UK-Halsey's Encyclopedia of Sails
-- Spinnaker Dousing
METHOD 1: LAZY GUY TAKEDOWN
The lazy guy takedown uses the idle guy on the leeward side to insure getting the spinnaker into the mainsail’s blanket zone. The lazy guy is led forward and under the foot of the genoa. When the sail is released from the pole, the lazy guy is quickly tightened and the spinnaker is gathered.
METHOD 2: RELEASING THE SHACKLE
The guy is eased until the pole reaches the forestay. Never let the pole smack the headstay, or you may break the pole, the headstay or both. The pole is lowered until it can be reached easily by the bowman who opens the snap-shackle that connects the guy to the spinnaker.
In this diagram the genoa is omitted to show the lazy guy brought forward to the fore-deck so that the crew can gather the spinnaker by the lazy guy under the genoa. Lazy Guy
As the spinnaker is released from the guy, one or more crewmembers sitting to leeward of the main pulls on the sheet and brings in the spinnaker. The halyard is eased quickly for the first third of the distance, which collapses the sail. Once the chute starts coming aboard, the rest of the halyard is eased as fast as the crew can gather without the sail falling in the water. Some racing crews prefer to take the sail down into the forward hatch to keep the sail from getting tangled with the jib sheet.
METHOD 3: RUNNING GUY
This system is basically the same as Method 1, except that the guy remains attached to the sail. First the guy is eased until the pole kisses the headstay, and then it is completely released as the crew gathers the sail. Great care must be taken to make sure that the guy is completely clear, with no knots, so it can run free. The sail is then gathered in the same location as in Method 1.
METHOD 4: STRETCH AND BLOW
This is a heavy air technique designed to depower the spinnaker. In this method, the foot of the spinnaker is pulled tight, making it impossible for the corners to fall into the water. To keep the clews out of the water and make the foot tight, the pole is eased forward to the headstay and the spinnaker sheet is tightened as much as possible. After the foot is pulled tight, the halyard is cast off and let run. The wind blows the sail parallel to the water allowing the crew to pull the sail in by its leeches. If the sail does touch the water, it won’t be able to scoop up a lot of water if the two clews are kept tight.
Monday, May 16, 2011
UK Halsey Spinnaker Jibe Techniques
UK-Halsey's Encyclopedia of Sails -- Spinnaker Jibes
Perhaps no sailing maneuver calls for better crew coordination than the spinnaker jibe. There are two basic jibing techniques:
1. Dip-Pole: This system is used on boats over 30 feet. It utilizes two sheets and two guys attached to each clew of the spinnaker.
2. End for End: This jibing technique is universally used on one designs and is workable on boats up to 30 feet.
The Dip-Pole Jibe:
With two sheets and two guys, this system converts the spinnaker jibe from the classification of “To be avoided at all costs” to the point where a practiced crew can handle a jibe with ease. The beauty of this method is the strain of the spinnaker is taken with one set of sheets and guys so that during the jibe the bowman can easily get the unloaded new guy into the pole. The dip pole method works like this:
1. When the call for the jibe comes, the mastman raises the inboard end of the spinnaker pole up the mast so that when the pole swings through the foretriangle it will clear the forestay.
2. The spinnaker pole topping lift is lowered so that the outboard end is just above the bow pulpit when it swings across the boat. (To ensure that the pole swings across the bow in the same arc, jibe after jibe you need to mark the mast and the topping lift. The mast should be marked at the height that the inboard end of the pole reaches when it is raised, while the topping lift is marked so that the outboard end of the pole may always be lowered to the same position. )
3. The bowman goes to the pulpit with unloaded spinnaker guy in hand.
4. The helmsman turns the boat dead downwind.
5. As the boat turns, the spinnaker guy is tight-ened until the pole is perpendicular to the centerline of the boat. Trimming the pole perpendicular like this rotates the spinnaker to what will be the new leeward side of the boat.
6. When the boat is dead downwind, the skipper yells “Trip” which tells the mastman to open the outboard jaw of the pole so that the guy flies free of the pole. (Make sure that the pole is always set with the jaws facing up.) With the guy free, the sail is controlled by the two spinnaker sheets.
7. The mastman pulls the pole to the bowman in the pulpit using the trip line.
8. As the pole comes over, the mainsail is swung over to the new side.
9. When the bowman gets the new guy in the spinnaker pole jaw, he yells “Made!” which tells the person trimming the guy that he can now tension it. Once the guy is tensioned, the old sheet is released.
10. Finally, the spinnaker is trimmed to the wind, the topping lift is raised and the inboard end of the pole is lowered.
THE END-FOR-END JIBE
The end-for-end method is only viable on boats below 30 feet because the spinnaker pole becomes free from the mast during the jibe. For the crew to handle the loose pole, the pole must be small and light enough to be lifted and pushed into position.
During an end-for-end jibe, the pole is disconnected from the mast, and disconnected from the sail. Free from the sail, the pole hangs from the topping lift. The end that was hooked to the mast is then connected to the spinnaker sheet and the end that was hooked to the spinnaker guy is hooked to the mast.
This system requires a bridle for both the topping lift and the foreguy so that neither require trimming during the jibe. The pole should be attached to the mast with the jaws up.
