It’s recommend that a professional yacht rigger be employed to set up the mast and rig. If you wish to carry out your own mast and rigging work / after the original commissioning, it is essential that you familiarise yourself with the basic principles of mast tuning. Tuning involves adjusting the tension in the shrouds and stays so that the mast will remain straight from side to side in most sailing conditions with an appropriate amount of rake and fore to aft bend for comfortable helm balance. Tuning must be carried out in two phases - tuning at the dock and tuning while under sail. Some definitions and explanations follow.
Standing rigging refers to the fixed pieces of stainless steel rod or wire supporting the mast. Those which offer fore and aft supports are called stays 1 (backstay, forestay, etc.). The forward-most stay which carries the genoa/reacher is known as the forestay; the Jib stay, next aft, is also known as the inner forestay. Those which provide athwartships (transverse) support are called shrouds. The shroud running from the masthead to a chainplate on the deck near the rail is the cap or upper shroud. Below it, originating at the upper spreader base is the intermediate shroud. At the lower spreaders, there are two lower shrouds on each side, the forward lowers (port and starboard) and the after lowers (port and starboard).
Mast partners is the hole in the deck through which the mast passes. The butt, or foot, of the mast sits on the mast step in the bilge. Both the boom and the mechanical vang are attached to the mast at universal joints known as goosenecks.
With a shroud running straight from the masthead to the chainplate the angle of support would be so narrow as to induce extremely large stress forces in the shroud and equally large compressive forces in the mast. To increase the angle between the mast and shroud, and reduce the strain, spreaders are positioned on the sides of the mast according to load requirements. The shrouds are then pushed out from the mast by the spreaders, reducing the strains in shroud and mast. Each spreader is angled upwards to bisect the angle formed by the shroud as it bends over the spreader tip. A horizontal spreader, or worse still a spreader angled downwards, is dangerous. The spreader may slip further down the shroud resulting in the loss of the spreader and possible collapse of the mast tube. On the SAGA mast, high-strength aluminum bars are located in the mast at each spreader position. Bent to the proper angle and pinned to the spreaders, they prevent the spreaders from moving. The spreaders are also swept aft at 8°. The aft sweep of the spreaders provides additional support in the fore and aft plane, establishes ‘pre-bend’ in the mast and allows us to do away with the complexities of running backstays. The forward lower shrouds further lessen the need for running backstays.
The spreader becomes a compressive member, and when properly loaded tends to push the middle of the mast to leeward and forward. To eliminate such a leeward bow, additional shrouds are installed, running from the mast at the base of each spreader down to the deck at the shroud chainplate. The intermediate shroud is one piece from mast terminal to the chainplate on a SAGA 43. This allows tuning the mast without the necessity of going aloft in a bosun’s chair. The addition of the spreaders, the intermediate shroud, and lower shrouds means that the mast is supported at more places transversely than fore and aft. The mast therefore has a lesser, but more aerodynamically efficient, transverse width than its fore and aft dimension.
Based upon the relationships described above, the more spreaders and shrouds used transversely, and the more intermediate forestays and running backstays used longitudinally, the smaller the allowable mast section may be. This can be advantageous as weight aloft and windage may be reduced in addition to minimising the undesirable aerodynamic effect of the mast on the mainsail. The smaller the mast section, the less disturbed is the air flow across the mainsail. However, a practical and functional balance of rig complexity, strength and aerodynamic efficiency has governed the design of the rig of the SAGA 43. A double spreader rig with a substantial mast section was specified over a triple spreader rig to reduce tuning complexity and increase overall reliability. Drag and its detrimental effect on the main is reduced by virtue of the aerodynamically shaped cross section to the mast.
As stated earlier, we recommend employing a professional rigger when your SAGA Yacht is being commissioned for the first time. The following description of mast preparation and stepping cannot cover all contingencies and is only a guide.
Most often, you will find that the boat yard removes the mast from the delivery truck using a fork lift. Three sturdy sawhorses, or mast supports, should be ready to receive the mast, spaced equidistant along the 67 ft. length of the mast. Once assembled, mast with rigging will weigh approximately 700 lbs, be sure the mast supports are strong enough. The mast will need to be placed where it can be worked on without interfering with traffic movement in the yard and convenient for the crane operator to pick it up.
Ask the crane operator, who will be placing the mast into the boat, for their preference as to whether the mast should be forward side up or aft face up on the supports. After the spreaders are attached, you will not be able to roll the mast on the supports. It is preferable to have the track (aft face) side up, it is then much easier to install the Batt-Cars®. Offshore SparsTM, our mast builder, labels all the components in your mast and rigging to avoid confusion. This is particularly important when attaching the spreaders and shrouds as mixing pieces will lead to extra hours of work. Labels should also be used whenever the mast is removed from the boat for winter storage or other reasons.
