Tartan 3700, Owner'S Manual

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Forward rake should be avoided. The main halyard may be used to measure rake. In calm wind and
sea, with the boat floating level on her lines, hang a plumb weight or equivalent, such as a hammer or
wrench, from the main halyard. Adjust the halyard so that the weight is suspended just above the
gooseneck. The fore and aft distance between the mast and the halyard at the gooseneck level is the
amount of rake. Ease off the forestay turnbuckles and tighten the backstay turnbuckle (or vice versa)
until the desired rake is achieved. Pin both fore and backstay turnbuckles.
Unless the rake has to be re-­‐adjusted in the future to correct helm balance, these turnbuckles will
need no more adjusting. Additional tension may be applied by the backstay adjuster.
Check that the outboard ends of the spreaders are padded and taped to avoid chafing the genoa.
Ensure that all turnbuckles are pinned. The mast should be fixed at the step to prevent fore and aft
movement and to hold the mast in the step.
You are now ready to complete the tuning procedure while sailing.
4.4 Tuning While Sailing
Select a day with a steady 8 to 12 knot breeze and reasonably flat sea. Put the boat on starboard tack,
close hauled. Sight up the luff groove of the mast. If the mast seems to fall off to leeward at the
spreaders, luff up slightly and tighten the starboard lower shroud as necessary. Put the boat back on
the wind and check the spar again, adjusting as necessary. When the mast appears straight, bring the
boat about and do the same on the port side.
Check the following carefully:
When the upper shrouds are at optimum tension and when at about 15 to 20 degrees of heel, the
leeward rigging should look slack. This is quite appropriate and should never be tightened. When
close hauled under genoa and main, the forestay may appear quite sagged. Tensioning the backstay
will reduce the amount of sag, but the sag itself can never be eliminated. As a rule of thumb, the
maximum static backstay pressure should never exceed one quarter of the backstay breaking
strength.
If your boat is brand new, the rigging may seat and stretch to the extent that tuning from scratch again
will become necessary in a matter of weeks. However, after this initial working-­‐in period, you will find
that the rig tends to hold its tune for considerably long periods of time. After becoming used to the
feel of the boat, you may wish to either increase or decrease the amount of weather helm. Any
sailboat, when sailing up wind, should have a slight tendency to "round up" or head into the wind if
the helm is let go. If you find it typically difficult to hold the boat off the wind, the boat is carrying too
much weather helm. This can be alleviated by reducing rake, which will move the center of effort of
the sailplan further forward. Conversely, if you find the boat tends to fall off when sailing upwind and
you must constantly push her to weather, then the boat carries lee helm and the rig will require more
rake.
With constant tuning as the season progresses, your boats performance will improve. The boat will
feel more comfortable to sail.