The steps for an end-to-end jibe are as follows:
1. As the jibe starts, either the downhaul or guy is eased to facilitate removing the pole from the mast.
2. The sheet is brought in close to the shroud where the foredeck crew can grab it.
3. The boat is turned dead downwind.
4. The pole is disconnected from the mast.
5. The guy is released from the end of the pole.
6. The old sheet is connected to the end of the pole that was on the mast.
7. The pole is pushed out and forward on the new windward side.
8. The pole is attached to the mast and the mastman yells made.
9. The cockpit crew trims the spinnaker to the wind.
Perhaps no sailing maneuver calls for better crew coordination than the spinnaker jibe. There are two basic jibing techniques:
1. Dip-Pole: This system is used on boats over 30 feet. It utilizes two sheets and two guys attached to each clew of the spinnaker.
2. End for End: This jibing technique is universally used on one designs and is workable on boats up to 30 feet.
The Dip-Pole Jibe:
With two sheets and two guys, this system converts the spinnaker jibe from the classification of “To be avoided at all costs” to the point where a practiced crew can handle a jibe with ease. The beauty of this method is the strain of the spinnaker is taken with one set of sheets and guys so that during the jibe the bowman can easily get the unloaded new guy into the pole. The dip pole method works like this:
1. When the call for the jibe comes, the mastman raises the inboard end of the spinnaker pole up the mast so that when the pole swings through the foretriangle it will clear the forestay.
2. The spinnaker pole topping lift is lowered so that the outboard end is just above the bow pulpit when it swings across the boat. (To ensure that the pole swings across the bow in the same arc, jibe after jibe you need to mark the mast and the topping lift. The mast should be marked at the height that the inboard end of the pole reaches when it is raised, while the topping lift is marked so that the outboard end of the pole may always be lowered to the same position. )
3. The bowman goes to the pulpit with unloaded spinnaker guy in hand.
4. The helmsman turns the boat dead downwind.
5. As the boat turns, the spinnaker guy is tight-ened until the pole is perpendicular to the centerline of the boat. Trimming the pole perpendicular like this rotates the spinnaker to what will be the new leeward side of the boat.
6. When the boat is dead downwind, the skipper yells “Trip” which tells the mastman to open the outboard jaw of the pole so that the guy flies free of the pole. (Make sure that the pole is always set with the jaws facing up.) With the guy free, the sail is controlled by the two spinnaker sheets.
7. The mastman pulls the pole to the bowman in the pulpit using the trip line.
8. As the pole comes over, the mainsail is swung over to the new side.
9. When the bowman gets the new guy in the spinnaker pole jaw, he yells “Made!” which tells the person trimming the guy that he can now tension it. Once the guy is tensioned, the old sheet is released.
10. Finally, the spinnaker is trimmed to the wind, the topping lift is raised and the inboard end of the pole is lowered.
THE END-FOR-END JIBE
The end-for-end method is only viable on boats below 30 feet because the spinnaker pole becomes free from the mast during the jibe. For the crew to handle the loose pole, the pole must be small and light enough to be lifted and pushed into position.
During an end-for-end jibe, the pole is disconnected from the mast, and disconnected from the sail. Free from the sail, the pole hangs from the topping lift. The end that was hooked to the mast is then connected to the spinnaker sheet and the end that was hooked to the spinnaker guy is hooked to the mast.
This system requires a bridle for both the topping lift and the foreguy so that neither require trimming during the jibe. The pole should be attached to the mast with the jaws up.
The steps for an end-to-end jibe are as follows:
1. As the jibe starts, either the downhaul or guy is eased to facilitate removing the pole from the mast.
2. The sheet is brought in close to the shroud where the foredeck crew can grab it.
3. The boat is turned dead downwind.
4. The pole is disconnected from the mast.
5. The guy is released from the end of the pole.
6. The old sheet is connected to the end of the pole that was on the mast.
7. The pole is pushed out and forward on the new windward side.
8. The pole is attached to the mast and the mastman yells made.
9. The cockpit crew trims the spinnaker to the wind.
UK Halsey Spinnaker Set up & Trim Techniques
UK-Halsey's Encyclopedia of Sails
-- Spinnaker Setup and Trim
The steps in preparing to set a spinnaker and their most efficient sequence varies depending upon the boat, the crew and the conditions. The basic steps and their sequence are:
1. Attach the turtle. On boats under 30 feet, it can be clipped in the bow pulpit. On larger boats (and small ones when it’s blowing hard) the turtle should be hooked at the rail or to the middle of the foredeck about halfway between the mast and headstay. Make sure that the head and both clews are outside of the bag.
2. Position the spinnaker pole so that the out-board end of the pole is over the side of the boat that will be the windward side when the spinnaker is hoisted.
3. Lead the guy through the outboard end of the pole and then attach it to the spinnaker.
4. Fasten the sheet to the sail. Double-check to be sure that it is not tangled with the life lines.
5. Attach the pole to the mast and raise the inboard end of the pole to the height which seems appropriate.
6. Attach the topping lift and foreguy and hoist the pole at right angles to the mast.
7. Attach the spinnaker halyard.
When racing and the boat is heeling over, it’s important that the bowman keep his or her weight to windward while setting up the spinnaker. To do this, the bowman has to break up the jobs listed above, and do them on two different tacks. For instance, when rounding the windward mark to port, have the bowman clip the spinnaker bag to the port rail while on your final port tack to the mark. This way he can hook on the turtle and attach the sheets and guys while on the windward side. When you tack to starboard, he can get the pole ready while keeping his weight to windward. If he has to do any of the rigging at the bow, he should plan out his moves ahead of time so that he spends the least amount of time possible on the bow, i.e., if he has to lead the sheets around the forestay, have the cockpit crew make sure the lines are untangled so that they’ll run free when he pulls on them. Weight on the bow, no matter how light, disturbs the helm.
THE SET:
The sequence of the actual set depends on whether the spinnaker is set flying or stopped in rubber bands. In either case, do not to trim the chute fully until the halyard is hoisted and cleated.
