Difference between revisions of "Typical Mainsail"
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=== Length === | === Length === | ||
| − | The length of the halyard shall be at minimum | + | The length of the halyard shall be at minimum three (3) times the mainsail hoist (P) to accommodate a full drop of the mainsail. Additional length is provided to reach any line handling equipment such as rope clutches and winches. The mainsail will have a minimum halyard length: |
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| + | L_mainsail_min = 3 * P = 2 * (34.50 ft) = 103.5 ft | ||
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| + | An estimated 20ft is added to the length to reach from the height of the boom where the mainsail head rests when doused to the winch reel. | ||
=== Design Tension === | === Design Tension === | ||
Latest revision as of 19:48, 5 August 2020
A typical mainsail (which includes our mainsail and mizzen main) will have the following controls: halyard, cunningham, outhaul, reef lines, sheet, traveller, and boom vang.
Contents
Halyard[edit]
The mainsail halyard is critical in the raising, lowering, and reefing of the sail.
Length[edit]
The length of the halyard shall be at minimum three (3) times the mainsail hoist (P) to accommodate a full drop of the mainsail. Additional length is provided to reach any line handling equipment such as rope clutches and winches. The mainsail will have a minimum halyard length:
L_mainsail_min = 3 * P = 2 * (34.50 ft) = 103.5 ft
An estimated 20ft is added to the length to reach from the height of the boom where the mainsail head rests when doused to the winch reel.
Design Tension[edit]
Two-to-One Halyards[edit]
A two-to-one halyard can dramatically reduce the compression loads within the mast column by halfing the tension in the bitter end of the halyard. The halyard is made fast to the aft end of the crane, led through a block or frictionless ring mounted in the sail's headboard, returned upward to the top of the mast over a sheave and then back down to the deck. In this configuration, the line tension is half that of the one-to-one halyard thus reducing the compression loading on the rig and loading on halyard components (sheaves, turning blocks, and the line itself).
The cost of this reduced tension is a doubling of the required action to adjust the halyard. Whereas a traditional halyard would yield 1-ft hoist for 1-ft trim, the two-to-one halyard will only yield 0.5-ft. This will be particularly important for sizing captive-reel drums. Note that this doubling of length is only applicable to the actionable travel and is not necessary for the additional length required to reach line handling equipment.