Rigging Small Sailboats Part 4

.....daggerboards and centerboards

Any object floating on the water will tend to be blown across the water in a leeward direction, or away from the direction which the wind is blowing. To prevent this from happening to a sailboat, and to enable it to sail more in a direction into the wind, a DAGGERBOARD or CENTERBOARD is used. A daggerboard or centerboard is a thin vertical plate sticking out the bottom of the boat that gives the boat a "grip" on the water thereby preventing or at least minimizing leeward movement. Contrary to popular belief, the daggerboard or centerboard does not keep the sailboat from tipping over. While daggerboards and centerboards are not strictly a part of the rigging in terms of its "transmission" function, they do help greatly in converting the power of the wind in the sails to forward motion. And because daggerboards and centerboards often require fittings and lines to make them operable, they are relevant to our discussion on rigging.

What's the difference between a daggerboard and a centerboard? Well, a daggerboard can be likened to an actual dagger that fits into its sheath or case. The "case" in the instance of the daggerboard is referred to as the DAGGERBOARD TRUNK. The daggerboard slips in and out of the daggerboard trunk, usually in a vertical direction only. The purpose of the daggerboard trunk is to provide bearing for the board and keep water out of the boat. Once the daggerboard is in the trunk there is very little movement of the daggerboard. The daggerboard can be made out of sheet metal (usually aluminum) or wood. The hole in the bottom of the boat where the daggerboard passes through is usually a fairly tight fit around the daggerboard. There is very little adjustment with a daggerboard. Once it is down in position, the position can only be varied up or down.

FIG. 1O-1 - A typical centerboard trunk in a small sailboat. Part of the centerboard can be seen protruding out the top of the trunk. The centerboard pennant passes through a sheave on the forward trunk upright and is knotted to the centerboard. This arrangement forms a "tackle" to ease the effort required to lift the board. A cleat on the centerboard trunk is used to secure the pennant.

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A centerboard on the other hand is hinged at its forward portion on a CENTERBOARD PIN. The centerboard pin is usually a bolt or rod about which the centerboard pivots up or down in the CENTERBOARD TRUNK (see Fig. 10-1). The centerboard trunk is similar in function to the daggerboard trunk. However, with a centerboard, it remains in the boat at all times in its trunk, while the daggerboard is removable through the top of the daggerboard trunk. Whereas the daggerboard moves up and down vertically in the slot of the daggerboard trunk, the centerboard "swings" about the centerboard pin. Because it can swing, the position of the centerboard can be varied to suit different courses of sailing, and changes in the loading and balance of the hull. From this standpoint, a centerboard is more efficient than a daggerboard. However, the slot for the centerboard where it passes through the bottom of the boat must necessarily be longer than for a daggerboard, and this adds to the resistance of the hull thereby slowing the boat down somewhat. One drawback of daggerboards is that should the boat sail into shallow waters or accidentally come up onto a beach, the daggerboard will not pivot back and up into the trunk as will a centerboard. The damage to the boat in such an encounter could be extensive, whereas with a centerboard, it would pivot back and up into the trunk with probably no damage at all.

When daggerboards or centerboards are made from wood, they have a tendency to float up out of the water just like a wood rudder. There are several ways to prevent this. Naturally, the board could be made from metal (aluminum or steel) or fiberglass, but this is not recommended unless the boat is originally equipped this way, or the designer specifies it. With daggerboards, spring stainless steel "clips" are available, which fit onto the board making the fit so tight in the trunk that the board cannot float up. Another method is to use an elastic "shock cord" across the top of the trunk slot secured at each end to screw eyes each side of the trunk. With both types of board, a removable "pin" can be used through the trunk sides and board that will "lock" the board in position. The boat shown in Fig. 6-8 features such a pin for the daggerboard trunk. By providing a series of holes in the board, the pin arrangement could be used to lock the board in various positions to suit sailing conditions. On centerboards of wood, a common method is to put a weight on the board. This can be a lead weight built right into a hole in the board, or a specially fabricated casting designed to fit the bottom of the board. The weight will pull the board down in position and then a pin arrangement can be used to lock the board in position.

