Saturday 29 December 2007
Thursday 27 December 2007
HMS vengeance
More old Photo of Hong Kong by photographer on board HMS Vengeance which arrived in HK in Sept, 1945 to repossess HK
http://www.hms-vengeance.co.uk/vengpic5.htm
http://www.hms-vengeance.co.uk/vengpic5.htm
Wednesday 26 December 2007
Tuesday 25 December 2007
Monday 24 December 2007
Sunday 23 December 2007
Monday 17 December 2007
Saturday 8 December 2007
Wednesday 28 November 2007
工业增加值增长速度(2007年10月)
| 工业增加值增长速度(2007年10月) |
| 指标名称 | 单位 | 比去年同期增长 % | |
| 本月 | 累计 | ||
| 工业增加值 | 亿元 | 17.9 | 18.5 |
| 其中：轻工业 | 亿元 | 14.4 | 15.9 |
| 重工业 | 亿元 | 19.4 | 19.6 |
| 其中：国有及国有控股企业 | 亿元 | 13.6 | 14.0 |
| 其中：私营企业 | 亿元 | 24.0 | 26.3 |
| 其中：集体企业 | 亿元 | 8.8 | 11.4 |
| 股份合作企业 | 亿元 | 13.5 | 17.2 |
| 股份制企业 | 亿元 | 20.3 | 20.4 |
| 外商及港澳台投资 | 亿元 | 16.7 | 17.4 |
Tuesday 27 November 2007
adventurer Steve Fossett
(CNN) -- The wife of missing adventurer Steve Fossett has asked a court to declare him dead.
Fossett was last seen in early September, flying a single-engine plane on a pleasure flight from a Nevada ranch. A month-long search for the plane was unsuccessful.
"As difficult as it is for me to reach this conclusion, I no longer hold out any hope that Steve has survived," wrote Peggy V. Fossett in court documents filed Monday with the Cook County [Illinois] Circuit Court.
She asked that the will of her husband of 38 years be admitted to probate.
Sunday 25 November 2007
Thursday 22 November 2007
Sunday 18 November 2007
Saturday 17 November 2007
Monday 5 November 2007
How to Point, Foot, and Shift Gears
| How to Point, Foot, and Shift Gears |
| Shifting gears is on a boat is one of the most difficult aspects of sailboat racing and requires a knowledge of your boat, the conditions, and plenty of practice. Greg Fisher breaks down how to find the baseline, and then shift gears to get your boat going fast in all conditions. From the SW Archives, our June 1998 issue. |
| Jul 25, 2006 By Greg Fisher (More articles by this author) |
http://www.sailingworld.com/from-the-experts/technique/how-to-point-foot-and-shift-gears-200894.html
Subtle gear changing is what truly separates those with just adequate boatspeed from those who always seem to be a click quicker and higher. While most of the fleet starts the race with a similar setup, created with the help of a tuning guide or by following standard principles, the fast boats are constantly making additional adjustments. When conditions suddenly change—a puff hits, or powerboat waves arrive—these sailors shift gears smoothly. Before we dive into the subtleties of their sail adjustments, let’s take a look at how you might create a basic pre-race setup.
Step 1: Set the depth
Try to memorize the depth that feels about right in 10 knots of breeze. Then set your mast bend and headstay sag to replicate that shape, using it as your starting point in other velocities. Another method is to increase mast bend until you just begin to see slight wrinkles (called inversion wrinkles) running from the clew of the mainsail to the lower quarter of the mast. For the jib, decrease headstay sag until you are just able to make the telltales on both sides of the sail fly easily. Any tighter, and the steering groove will become too narrow.
Step 2: Set the draft position
For most boats, the main draft should be positioned nearly halfway back. Pulling the cunningham tighter pulls the draft forward, while easing it allows the draft to move aft. Use the jib halyard or jib cunningham to position the fullness in the jib. The draft should be slightly farther forward than in the main, usually about 35 percent, or roughly one-third, of the way back.
Step 3: Set the twist
To set the leech tension for the main, sight from under the boom and set the sheet so that the chord of the top batten is parallel to the boom. For the jib leech, set the sheet so that the last 6 inches of the middle of the leech (a mid-leech batten helps here) are parallel to the centerline of the boat. Easing the sheets allows the outboard end of the battens to fall away, increasing twist. Trimming the sheets does the opposite, decreasing twist.
Step 4: Set the angle of attack
If you drop the tiller, the boat should continue to track straight, or slowly head up into the wind. Any more helm than that means excessive rudder drag. If the boat has excessive windward helm, ease the traveler to until the helm is balanced. This four-step process for setting your sails is only a starting point. It’s still a great idea to line up with someone you know is fast before the race to see if you are "on the money." If you’re faster, great! If you’re off the pace, just ask your crew, "Are we lacking speed or pointing ability?"
Solving Pointing Problems
An inability to hold a lane or position close to other boats can really destroy a tactical game plan. Pointing problems are not so much indicated by the angle that the boat seems to be sailing relative to the boats around us, but more by the fact that the boat is actually sliding to leeward.
Trying to pinch to maintain height can be the crux of the problem. The old adage, "foot, then point," says a lot. A boat needs to go fast before the underwater foils can develop enough lift to hold their position in the water. To regain pointing ability, ease the sails out, bear off slightly, and get back up to speed. Once up to top speed, re-trim to your starting point trim and reevaluate your pointing problem. If the problem persists, check your sail trim.
When sail trim is the cause of the problem, it’s usually the main, not the jib. The upper leech of the main provides most of your pointing ability. Be sure to trim the main so the upper batten is at least parallel to the boom. If you need more pointing ability, try trimming the main tighter. You can hook the upper batten as much as 15 degrees to weather for short periods. Avoid the temptation to overtrim the jib to help pointing ability. Hooking the jib leech will choke the slot between the main and jib, stalling the entire sailplan. The jib should never have less twist than described in the "basic setup."
Only after you’ve decided to trim the main harder should you try to pinch the boat. In this mode, the weather telltales on the jib will be stalled. In big puffs, the luff of the jib can break as much as 8 inches back. This "super pinch" mode can only be held for short bursts and in flat water. Once the boat starts to slow down, be sure to ease the sails out, regain your speed, then start the process again.
While it may seem natural to let the boat heel more when trying to point, fight the urge. Keeping the boat flat will help maintain a balanced helm and maximize the efficiency of your underwater foils. Still not pointing? Either your rig is too loose, resulting in too much headstay sag (i.e., the jib is too full) and sometimes too much mast bend, which makes the leech too open, or the luff tension on either sail is too tight (the draft is too far forward).