TO SET FLYING
1. Trim the spinnaker guy so that the clew of the spinnaker reaches the jaw of the pole when the pole is laying against the headstay.
2. Trim the spinnaker sheet until the clew is just past the shrouds.
3. Hoist the spinnaker all the way up, then drop the jib.
4. Trim the spinnaker to the wind.
TO SET STOPPED
Having the sail stopped in rubber bands is some-times used when setting a spinnaker in heavy winds. The rubber bands keep the sail under control and break away when your crew trims the sheet.
1. Trim the spinnaker guy so that the clew of the spinnaker reaches the jaw of the pole when the pole is laying against the headstay.
2. Trim the spinnaker sheet until the clew is just past the shrouds.
3. Hoist the sail until it is all the way up.
4. Over-trim the sheet to break open the stops.
5. Trim the sheet and the guy as required by the wind, starting with the guy first.
6. Drop the jib.
TRIMMING THE SPINNAKER
The tools available for maintaining the proper trim of a spinnaker are limited; they consist of pole position and sheet position. Pole position is variable both fore and aft and up and down. Sheet position is varied primarily by pulling it in or letting it out. Normally, the sheet is led to the leeward rail, at or near the stern, but sheet position can also be varied by the use of a spinnaker twing (a block and tackle that changes the lead angle of the sheet). A forward lead is only recommended when running in strong winds to help stabilize the spinnaker.
The spinnaker is a versatile sail which can be used when the wind is blowing anywhere from 60 to 180 degrees off the bow. Optimal sailing angles are determined by wind strength. In stronger winds, you won’t be able to fly the spinnaker as close to the wind because your boat will be overpowered by the spinna-ker at the closer angles. If the wind is too light, sailing at the broader angles will be too slow.
At the forward end of this range, from 60 to 130 degrees, the wind will be flowing across the spinnaker from the luff to leech. (The principles involved in trimming a genoa are also applicable here.) At some point behind 130 degrees, or thereabouts, the wind blows directly into the sail and ceases to move across it. The sail is then said to be “stalled”, and the principles of trim change accordingly.
REACHING TRIM
When the wind is flowing across the spinnaker from luff to leech, reaching considerations apply. If the wind is forward of abeam, the pole should be close to the headstay. “Close” means as close as possible to the headstay without allowing the two to touch. If the pole does rub against the stay, there’s a risk of damage to the pole, the rig, or both. Fore and aft position is controlled by the afterguy. The sheet should be trimmed just enough to prevent the sail from collapsing. The trim should be constantly tested by easing the sheet slightly until the luff commences to curl, then trimming again when the curl becomes excessive.
Put telltales on the leeches of the spinnaker midway between the head and clews. When reaching, read the telltales as you would on a jib. Keep both the windward and the leeward telltales streaming straight back. When both are streaming aft, the leading edge of the chute will curl some — but don’t worry. A little bit of curl is fast.
Pole height is adjusted by means of the pole lift and foreguy. In any given wind condition, the clew will find its own height. It is commonly recommended that the pole height be adjusted to match that found by the clew. In that condition, the draft will be approxi-mately in the center of the sail, which is the right place for it. If the pole is slightly lower than the clew, the sail will become asymmetrical, with the draft slightly forward of the center. This asymmetrical trim will be faster on close reaches. Putting the pole higher than the clew moves the draft behind the middle. But this always produces slow going: NEVER CARRY THE POLE HIGHER THAN THE CLEW.
At all times, sufficient tension should be maintained on the pole lift, the foreguy and the afterguy to keep the outboard end of the pole firmly in position. When all other adjustments have been made, the inboard end of the pole should be moved up or down on its track to keep the pole perpendicular to the mast. Remember that adjustments to the inboard end are a low priority item. Unless it’s grossly out of position, meaning feet, not inches, don’t waste time on it until everything else is set correctly.
As the wind moves aft, ease the sheet, while at the same time bringing the pole aft. If the pole is correctly placed fore and aft, the depth of the draft in the sail will be uniform from the top to bottom, and the luff of the sail will extend directly upward from the end of the pole. If the pole is too far forward, the pocket in the lower part of the sail will be too deep, and the luff will angle out to windward from the end of the pole. If the pole is too far aft, the foot of the sail will be too flat, and the luff will angle off to leeward from the pole end.
RUNNING TRIM
When on a run, with the wind blowing directly into the sail, it is desirable to present as much area as possible, subject to certain limitations. The pole should be kept as far aft as possible without making the foot too flat or causing the luff to be other than straight up from the pole end.
On a run, in a good breeze (you shouldn’t be on a run unless the wind is blowing over 14 knots), the clew may seek to rise higher than is desirable. If the foot gets too high, you lose projected area. Therefore, move the spinnaker sheet lead forward to keep the clew down. That way you won’t have to raise the pole too high.
Even in a “stalled” sail, there is some flow of air along the leeward side of the sail and therefore some aerodynamic force, which increases the wind’s normal force. This flow occurs at the sides of the sail, moving from both leeches for a short distance toward the center of the sail. A flatter sail projects more area, hampering flow on the leeward side of the sail. A fuller sail projects less area, but generates more flow. A similar flow of air also moves over the top of the sail and down the front toward the center. This overhead flow travels further and is more powerful than the flow atthe sides. If the foot of the sail is held too low, this overhead flow will be curtailed; if not low enough, too much projected area will be lost.
