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)

4:1 Fiddle
This 4:1 tackle is the most common system on boats under 28 ft (8.5 m).

6:1 Reeved Right Angle
Boats with mainsails to 375 ft2 (35 m2) often use a 6:1 system.

8:1 Beachcat
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.

6:1/24:1 Gross/Fine
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.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Double	2638 2602	2602	2662
B	Triple	2647 2629	2629	1555
C	Single	2636 2600	2600	2660
D	Fiddle	2655	053	060
E	Fiddle	2658	028	042

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4:1/16:1 Gross/Fine
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.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Single	2636	2600	2660
B	Double	381	2642	2602
C	Fiddle	2658	060	042
D	Fiddle	059	1565

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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.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Single	2636	2600	2660
B	Single	019	2625	1549
C	Cam base	205	144	1574
D	Double	342	2638	2602
E	Single	349	2652	2600
F	Cam cleat	423	423	150

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7:1/28:1 Gross/Fine
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.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Single	2600	2660
B	Triple	2629	2685
C	Straphead	2650	2650
D	Triple	2604	2664
E	Fiddle	2655	2621
F	Cheek	2644	2606
G	Thru-deck	046	047
H	Pivoting exit	140	140

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4:1 with Dedicated Winch
This system moves the traveler over the companionway to clean up the cockpit. A favorite on cruising boats.

Diagram Ref.	Description	Small Boat Part No.	Midrange Part No.	Big Boat Part No.
A	Single	2600 2660	1958