Solving Footing Problems
What if your pointing is fine, but your straight-line speed is lacking? The simplest fix is easing the sails. More open leeches on both sails will help the boat sail lower and faster in a straight line. Sometimes, however, this results in a pointing problem. If so, first check your helm balance. Weather helm can seriousIy hinder the boat’s ability to go fast. Instead of easing sheets, it’s often better to find a way to ease helm. First, try to sail the boat more level. If you can’t keep the boat flat, induce more mast bend to flatten the main. The next step is to ease the traveler until the helm is balanced. Finally, tighten the outhaul, tension the cunningham/jib halyard to pull the draft forward and open the leeches of both sails.
Gear Shifting: Puff On!
We’ve got you going with good speed and good height. Then what happens? The wind velocity changes and it’s time to shift gears. First, let’s look at some of the automatic trimming change that should happen as soon as a puff hits. 1. Ease the main, and sometimes the jib 2. Steer up to "feather" the boat 3. Re-trim sails.
Since a puff typically lifts you, due to a change in the apparent windspeed, you need to ease sheets and head up as it hits. Be sure to let the boat climb up into the wind and steer toward the upper end of your groove with the jib luff actually breaking. In flat water, all that may be required is a quick ease of the mainsheet. But in chop, it may be necessary to ease the jib as well.
If the puff packs some real velocity, more adjustment may be necessary. If you can’t hold the boat down, and there’s still too much helm, try the following, one at a time, until the helm is balanced. 1. Ease the traveler 2. Bend the mast (vang tension, backstay tension, etc.) 3. Tension the cunningham on both main and jib.
Gear Shift: Into a Lull
For the same reason that puffs are lifts, lulls usually appear as headers. In a lull, it’s important that you bear off as smoothly as possible. Make sure the boat remains flat and resist the temptation to add heel to maintain "feel" in the helm.
Ease the main so the top batten angles outboard from parallel to the boom. Leave the jib trimmed initially until the bow is pulled down to the lower end of your groove with both telltales streaming aft. At that point, the jib should be eased so the leeward telltale doesn’t stall.
Here’s how to maintain speed in a lull. 1. Ease the main 2. Allow the boat to heel to weather, creating lee helm, to steer the boat down 3. Ease the jib 4. Level the boat 5. Pull the traveler up (if the boom is below centerline).
If the lull is long-lived, you may need to take additional steps to maintain speed. 1. Straighten the mast and induce luff sag in the jib 2.) Ease main and jib cunninghams to maintain correct draft position. The smoother you shift gears the faster you’ll be, so practice until it’s automatic. Heck, manual transmissions went out years ago!
Saturday 3 November 2007
Learning the Ropes
Learning the Ropes: "With my partner making large adjustment changes, I could sit forward and watch mast, main and jib changes. When he pulled on the boomvang, the mast bent low, the main flattened, the leech got tighter and the jib luff sagged off. When he pulled on the mast fore puller the mast bent lower, the main flattened, the leech got looser and the jib luff sagged off. When he pulled on the mast aft puller, the opposite happened. When he pulled on the main cunningham the draft moved forward, the leech got looser and the sail got flatter as the mast section above the hounds fell off to leeward. When he pulled the mainsheet in, the mast bent, the mainsail got flatter, the leech got tighter and the jib luff got tighter. The opposite happened when the mainsail was eased. With this knowledge, scenarios developed in my mind. As the wind builds, the mainsheet gets trimmed tighter and both sails flatten simultaneously. Perfect reaction. However, when the mainsheet must be dumped for larger puffs, both the main and jib get fuller. Bad reaction. To combat this we can use the vang, which flattens the main but makes the jib fuller, To improve this we can tighten the aft puller, which flattens the jib but powers up the main. Using both the boomvang and the aft puller, their negatives and positives combine to create the best compromise to flatten the main while controlling jib luff sag. With the mainsheet in tight, the main and jib are flat. When the main must be dumped in a puff, the aft puller and the vang help maintain that sail shape. In real high winds you also pull the main cunningham hard to flatten the top of the sail. These discoveries dramatically improved my heavy air speed.
Return to the Snipe Page"
CAUSE AND EFFECT
CONTROL MAST MAIN JIB
---------------------------------------------------------------------------
Vang bends low flatten, leech tight sags
Fore Puller bends low flatten, leech loose sags
Aft Puller straighten low full, leech tight tight
Main Cunningham tip to leeward draft foreward, leech loose --
Mainsheet--in bends flatten, leech tight tight
--ease straightens full, leech loose --
Heavy Air--Combine these for maximum effect
Vang flatten full
Aft Puller power-up flat
Main Cunningham flatten top
Problem solving is part of sailing. Knowing the effect of all your adjustments and confidently making these changes during a race is part of the success formula. In shifty, puffy winds it is better to set these adjustments for the lighter end of the wind range instead of making an adjustment for every wind change. Too much time is spent making sail adjustments and not enough time keeping track of the next wind shift. Setting your adjustments for the lighter end of the wind range is best as it is easier to keep your boat speed up in heavy air when setup wrong than it is in light air. Do your best to set up correctly but be wary of losing track of the race.
Successfully racing your boat should be much like sitting on the couch at home. There you have the TV clicker and the cordless phone within reach and you know how to lie on it to be the most comfortable. Your boat should be the same. All my Snipes I have either rigged myself or specified where the hardware would be placed. Rigging is highly personal and must adapt to the interests of each team of people. Decide who is going to do each job and place the controls near that person. Every adjustment must be positioned to make sense relative to when it is used. The upwind adjustments must all be within reach when hiking with the downwind or light air upwind adjustments put inside the boat to avoid deck clutter, putting too many adjustments in one place requires a distracting glance to confirm that you have the right line. When action is quick in a race, a well thought out deck layout is worth boat lengths on the course.
Good sailing
http://www.snipe.org/articles/ropes.htmlCraig Leweck is a sailmaker for Sobstad Sailmakers in San Diego. Craig has been US National Champion twice and has won the North American Championships. He has represented the US in two World Championships, and continues to finish in the top at regattas on the US Circuit.
Return to the Snipe Page"
Wednesday 31 October 2007
GROSS DOMESTIC PRODUCT: THIRD QUARTER 2007 (ADVANCE)
Real gross domestic product -- the output of goods and services produced by labor and property
located in the United States -- increased at an annual rate of 3.9 percent in the third quarter of 2007,
according to advance estimates released by the Bureau of Economic Analysis. In the second quarter,
real GDP increased 3.8 percent.
The increase in real GDP in the third quarter reflected positive contributions from personal
consumption expenditures (PCE), exports, federal government spending, equipment and software,
nonresidential structures, private inventory investment, and state and local government spending that
were partly offset by a negative contribution from residential fixed investment. Imports, which are a
subtraction in the calculation of GDP, increased. The US economy is growing strongly. No need for
rate cut
Federal Reserve Chairman Ben Bernanke and his colleagues were wrapping up a two-day meeting Wednesday and many economists believe they will announce that they have decided to follow September's half-point cut in the federal funds rate with a quarter-point cut at this meeting.