Insert the spreader bars into the mast. Layout the shrouds on each side of the mast in their respective positions, attach the spreaders to the spreader bars with the clevis pin heads on the upper side of each spreader. Insert the cotter (split) pins and spread the legs about 45°. Tape over the pins with a continuous wrap completely around the spreader using a stretchy plastic tape. (Rig RapTM is one - brand). When you have unrolled the shrouds, you will see a tag on each identifying it. Wrap the turnbuckles in rags or cover with plastic bags to keep them clean while you drag the shrouds around the mast. Attach the lower shrouds to their respective tangs and then with twine tie them to the mast at their bottom ends. Be sure the forward lowers are forward and the aft lowers are aft; port and starboard can be swapped but not forward and aft. The intermediate shrouds are then attached and led down along the mast, don’t put them into the spreader caps until after the cap shrouds have been attached.
At the end of each spreader is a cap held on by two screws. The upper spreader caps have one hole for the cap shroud. Remove the caps and lay the cap shroud into the groove and reattach the spreader cap. It is advisable to put a small amount of silicone sealant onto the threads of the screws. This has a double purpose: It prevents the screws from backing out and it reduces dissimilar metal corrosion between the SS screws and the aluminum of the spreader. You will see two holes in the lower spreader cap, the larger diameter one is for the cap shroud, the other of course is for the intermediate shroud. Replace caps the same as for the upper spreaders.
Pull all shrouds as tight as possible down along the mast and tie them off. Be sure that the lines holding the shrouds can be reached from the deck as themast is being lowered into the mast partners. The furling gear should be put together by a professional yacht rigger to ensure correct assembly. This is a responsibility of the commissioning dealer. The furling lines are marked for genoa and jib and they are also of differing sizes: 5/16” x 70 ft. for the jib and 3/8” x 90 ft. for the genoa. After the two furling headstays are assembled, they may be attached to their proper tangs as can be the backstay. The weight of the furling drums requires secure lashing to the mast. Although the headstays will sag to the ground along their length, don’t tie them up to the mast. They need to be free as the mast is lowered into the mast partners. The halyards are marked as to purpose and there are messenger lines run in, the mast to facilitate pulling the halyards through. Even when you have accomplished rigging your mast by yourself, at this point a 1 crane is necessary for the actual stepping. Let the boat yard do it! You can facilitate matters by removing the saloon table, picking up the floorboards in the way of the mast, taking down the wooden mast ring on the overhead and having cardboard ready to wrap around the mast as it is lowered into the deck. The cardboard will keep scratches on the mast to a minimum.
All turnbuckles are equipped with toggles to eliminate bending load on the terminals and turnbuckles. Toggles are also fitted to both ends of the forestay. As the boat tacks and the headsail loading varies from side to side, the forestay terminals are subject to side loading; i.e., loads not in the straight line from masthead to tack fitting.
Begin tuning the spar by ensuring that the mast is in the centre of the boat, perpendicular to the deck. Slacken the lower shrouds by unwinding their turnbuckles until they are without tension. The backstay should be just tight enough to remove any visible sag. Take the main halyard and lead the shackle end to a point on the rail or chainplate. Look up to ensure the halyard is not wrapped around the lazy jacks or a spreader and is running in a straight line from the masthead. NOTE: It is easier to tune the mast before attaching the boom to its gooseneck. Adjust the halyard so that the shackle just touches the reference point with a given downward tension, then cleat the halyard. Take the halyard to the same reference point on the opposite side of the boat, again look up to check that halyard is clear. With the same amount of downward tension, you should be able to just touch the shackle to the reference point then the mast is plumb transversely. If not, unscrew the upper shroud tumbuckle on the side where the halyard indicates the masthead is further away and take up on the other in order to bring the masthead closer to centre line until the halyard shackle touches both reference points using the same downward tension.
The particular part of the rail or deck you choose as your reference point is not important as long as it is the same point on each side and close to the chainplates. Once the mast is centred transversely, tighten both upper shroud turnbuckles uniformly, one turn one side, then one turn on the other, using a 12 in. wrench and a 12 in. screwdriver. NOTE: It is preferable to use the proper size of open-end wrench but a crescent wrench may be used. Repeat until the turnbuckles become difficult to turn. Pin the turnbuckles.
Tighten the intermediate shroud turnbuckles so that almost all of the slack is removed. Sight up the aft side of the mast to make sure that it is straight athwartships, then tighten alternately port and starboard until the turnbuckles become difficult to turn with the wrench. Pin the turnbuckles. Repeat this procedure with the lower shrouds. The lower shrouds may require adjustment to straighten the mast.
Now check for pre-bend. There should be 4 to 6 inches of fore and aft bend in the mast. If not, tension the backstay adjuster (if fitted) or the backstay tumbuclles until 6” of bend appears when sighted up the aft edge of the spar. Then equally tension upper and intermediate shrouds going alternately from port to starboard turnbuckles. Release back stay tension and 4-6 inches of pre-bend should remain in the mast. The lower shrouds may require adjustment to straighten the mast athwartships after this step.