Daggerboards are simpler in nature than centerboards, and therefore require few if any fittings other than those described above. Centerboards, however, can get more complex, especially the bigger the board gets in size and weight. The line used to raise and lower the centerboard is known as the CENTERBOARD PENNANT. On lightweight boards, the line may be attached by a knot through a hole in the board, and lead to a cleat somewhere on the trunk or hull structure. On heavier boards, the centerboard pennant can be rigged in a tackle arrangement to decrease the effort required to raise the centerboard. Pulleys or sheaves can be fastened to the centerboard and/or to the trunk to come up with the proper tackle.

On many of the trailerable cruising sailboats from about 17' in length and up, the centerboard is often a piece of steel plate or even a casting of steel or lead. Sometimes the latter are referred to as "retractable keels" because they also add to the stability of the boat. In either case, the weight of the unit is often such that a tackle will not be practical. When this is the case, a winch is used with a wire rope pennant to raise and lower the centerboard. The winch is best a two-way type with positive ratchet action on both the "down" and "up" directions. Worm-gear winches are available for use on boat trailers that are suitable for centerboard use, as are more deluxe types especially designed for centerboard use. All components used in such an installation should be of extra heavy duty and arranged so no jamming or fouling of the gear will result in use.

As noted previously, the centerboard or daggerboard trunk helps keep water out of the boat. This means that no holes or leaks should be permitted in the trunks AT LEAST BELOW THE WATERLINE. Sometimes this is a problem with centerboard trunks, especially at the centerboard pin. The centerboard is constantly "working" and causing stress on the pin that tends to loosen and let water seep into the boat. There are so many variations in the design of centerboard pin mechanisms (probably in an attempt to make a good one that won't leak) that it is not possible to specify a "cure-all" which will work in all cases. If the pin area is leaking, check to make sure that the bolt is tight, and if it has worked to where it fits too loosely in the hole, it should be replaced with a larger pin. Also check the gaskets, if so equipped, to see that they are in good condition, and replace if necessary. The structure of the centerboard trunk should be checked to see that all members are tight and well fastened. Sometimes a leaking pin is the result of a weakened trunk structure. If this is the case, repairs or replacement of structural members may be in order. Sometimes a little fiberglass tape and resin can work wonders in patching up leaks and reinforcing weak members, but make sure the areas to be fiberglassed are clean and dry first. Because the inside of the trunks will not be accessible after assembly, it is advisable to fiberglass the inside prior to assembly to seal the trunk and protect against abrasion by the board.

In use of the boat, sometimes there will be a vibration or "chatter," especially noticeable when the boat is moving along at top speed. This chatter is usually caused by an unfair centerboard or daggerboard, and sometimes an unfair rudder. What this means is that the edges and general sectional shape through the board have not been finished correctly. Obviously a board with a square edge forward or aft will not go through the water as effectively as a board with edges that are shaped or "faired." With sheet metal centerboards or daggerboards, about the only fairing that can be done is to radius the edges. If wood is used, a better "shape" can be incorporated. One method of fairing a wood board that gives good all around results is shown in Fig. 10-2. While very fine edges give least resistance, it is best not to make them "razor sharp" because they damage too easily in use. It is possible to build up the correct "shape" to any board by using foam shaped to suit and covered with fiberglass. If fiberglassing the outside of the hull, it is best to tuck fiberglass cloth into the trunk to protect the exposed plywood edge.

FIG. 10-2 - A section through a "faired" wood daggerboard. The same principle can be applied to rudders and centerboards. Note that the thickest part is located approximately 1/3 the width of the board aft of the forward or leading edge. Edges should be radiused slightly to prevent damage.

