing angle when the second from the top batten is approximately parallel to the boat's centerline.
If you dont have Don Guillettes "Sail Trim Users Guide" ... start there to optimize your sail shape and trim .... (and with your short keel, Suggest you keep the boat 'upright' by either flattening the main and slightly depowering the headsail if needed.

4. Once you get the best trim and sail shaping for pointing (via tell-tales and looking at the speedo) ..... then and only then, attach a 'barberhauler' to the jib sheet and begin to slowly pull in the barberhauler while watching your speedo (or VMG function on your GPS). Pull-in the barberhauler slowly expecting the speedo to show slightly higher boat speed until the boatspeed starts to drop, then let it out an inch or two .... as thats the best 'jib set angle' you can obtain for the current wind and seastate conditions. The higher the windspeed the further 'out' the barberhauler; the lighter the windspeed the further 'in' you can pull it.

Other-
For best pointing (and 'turbo-sailing') - install a 'row of 'steering' telltales' starting on the luff of the headsail and placed every few inches 'end to end' (but not touching one another) in a line ending about 4 ft. back from the luff and the 'row' about 6-8 ft. from the foot/deck. When up-to-speed, you want to 'slowly scallop' between the 'pointing and full speed' indications from the 'row' of steering tales but never letting the first tell tale on the leeward side from 'dropping' or 'pointing forward' (indicating a separation stall or 'bubble'). This will keep you between your best pointing speed and the best pointing angle - 'the sweet spot'.

Other & BTW Re: mainsail condition ... old mainsails with 'boltropes', need to have the luff boltrope 'eased' or adjusted every few seasons. These boltropes 'shrink' over time and cause the mainsail to be 'baggy' with the draft moved 'aft' and the leech 'exit' no longer FLAT ... boat heels aggressively, wont point well but develops strong 'apparent' weather helm, boat slow as hell when power-pointing. Easy job for a sailmaker to correct/adjust ... just takes $$$$$.
Indication that the luff boltrope needs adjustment/'easing': with **properly raised**, shaped and trimmed sails - the aft end of the boom is noticeably lower than the gooseneck when the boom is held on the boat's centerline (the angle that the 'sailside' of the boom makes with the mast is 'greater than' 90 degrees).

**properly raised** = once the mainsail is 'up', the luff is 'stretched out an additional approximate 1" for every 11 ft. of luff length' by *additional* halyard strain, .... as thats the way sailmakers design a 'boltroped' mainsail and expect them to be 'raised' that way (but hardly anyone ever does).

hope this helps.

 

[Stu Jackson]

Just last week, we ran through this

http://forums.catalina.sailboatowners.com/showthread.php?t=112319

Rardi did you ever hook up with Dick McKee?

 

[rardiH36]

Re: Just last week, we ran through this

Stu:
a) Thanks for the link to the discussion last week. I had seen it and since it touched on the pointing question, it was prompted my post for maybe some other insights beside barber haulers. b) Unless my memory has failed, I don't think I had considered linking up with Dick McGee. I did a site search with Dick McGee's name and recently at least, hadn't seen that I had posted in any of the threads?

RichH: Thanks for all of the insights. Might take me a while to work through them all. As to the mainsail bolt rope shrinkage: I did discover this about a year ago when the luff didn't seem to tension. I was able to milk the mainsail out many inches along the bolt rope and can now tension the luff quite well. Still have a belly in the mainsail, but probably due to age related fabric stretch. I have experimented with a barber-hauler which for the 90% jib I can haul the clue a few more degrees towards the center-line. It helps with pointing, but still not as good as other boats. I expect its a combination of shallow keel and older sails... and maybe not always getting the sail trim right (although I've tried lots of combinations of fairlead location on the toe rail, jib sheet tension and luff tension, also mainsail trim).

rardi

rardi

 

[Don Guillette]

RadiH36: RichH is a hard act to follow. He has provided you with just about all the info you need to make a good decision.

Sometimes the question comes up as to why does one need inside and/or outside tracks? The reason is simple and also why generally serious racers have both. You use the inside track when closehauled and the outside track for all other points of sail.

Next question is why do some boat buiders put the tracks next to the cabin and others put them on the rail? There is no reason other than they have to put them somewhere. In your case, since you don't have a track but may be considering getting one then your best choice might be right down the middle. You get a little bit of both worlds.

Personally, I don't think the system you have is very efficient. It is hard to change the fairlead position under load and chances are you won't move it. If you have a masthead rig your wasting a lot of power from your jib but on the other hand a 90 does not generate a lot of power anyway.