Mumm 30 guide 11-99 - BLUR · Mumm 30Tuning Guide 5 NOTE: All measurements are taken to the...

MUMM30TUNING GUIDE

SOLUTIONS FOR TODAY’S SAILORS

NORTH SAILS

10/00

The Mumm 30 follows closely on the heels of the successful Mumm 36 classwith the Mumm 30 designed as an exciting yet simple boat to sail. Theabsence of running backstays and large genoas do a lot to simplify

boathandling. A generous mainsail, asymmetric spinnaker and larger rudderensure superb light air performance with complete control as the breeze freshens.This is further helped by the very high stability designed into the hull. We are veryexcited about the potential of the Mumm 30 and look ahead to a great, well-organized class of owner-driven boats.

The boat can be easily trailed and launched with its optional single point liftingeye. It’s simple enough for the whole family to rig and sail yet lively enough to thrillthe most seasoned sailor.

Bruce Farr and Associates, Inc. and the respective class builders under themanagement of Geoff Stagg of Farr International, have proven their ability toproduce high-quality uniform boats as evidenced by the Mumm 36 class, and nowthe Mumm 30. The class has established itself firmly in the North American racingscene.

At North Sails, we’re proud to have been involved with the Mumm 36 and Mumm30 from their inception. We have worked hard to develop sails that will deliver thespeed you need to win and the durability you need to keep winning, season afterseason. We’ve also worked hard to prepare this Mumm 30 Tuning Guide to helpyou get your boat and crew competitive fast. Use it...it works!

Tom WhiddenCEO, North Sails Group

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UPDATESNorth 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 Mumm

30 tuning developments.

Mumm 30 Tuning Guide

3

Deck plan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Setting up the Rig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Mainsail Trim. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Genoa Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Asymmetric Spinnaker Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Symmetric Spinnaker Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Tacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Gybing the Asymmetric Spinnaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Gybing the Symmetric Spinnaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Crew Weight in Light Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Crew Weight in Medium Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Mainsail Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Light Headsail Shape. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Medium Headsail Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Heavy Headsail Shape. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Asymmetric Spinnaker Tips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Masthead Spinnaker Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Sail Range Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Running Rigging List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25North Sails Lofts and Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Tips & Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

TABLE OF CONTENTS CONTRIBUTORS

David Hirsch, Sail DesignerA leader in sail design for over 20 years, and amember of Norths Performance Resource Group(PRG). David designed the sail inventory for theMumm 30 with special emphasis on developingREGATTA 3DL sails and Asymmetric spinnakers. Aveteran of seven America’s Cup syndicates andmany grand prix racing programs, David’sexpertise in sail analysis are what make Northsails consistently fast out of the bag.

Andreas Josenhans, Performance DevelopmentAndreas is an expert in developing boat speedand tuning. Involved in a variety of grand prixprojects, Andreas is a winner of six worldchampionships in one design and a veteran ofthree America’s Cup syndicates. Andreas was thesail coordinator for Pact ’95 in the recentAmerica’s Cup. Andreas is a member of theCanadian Sports Hall of Fame.

Dave Scott, Product Development Dave’s wide range of experience onboard all typesof racing boats makes de-bugging and speeddevelopment look easy. A sailmaker with Northsince 1986, Dave is constantly on the go sailingwith clients from Mumm 36s to SuperYachtswhere he has cultivated a reputation forconsistency and diligence. When Dave sails forfun, he’s a heck of a helmsman, too.

Grant (Fuzz) Spanhake, Product DevelopmentAuthor- Mumm 30 tuning guide. Following the‘95 America’s Cup where he was a tailer onboardYoung America, Fuzz works as a consultant toNorth on special projects. Previous America’sCup experience includes Team New Zealand in‘87-(tailer), and coach for B. Koch’s ‘92 defense.In the Whitbread, Fuzz raced onboard Lion NewZealand in ‘84 & in ‘89 on Fisher & Paykel.