Proper downwind trim involves balancing the extra thrust resulting from the aerodynamic forces acting around the edges of a deeper setting against the greater projected area obtained with a flatter setting. Normally, best results are obtained at the flatter end of the range, but remember that it is quite possible to trim the sail too flat or have the foot too low. Thus, the only way to find the best shape is to experiment while watching your speedometer.
-- Spinnaker Setup and Trim
The steps in preparing to set a spinnaker and their most efficient sequence varies depending upon the boat, the crew and the conditions. The basic steps and their sequence are:
1. Attach the turtle. On boats under 30 feet, it can be clipped in the bow pulpit. On larger boats (and small ones when it’s blowing hard) the turtle should be hooked at the rail or to the middle of the foredeck about halfway between the mast and headstay. Make sure that the head and both clews are outside of the bag.
2. Position the spinnaker pole so that the out-board end of the pole is over the side of the boat that will be the windward side when the spinnaker is hoisted.
3. Lead the guy through the outboard end of the pole and then attach it to the spinnaker.
4. Fasten the sheet to the sail. Double-check to be sure that it is not tangled with the life lines.
5. Attach the pole to the mast and raise the inboard end of the pole to the height which seems appropriate.
6. Attach the topping lift and foreguy and hoist the pole at right angles to the mast.
7. Attach the spinnaker halyard.
When racing and the boat is heeling over, it’s important that the bowman keep his or her weight to windward while setting up the spinnaker. To do this, the bowman has to break up the jobs listed above, and do them on two different tacks. For instance, when rounding the windward mark to port, have the bowman clip the spinnaker bag to the port rail while on your final port tack to the mark. This way he can hook on the turtle and attach the sheets and guys while on the windward side. When you tack to starboard, he can get the pole ready while keeping his weight to windward. If he has to do any of the rigging at the bow, he should plan out his moves ahead of time so that he spends the least amount of time possible on the bow, i.e., if he has to lead the sheets around the forestay, have the cockpit crew make sure the lines are untangled so that they’ll run free when he pulls on them. Weight on the bow, no matter how light, disturbs the helm.
THE SET:
The sequence of the actual set depends on whether the spinnaker is set flying or stopped in rubber bands. In either case, do not to trim the chute fully until the halyard is hoisted and cleated.
TO SET FLYING
1. Trim the spinnaker guy so that the clew of the spinnaker reaches the jaw of the pole when the pole is laying against the headstay.
2. Trim the spinnaker sheet until the clew is just past the shrouds.
3. Hoist the spinnaker all the way up, then drop the jib.
4. Trim the spinnaker to the wind.
TO SET STOPPED
Having the sail stopped in rubber bands is some-times used when setting a spinnaker in heavy winds. The rubber bands keep the sail under control and break away when your crew trims the sheet.
1. Trim the spinnaker guy so that the clew of the spinnaker reaches the jaw of the pole when the pole is laying against the headstay.
2. Trim the spinnaker sheet until the clew is just past the shrouds.
3. Hoist the sail until it is all the way up.
4. Over-trim the sheet to break open the stops.
5. Trim the sheet and the guy as required by the wind, starting with the guy first.
6. Drop the jib.
TRIMMING THE SPINNAKER
The tools available for maintaining the proper trim of a spinnaker are limited; they consist of pole position and sheet position. Pole position is variable both fore and aft and up and down. Sheet position is varied primarily by pulling it in or letting it out. Normally, the sheet is led to the leeward rail, at or near the stern, but sheet position can also be varied by the use of a spinnaker twing (a block and tackle that changes the lead angle of the sheet). A forward lead is only recommended when running in strong winds to help stabilize the spinnaker.
The spinnaker is a versatile sail which can be used when the wind is blowing anywhere from 60 to 180 degrees off the bow. Optimal sailing angles are determined by wind strength. In stronger winds, you won’t be able to fly the spinnaker as close to the wind because your boat will be overpowered by the spinna-ker at the closer angles. If the wind is too light, sailing at the broader angles will be too slow.
At the forward end of this range, from 60 to 130 degrees, the wind will be flowing across the spinnaker from the luff to leech. (The principles involved in trimming a genoa are also applicable here.) At some point behind 130 degrees, or thereabouts, the wind blows directly into the sail and ceases to move across it. The sail is then said to be “stalled”, and the principles of trim change accordingly.
REACHING TRIM
When the wind is flowing across the spinnaker from luff to leech, reaching considerations apply. If the wind is forward of abeam, the pole should be close to the headstay. “Close” means as close as possible to the headstay without allowing the two to touch. If the pole does rub against the stay, there’s a risk of damage to the pole, the rig, or both. Fore and aft position is controlled by the afterguy. The sheet should be trimmed just enough to prevent the sail from collapsing. The trim should be constantly tested by easing the sheet slightly until the luff commences to curl, then trimming again when the curl becomes excessive.
Put telltales on the leeches of the spinnaker midway between the head and clews. When reaching, read the telltales as you would on a jib. Keep both the windward and the leeward telltales streaming straight back. When both are streaming aft, the leading edge of the chute will curl some — but don’t worry. A little bit of curl is fast.
Pole height is adjusted by means of the pole lift and foreguy. In any given wind condition, the clew will find its own height. It is commonly recommended that the pole height be adjusted to match that found by the clew. In that condition, the draft will be approxi-mately in the center of the sail, which is the right place for it. If the pole is slightly lower than the clew, the sail will become asymmetrical, with the draft slightly forward of the center. This asymmetrical trim will be faster on close reaches. Putting the pole higher than the clew moves the draft behind the middle. But this always produces slow going: NEVER CARRY THE POLE HIGHER THAN THE CLEW.
