How do you decide on your control lines for your sails?

[jssailem]

Running Rigging, specifically control lines for your sails - sheets. How do you go about deciding about what to buy?

1. My boat builder gave me a owners manual. I look at the page on running rigging and follow the manual to the letter.
2. I look for the cheapest rope I can find. I have found some good buys in the discount bin at the local marine store.
3. I have no clue. I just ask the internet.
4. I am a professional sailor. There are specific load requirements that must be considered.

It is that time of year when the marine stores start advertising their sales on various lines/ropes. It is enticing to consider new sheets for you and your boat to start the season.

But how do you know you are getting the right line for the task you intend?
Do you buy the strongest line possible? (Dyneema is the only line for me)
Is the right line the one that feels good?

Recently considering this idea, I discovered some science based links on the Harken website.

Calculators | Harken Marine

www.harken.com

Your sail control lines are used to trim the sail while under load. It is your connection to the boats engine from the winch to the clew on the jib or the boom on the main sail. When selecting a line you will want the line to be able to handle the forces you are asking it to endure, while at the same time not breaking the sailing budget.

How do you start this task?

First discover the size of your sail. What is the square foot or square meter of the sail.

You can find your tape measure in that drawer of knick knack's you know the one that is always over flowing and difficult to open or close, or you can look up your boat data using SailboatData.com and get a reasonable estimation.

• Using my boat as an example the Jib is 294.00 ftsq / 27.31 msq and the main is 252.00 ftsq / 23.41 msq
• Since I have a 135% Genoa, my approximate foresail area ftsq would be 294x135% or 397ftsq
• This is what I would use in the "Genoa System Loading Calculator" to get an approximation of the line loading at various wind conditions.
  • Because wind speed is squared, it is the most important variable and can greatly influence loading. Wind speed (the apparent wind) should be calculated for the specific sail being analyzed. For example, the #1 genoa on 7 m (25 ft) boat might only be carried in 15 knots of wind while the #3 blade on a Maxi-boat could well be carried in 40 knots.
    
    To calculate loading on a genoa lead car, multiply sheet load by the load factor of the sheet. Most #1 genoas will deflect about 45° while a #3 genoa may deflect 75° or more.
    
    Lead car adjuster tackle load is dependent on the angle of deflection of the sheet in the lead car, but is generally assumed to be .3 of lead car load when deflection is 45° and .5 of lead car load when deflection is 60°.
  • Enter the sail area in square feet 397
    Enter the wind speed in knots 15knts
    Calculate.
    Sheet load in pounds: 385

In this example, based on the calculator, I should be looking for rope/line that fits my rig sheaves, feels good to my hand, and can sustain a load of 385 lbs when the sail is fully deployed.

I do not need to use a 5000lb breaking strength dyneema line as that is not the force being controlled.

Deciding on the line you need for the coming season can appear to be a daunting task. Applying the resources available to you, I hope can reduce the stress and improve your sailing experience.

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[sail sfbay]

Running Rigging, specifically control lines for your sails - sheets. How do you go about deciding about what to buy? My 2 cents:

1. My boat builder gave me a owners manual. I look at the page on running rigging and follow the manual to the letter. That is a starting point but individual lines are specified based on the required tensile strength, elasticity, diameter and finally color for the specific line application (halyard, control, topping lift and continuous furling).
2. I look for the cheapest rope I can find. I have found some good buys in the discount bin at the local marine store. I either purchase lines from my local West Marine rigging shop if I want it fast, Defender OR my rigger, if it is a continuous line or requires climbing the mast.
3. But how do you know you are getting the right line for the task you intend? I read the specifications and match the required tensile strength and elasticity.
4. Do you buy the strongest line possible? (Dyneema is the only line for me) Depends on the application.
5. Is the right line the one that feels good? Only for a control line.
6. How do you start this task? I attach a tag line, pull the old line through, remove line, measure it, purchase new line and reverse the process.