"They are going to cut rates," predicted Mark Zandi, chief economist at Moody's Economy.com. "The economy is weakening and financial markets remain unsettled."
Sunday 28 October 2007
Saturday 27 October 2007
TUNING THE 505 RIG by Steve Taylor
http://hem.passagen.se/waterat/tuning_the505rig.htm
Retyped from
505 Great Britain No.16
Summer 1980
Steve Taylor/David Penfield won the 505 Worlds in Durban 1979. Their series: 1, 1, 3, DNF = 5.7pts. 2nd: Dennis Surtees/Paul Cayard, 3rd: Dan Thompson, 4th: Jorgen Schonherr. 85 boats participated. Other americans were Steve Benjamin(11), Jon Andron(10), Ethan Bixby(12), Jim Wondolleck(21). 15 boats from the US.
The still chute-less bow of Steve Taylor's three year old boat.
World champion Steve Taylor describes the functions of the 505 rig and the effects rig controls have on sail shape and overall speed.
You've fitted out a well-rigged hull with a good board and rudder, and you're on your way down to the club with newly acquired sails, ready to step the mast and attempt to transform your magnificent efforts with wallet and toolbox into speed on the race course.
Naturally, every time you touch a control line, it moves effortlessly, with no friction, and whatever it controls works beautifully - you just don't know quite where to set it. Lots of practice in the old boat has given you some idea where to start and certainly means that your boat handling is smooth, your steering second nature and your relationship with your team-mate gracefully established. Ever since your last frostbite season your starts have been good and your tactics consistent. Now the problem is to learn to think a little more clearly about how to set up your rig in all conditions, how to adjust it quickly as the conditions change and how to see what shapes are produced in your sails as you make these adjustments.
On 505s and any other boat in which the loads of the rig and the mast are supported by the luff wire in the jib, the headstay, if there is one, is generally left slack when sailing and is only used to hold the mast up in the parking lot. Once the shrouds are fixed, increasing tension on the jib halyard does two things:
1) it straightens the rake, pulling the mast forward, and
2) it pulls against the shrouds and increases rig tension (diagram).
Because the fore-and-aft angle of the jib luff to the mast is much greater than that of the shrouds (diagram), a small change in jib halyard length will affect rake more than rig tension; likewise, a change of equal length in the shrouds will affect tension more than rake (diagram). A good way to start thinking about your rig is to consider the jib halyard as your rake control and the shrouds as your tension control.
Jib halyard tension reduces rake and can also increase rig tension
Angle A, between the jib luff and the mast, is much larger than angle B, between the shrouds and the mast. This causes the jib luff tension, to be the dominant factor in rake, and shroud length to be the dominant factor in rig tension.
Both rake and tension are important adjustments, but with the exception of the FD, which uses rake to control the genoa lead, tension is usually the more important of the two. Therefore, for simplicity's sake, you can first choose a basic rake setting and set your jib luff to that point. Then, if your shrouds are adjustable, you will be able to regulate tension easily with a control line. If your shrouds are fixed by chainplates with rows of holes, to effect tension change you may have to first release the jib halyard, then change the shroud pin location and finally put the jib halyard back in the desired position. In any event, remember that it is shroud length that makes the tension difference - the jib halyard is for rake.
The two most important effects of rig tension are jib luff sag and mast bend, both of which control, to a large degree, the shape of the sails to which they are attached. The table shows how jib luff sag affects jib shape.
The Effects of Jib Luff Sag on Jib Shape
Too Much Sag Correct Sag Too Straight
Draft draft too far
forward draft in correct position draft too far aft
Fullness sail too full,
especially head depth correct sail too flat,
especially entry
Leech upper leech too
close to mainsail
when sheet is
trimmed leech twist
balanced with
sheet and lead upper leech too
open relative to
sheet and lead
Luff loose luff may
'pump' in seas,
causing rapid
shape variations luff stable,
but forgiving rigid luff
unforgiving and
prone to stalling
-entry too fine
Steering Groove steering groove
too wide, can't
get accurate
course from
telltales steering groove
reasonable,
telltales normally
responsive steering groove
too narrow,
telltales too
nervous - both
leeward and
windward flutter
at once.
Understanding how rig tension affects the shape of the mainsail through mast bend is a bit more involved. First, tension affects bend primarily through the spreaders, especially if the shrouds intersect the mast at about the same place as the jib halyard at the hounds. Unlike jib luff sag, which happens in a direction roughly aligned with the wind, mast bend can be controlled and thought of in two different directions - fore and aft or sideways (diagram).
More forward cant on the spreaders, coupled with more shroud tension, causes less fore and aft mast bend. A reduction in either cant or tension will allow more fore and aft bend. If the spreaders are swept aft of a neutral position, increasing tension will induce more fore and aft bend.
At this point, it should be mentioned that this is true only while the mast is still basically in column, or only up to the point where further shortening the shrouds ceases to add tension. At some point after the mast is bent like an archer's bow, shortening the shrouds will not add tension, but actually reduce it or leave it constant as the mast buckles out of column and simply bends more in whatever direction it had already begun. It very rarely pays to sail with the spar set up this way, and particularly with stiff boats and powerful rigging systems, care should be taken not to attempt to 'tighten' the rig past this point of 'no return'.
Sideways bend is controlled largely by the degree to which the spreaders deflect the shrouds outboard position, or poke. For the purposes of this discussion, more side bend means the middle of the mast comes to windward and the tip to leeward; less side bend means the mast is straight sideways; and negative side bend means the middle of the spar depresses into the slot to leeward - regardless of whether the tip is also to leeward (S-bend) or is held straight, or to windward, through either natural stiffness or very high trapeze wires (diagram).
Longer spreaders, or more poke, tends to reduce side bend and can even force it negative. Shorter spreaders allow more side bend. Changes in tension work to increase or decrease the effect of the spreaders correspondingly - more tension and the spreaders do more work.
Having established, to a degree, how tension and spreader adjustment control mast bend, the important questions become, how does mast bend affect sail shape, and what do you want when?
Although sideways bend also affects the entire shape and twist of the sail in very similar ways to the table on fore and aft mast bend, it is important to discuss it separately in terms of twist and the effect on the size of the slot between main and jib. Twist in a sail is defined as the change in the angle of attack of the cross-sectional shapes of the sail in progression up from the foot (diagram). A chord is the imaginary line between luff and leech, at any height, and if these lines change their angles to the wind, then the sail has twisted. When the leech is tightened, the aft ends of the chord lines move to windward and twist is reduced. Likewise, if the middle of the mast moves to leeward (negative side bend), the front end of the chord line (a point on the luff) moves to leeward, and again, twist is reduced.