At all times, sufficient tension should be maintained on the pole lift, the foreguy and the afterguy to keep the outboard end of the pole firmly in position. When all other adjustments have been made, the inboard end of the pole should be moved up or down on its track to keep the pole perpendicular to the mast. Remember that adjustments to the inboard end are a low priority item. Unless it’s grossly out of position, meaning feet, not inches, don’t waste time on it until everything else is set correctly.
As the wind moves aft, ease the sheet, while at the same time bringing the pole aft. If the pole is correctly placed fore and aft, the depth of the draft in the sail will be uniform from the top to bottom, and the luff of the sail will extend directly upward from the end of the pole. If the pole is too far forward, the pocket in the lower part of the sail will be too deep, and the luff will angle out to windward from the end of the pole. If the pole is too far aft, the foot of the sail will be too flat, and the luff will angle off to leeward from the pole end.
RUNNING TRIM
When on a run, with the wind blowing directly into the sail, it is desirable to present as much area as possible, subject to certain limitations. The pole should be kept as far aft as possible without making the foot too flat or causing the luff to be other than straight up from the pole end.
On a run, in a good breeze (you shouldn’t be on a run unless the wind is blowing over 14 knots), the clew may seek to rise higher than is desirable. If the foot gets too high, you lose projected area. Therefore, move the spinnaker sheet lead forward to keep the clew down. That way you won’t have to raise the pole too high.
Even in a “stalled” sail, there is some flow of air along the leeward side of the sail and therefore some aerodynamic force, which increases the wind’s normal force. This flow occurs at the sides of the sail, moving from both leeches for a short distance toward the center of the sail. A flatter sail projects more area, hampering flow on the leeward side of the sail. A fuller sail projects less area, but generates more flow. A similar flow of air also moves over the top of the sail and down the front toward the center. This overhead flow travels further and is more powerful than the flow atthe sides. If the foot of the sail is held too low, this overhead flow will be curtailed; if not low enough, too much projected area will be lost.
Proper downwind trim involves balancing the extra thrust resulting from the aerodynamic forces acting around the edges of a deeper setting against the greater projected area obtained with a flatter setting. Normally, best results are obtained at the flatter end of the range, but remember that it is quite possible to trim the sail too flat or have the foot too low. Thus, the only way to find the best shape is to experiment while watching your speedometer.
UK Halsey Genoa Sail Trim Techniques
UK-Halsey's Encyclopedia of Sails
-- Genoa Trim
The major characteristics of genoa, or jib shape, are the amount and location of draft, and the angle of entry. The shape of the jib is controlled by the fore and aft location of the jib leads, luff tension, sheet tension and headstay tension.
LUFF TENSION: Tension on the leading edge of the sail is controlled by jib halyard and by jib Cunningham. The principal effect of luff tension is to position draft in the sail. Increased luff tension moves draft forward. Decreased luff tension moves draft aft.
LEAD POSITION:
Most boats have provisions for moving the jib sheet lead block fore and aft. The position of the lead controls the tension on the leech and the foot, as well as the draft location in the upper and lower portions of the sail:
Jib lead aft moves the draft in the top of the sail forward and moves the draft in the bottom of the sail aft. With the lead aft, the leech is loose and foot is tight.
Jib lead forward moves the draft in the top of the sail aft and moves the draft in the bottom of the sail forward. The leech is tight and the foot is loose.
The correct jib lead position distributes draft evenly in the sail and the tension on the leech and foot are relatively equal.
Jib leads can be located by observing which portion of the sail begins to luff first.
Luffing in the upper portion means that the lead should be moved forward.
Luffing in the lower portion requires the lead point to be moved aft.
SHEET TENSION:
Along with controlling the angle to the wind (trim), the jib sheet controls the amount of draft and twist in the jib. A tight jib sheet will remove draft from the sail; easing the sheet will add draft to the sail.
HEADSTAY TENSION:
The straightness of the headstay is controlled by tension on the backstay on a masthead rig or by running backstays on a fractionally rigged boat. The looser the headstay, the more the middle of the stay sags to leeward and astern. Increased tension reduces the draft of the genoa and flattens the entry angle. Decreased tension increases the draft and creates a rounder entry.
JIB SHAPE:
Variations in wind velocity, wind angle, and sea conditions make adjustments in jib shape desirable. The following adjustments can be made to adapt to changing conditions.
CHANGING WIND VELOCITY:
Decreased velocity requires more draft in the sail. A fuller sail creates more power. As the wind increases, you flatten the sail. To help understand this, think of an airplane; to create lift at slow speeds, a pilot lowers the flaps , which creates more draft in the wing. Once up to speed, the flaps come up and the wing gets flatter. In-creased velocity calls for decreased draft.
Another adjustment you have to make as the wind increases is increased amounts of halyard tension. As the wind blows harder, the draft of the sail gets pushed aft. By increasing halyard tension, you return the draft back toward the middle or forward third of the sail where it belongs. Some boats can move the draft forward with a jib Cunningham.
CHANGING WIND DIRECTION:
When the wind goes forward so that you are sailing on a beat or a close reach, less draft and a flatter entry angle are required for pointing ability. When the wind goes aft, additional draft and rounder entry are required for added power.
CHANGING SEA CONDITIONS:
Rough sea conditions make a slightly fuller sail with a rounder entry angle desirable. In smooth seas you trade power for pointing by flattening the entry angle.
Modern, easily driven boats can trade speed for pointing especially if they have a tendency to be overpowered in heavy air. This means setting the boat up with less draft and a flatter entry angle. A flat entry angle lets you point higher, but the sail stalls out easier. To power up the sails in light winds or in choppy seas, tighten the jib halyard to move the draft of the jib forward, which also increases the entry angle. A rounder entry angle will also make it easier for a less-than- attentive helmsman to keep the boat going fast since the sail will not stall as easily.
