Jib Sheets

Aug 11, 2011
857
O'day 30 313 Georgetown MD
As most know this '83 O'day 30 is new to me. With all the work that I've been doing, getting it splashed and now working on top side and inside, I'm starting to get some sort of timetable together. I have a question though. I do not have any jib sheets. How do I know the length I need. My sails are hank ons, no furler. I have a 130 genoa and a trisail which i believe is a 90.
MaybeI'v got this all wrong, however how does one calculate the amount of sheet needed. My aim is to use one set for both sails. As always all answers are welcomed.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
So your boat is 30 foot. So that could be a start point. Your 90% sail will com back to about the mast. How far is the mast back from the bow? Say it’s 10 feet. So now we have at least a need for 20 feet. Your going to need at least the width of your boat in your cockpit. What is that about 10 feet. You don’t need the distance from the stern to the winch. What 5 feet? We’re about 25 feet. And of course when you tack the line would cross the boat, about 9 feet. So we’re up to 34 feet. You may need a couple of feet to deal with splices. So 35-36 feet each side.

I suspect about 75 feet would do it. You can cut off any extra and make it into dock lines.

For the first couple of seasons use a single line with a cow hitch in the center at the jib/genoa clew. Then when the knot get worn you have enough to cut off the end and you can make eye splices then connect the sheets to the clew with a dyneema soft shackle.

The that’s what I did. You PM me and I’ll help with the soft shackle.
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
As most know this '83 O'day 30 is new to me. With all the work that I've been doing, getting it splashed and now working on top side and inside, I'm starting to get some sort of timetable together. I have a question though. I do not have any jib sheets. How do I know the length I need. My sails are hank ons, no furler. I have a 130 genoa and a trisail which i believe is a 90.
MaybeI'v got this all wrong, however how does one calculate the amount of sheet needed. My aim is to use one set for both sails. As always all answers are welcomed.
The basic formula for jib sheets is approx. 1.5 x boat length per sheet.... so 45-50 ft per sheet. The "lazy" sheet must be able to reach around the mast from the clew then back to the winch with a few feet left for the tail. Use two sheets rather than one continuous line, makes changing sails speedier and way more efficient....use a bowline knot to connect them to the sail..... especially since you have hank on sails and will be removing, folding and bagging them after each use... The bowline will not bind up and is easy to open... again, making sail changes more efficient.

Do NOT store your sails with the sheets attached. That is a big no, no. Coiling and storing the sheets in your rope locker will keep them cleaner, they will last infinitely longer because they stay out of the weather and get rotated every time you use them. There is absolutely no reason to put an eye splice in your sheets.... If you get them cut to order at a brick and mortar chandlery or online, they will seal the ends with a hot knife. Then you can "whip" the ends for a neat finish.

I'm not sure what you're "trysail" is. Did you mean "storm jib"? A trysail is a small triangular heavy weather piece mounted on the mast when the mainsail is lowered. It doesn't connect to the boom, which will be secured so it won't swing around, but rather directly to the boat. A storm jib will have a pendant at the tack to get it off the deck, hanks for attachment to the forestay and be sheeted like a regular headsail. Size wise it's usually around 50-70%. No problem with you 130% genoa sheet length since there is no overlap.

Besides length you must consider line diameter. On a 30 footer I think 7/16 ", normal "club race" level polyester double braid would be more than adequate and fit well in your winches and cleats. Here's some examples: https://www.apsltd.com/line/polyester-double-braids.html There's lots more to choose.... I suggest you explore the site... another line you might like is the Samson Trophy Braid, it's got a spun polyester exterior that gives it a "fuzzy" feel in the hand and creates an excellent connection to the winch drum.
 
Jan 27, 2008
3,045
ODay 35 Beaufort, NC
An advantage to using two sheets is you can flip them end over end so the end with the knot at the clew wears evenly. Also use a figure eight stopper knot on the end that goes around the winch so it won't pull through your fairlead blocks. A figure eight knot won't jam like a granny knot. It will add another foot to the length. If your boat is a 30 footer you will need about 50 feet on each side. When the jib is furled on the roller furling you will add a couple wraps of the sheets around the sail. When sailing wing on wing with the jib poled out your lazy sheet will go all the way out to the clew on the opposite side of the boat, or close hauled with a 150 will reach all the way around to the winch on the opposite side. If you have a cruising chute it will be two boat lengths or more.
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
I agree with the others that 50' per sheet sounds pretty good. I've used both bowlines and cow hitches to attach to the sail. Both have worked fine for me. The eye splice and soft shackle sounds like an elegant solution, but could be overkill compared to a simple knot. I've never really felt compelled to take the sheets off to store the sails. If they're damp I would just coil them and fold the sail, then bag the sail leaving the coils on the outside of the bag. Did this for over 25 years on our O'Day and the sheets were still in fine shape.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
@eherlihy searching out a nearby supply of quality rope is like finding the best bakery for a mouth watering cannoli. You got to look in all the usual places and sometime not.
I stopped at the local arborists climbing shop used by the regional logging companies. The sold me 200 feet of 1/4 “ polyester double braid to be used as lazy-jacks to capture my main sail for $30.

Granted it is likely a few extra feet than absolutely needed. I’ll find a use for the surplus.
 
Aug 17, 2010
311
Oday 35 Barrington
The Genoa sheets for my 135% Genoa on my O'day 35 are 38 feet long. The main sheet for the same boat is 41 feet.
 
Aug 17, 2010
311
Oday 35 Barrington
I should have thought of checking the Owner's Manual...
Here is the relevant page for the O'day 34/35:
Running Rigging.jpg