Because twist (angle of attack) is perhaps the primary determinant of how much power (and drag) a sail develops, and because side bend has a linear relationship to twist, side bend is a very powerful variable in rig control. One-half inch of sideways movement of the luff at spreader height will make a far greater difference to your performance than one-half inch of fore and aft bend.
The 'slot' effect is also important, particularly in terms of preventing interference between the jib and main while retaining maximum useable power in a given condition. Although traditionally held ideas about the slot working as 'Venturi' are not especially accurate (which will be left to the aerodynamicists to explain), there is no question that the jib/main relationship is important.
The jib luff is standing up straight but the mast appears to be bending to leeward which closes the slot between jib and main when it is very windy.
Most critical is the ability to open the slot in heavy air without sacrificing pointing ability (which happens if you simply go to extremes of twisting or easing the jib). Getting the middle of the mast to come slightly to weather in a blow can be extremely fast, and the resulting twist in the main, as well as the opening of the slot, work together as an efficient means of depowering, often allowing great increases in speed with little or no loss of pointing.
Conversely, it is very important to hold the mast straight in lighter conditions, and accomplishing these things is largely a matter of correct spreader length and rig tension. Spreaders which, are simply too long will never allow enough side bend in a blow - those too short will give way too early. On 505 rigs which allow the side bend tendencies to be balanced by the height of the shrouds' attachment point to the mast, it is possible to have a mast which will go through the following routine with regard to side bend:
*
very light air - stands straight because static rig tension dominated wind load.
*
fully hiking air with boom on centreline, little twist in main - mast bends negatively sideways due to high-mounted shrouds; less twist, more power.
*
fully trapezing air stands straight as thrust from boom slightly off centreline coupled with more twisted main pulling tip more sideways and less aft, which counteracts tendencies of high-mounted shrouds to produce negative bend.
*
heavy air - bends to weather in middle, opening slot, twisting main; this is caused by boom well off centerline thrusting mast to weather in loose mast partners and well-twisted sail pulling tip even more sideways to leeward, less aft. Short spreaders offer little resistance to this tendency while still working effectively to limit fore and aft bend as desired.
The 505 offers nearly ideal opportunities for controlling side bend, due to the optional height of the shrouds. Some other boats (420, 470) require that the shrouds be so low that longer spreaders are required to keep the mast from developing too much side bend too early; therefore, it is impossible to attain negative bend in power conditions without spreaders so long that the mast will never open up in a breeze. The best compromise on these boats is to hold the mast straight up until you get in heavy air (fairly long, but not extreme spreaders), then let some side bend into the rig when the wind qets really heavy.
Extreme conditions often require special attention to keep the sails working well. In very light air, no tension can be put on the mainsheet or vang without over-tightening the leech. Therefore, there are no natural forces to bend the mast. The luff curve in the main, which is necessary for more wind, will hang lifeless behind the mast, and the sail will be much too full, with the draft forward and leech tight (slow). Something must be done to force bend without pulling on the leech. If the bend is attained with aftcanted spreaders and rig tension, the jib sag is undoubtedly too straight, the jib entry too fine, etc. So the mast must be 'pre-bent' by pushing or pulling it forward at or above deck level with blocks, wires, 'mighty screws', struts or something. Once pre-bend is attained, proper draft and twist will fall into the mainsail, the jib will sag appropriately and speed becomes possible.
The jib luff is standing up straight but the mast appears to be bending to leeward which closes the slot between jib and main when it is very windy.
Light air usually requires the mast rake to be a little less (more vertical), and it is an unfortunate trade-off to have to ease the jib halyard to attain sag - better to ease the shrouds.
In short, boats which are allowed variably adjusted shrouds really ought to have them - it is also very fast downwind to be able to let the rig lean forward.
Heavy air often requires more rake and also, more tension, again calling for a change in the shrouds and not simply easing the jib halyard. In particularly heavy air, extremes of mast bend can sometimes be very fast.
A mainsail which is 'inverted' (bent beyond its luff curve) develops large diagonal wrinkles that run roughly from clew to spreader (diagram), almost as though the back of the boom was bent off to leeward. This can provide a means of depowering without easing the sail too far outboard, retaining pointing ability.
In fact, very good control over the angle of the bottom batten (lower leech) can be had in some sail designs even before the inversion wrinkle develops. More lower mast bend can help open the leech if the sail is right as well. This can extend the effect of opening and closing the lower leech into more moderate as well as very heavy air.
There are very few magic numbers which will solve all one's problerns. Even with a specific suit of sails for a given boat, for which some guidelines could be offered (most sailmakers do), changing sea conditions will grossly alter what shapes you want, even for the same wind velocity. However, knowing how your controls affect your shapes, and arranging your boat so that the controls work easily and within the range you need, will allow you to make decisions as you sail and try them out. Experience will let you know what works and what doesn't, but it's important to know what's going on (and why) as things change or you change them.
Most importantly, it is vital to practice enough to develop a ready feel for what you need to do as conditions vary; otherwise, you'll find yourself off beyond the layline while you fiddle with the rig.
Retyped from
505 Great Britain No.16
Summer 1980
Steve Taylor/David Penfield won the 505 Worlds in Durban 1979. Their series: 1, 1, 3, DNF = 5.7pts. 2nd: Dennis Surtees/Paul Cayard, 3rd: Dan Thompson, 4th: Jorgen Schonherr. 85 boats participated. Other americans were Steve Benjamin(11), Jon Andron(10), Ethan Bixby(12), Jim Wondolleck(21). 15 boats from the US.
The still chute-less bow of Steve Taylor's three year old boat.
World champion Steve Taylor describes the functions of the 505 rig and the effects rig controls have on sail shape and overall speed.
You've fitted out a well-rigged hull with a good board and rudder, and you're on your way down to the club with newly acquired sails, ready to step the mast and attempt to transform your magnificent efforts with wallet and toolbox into speed on the race course.
Naturally, every time you touch a control line, it moves effortlessly, with no friction, and whatever it controls works beautifully - you just don't know quite where to set it. Lots of practice in the old boat has given you some idea where to start and certainly means that your boat handling is smooth, your steering second nature and your relationship with your team-mate gracefully established. Ever since your last frostbite season your starts have been good and your tactics consistent. Now the problem is to learn to think a little more clearly about how to set up your rig in all conditions, how to adjust it quickly as the conditions change and how to see what shapes are produced in your sails as you make these adjustments.