Even on top racing boats, when a new person takes the helm, they usually ask for more halyard tension, which produces a rounder entry angle, to make it easier to keep the boat sailing in the groove. After they get the feel of the boat in the current conditions, then they ease the halyard slightly for higher pointing.
SHEETING THE SAIL
Once the shape is set, the sail can be trimmed to the desired angle to the wind. Two controls are available: jib sheet lead position and jib sheet tension. Jib sheet tensioning will be covered in the following section on using telltales.
On many older boats, the only jib or genoa sheeting point available is a lead block on the toe rail. While some cruising sailors may be content with this As the wind velocity increases when beating and the boat starts to heel too much, the lead should be moved progressively aft on the inboard track to reduce heeling. Heeling is reduced by moving the lead aft because the top of the genoa is allowed to twist off and luff. The top of the sail luffs because the jib sheet is pulling the sail back more than it is pulling it down. (See diagram below.) Pulling the lead aft also flattens the lower section of the sail. Flatter sails produce less heeling moment.
As the wind velocity decreases, moving the lead forward adds draft to the sail, which makes it more powerful.
In wavy conditions on a beat, move the lead outboard to a block on the toe rail to increase drive at the expense of pointing. The boat needs power to get through the waves.
After a while, you will find an average point on the track where you will keep the lead for each genoa in your inventory. Mark these positions so that you can quickly set the lead. Any adjustments you make from the average position will then be fine tuning. The most common ways of marking lead positions are with stick-on numbers or a magic marker. Place the number “1” where the No. 1 genoa sheets to, and a number “2” and number “3” where they sheet to if you have those sails.
Cruising sailors with roller/reefing genoas need two marks on the track; one mark aft for when the genoa is rolled out all the way, and one mark forward for where the lead should be when the sail is reefed to the reef point on the foot (which all UK Passagemaker genoas have).
As the wind angle frees up from a reach to a run, move the lead outboard and forward to a block on the toe rail, assuming there are attachment points on your rail for this. The lead moves outboard to open up the slot between the jib and the main, and the lead goes forward to counteract the tendency of the sail to twist. With the jib shaped to the conditions, and the lead located in the best position, the sheet is trimmed to control the sail’s angle to the wind. When sailing to windward, the spreaders provide a good reference point. Experimenting with a sensitive speedometer or with another boat will show how close the sail can be trimmed in given conditions.
When sailing off the wind, set a course, then ease the jib to the point of luffing, or until the inside telltales stop streaming aft. Then trim slightly. If the leads have been set for windward sailing, they will have to be moved forward to counteract the tendency of the sail to twist.
-- Genoa Trim
The major characteristics of genoa, or jib shape, are the amount and location of draft, and the angle of entry. The shape of the jib is controlled by the fore and aft location of the jib leads, luff tension, sheet tension and headstay tension.
LUFF TENSION: Tension on the leading edge of the sail is controlled by jib halyard and by jib Cunningham. The principal effect of luff tension is to position draft in the sail. Increased luff tension moves draft forward. Decreased luff tension moves draft aft.
LEAD POSITION:
Most boats have provisions for moving the jib sheet lead block fore and aft. The position of the lead controls the tension on the leech and the foot, as well as the draft location in the upper and lower portions of the sail:
Jib lead aft moves the draft in the top of the sail forward and moves the draft in the bottom of the sail aft. With the lead aft, the leech is loose and foot is tight.
Jib lead forward moves the draft in the top of the sail aft and moves the draft in the bottom of the sail forward. The leech is tight and the foot is loose.
The correct jib lead position distributes draft evenly in the sail and the tension on the leech and foot are relatively equal.
Jib leads can be located by observing which portion of the sail begins to luff first.
Luffing in the upper portion means that the lead should be moved forward.
Luffing in the lower portion requires the lead point to be moved aft.
SHEET TENSION:
Along with controlling the angle to the wind (trim), the jib sheet controls the amount of draft and twist in the jib. A tight jib sheet will remove draft from the sail; easing the sheet will add draft to the sail.
HEADSTAY TENSION:
The straightness of the headstay is controlled by tension on the backstay on a masthead rig or by running backstays on a fractionally rigged boat. The looser the headstay, the more the middle of the stay sags to leeward and astern. Increased tension reduces the draft of the genoa and flattens the entry angle. Decreased tension increases the draft and creates a rounder entry.
JIB SHAPE:
Variations in wind velocity, wind angle, and sea conditions make adjustments in jib shape desirable. The following adjustments can be made to adapt to changing conditions.
CHANGING WIND VELOCITY:
Decreased velocity requires more draft in the sail. A fuller sail creates more power. As the wind increases, you flatten the sail. To help understand this, think of an airplane; to create lift at slow speeds, a pilot lowers the flaps , which creates more draft in the wing. Once up to speed, the flaps come up and the wing gets flatter. In-creased velocity calls for decreased draft.
Another adjustment you have to make as the wind increases is increased amounts of halyard tension. As the wind blows harder, the draft of the sail gets pushed aft. By increasing halyard tension, you return the draft back toward the middle or forward third of the sail where it belongs. Some boats can move the draft forward with a jib Cunningham.
CHANGING WIND DIRECTION:
When the wind goes forward so that you are sailing on a beat or a close reach, less draft and a flatter entry angle are required for pointing ability. When the wind goes aft, additional draft and rounder entry are required for added power.