Luc DuBois & J.P. Baudet, 3DL Inventors Swiss natives, sailmaker J.P. Baudet racedonboard Whitbread winner, UBS Switzerland in‘84 and was the Sail Coordinator to Merit in ’88.Teaming up with engineer Luc DuBois, theyintroduced 3DL to North Sails in 1989, creating asailmaking revolution. J.P. heads 3DL R&D wherenew applications of 3DL in one design and clubracers will make sails lighter, faster and moreaffordable.

VERSION 5 (10/00)© North Sails, 2000 All Rights Reserved

Dave Hirsch

Dave Scott Grant “Fuzz” Spanhake3DL inventors J.P. Baudet(left) and Luc Dubois

Andreas Josenhans


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Backstay

Spinnaker Guy

Spinnaker Tweakers

Spinnaker Sheet

Headsail Sheet

HeadsailBarberhaulers

ForeguyBobstay

DECK LAYOUT

Deck plan drawing supplied courtesy of BruceFarr & Associates, Inc. and Farr International


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NOTE: All measurements are taken to the centerline of clevis pins, bolts, etc.Please refer to diagram1 for specific measurement locations.

a) 3.481m (11’ 5”)From below decks, measure from the forward bolt of the stemhead fitting to theforward side of the mast above the mast plate.

b)1.146m (3’ 9”)Distance from the aft face of the forward bulkhead to center of the mast screwon the starboard side. NOTE:Distance to the base of the mast fitting is 50mm - 2”.

c) 2.329m (7’ 7-3/4”)Distance from the bottom of the mast step to the top of the bottom band (BAS).

d) 3.290m (10’ 9-1/2”) ‘J’ measurementTaken from the forestay pin to the front edge of the mast, excluding the spin-naker pole track and above the mast partners.

15.19m (49’ 10”)Max hoist using the main halyard to the intersection of the hull/transom with noload on the backstay.

The challenge and fun of One Designracing begins with having your boatoptimized for top performance. To getthe best out of your new Mumm 30,first be sure the rig is in the center ofthe boat. Then you can set mast rake,forestay & backstay length, and setthe tension on the cap shrouds anddiagonals. To center the rig:• Use a tape measure on the center-

line halyard from the hounds to thechainplate pin centers.

• Place a mark on the front center ofthe mast at the bottom spreader.

• From this point measure to the chainplate pin centers.

This provides two points to lookthrough when gauging mast tune.

(c)

(b)

(a)

(d)

MAST PARTNERS - With the mast at maximum J,make sure the mast partners are secure. Avoid point-loading the mast by spreading the load evenly aroundthe spar.

SETTING UP THE RIG


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FORESTAYThere are two methods you can use tomeasure the forestay length.

Pin-to-Pin: 12.18m (39’11-1/2”) • Send a crewmember up the mast with

a (15m) 50’ tape measure.• Hold the end of the tape measure at

the junction of the mast and T-ball fit-ting, measure down to the pin- centeron the stemhead fitting.

A) 1.80m (5’10-7/8”) see diagram

• Take the topping lift halyard and raiseto the BAS (top of the black band) atthe gooseneck.

• Swing an arc between the mast andthe headstay.

• Where the halyard intersects at theheadstay, place a mark on the headfoiland measure to the center of theforestay pin at the stemhead fitting.

NOTE: Use a centerline halyard forthe most accurate measurement.

BACKSTAYMeasure the backstay using the main-sail halyard. • Attach a tape measure to the main

halyard and raise to the mastheaduntil two-blocked at the masthead.

• 1300m (42’ 8”)With no tension on the backstay,measure down to the eyesplice.Place a batten (marked at 50mm or2” intervals) to measure offsets. Thebackstay flicker (see diagram above)

should be strong enough to hold thebackstay clear of the mainsail leechin light air.

CAP SHROUDSOnce the mast is centered and youhave measured and adjusted theforestay and backstay, adjust the capshrouds. • Start with the caps hand tight. Add

16.5 full turns (360 degrees). • The mast pre-bend (deflection) is

approximately 77mm (3-1/4”)measured from the boom to the topof the mast or 1/2 of the mastsection.