With daggerboards that tend to bind or jam in use, a little paraffin will usually smooth things out. Sometimes the board will warp or the slot will not be quite the same shape as the board. This may require reshaping or replacing the board. Sometimes the board will fit too loosely in the slot. This will cause working at the pin on centerboards, and sometimes banging from side to side. Small blocks or metal angles can be used to make the fit at the slot tighter. Some device is often provided, especially with steel centerboards, to limit the forward travel of the centerboard to keep it from banging against the forward portion of the centerboard trunk. This is a good idea because pennants sometimes break, or a lock pin will fail, and the board will fall forward at a crashing speed.

.....rigging maintenance

Give your rigging a comprehensive check at least twice each season, preferably just before and just after the season. The maintenance routine will vary depending on whether you leave your boat in the water year-round, or haul out between seasons, or if you trailer your boat in and out of the water with each sail. The rigging deserves the same attention as that given to any "machine". That is, maintenance is a never-ending duty of the owner. You must keep an eye out at all times for danger signals which may cause a failure in the rig. Any chafed lines or sails, or fraying wire ropes should be repaired or replaced BEFORE the next voyage. Corroded fittings, frozen sheaves, or fastenings working loose in deck hardware should be attended to as soon as possible. A little oil or wax can sometimes work wonders. Care of the spars will vary depending on what they are made from. Aluminum spars require virtually no maintenance except for keeping them clean and preferably coated with wax. Aluminum tends to give off an oily residue that is not harmful, but can discolor the sails. Check for corrosion of the spars, especially where fittings are fastened. Also sight along the spars to make sure there are no bends, crimps, or "twists". A little paraffin in the boltrope groove will aid in hoisting the sails.

Wood spars require more attention. They should be well protected with a surface coating of spar varnish or synthetic coating such as polyurethane or paint. Also check for dry rot, especially at the mast base. If the mast is a glued-up type, check to see that glue joints are tight. Also give a check to all fastenings to see that they are tight and haven't worked free. Whether the mast is aluminum or wood, it should be stored so it is well supported along its length. If the mast is fitted with diamond stays or jumper stays, these can be left set-up while the mast is stored. Wood masts should be stored covered, but with good air circulation.

Always try to keep some spare parts with the boat for the rigging. Turnbuckle parts, cotter keys, and clevis pins always seem to get lost or damaged just when you need them. If you trailer your boat, be sure that no part of the rigging hangs down and drags on the pavement. A few miles of this will wear the jaws right off a turnbuckle. It is also a good idea to secure the ends of turnbuckles to the rigging as it is common for them to vibrate loose and be lost on the trip to or from the water. Also avoid putting bends or crimps in the stays when coiling them for travel. With rudders or dagger boards made from wood, avoid storing these in direct sun as they may tend to warp.

The number one enemy of Dacron sails is friction and chafing, mainly against other parts of the boat. Wrap the stays, spreaders, and other parts that contact the sails, with tape or other "chafing gear" to prevent wear on the fabric or stitching. Keep a close check for wear in the area of the headboard and clew regions. Keep sand out of the bolt rope groove of the mast and don't allow the sails to get dirty or sandy. Inspect the sails before each trip for small rips or torn stitching and take care of it as soon as possible to avoid more extensive damage and higher repair costs. Clean Dacron sails in a bathtub with fresh water and mild detergent. Air dry the sails, but avoid direct sunlight and condensation on the "down" side. Never expose the sails to any source of extreme heat. Don't wash Dacron sails in a washing machine nor dry them in a dryer. Never cram your sails tightly in the sail bag, especially if they are damp. Fold them or stuff them loosely AFTER you have removed the battens. Try to keep the bag open somewhat and store them where air will circulate. Don't put clean sails into a dirty sail bag; wash the bag as well.