Now check the rake. Rake is the fore and aft angle of the spar. The SAGA 43 spar is designed to carry a maximum rake of 12 inches. Rake effects the position of the centre of effort of your sail plan and, consequently, the balance of the helm. The effects are more pronounced in heavier winds. The extent of rake on your boat should be determined by your particular sailing characteristics, the typical local wind conditions and your sail maker’s suggestions.
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 tumbuckle (or vice versa) until the desired rake is achieved. Pin both fore and backstay turnbuckles.
Unless the rake has to be readjusted in the future to correct helm balance, these turnbuckles will need no more adjusting. Additional tension may be applied by the backstay adjuster.
The outboard ends of the spreaders will need to be padded and taped to avoid chafing the genoa/reacher. Ensure that all turnbuckles are pinned. You will be ready to complete the tuning procedure while sailing once the boom is installed.
Select a day with a steady 12 to 15 knot breeze and reasonably flat seas. Put the boat on starboard tack, close hauled. Sight up the luff track of the mast. If the mast seems to fall off to leeward at the spreaders, tack and tighten the starboard lower shroud or intermediate as necessary. Put the boat back on starboard tack and check the spar again, repeat as necessary. When the mast appears straight, bring the boat about and do the same on the port side. When you first sight up the mast, the mast head may appear to be falling off to leeward. The cap shrouds may be too loose but the intermediate and lowers might be too tight. Or - the mast may have an S-curve, falling off at one spreader and poking up to windward at the other with the masthead to windward or to leeward.
The many possible variations in the tension of the shrouds cause us to emphasize the importance of employing a professional yacht rigger at least initially in tuning your mast. You will find it far easier to duplicate the tuning if it has been performed properly the first time.
Check the following carefully. When the upper shrouds are at optimum tension, in 15 to 20 knots of wind, the leeward shrouds will feel “looser” than the windward but they should not be visibly slack. If too slack the rig will shock load when tacking. 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 can never be totally eliminated.
When the rig is new, the rigging may stretch to the extent that retuning 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 throughout the sailing season. 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” (head into the wind) if the helm is let go. If you find it 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 centre of effort of the sail plan further forward. Conversely, if you find the boat tends to fall off (turn away from the wind) when sailing upwind and you must constantly push her to weather, then the boat carries lee helm and the rig will require more rake.
The important thing to remember about setting up your mast is to go about the process in a slow and orderly fashion. Record the details of the tuning and re-tune procedures as well as the results achieved. This will provide you with a better understanding of the rig and will serve as a useful reference for rigging the boat on subsequent occasions.
Some preconceived notions about conventional sloops or cutters may need to be discarded in order to understand how the Saga 43’s Variable Geometry rig works. It’s not a cutter or a sloop in the usual sense and the techniques for sailing it are a tad different than what you may be used to. The rig is proportioned so that an overlapping head sail is never required. The inner head sail is used when sailing close-hulled, even in moderate air. As it is self-tending, tacking simply requires a turn of the wheel, no crew required. Off the wind, the reaching genoa is deployed to both add sail area and shift the center of pressure forward to maintain an extra light helm pressure on all points of sail. At deeper angles downwind an asymmetrical spinnaker can be flown from the bowsprit. Furthermore, the Saga 43 will remain well balanced and easily steered even when pressed hard on a tight reach, unlike conventionally rigged boats. Mainsail hoisting and reefing chores are easily taken care of inside the safety of the cockpit with a push of the button on the two speed self-tailing electric winch.
The Saga 43 is no slouch on the water. Impressive sail area/displacement ratio of 18.7-20. Most recently 73 PHRF; NE PHRF is 81.
Remember stainless wire rope creep deformation generally starts around 65% of breaking strength.
Saga “Variable Geometry” rig. Self-draining line organizer boxes molded into both cockpit coamings. Storage wells at either side of mast base for winch handles, snubbers, etc. All halyards, reefing and control lines are led aft to the safety of the cockpit beneath a carapace, keeping them from underfoot to reduce trip hazards while on deck and protecting them from the elements.
Running rigging replaced 2013. Standing rigging replaced 2015.
|9/32in (7.1mm)||9,261 lb||1389||1575||1852||17.0 lb|
|5/16in (7.9mm)||10,600 lb||1590||1802||2120||21.0 lb|
|3/8in (9.5mm)||14,800 lb||2220||2516||2960||29.4 lb|
Polished stainless steel weldments bolted to the structure of the hull to which the shrouds are attached. The primary chainplates have 10 x 1/2” 13TPI bolts.
Keel stepped double spreader aluminum mast. Mast and boom stripped and repainted in 2011. Heights have not been adjusted or confirmed since mast step and hull reinforcements in 2014.
Offshore Spars 810.598-4700
Mast step replaced (’15)
Harken http://www.harken.com 262.691-2230