On 505s and any other boat in which the loads of the rig and the mast are supported by the luff wire in the jib, the headstay, if there is one, is generally left slack when sailing and is only used to hold the mast up in the parking lot. Once the shrouds are fixed, increasing tension on the jib halyard does two things:
1) it straightens the rake, pulling the mast forward, and
2) it pulls against the shrouds and increases rig tension (diagram).
Because the fore-and-aft angle of the jib luff to the mast is much greater than that of the shrouds (diagram), a small change in jib halyard length will affect rake more than rig tension; likewise, a change of equal length in the shrouds will affect tension more than rake (diagram). A good way to start thinking about your rig is to consider the jib halyard as your rake control and the shrouds as your tension control.
Jib halyard tension reduces rake and can also increase rig tension
Angle A, between the jib luff and the mast, is much larger than angle B, between the shrouds and the mast. This causes the jib luff tension, to be the dominant factor in rake, and shroud length to be the dominant factor in rig tension.
Both rake and tension are important adjustments, but with the exception of the FD, which uses rake to control the genoa lead, tension is usually the more important of the two. Therefore, for simplicity's sake, you can first choose a basic rake setting and set your jib luff to that point. Then, if your shrouds are adjustable, you will be able to regulate tension easily with a control line. If your shrouds are fixed by chainplates with rows of holes, to effect tension change you may have to first release the jib halyard, then change the shroud pin location and finally put the jib halyard back in the desired position. In any event, remember that it is shroud length that makes the tension difference - the jib halyard is for rake.
The two most important effects of rig tension are jib luff sag and mast bend, both of which control, to a large degree, the shape of the sails to which they are attached. The table shows how jib luff sag affects jib shape.
The Effects of Jib Luff Sag on Jib ShapeToo Much Sag Correct Sag Too Straight
Draft draft too far
forward draft in correct position draft too far aft
Fullness sail too full,
especially head depth correct sail too flat,
especially entry
Leech upper leech too
close to mainsail
when sheet is
trimmed leech twist
balanced with
sheet and lead upper leech too
open relative to
sheet and lead
Luff loose luff may
'pump' in seas,
causing rapid
shape variations luff stable,
but forgiving rigid luff
unforgiving and
prone to stalling
-entry too fine
Steering Groove steering groove
too wide, can't
get accurate
course from
telltales steering groove
reasonable,
telltales normally
responsive steering groove
too narrow,
telltales too
nervous - both
leeward and
windward flutter
at once.
Understanding how rig tension affects the shape of the mainsail through mast bend is a bit more involved. First, tension affects bend primarily through the spreaders, especially if the shrouds intersect the mast at about the same place as the jib halyard at the hounds. Unlike jib luff sag, which happens in a direction roughly aligned with the wind, mast bend can be controlled and thought of in two different directions - fore and aft or sideways (diagram).
More forward cant on the spreaders, coupled with more shroud tension, causes less fore and aft mast bend. A reduction in either cant or tension will allow more fore and aft bend. If the spreaders are swept aft of a neutral position, increasing tension will induce more fore and aft bend.
At this point, it should be mentioned that this is true only while the mast is still basically in column, or only up to the point where further shortening the shrouds ceases to add tension. At some point after the mast is bent like an archer's bow, shortening the shrouds will not add tension, but actually reduce it or leave it constant as the mast buckles out of column and simply bends more in whatever direction it had already begun. It very rarely pays to sail with the spar set up this way, and particularly with stiff boats and powerful rigging systems, care should be taken not to attempt to 'tighten' the rig past this point of 'no return'.
Sideways bend is controlled largely by the degree to which the spreaders deflect the shrouds outboard position, or poke. For the purposes of this discussion, more side bend means the middle of the mast comes to windward and the tip to leeward; less side bend means the mast is straight sideways; and negative side bend means the middle of the spar depresses into the slot to leeward - regardless of whether the tip is also to leeward (S-bend) or is held straight, or to windward, through either natural stiffness or very high trapeze wires (diagram).
Longer spreaders, or more poke, tends to reduce side bend and can even force it negative. Shorter spreaders allow more side bend. Changes in tension work to increase or decrease the effect of the spreaders correspondingly - more tension and the spreaders do more work.
Having established, to a degree, how tension and spreader adjustment control mast bend, the important questions become, how does mast bend affect sail shape, and what do you want when?
Although sideways bend also affects the entire shape and twist of the sail in very similar ways to the table on fore and aft mast bend, it is important to discuss it separately in terms of twist and the effect on the size of the slot between main and jib. Twist in a sail is defined as the change in the angle of attack of the cross-sectional shapes of the sail in progression up from the foot (diagram). A chord is the imaginary line between luff and leech, at any height, and if these lines change their angles to the wind, then the sail has twisted. When the leech is tightened, the aft ends of the chord lines move to windward and twist is reduced. Likewise, if the middle of the mast moves to leeward (negative side bend), the front end of the chord line (a point on the luff) moves to leeward, and again, twist is reduced.Because twist (angle of attack) is perhaps the primary determinant of how much power (and drag) a sail develops, and because side bend has a linear relationship to twist, side bend is a very powerful variable in rig control. One-half inch of sideways movement of the luff at spreader height will make a far greater difference to your performance than one-half inch of fore and aft bend.
The 'slot' effect is also important, particularly in terms of preventing interference between the jib and main while retaining maximum useable power in a given condition. Although traditionally held ideas about the slot working as 'Venturi' are not especially accurate (which will be left to the aerodynamicists to explain), there is no question that the jib/main relationship is important.The jib luff is standing up straight but the mast appears to be bending to leeward which closes the slot between jib and main when it is very windy.
Most critical is the ability to open the slot in heavy air without sacrificing pointing ability (which happens if you simply go to extremes of twisting or easing the jib). Getting the middle of the mast to come slightly to weather in a blow can be extremely fast, and the resulting twist in the main, as well as the opening of the slot, work together as an efficient means of depowering, often allowing great increases in speed with little or no loss of pointing.
Conversely, it is very important to hold the mast straight in lighter conditions, and accomplishing these things is largely a matter of correct spreader length and rig tension. Spreaders which, are simply too long will never allow enough side bend in a blow - those too short will give way too early. On 505 rigs which allow the side bend tendencies to be balanced by the height of the shrouds' attachment point to the mast, it is possible to have a mast which will go through the following routine with regard to side bend:
*
very light air - stands straight because static rig tension dominated wind load.
*
fully hiking air with boom on centreline, little twist in main - mast bends negatively sideways due to high-mounted shrouds; less twist, more power.
*
fully trapezing air stands straight as thrust from boom slightly off centreline coupled with more twisted main pulling tip more sideways and less aft, which counteracts tendencies of high-mounted shrouds to produce negative bend.