 

Glossary

BACKSTAY -The wire that supports the mast from the aft side, running from the masthead to the aft end of the boat.
BATTENS-Thin semi-rigid strips of wood or synthetic material inserted into pockets in the sail in order to maintain the shape of the sail.
BATTEN POCKETS-Pockets sewn in the sail that receive the battens.
BECKET-A fitting on a block for splicing or tying off the end of a line, or to receive a fitting.
BELAY, TO-To belay means to stop and secure a line so it won't move.
BEND, TO-To bend is to fasten something; specifically, to fasten or attach the sails to the spars and rigging.
BLOCK-A wood, metal, or synthetic casing containing one or more pulleys or sheaves.
BOLT ROPE-A length of rope sewn along the length of the luff, and sometimes the foot of a sail, for fitting it into the groove of the spars.
BOOM-The pivoting horizontal "pole" attached to the aft side of the mast to control the foot of the sail.
BOOM BAIL-A "U"-shaped strap wrapped around the lower portion of the boom to which fittings can be attached.
BOOM CRUTCH-A vertical support to hold up the boom when the sails are furled or when hoisting the mainsail in order to keep the boom in position.
BOOM VANG-A tackle used to pull the boom down in order to control the shape of the sail and movement of the boom.
BRIDLE-A line secured at each end with attachment or control taken at the middle.
BRUMMEL HOOK-A patented hook used in pairs to join or connect two objects, usually lines to other lines or to sails.
BULLET BLOCK-A small block with a single sheave and no shackle.

CAM CLEAT-A fitting used to belay a line utilizing two pivoting serrated cams that allow for immediate adjustment.
CAT RIG-A sail rig with a single mast well forward and a single sail attached to the aft side of the mast.
CENTERBOARD-A vertical plate sticking out the bottom of the boat that pivots up and down about the centerboard pin.
CENTERBOARD PENNANT-The line used to raise and lower the centerboard.
CENTERBOARD PIN-A bolt or rod that secures the centerboard to the centerboard trunk and allows the board to pivot up and down.
CENTERBOARD TRUNK-The casing in boat that houses the centerboard.
CHAINPLATE-Metal strap connected to the hull to which the shrouds are attached in order to distribute the strains set up in the rigging to the boat.
CHAINPLATE COVER-A plate used to cap the area of the deck where the top of the chainplate protrudes.
CHEEK BLOCK-A block with a base that is fastened to a surface, such as a deck. The sheave of the block is usually parallel with this base.
CLEAT-A fitting to which a line can be belayed.
CLEW-The lower aft corner of the sail, usually fitted with a cringle for the outhaul.
CLEW OUTHAUL-Any device or fitting used to adjust and secure the clew of the mainsail. Sometimes referred to as the "boom outhaul".
CLEVIS PIN-A pin used to close the opening of a shackle or clevis.
COAMING PULLEY-See SHEAVE BOX.
CRINGLE-A metal ring or grommet around a hole in the sail for reinforcement.
CUNNINGHAM-A line device or cringle located several inches above the tack of the sail and used with a downhaul to control the tension along the luff and hence the shape of the sail. Primarily used in competition craft.

DAGGERBOARD-A vertical plate that sticks out the bottom of the boat by sliding up and down within the daggerboard trunk.
DAGGERBOARD TRUNK-The case or the housing in the boat for the daggerboard.
DEADEYE-An eye fitting which secures the "deadend" (knotted or spliced) or standing end of a line.
DIAMOND SPREADER; STAY-An intermediate spreader and stay arrangement to reinforce the mast, with the configuration forming a "diamond" shape. The stays do not attach to the boat, only to the mast.
DOWNHAUL-Any line designed to haul down something, for example the downhaul used to pull down on the gooseneck when on a slide, or a "Cunningham".

EYE STRAP-A metal strap fitting shaped to form an "eye" which can be used to secure a fitting or line.

FAIRLEAD-Any fitting used to guide or change direction of a line, giving it a "fair lead" in its travel. Fairleads pre vent chafing as well.
FIDDLE BLOCK-A block with two sheaves, one above the other, one usually being smaller than the other. It resembles a "fiddle".
FOOT-The lower portion of the sail.
FORESTAY-The wire that supports the mast from the forward side, running from the top or near the top of the mast to the forward point of the hull. Also used to support the luff of the jib on sloop rigs.

