SOLUTIONS FOR TODAY S SAILORS Tuning Guide 05/11 NORTH SAILS
The Farr 40 One-Design is a modern Grand Prix-type yacht designed specifically for the fun-loving owner-driver. A highly competitive Offshore One-Design, it was designed to be compatible with the IMS rule. The boat has lighter displacement, higher stability and more sail area than the typical IMS boat, although Farr International has made no concession to the current trend to better one s rating at the expense of speed. The result is a fast, safe, fun boat that guarantees enjoyment on the water. North Sails is proud to have helped more Farr 40 teams achieve success than any other sailmaker. Teams equipped with North 3D thermo-molded sails have finished first in 14 consecutive F40 World Championships (1998-2011)...a strong testament to our continuing dedication to the class. The Farr 40 One-Design tuning guide is the latest update to our expanding library of tuning guides. Others available include the Farr 30, Flying Tiger, J/105, J109, J111, J/35, J/120, Melages 32, Soto 40, Swan 42, Swan 45, X-35, and the X-41. All North Sails tuning guides are designed to help you get up to speed...fast! (We call it turnkey speed. ) Included are all the references you need for setting-up the Farr 40 One-Design for maximum performance to help you replicate fast settings. 3DLT thermo-molded and 3DiT composite foil sails are featured almost exclusively in upwind sails, both for weight savings and use over a wider wind range. Comments on sail trim, and tips on boat handling are written as if your North Sails representative were sailing with you. If you currently own a Farr 40 One-Design, you may have some of your own go-fast tips to add to this guide. We d love to hear from you. If you are new to sailing the Farr 40 One-Design, we d also appreciate your comments and feedback. We wish you good sailing. Sail Fast! Sail Smart! Tom Whidden, CEO, North Technology Group 2
Contents Seven Steps for Base Settings...4 Step 1: Max J...4 Step 2: Mast Butt Position...4 Step 3: The Reference Arc...5 Step 4: Centering the Hounds & Partners...5 Step 5: Jack the Spar Up to Nominal Pressure...6 Step 6: Jib Leech Trim Marks...6 Step 7: Go Sailing!...7 North Sails Base Matrix Setup Adjustments...7 Headstay Length...8 Light Air Jack...8 Medium Air Jack...8 Heavy Air Jack...9 Class Notes...9 Class Rules...10 Worldwide Service (loft list)... 11 Updates North Sails is constantly refining tuning techniques and rig settings as we and our customers gain experience in individual classes. This information is shared daily among North staff worldwide via our corporate intranet. While this Tuning Guide provides a giant step toward achieving competitive speed in your class, be sure to contact your North representative about the latest Farr 40 tuning developments. Note: This tuning guide does not supercede Class, ORC, or US Sailing rules. 3
We are going to describe seven steps to help you set up your new Farr 40 to the North Sails Base Settings. These settings will enable you to be competitive the first time you go sailing. Later we will offer you some additional suggestions to help you optimize your Farr 40 for specific sailing conditions. It s a good idea to keep an accurate, ongoing log of your boat s specific measurements (within tolerances allowed by the class) for reference to the North Base Settings. Ultimately you will develop your own settings that work with the way you drive and sail your boat in different wind and wave conditions. Don t be intimidated. The initial setup can be accomplished in as little as one hour s time. You ll need the following: 30 metre tape measure Rig adjustment tools WetNotes book Safety harness / boatswains chair North Sails Tuning Guide A crew of six Step 1 Max J Measure from the center of the headstay at the deck to the forward face of the spar above the deck. This should be a maximum of 4.735 metres. NOTE: Measure to the carbon spar above the partners, not the spinnaker pole track. Step 2 Butt Position Headstay to pin meas. OD Arc measurement = 1.45m Mast butt Aft of mast to aft of keel frame=1.160m Cap shroud tension loose Loose Guage 12 = 60 units D1 Tension Loose Guage 12 = 12 units D2 Tension Hand Tight = +3 Full turns J Dimension Headstay to Front of Mast=4.735m Max Distance from the back of the mast to the back of the keel frame as shown here = 1.16m with the mast on all bricks. 4
Step 3 The Reference Arc From the top of the white band at the gooseneck, measure 1 metre down and paint a 2.5cm wide white line on the mast. From this line (which you marked on the spar) swing the centerline halyard to the headstay and make an indelible mark. The measurement from the headstay indelible mark (Simplified Arc) to the center of the load cell pin should be 1.45m Simplified Arc. This is the North Sails Farr 40 Base headstay setting with 3400 psi of jack pressure. (Above) Simplified Arc 1.45m, base setting. (Left) Mark the spar 1m below top of gooseneck mast band. Step 4 Centering the Hounds & Partners At 2500psi Jack Pressure with just the verticals attached, measure down to the top of the Port and Starboard vertical shroud pins at the chain-plates using the center line halyard or a metal tape measure attached to the centerline halyard. When the measurement to Port and Starboard pins are the same the hounds are centered. Measure across the boat in front of the mast, from one vertical shroud to the other just above the partners, and parallel to the water. Make sure the centerline of the front face of the mast is equidistant between the two vertical shrouds. NOTE: Position the center of the spar relative to the cap shrouds, not the center of the partner hole. 5