CHANGING SEA CONDITIONS:
Rough sea conditions make a slightly fuller sail with a rounder entry angle desirable. In smooth seas you trade power for pointing by flattening the entry angle.
Modern, easily driven boats can trade speed for pointing especially if they have a tendency to be overpowered in heavy air. This means setting the boat up with less draft and a flatter entry angle. A flat entry angle lets you point higher, but the sail stalls out easier. To power up the sails in light winds or in choppy seas, tighten the jib halyard to move the draft of the jib forward, which also increases the entry angle. A rounder entry angle will also make it easier for a less-than- attentive helmsman to keep the boat going fast since the sail will not stall as easily.
Even on top racing boats, when a new person takes the helm, they usually ask for more halyard tension, which produces a rounder entry angle, to make it easier to keep the boat sailing in the groove. After they get the feel of the boat in the current conditions, then they ease the halyard slightly for higher pointing.
SHEETING THE SAIL
Once the shape is set, the sail can be trimmed to the desired angle to the wind. Two controls are available: jib sheet lead position and jib sheet tension. Jib sheet tensioning will be covered in the following section on using telltales.
On many older boats, the only jib or genoa sheeting point available is a lead block on the toe rail. While some cruising sailors may be content with this As the wind velocity increases when beating and the boat starts to heel too much, the lead should be moved progressively aft on the inboard track to reduce heeling. Heeling is reduced by moving the lead aft because the top of the genoa is allowed to twist off and luff. The top of the sail luffs because the jib sheet is pulling the sail back more than it is pulling it down. (See diagram below.) Pulling the lead aft also flattens the lower section of the sail. Flatter sails produce less heeling moment.
As the wind velocity decreases, moving the lead forward adds draft to the sail, which makes it more powerful.
In wavy conditions on a beat, move the lead outboard to a block on the toe rail to increase drive at the expense of pointing. The boat needs power to get through the waves.
After a while, you will find an average point on the track where you will keep the lead for each genoa in your inventory. Mark these positions so that you can quickly set the lead. Any adjustments you make from the average position will then be fine tuning. The most common ways of marking lead positions are with stick-on numbers or a magic marker. Place the number “1” where the No. 1 genoa sheets to, and a number “2” and number “3” where they sheet to if you have those sails.
Cruising sailors with roller/reefing genoas need two marks on the track; one mark aft for when the genoa is rolled out all the way, and one mark forward for where the lead should be when the sail is reefed to the reef point on the foot (which all UK Passagemaker genoas have).
As the wind angle frees up from a reach to a run, move the lead outboard and forward to a block on the toe rail, assuming there are attachment points on your rail for this. The lead moves outboard to open up the slot between the jib and the main, and the lead goes forward to counteract the tendency of the sail to twist. With the jib shaped to the conditions, and the lead located in the best position, the sheet is trimmed to control the sail’s angle to the wind. When sailing to windward, the spreaders provide a good reference point. Experimenting with a sensitive speedometer or with another boat will show how close the sail can be trimmed in given conditions.
When sailing off the wind, set a course, then ease the jib to the point of luffing, or until the inside telltales stop streaming aft. Then trim slightly. If the leads have been set for windward sailing, they will have to be moved forward to counteract the tendency of the sail to twist.
UK Halsey Main Sail Trim Techniques
UK-Halsey's Encyclopedia of Sails
-- Mainsail Trim
Mainsails must perform over a wide variety of sailing conditions. This required versatility is achieved by adjustment and trimming.
The mainsail can be adjusted to vary the amount and location of draft, and trimmed to control the shape of the leech and its angle to the wind. While bewildering verbiage is sometimes used to describe this process, we are doing only three things to the sail:
1. Adjusting the tension on the three edges.
2. Adjusting the shape of the leading edge if mast bend is possible.
3. Trimming the boom in and out.
Here’s a brief explanation of terms dealing with mainsails:
DRAFT:
The amount of curvature in the sail. Sometimes called depth, draft is measured along a straight line running between the leech and the luff.
DRAFT LOCATION:
The point where the draft is the greatest, measured along a straight line running between the leech and the luff.
LEECH SHAPE:
The straightness or curve of the leech.The mechanics of attaining proper mainsail characteristics vary according to class rules, rating rules, and personal preference. The basics of control are:
LUFF TENSION:
Controlled by the halyard, Cunningham (at least 4 to 1 purchase), and boom downhaul if the boat is equipped with one.
FOOT TENSION:
Controlled by the outhaul and flattening reef.
LEECH TENSION:
Controlled by the mainsheet and traveler upwind, and by the boom vang off the wind. The leech line is used primarily to remove flutter from the very edge of the sail.
MAST BEND:
Controlled by various combinations of the backstay, babystay and running backstays. Blocks of wood or hard rubber can also be used to chock the mast where it goes through the deck to control bend.
TRIM:
Controlled by the mainsheet and the traveler. Although closely interrelated, each control has a distinct effect on the mainsail’s characteristics. It is instructive and fun to work the controls and observe the effects
LUFF TENSION
Increased luff tension moves the draft forward.
Decreased luff tension moves the draft aft.
TO ADD LUFF TENSION:
1. Increase halyard tension until the headboard reaches the upper black band.
2. Pull down the main boom downhaul until the lower black band is reached.
3. Put tension on the Cunningham.
FOOT TENSION
Increased foot tension removes draft from the sail.
Decreased foot tension adds draft to the sail.
TO ADD FOOT TENSION
1. Tighten the outhaul. Note: The effects of foot tension are most pronounced in the lower third of the sail.
LEECH TENSION
Increased leech tension straightens the leech and cups the sail.
Decreased leech tension eases the leech and twists the sail.
