How To Build Mainsheet System With Harken Blocks
Harken Mainsheet Systems
Mainsheets are simple hardware systems, but are among the most important as they are in almost constant use.
Typical boat length:
Small Boat: 22' - 28' (6.7 - 8.5 m)
Midrange: 29' - 34' (8.8 - 10.4 m)
Big Boat: 35' - 42' (10.7 - 12.8 m)
This 4:1 tackle is the most common system on boats under 28 ft (8.5 m).
|Diagram Ref.||Description||Small Boat Part No.||Midrange Part No.||Big Boat Part No.|
6:1 Reeved Right Angle
Boats with mainsails to 375 ft2 (35 m2) often use a 6:1 system.
This 8:1 purchase handles high mainsheet loads on Beachcats up to 20 ft (6 m).
4:1 Swivel Base
Position the swivel base block off the traveler car to allow mainsail adjustment without dragging the car to windward in light air. To avoid tightening the leech, curve the track ends up.
This 6:1/24:1 cascading system is used on boats with end-boom sheeting and mains as large as 275 ft2 (25.5 m2) and end-boom sheeting.
This powerful gross-trim/fine-tune cascading system allows crew to use the 4:1 gross-trim for most trimming and the 16:1 fine-tune for precise adjustments.
4:1/16:1 Double-ended Fine Tune
This 4:1/16:1 system uses a dinghy-like double-ended tackle that locates the sheet ends on the cockpit sides.
This gross trim/fine tune system is found on racing multihulls where it is desirable to split the gross trim from the fine tune. Placing the fine tune in the boom provides a very clean system that the trimmer can get a hold of and put his weight into it. The powerful cascading fine tune portion is used to haul the boom in that last little bit.
4:1 with Dedicated Winch
This system moves the traveler over the companionway to clean up the cockpit. A favorite on cruising boats.
5.1 with Dedicated Winch
This system is popular on cruising boats with cabintop travelers. The sheet leads forward to the gooseneck and then down and back to a winch on the aft edge of the cabintop.
2:1 with Dedicated Winches
This simple double-ended system lets the mainsheet run freely through the blocks which allows the traveler car to move easily. The trimmer makes sail adjustments from the high side.
Admiral's Cup 2:1 with Dedicated Winch
In this system, the traveler is independent of the mainsheet so it rolls freely. The sheet leads forward along the boom before it turns down and aft to winches. Used on race boats like the Farra40.
3:1 with Dedicated Winch
Many large boats use this simple 3:1 system. A block on deck turns the sheet to a winch.