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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).


Diagram Ref.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
AFiddle2621
053
028
1559
BFiddle060
042
1566






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


Diagram Ref.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ATriple2640
2604
2604
2664
1546
BTriple2630
2648
2613
2141
2630
2669
1556






8:1 Beachcat
This 8:1 purchase handles high mainsheet loads on Beachcats up to 20 ft (6 m).


2631
Diagram Ref.Multihulls8' - 14' 15' - 20'
AQuad2654
BTriple2619
2632










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.


Diagram Ref.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
A Single 2636
2600
2660
1540
B Single 2637
2601
2661
1541
C Single 2636
2625
2660
1549
D Cam base 205
144
1574






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.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ADouble 2638
2602
2602 2662
B Triple 2647
2629
2629 1555
C Single2636
2600
2600 2660
DFiddle2655
053 060
EFiddle2658 028 042





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.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ASingle2636 2600 2660
B Double381 2642 2602
CFiddle2658 060 042
DFiddle059 1565





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.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ASingle2636 2600 2660
BSingle019 2625 1549
CCam base205 144 1574
DDouble342 2638 2602
E Single349 2652 2600
FCam cleat423 423 150





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.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ASingle2600 2660
BTriple2629 2685
CStraphead2650 2650
DTriple2604 2664
EFiddle2655 2621
FCheek2644 2606
GThru-deck046 047
HPivoting exit 140 140





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.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ASingle2600
2660
1958
1969
BFiddle1559
1975
1975
CSingle w/becket2661
1959
1959
1970
D Footblock 1548
1963
1963
1972
F WinchB32.2ST
B40.2ST
B40.2ST
B44.2ST





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.


Diagram Ref.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ASingle2600 2660
1540
1958
1969
BTriple
w/becket
2603 2663
1560
1961
1962
CFootblock2606 15481963
1972
DWinchB16ST
B32.2ST
B40.2ST
B44.2ST
B46.2ST
B48.2ST





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.


Diagram Ref.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ASingle1586 1969
BSingle15401958
CFootblock1548 1963
DWinchB32.2ST
B40.2ST
B40.2ST
B44.2ST





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.


Diagram Ref.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ADouble
15441960
BSingle1586 1958
1969
3007
CSingle1540 1969
Footblock1548 1963
BWinchB32.2ST B40.2ST
B44.2ST





3:1 with Dedicated Winch
Many large boats use this simple 3:1 system. A block on deck turns the sheet to a winch.


1970
3008
3007
3129
1969
3185
Diagram Ref.DescriptionSmall Boat Part No.Midrange Part No.Big Boat Part No.
ASingle w/becket
Single
CStand-up1974
3012
3138
DWinchB46.2ST
B48.2ST


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