GENOA ("jenny")-A large oversize jib sail that overlaps the mainsail.
"GO FASTER"-See BOOM VANG.
GOOSENECK-The fitting used to attach the boom to the mast and which permits the boom to pivot, usually by a universal joint-type action. The gooseneck can also be used to secure the tack of the sail.
GUDGEONS-Eye fittings used on the aft end of the boat (or sometimes on the rudder) to receive the pintles in order for the rudder to pivot.

HALYARDS-The lines used to raise and lower the sails. External halyards are located outside the mast; internal halyards pass through the inside of a hollow mast.
HALYARD HOOK-A restraining fitting used with wire rope halyards that have ball joint fittings in order to lock and belay the ball joint at a predetermined position.
HANKS-Clip or snap fittings sewn into the luff of the jib for attaching the sail to the stay.
HEAD-The top corner of the sail.
HEADBOARD-The reinforcing member sewn into the sail at the head, usually fitted with a cringle.
HEAD SAIL-Any sail forward of the mast, such as the jib.
"HIKING STICK"-See TILLER EXTENSION.
HOUND-A wraparound strap-type mast fitting used to secure stays and other fittings to the mast.
HYFIELD LEVER-A lever actuator with scissors action for adjusting tension on stays, halyards, etc. Usually used with competition craft.

INSIGNIA-The decal or emblem sewn into the sail to graphically portray the class or design of a boat. Sometimes in combination with a number which identifies the registry of the particular boat in the class organization.

JAM CLEAT-Any cleat into which a line can be "jammed" in order to belay it, as opposed to a cleat, which must have the line "turned" or wrapped around it.
JIB-The sail located forward of the mast. Sometimes called the "headsail".
JIB HALYARD BLOCK-A block used on jibhead rigs to change direction of the jib halyard near the head of the jib when it is raised.
JIBHEAD RIG-A sloop rig where the forestay does not reach to the masthead.
JIB SHEET-The line used to control the jib.
JUMPER STAY; STRUT-An arrangement used on jibhead rigs to reinforce the forward side of the mast at the top. The stay does not attach to the boat only to the mast.

"KICKING STRAP"-See BOOM VANG.

LATEEN RIG, SAIL-A sail rig with an unsupported mast, usually short, with a triangular shaped sail attached to one or two "booms". The upper boom is usually called a "yard". The sail is not attached to the mast.
LEECH-The aft portion of the sail.
LEEWARD-Pronounced "loo-erd". Downwind, or away from the direction which the wind is coming.
LINE-A length of rope or wire rope performing some function in the boat.
LOOSE FOOTED-A mainsail attached to the spars only at the tack and clew in the foot portion so that the foot can form freely to the wind.
LUFF-The forward portion of the sail.

MAINSAIL-The "main sail" on the boat, or one located on the aft side of the mast.
MAINSHEET-The line used to control the mainsail, indirectly through controlling the boom position.
MAST-The vertical spar used to support the sails.
MASTHEAD-The top of the mast.
MASTHEAD RIG-A sloop rig where the forestay reaches to the masthead.
MAST RAKE-The angle the mast makes from vertical when viewed in profile. A mast set exactly vertical has no rake.
MAST STEP-The fitting or receptacle that receives the base of the mast to secure it in position.

NICOPRESS-A patented method used to form an eye splice in wire rope by the use of special clamping devices.

PAD EYE-An eye fitting with a substantial base used to secure fittings such as blocks to the deck or cabin top.
PINTLES-The "pins" attached to the rudder (or sometimes to the boat), which fit into the gudgeons thereby allowing the rudder to pivot.

REEVE, TO-To reeve is to pass a line through any aperture such as a block or eye. The past tense is ROVE.
RIG-The configuration of the spars and sails of a boat.
RIG, TO-To put the spars and related equipment in position so the boat is ready for sailing.
RIGGING-Equipment used to support the spars and manipulate the sails.
ROLLER REEFING-Equipment that allows the boom to roll thereby furling the sail onto the boom and reducing sail area, especially in heavy weather. Reefing means to decrease sail area by folding or furling the sail.
ROACH-The up and outward curve in the leech of the sail.
ROPE-Generally, any stranded or braided cordage.
RUDDER-Device that steers the boat.
RUDDER STOP-Device that prevents the rudder from floating up and out of secure it in position.
RUNNING RIGGING-The lines that literally "run" or move about the boat for use in hoisting, lowering, and controlling the sails.