NOTE: There are two methods of measuring jack pressure: 1) Ease the mast down until plates just stop moving. Pump slowly up until the top plate barely moves. Repeat 3 or 4 times and take the average pressure number from the gauge. (This method records a slightly higher number than method 2.) 2) Using a pair of vice grips on the jack pump valve slowly lower the mast onto the mast plates. Record the pressure when the plates just become pinched and stop moving. As in the first method repeat 3-4 times to average the number. This is the preferred method to be used with the North base settings. Step 5 Jack the Spar Up to Nominal Pressure The spar should be ready for maximum Jack Pressure. Begin by tightening all the Diagonals to hand tight. Now add 4 turns to the D1 s and 5 turns to the D2 s. The total jack pressure with this rig setting and the Simplified Arc at 1.45m is 3400psi. This is the North Base setting measured as in method #2 above. Note: It is important that the mast has plenty of wax/lubricant at the mast partners throughout the Spar-tite area to help reduce friction that will alter the true Jack Pressure readings. Step 6 Jib Leech Trim Marks Mark the spreaders port and starboard with white tape parallel to the centerline of boat, or in line with the jib tracks when sighting down from the spreader. From the mainsail mast groove to the back face of the spreader the distance should be: Lower Spreader: S1: Outer Mark: 1.13m (3' 8 1 2") Inner Mark: 0.914m (3') Upper Spreader: S2: Single Mark: 0.71m (2'4") 6
Step 7 Go Sailing in 10+, But Less Than 20 Knots The boat should be in racing trim with a headsail and mainsail fully trimmed and the crew hiking. To finish the spar tune sight up the sail groove from the aft face with the boat in racing trim. This allows the rig to be tuned under the same pressure as found while racing. Adjust tension on the D1s and D2s until the rig is straight sideways. North Sails Base Settings 2011 Mast Butt Position: measured aft 1.16m. Simplified Arc 1.45m Jack pressure 3400m. Note: Four turns on the headstay = 1cm of adjustment North Sails Base Matrix Set-Up Adjustments True Wind Speed Sail Selection Headstay V D1 s D2 s Jack Very Light Winds (0-6kts) LC-1-12 -4 turns -3.5-2 Light Winds (6-10kts) LMC-1-8 -2 turns -1.5 0 Medium Winds (9-10kts) MC-1-4 -1.5-1 0 Medium Winds (11-12kts) MC-1 0 0 0 0 Medium Winds (13-15kts) MC-1 4 2 1 1 Medium Winds (16-18kts) HC-2 8 3 2.5 2 Heavy Winds (19-21kts) HC-2 12 4 4 4 Very Heavy (22kts+) HWJ-1 16 5 4 4 Note- All previous numbers and measurements have been proven to be competitive in the fleet today. All turns from Base. For previous chart add your bases and feel free to change wind ranges or column headers. 7
Following are some additional suggestions being used in the fleet. Give them a try! Headstay Length Headstay length adjustments from light to heavy air are typically 6-7cm. This translates to 28 turns on the headstay (1cm = 4 turns). Light Air In light air most boats tend to soften up the rig, increasing headstay sag to power-up the sail plan and induce weather helm. The determining factor is reduced Jack pressure. Methods used to lower Jack pressure are: A) Increasing the headstay length drops jack pressure. Use the range of turns from the base matrix. Effect: Promotes headstay sag and increases mast rake. The increased mast rake means the mast is set up with more pre-bend. Without other rig adjustments this change will cause the mast to have more low-bend Vs. high bend so the mainsail sets up relatively flatter in the bottom compared to the top. B) Taking turns off any of the Diagonal rigging reduces jack pressure. Use the range from the North base matrix. Effect: Promotes a more even bend for the mast that supports the static Luff curve built into the mainsail. The wind pressure and mainsheet tensions are not sufficient to bend the mast when the loads are so light. A couple of boats sag the mast to leeward below the hounds, up to 5cm, by taking turns off the Diagonals in the very light wind conditions. This powers up the mainsail at lower wind speeds. The mast head will also set up to weather above the hounds. Medium Air In medium air, consistently fast trim is a challenge. The Farr 40 is searching for power in 8 Tws, and has everyone hiking in 9 Tws. A) Have the D2 just soft on the leeward side when sailing upwind. Effect: Great method to monitor Jack Pressure vs. Headstay length for overall mast bend and how it fits the mainsail luff curve. When the mainsail is the desired depth and the leeward D2 is loose the trigonometry of all the forces, 8
Headstay, Jack Pressure, Diagonals, and Mast Butt Location are working perfectly together. C) Tune the mast to be straight through the masthead athwartship. Heavy Air In Heavy air the rig needs to be tightened up well past our Base numbers. We are now looking to depower the sail plan. The best method is by increasing the jack pressure and shortening the headstay. A) Tightening the headstay turnbuckle. Shortest Simplified arc 1.39m in very heavy winds 27+ Tws Effect: Less headstay sag and keeps the center of effort forward, reduced relative helm for the heavy breeze. B) Tighten up the Diagonals: Effect: Keeps the mast in column especially since backstay is now used. C) Tighten the Verticals: Effect: Minimizes the rig twist with the swept back spreaders. Notes Race 1 Race 2 Race 3 Race 4 Race 5 Notes Headstay Caps D1s D2 Note - For previous chart, double check your rows are properly headed for your class. 9
CLASS RULES 10
Worldwide Service At North Sails, we view each sail purchase as the beginning of a long and rewarding relationship. We base this expectation on a strong service commitment that includes preventive maintenance, sound advice, education and expert repairs. Your nearby North loft offers a wide range of services including... annual checkover sail tune-up educational sail washing retrofitting resources winter storage seminars North Sails is a network of over 100 lofts in 28 countries around the world. Each offers knowledgeable, friendly, personal sales and service. Our size and worldwide reach also means North has the world s most expansive sailmaking database. It would be hard to find a sailboat for which we cannot make a fast, durable and long lasting sail. NORTH SAILS Please visit the North Sails Class Sail Development website at: http://na.northsails.com/farr40/tuning.aspx Farr 40 Class website: www.farr40.org 11