*
heavy air - bends to weather in middle, opening slot, twisting main; this is caused by boom well off centerline thrusting mast to weather in loose mast partners and well-twisted sail pulling tip even more sideways to leeward, less aft. Short spreaders offer little resistance to this tendency while still working effectively to limit fore and aft bend as desired.
The 505 offers nearly ideal opportunities for controlling side bend, due to the optional height of the shrouds. Some other boats (420, 470) require that the shrouds be so low that longer spreaders are required to keep the mast from developing too much side bend too early; therefore, it is impossible to attain negative bend in power conditions without spreaders so long that the mast will never open up in a breeze. The best compromise on these boats is to hold the mast straight up until you get in heavy air (fairly long, but not extreme spreaders), then let some side bend into the rig when the wind qets really heavy.
Extreme conditions often require special attention to keep the sails working well. In very light air, no tension can be put on the mainsheet or vang without over-tightening the leech. Therefore, there are no natural forces to bend the mast. The luff curve in the main, which is necessary for more wind, will hang lifeless behind the mast, and the sail will be much too full, with the draft forward and leech tight (slow). Something must be done to force bend without pulling on the leech. If the bend is attained with aftcanted spreaders and rig tension, the jib sag is undoubtedly too straight, the jib entry too fine, etc. So the mast must be 'pre-bent' by pushing or pulling it forward at or above deck level with blocks, wires, 'mighty screws', struts or something. Once pre-bend is attained, proper draft and twist will fall into the mainsail, the jib will sag appropriately and speed becomes possible.
The jib luff is standing up straight but the mast appears to be bending to leeward which closes the slot between jib and main when it is very windy.
Light air usually requires the mast rake to be a little less (more vertical), and it is an unfortunate trade-off to have to ease the jib halyard to attain sag - better to ease the shrouds.
In short, boats which are allowed variably adjusted shrouds really ought to have them - it is also very fast downwind to be able to let the rig lean forward.
Heavy air often requires more rake and also, more tension, again calling for a change in the shrouds and not simply easing the jib halyard. In particularly heavy air, extremes of mast bend can sometimes be very fast.
A mainsail which is 'inverted' (bent beyond its luff curve) develops large diagonal wrinkles that run roughly from clew to spreader (diagram), almost as though the back of the boom was bent off to leeward. This can provide a means of depowering without easing the sail too far outboard, retaining pointing ability.
In fact, very good control over the angle of the bottom batten (lower leech) can be had in some sail designs even before the inversion wrinkle develops. More lower mast bend can help open the leech if the sail is right as well. This can extend the effect of opening and closing the lower leech into more moderate as well as very heavy air.
There are very few magic numbers which will solve all one's problerns. Even with a specific suit of sails for a given boat, for which some guidelines could be offered (most sailmakers do), changing sea conditions will grossly alter what shapes you want, even for the same wind velocity. However, knowing how your controls affect your shapes, and arranging your boat so that the controls work easily and within the range you need, will allow you to make decisions as you sail and try them out. Experience will let you know what works and what doesn't, but it's important to know what's going on (and why) as things change or you change them.
Most importantly, it is vital to practice enough to develop a ready feel for what you need to do as conditions vary; otherwise, you'll find yourself off beyond the layline while you fiddle with the rig.
The MiG-15 Finally Fades Away
Warplanes: The MiG-15 Finally Fades Away: "The MiG-15 Finally Fades Away November 14, 2005: Albania has retired the last MiG-15 fighters still in service. A late 1940s design, partly based on work Germany had done during World War II (and using captured German engineers and plans, as well as British technology and Russian aircraft design ideas), the MiG-15 looked good on paper. The six ton MiG-15 was fast, rugged and resistant to damage. But the flight controls made it difficult to maneuver as effectively as 'inferior' American aircraft. MiG-15s were usually the losers in aerial battles with aircraft like the F-86 or F-80. Recognizing those flaws, there followed the six ton MiG-17, which corrected most of the MiG-15s faults, and added a new one; difficulty maneuvering at low altitudes. In the mid 1950s, the nine ton MiG-19 showed up, further refining the original MiG-15 idea. The MiG-19 was supersonic, but as pilots discovered, it was maneuverability, not speed, that brought victory. The MiG-19; was quickly followed in the late 1950s by the 8.5 ton MiG-21, which is still serving in dozens of air forces. Most modern jet fighters weigh in at twenty tons or more, and dwarf the MiG-15 in other ways as well. Albania got its first MiG-15s from Russia in the 1950s, but later got the Chinese version (the J-2). There are only ten J-2s left in Albanian service,"
Thursday 25 October 2007
Wednesday 24 October 2007
Tu-95: world's only swept-wing turboprop
The Tu-95 is the world's only swept-wing turboprop ever to enter service. Its distinct engines, each with two counter-rotating propellers, also make the Bear the fastest propeller-driven airplane ever built. An interesting feature of the Tu-95/Tu-142 Bear is that it is actually a turboprop, not a piston engined aircraft, so technically it is a jet powered aircraft. The blades are very course and so it can fly about 100km/h faster than the western experts expected it to. It was the first swept wing propeller driven aircraft in the world and is also the fastest propeller driven aircraft in the world. The original Tu-95 was designed to carry two nuclear bombs to targets in the continental US. Later versions carried cruise missiles for long-ange stand-off missions. The Bear has also been used for reconnaissance, especially by the Soviet/Russian Navy which used the aircraft to locate US aircraft carrier task forces. A specialized variant of the Bear is the Tu-142 dedicated to maritime surveillance and anti-submarine warfare. Over 300 Bears were built.