TO TIGHTEN THE LEECH:
1. Trim mainsheet harder when sailing on the wind.
2. Tension boom vang when sailing off the wind.
3. Tighten leech line to control leech flutter.
TO EASE THE LEECH:
1. Ease tension on mainsheet and boom vang. When beating in light winds, you’ll need to pull the traveler above the center line in order to trim the mainsail close enough while keeping the upper leech open.
2. Ease the leech cord.
3. In very light air, reduce the effect of the weight of the boom by tightening the topping lift.
MAST BEND
Bending the mast decreases the draft in the sail, it flattens the sail. Removing mast bend adds draft to the sail.
TO BEND THE MAST:
1. Tighten backstay.
2. Tighten baby or midstay, or forward lowers.
TO STRAIGHTEN MAST:
1. Ease backstay and/or tighten headstay.
2. Ease babystay and/or forward lowers.
3. Tighten running backstays and/or after lowers.
Before working on sail shape and trim, check these points:
1. Battens should be straight with the flexible end forward and the back end snug against the pocket. The most flexible batten should be in the top pocket.
2. Telltales should be installed on the leech near the top two battens. Additional telltales midway between the luff and the leech are also useful.
3. Check mast tune with the main and jib set. Some bend aft is desirable, while there should be no bend to the side.
Variations in wind velocity, wind direction, and sea state require the mainsail to be very adjustable. Experimenting will help you get the best results on your own boat, but these general principles should be kept in mind.
1. Sailing upwind requires a flatter sail than reaching and running.
2. Rough water requires a fuller setting than smooth water.
3. Light winds require a fuller setting than strong winds.
-- Mainsail Trim
Mainsails must perform over a wide variety of sailing conditions. This required versatility is achieved by adjustment and trimming.
The mainsail can be adjusted to vary the amount and location of draft, and trimmed to control the shape of the leech and its angle to the wind. While bewildering verbiage is sometimes used to describe this process, we are doing only three things to the sail:
1. Adjusting the tension on the three edges.
2. Adjusting the shape of the leading edge if mast bend is possible.
3. Trimming the boom in and out.
Here’s a brief explanation of terms dealing with mainsails:
DRAFT:
The amount of curvature in the sail. Sometimes called depth, draft is measured along a straight line running between the leech and the luff.
DRAFT LOCATION:
The point where the draft is the greatest, measured along a straight line running between the leech and the luff.
LEECH SHAPE:
The straightness or curve of the leech.The mechanics of attaining proper mainsail characteristics vary according to class rules, rating rules, and personal preference. The basics of control are:
LUFF TENSION:
Controlled by the halyard, Cunningham (at least 4 to 1 purchase), and boom downhaul if the boat is equipped with one.
FOOT TENSION:
Controlled by the outhaul and flattening reef.
LEECH TENSION:
Controlled by the mainsheet and traveler upwind, and by the boom vang off the wind. The leech line is used primarily to remove flutter from the very edge of the sail.
MAST BEND:
Controlled by various combinations of the backstay, babystay and running backstays. Blocks of wood or hard rubber can also be used to chock the mast where it goes through the deck to control bend.
TRIM:
Controlled by the mainsheet and the traveler. Although closely interrelated, each control has a distinct effect on the mainsail’s characteristics. It is instructive and fun to work the controls and observe the effects
LUFF TENSION
Increased luff tension moves the draft forward.
Decreased luff tension moves the draft aft.
TO ADD LUFF TENSION:
1. Increase halyard tension until the headboard reaches the upper black band.
2. Pull down the main boom downhaul until the lower black band is reached.
3. Put tension on the Cunningham.
FOOT TENSION
Increased foot tension removes draft from the sail.
Decreased foot tension adds draft to the sail.
TO ADD FOOT TENSION
1. Tighten the outhaul. Note: The effects of foot tension are most pronounced in the lower third of the sail.
LEECH TENSION
Increased leech tension straightens the leech and cups the sail.
Decreased leech tension eases the leech and twists the sail.
TO TIGHTEN THE LEECH:
1. Trim mainsheet harder when sailing on the wind.
2. Tension boom vang when sailing off the wind.
3. Tighten leech line to control leech flutter.
TO EASE THE LEECH:
1. Ease tension on mainsheet and boom vang. When beating in light winds, you’ll need to pull the traveler above the center line in order to trim the mainsail close enough while keeping the upper leech open.
2. Ease the leech cord.
3. In very light air, reduce the effect of the weight of the boom by tightening the topping lift.
MAST BEND
Bending the mast decreases the draft in the sail, it flattens the sail. Removing mast bend adds draft to the sail.
TO BEND THE MAST:
1. Tighten backstay.
2. Tighten baby or midstay, or forward lowers.
TO STRAIGHTEN MAST:
1. Ease backstay and/or tighten headstay.
2. Ease babystay and/or forward lowers.
3. Tighten running backstays and/or after lowers.
Before working on sail shape and trim, check these points:
1. Battens should be straight with the flexible end forward and the back end snug against the pocket. The most flexible batten should be in the top pocket.
2. Telltales should be installed on the leech near the top two battens. Additional telltales midway between the luff and the leech are also useful.
3. Check mast tune with the main and jib set. Some bend aft is desirable, while there should be no bend to the side.
Variations in wind velocity, wind direction, and sea state require the mainsail to be very adjustable. Experimenting will help you get the best results on your own boat, but these general principles should be kept in mind.
1. Sailing upwind requires a flatter sail than reaching and running.
2. Rough water requires a fuller setting than smooth water.
3. Light winds require a fuller setting than strong winds.
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