SHACKLE-A "U"-shaped link with openable pin for connecting or attaching various components.
SHEAVE-Pronounced "shiv". A grooved wheel or pulley with axle, used for example in a block, to prevent line wear and to change direction of the line.
SHEAVE BOX-A fitting with a sheave used at the exit point on a spar where internal halyards pass through.
SHEET-A line used to control directly or indirectly the trim of a sail.
SHEET LOAD-The direction the line used for the sheets takes.
SHROUDS-The stays that support the mast at the sides.
SLOOP-A single masted sailboat with at least one sail forward of the mast, and one sail aft of the mast.
SNUBBING WINCH-A small winch with no handle used to control a sheet.
SPAR-A general term for any mast, boom, or other "pole" used to spread out the sails. SPINNAKER ("chute")-The big parachute-shaped sail located forward of the mast used mostly on competition boats on courses before the wind.
SPREADERS-Cross members jutting out sideways from the mast to "spread out" the shrouds in order to reinforce the mast.
STANDING RIGGING-The fixed wires and ropes that "stand" or stay in position at all times when the mast is stepped. The standing rigging consists of all the stays.
STAYS-The wires that support the mast and spars.
STAY ADJUSTER-A fitting which both connects the stay to the boat and allows the length of the stay to be adjusted. It is different from a turnbuckle in that the adjustment mechanism consists of a series of holes with a clevis pin.
STEP, TO-To step the mast means to put the mast in position on the boat.
STEMHEAD-Literally the head of the boat at the stem, or the farthest forward point on deck. Generally considered the point where the forestay attaches to the hull.
SWAGE-To press a fitting onto wire rope by the use of cold dies in pairs.
SWIVEL DECK BLOCK-A block with a base for deck mounting and which allows the block to swivel to any position and stand vertical in use.

TACK-The lower forward corner of the sail usually fitted with a cringle. Also means sailing a zigzag course.
TACKLE-A system of blocks and rope arranged to decrease the effort required to move a load or object.
TANGS-Fittings used to secure stays to the mast.
THIMBLE-A teardrop-shaped grooved ring in a looped or spliced eye to prevent chafe and wear in the eye.
TILLER-The handle used to control the rudder.
TILLER EXTENSION-An additional handle connected to the forward end of the tiller by a pivot or universal-type fitting so the helmsman can control the rudder when hiking outboard on a tack.
TOGGLE-A universal swivel connector used to reduce bending at the jaws or forks of swaged fittings on wire rope, such as with stays.
TRACK-A formed metal or plastic rail used to carry fittings or to allow them to move.
TRACK SLIDE-A fitting designed to slide along a track and often to which other fittings are attached, or which may be connected to a sail for use in hoisting.
TRAVELER-A line or fitting which allows the mainsheet tackle to travel or move from one side of the boat to the other.
TRAVELER BLOCK-A block with two sheaves and no shackle, one sheave above the other and at right angles to each other, for use with rope travelers.
TURNBUCKLES-A fitting that connects the stay to the boat and allows adjustment by means of screw threaded barrels.

WHIPPING-The binding agent or method used on the end of a piece of rope to prevent fraying and unraveling.
WINCH-A mechanical revolving drum appliance used to gain power in hauling or pulling in a line.
WINDWARD-Toward the direction from which the wind is blowing.
WIRE ROPE-Rope made from twisted strands of iron or steel.
WORKING SAILS-The sails used under normal sailing conditions, usually consisting of the mainsail and the regular or working jib on a sloop rig.

YACHT BRAID-Special braided rope that is easy on the hands and resistant to kinks and jamming.

The End