Tuesday 23 October 2007
深化金融改革 人民幣已升值逾10%
人民銀行周二召開了黨委會議暨黨委中心組集中學習。會議指出，央行 將進一步深化金融改革，提高金融業競爭力。推動金融市場產品創新和制度建設，大力發展企業融資產品，培育和發展外匯市場。繼續深化外匯管理體制改革，完善人民幣匯率形成機制，穩步推進人民幣資本項目可兌換。繼續推進金融穩定機制建設。建立健全風險監測和評估體系，加快建立存款保險制度。
對於人行會否在年底前加息，人行行長助理易綱表示，人行目標為正數利率，尚需觀察一段頗長時間才能決定。對於人民幣兌美元今日曾升穿1.5，漸進及小幅上漲是合理的。由05年7月1日至今年，人民幣已升值逾10%。
對於人行會否在年底前加息，人行行長助理易綱表示，人行目標為正數利率，尚需觀察一段頗長時間才能決定。對於人民幣兌美元今日曾升穿1.5，漸進及小幅上漲是合理的。由05年7月1日至今年，人民幣已升值逾10%。
Sunday 21 October 2007
Thursday 18 October 2007
International Marine Signal Flags
International Marine Signal Flags: "flag image A; flag image B; flag image C; flag image D; flag image E; flag image F; flag image G; flag image H; flag image I; flag image J; flag image K; flag image L; flag image M; flag image N; flag image O; flag image P; flag image Q; flag image R; flag image S; flag image T; flag image U; flag image V; flag image W; flag image X; flag image Y; flag image Z;"
Monday 15 October 2007
未來幾年環球信貸市場仍會面對挑戰
匯豐銀行行政總裁霍嘉治說，暫難確定美國次按導致的信貸收縮問題，是否已告一段落，因為企業的會計賬目，可能未全面反映次按造成的影響。他相信，未來幾年環球信貸市場仍會面對挑戰
Sunday 14 October 2007
Racing Rules of Sailing -
http://www.autohoot.com/the_perfect_start.htm#Starting%20sequences
Racing Rules of Sailing - Wikipedia, the free encyclopedia: "Start Signal These signal flags are used in the pre-start procedure. Class flags can be numeral pennants 1 , 2 , and 3 however they can be substituted to avoid confusion with the postponement signals relating to a particular class. When one race signal is displayed over one class flag, the race signal is intended to be read only by that class, and has no effect for the other class. For some classes the class flag is a special, own designed, flag, while for some other classes a flag taken from the International maritime signal flag set are used. The following table shows an example start sequence for Class or Division 3 fleet. Flag Signal Number of sound signals when raised Number of sound signals when lowered Description
3 ↑ Warning Signal. 5 minutes to race start when class flag raised.
3 P ↑ Preparatory signal. 4 minutes to start when P flag raised. Flag P used or if a starting penalty applies I, Z, Black flag or I over Z is used in place of P.
3 P ↓ Long Sound Preparatory signal. P flag removed 1 minute before start. Flag P used or if a starting penalty applies I, Z, Black flag or I over Z is used in place of P.
3 ↓ Start Signal. Race start when class flag removed.
http://en.wikipedia.org/wiki/Racing_Rules_of_Sailing
Wing Morphing Of The Swift
Wing Morphing Of The Swift Could Inspire New Aircraft Designs
Science Daily — A swift adapts the shape of its wings to the immediate task at hand: folding them back to chase insects, or stretching them out to sleep in flight. Ten Dutch and Swedish scientists, based in Wageningen, Groningen, Delft, Leiden, and Lund, have shown how 'wing morphing' makes swifts such versatile flyers. Their study, published as cover story in Nature on April 26, proves that swifts can improve flight performance by up to three-fold, numbers that make 'wing morphing' the next big thing in aircraft engineering.
Turning swifts keep their head horizontal during a banked turn. (Credit: Copyright: Jean-Francois Cornuet)
Swifts spend almost their entire life in the air. During flight, they continually change the shape of their wings from spread wide to swept back. When they fly slowly and straight on, extended wings carry swifts 1.5 times farther and keep them airborne twice as long. To fly fast, swifts need to sweep back their wings to gain a similar advantage.
Swifts spend almost their entire life in the air. During flight, they continually change the shape of their wings from spread wide to swept back. When they fly slowly and straight on, extended wings carry swifts 1.5 times farther and keep them airborne twice as long. To fly fast, swifts need to sweep back their wings to gain a similar advantage.
Economic turns
During the summer, we can observe swifts circling above town squares, where they catch up to 20.000 insects a day. Swift can triple their efficiency by turning with their wings stretched out. When chasing rivals and flying insects, swifts also want to make their turns fast and tight. However, in fast and diving turns, the load on the wings easily reaches more than four times the swift's body weight. So in extreme turns, swifts need to sweep back their wings or else risk breaking them.
Night's rest
Swifts do not land to roost, but spend the night at 1.5 km above the ground. To measure their flight speed, Swedish scientists used radar. They found that swifts let the air blow past their wings at 8 to 10 m/s (29-36 km/h). At these air speeds, swift wings deliver maximum flight efficiency. For the swift that means more gliding and less flapping to maintain altitude.
The scientists figured all this out when they measured just how much lift and drag a swift wing generates. The wings were tested to their limit in a windtunnel at speeds of up to 108 km/h (30 metres per second).Scientists compared extended and swept wings, and learnt that flying slowly with extended wings gives swifts maximum flight efficiency. But swept wings deliver a better aerodynamic performance for flying fast and straight. Swept wings are also better for fast and tight turns; but this time swept wings are better because they do not break as easily as extended wings.
Airplanes
Morphing wings are the latest trend in aviation. The best wing shape to save fuel costs depends on flight speed. In 2003, birds inspired NASA to design a revolutionary "morphing wing" aircraft. Also so-called micro-aircraft, which are the size of a bird, begin to exploit the benefits of varying wing shape. These tiny flyers, equipped with cameras and sensors to assist in surveillance and espionage, imitate faithfully the flight behaviour and appearance of birds. In an ongoing project, students at Delft University cooperate with scientist at Wageningen, to make such a small airplane fly like a swift.
The swifts for this study had been brought in dead or dying to seven Dutch bird sanctuaries. Swifts, when forced to land on the ground, cannot take off by themselves and will starve unless a kind and timely passer-by throws them in the air. Swifts are the most aerial of birds. They migrate annually from South Africa to Europe. Over their lifetime, swifts cover 4.5 million kilometres, a distance equal to six round trips to the moon or 100 times around the Earth. At day, swifts hunt insects; at night they 'roost' in flight. Swifts even mate in the air and land only lay their eggs, in nests tucked away into crevices of walls and cliffs. Swifts are not related to swallows. They are family of another well-known aerial acrobat, the hummingbird.
Note: This story has been adapted from material provided by Wageningen University and ResearchSunday 7 October 2007
鼓勵市民生育
行政長官曾蔭權後日發表新一份施政報告，預料會提出措施，鼓勵市民生育，改善持續偏低的出生率。政府上年度，已提高新生嬰兒免稅額至五萬元，又將第三名子 女的免稅額與首兩名子女看齊。但有學者指，單靠一次性的稅務優惠，不足以鼓勵市民多生幾個，建議當局仿傚鄰近的新加坡，推行長期的財政優惠，例如設立兒童 發展戶口，由政府每年存款入戶口，令收入較低的家庭亦有能力多生育。
Thursday 4 October 2007
Real Earnings August 2007 usa
Real Earnings: "REAL EARNINGS IN AUGUST 2007 Real average weekly earnings rose by 0.5 percent from July to August after seasonal adjustment, according to preliminary data released today by the Bureau of Labor Statistics of the U.S. Department of Labor. This increase stemmed from a 0.3 percent rise in average hourly earnings and a 0.2 percent decline in the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). Average weekly hours were unchanged."
Wednesday 3 October 2007
Sailing Upwind through A Chop in Lightning
Sailing Upwind In A Chop
http://www.lightningclass.org/Articles/SailingUpwindInAChop.htmBy Greg Fisher
Columbus, Ohio
Fleet 353, Hoover Yacht Club 1990 North American Champion
(From Racing the Lightning)
Steering a Lightning through a heavy chop is not an easy task. The “resonation” made by the bow slamming the waves when it isn’t “done right” is the best tattletale there is of improper tune and steering. While it isn’t possible to miss them all, there are some things that can be done, sail trim, tuning, and steering wise to help make the job a little bit easier.
The natural inclination when sailing through chop is to power the boat up as much as possible. While obviously the boat does need extra punch, how that punch is directed is most important. The first indication that the boat is not set up just right and that there is maybe too much power for the wind is the feel at the helm. If there is too much weather helm (the boat wants to round up into the wind) the boat will be very difficult to steer through the chop. Excessive weather helm means the tiller will be pulled to windward of centerline and the rudder will be literally dragged through the water.
Usually it is not too little backstay or too much mainsheet that creates the problem of excessive weather helm. Most Lightning sailors are comfortable with setting the mainsheet so the upper batten is angled outboard slightly from parallel to the boom. Most also just pull the backstay until the slop is just barely removed (unless it is blowing really hard). However, it is the traveler position that usually unbalances the boat. Normally we think that we want to pull the traveler up to a point where the boom is close to centerline since the mainsheet is eased and the upper batten is open. However, the bottom of the main is still powerful and the lower leech is hooked in relation to the centerline of the boat. In chop it is not unusual in a 8-10 mph breeze for the traveler to be down to leeward perhaps as much as 6”. Actually, the true gauge will be the feel on the helm. The helm must be nearly balanced so the boat can almost steer itself straight upwind all by itself. In flat spots, the traveler can be pulled back near centerline and the mainsheet trimmed to the batten parallel to the boom position. However, as soon as the boat enters waves again, traveler must go down and the sheet eased.
It is also natural to want to heel the boat a great deal because it seems to put a more ”V’ed” hull shape to enter the waves. While this may be true, a boat sailed with more heel develops more windward helm. Instead, try to keep the boat flatter, maintaining the weather chine no more than 3" to 6" out of the water. Many Lightning sailors sail with the chine just barely touching the water so that the boat is only heeled 10 degrees at the most. A boat that is balanced and sailing fast can still be steered to miss the biggest waves.
Steering around the waves should not be accomplished with only the tiller. The more the tiller is wiggled, the greater drag and the more the boat will slow down. Instead, ease the mainsheet (sometimes as much as a foot) to help the boat bear off and then trim it back in to help the boat head up. Be sure when trimming the main back in not to overdo it so the weather helm again won’t load up.
Be sure to adjust the jib also as the-boat heads up and bears off, but don’t overdo that either. If the jib is eased more than the ease of the main, the boat will not have the tendency to bear off and it will be much more difficult to "steer" through the waves. Unless it is extremely light, the jib should be eased out so the batten is angled close to the tip of the spreader and never trimmed inboard more than 1" to 1.5" inside the tip. In light winds, don’t be afraid to ease it out to as much as 2” outside the tip of the spreader.
Check that the extra life jackets, tools, water bottles, spinnaker poles, etc. are brought in from the ends of the boat and centered as close to the centerboard pin as possible. The crew weight too needs to be centered close with the skipper moving forward and the forward crew moving aft to help minimize the boat’s tendency to hobby horse through the waves.
Finally, be careful to avoid pinching at all costs. A boat that is going fast through the water will go up and over the waves much easier than one that is slow and loaded up with excessive weather helm.
Good luck and happy slamming.
Another sail trim guide
http://www.mssa.org/cms/pdf/pub/MSSAsailTrim.pdf
How to Maximize Lift
(and minimize drag)
• Lift and drag is variable
• Sails may be adjusted:
– Light Air
• Deep Draft, Draft Aft, more sail area
• Fuller shapes work because light air produces less
drag.
– Medium Air
• Reduce Draft, Draft Forward, maintain sail area
• Flatter shapes provide lift without excessive drag
– Heavy Air
• Reduce sail
– High wind velocities produce sufficient lift with much less
sail area.
– Overpowered is not fast
– Smaller flatter genoa/jib
– Reefed mainsail, full out haul to flatten the mainsail
General Sailtrim/Boatspeed
Guidelines
• Light Air,
– Sail trim
• Full Shapes, deep draft
• Ease halyards, Outhaul and Cunningham
– Steering
• Foot off to keep the boat moving. Helm and Trimmers work
together to continually adjust sail and helm to the varying
conditions. As boat speed increases, point a little higher to
make distance toward the mark.
–Move crew to leeward
• Keep the boat heeled so it is ready to take advantage of any
– breeze.
• Light Air, Choppy seas
– Arrgh! This is the worst!
– Foot off, keep boat moving, one wave can stop
you dead in your tracks, and take minutes to get
moving again. Don’t be greedy and try to point
too high.
• Move Crew to Leeward
– – Try to sails from collapsing/flopping
• Medium Air,
– Yeah! This is by far the easiest to sail
– Start reducing draft in the sails (flattening)
• Outhaul
• Halyards (move draft forward)
• Cunningham
– •
• Medium Air, Choppy Seas
– With a continuous breeze, it is easy to get the
boat moving.
– Watch for the waves, if you hit one head on,
you will loose momentum. If you are about to
take a wave on the bow, steer down,
momentarily.
– – Anticipation is key, don’t get caught sleeping
• Heavy Air,
– This is a transition state, most likely the wind
has just come up.
– You will need to reduce, flatten sail.
– Don’t be fooled. This state is short lived. The
waves will likely come soon. Use this time to
– get ready.
• Heavy Air, Choppy Seas
– Reefed main, Tight Halyards, Cunningham
– Small, Flat
• 90% to 110%
• Roller Reefing will reduce sail area, but don’t
expect to point very high.
– Watch out for big waves, they’ll stop you dead
– in you tracks.
• Velocity Made Good (VMG)
– Strong Winds
• Sail more direct course toward mark, Run down
wind, boat speed will be maintained for Best VMG
– Light Winds
• Sail more of a broad reach to maintain boat speed
– for best VMG.
Down Wind Sail Trim
• Loosen most sail Controls
– Ease Halyards
– Ease Outhauls
• Sails will be let out, air flow over sails will be
reduced, Sails will work in two modes:
– Drag Mode: Wind is pushing sails and boat down wind
– Lift Mode: Air flowing over sails produce lift when
– sailing a broad reach
–
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