• The maximum bend will beapproximately 254mm (10”) at thedock.

DIAGONALSD1Just like the caps, the diagonalsshould start by being hand tight. Add7 full turns (360 degrees). 4064mm (13’ 4”) Length of the D1measured from the top of the fitting tothe top of the shroud plate.

D2Start at hand tight. Add 10 full turns(360 degrees). 3924mm (12’ 10-1/2”) Length ofthe D2 measured from the top of thefitting to the top of the spreader tipcup.

Backstay flicker

A B1.80m(5’10-7/8”)Black band onheadfoil toforestay pin.

SETTING UP THE RIG


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2:1 Backstaystrop attaches toupper floatingblock length:2070m (6’9-1/2”)

4:1 Backstaystrop attaches tolower floatingblock length: 1780m(5’10”)

BACKSTAY ADJUSTMENTS The backstay purchase is the most important adjustment you have on a Mumm 30. In light air (5 knots), a general rule of thumb isto have the bottom floating block 50mm (2”) below the top lifeline. As the wind increases, more tension is applied to the backstay.Two things happen; a) the headstay straightens, b) the mast bends which depowers the rig.

For maximum backstay adjust the bottom floating block to 230mm (8”) or two-blocked below the bottom lifeline (see photo 3). Keep the stern lifelines tight for measuring this distance.

SPREADER MARKSYou can adjust headsail trim easily by using spreader marks. Either the mainsheettrimmer or helmsperson sitting on the weather rail can see the jib leech through thespreader window in the main. To place accurate spreader marks, use white paint ortape to mark the lower spreader. Measuring from the inside edge of the cap shroud,place your marks at the following intervals:

22cm (8”) 28cm (10”) 30.4cm (12”)

35.5cm (14”) 40.5cm (16”) 45.7cm (18”)

BARBERHAULERSFor accurate barberhauler measure-ment, the outside edge of the fairleadwill be 467mm (18-3/8”) (measured

from the aft face of the mast partners).From the inboard edge of the jib sheet,through the barberhauler block • measure in 9cm (3-5/8”)• mark the line every 3cm (1-1/8”)

until there are 7 marks.

Mark #540.5cm-(16”)

Mark #1 22cm-(8”)

SETTING UP THE RIG

Off On 50% On full


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Batten Type Length WidthPosition Apex/Bluestreak (meters & ft.) Apex/Bluestreak

TOP 6T OR 5T (Apex) 1.760m/5’ 9-5/16” 45mm (1-3/4”) / 20mm (3/4”)

Upper Mid TM 5/ OR 2 1.595m/5’ 2-13/16” 45mm (1-3/4”) / 20mm (3/4”)

Lower Mid TM 5/ OR 3 1.595m/5’ 2-13/16” 45mm (1-3/4”) / 20mm (3/4”)

BOTTOM TM 5/ OR 4 1.595m/5’ 2-13/16” 45mm (1-3/4”) / 20mm (3/4”)

Set-Up Attach the mainsailonto the boom and place the tack slugin the mast. Attach the cunninghamand secure the outhaul. The clew isheld securely to the boom with thevelcro webbing strap supplied withyour 3DL mainsail.

Headboard Attach thehalyard to the headboard, using theforward hole which is 40mm (1.5”)aft of the front edge of the boltrope. Theheadboard hole should be at least12mm (1/2”) diameter. Set thebackstay with the floating block 50mm(2”) below the top lifeline wire.

z

Battens supplied with your3DL mainsail are either Apex orBluestreak. Starting at the top, placethe top batten (tapered end forward)

into the mainsail pocket. Use firmtension on all mainsail battens. As areference, the table to the right detailsthe type, size, length and width ofmainsail battens, helpful for replacingbattens or ordering spare sets.

LIGHT AIR TRIM: If your mainsheet trimmer is strong, you canremove the fine tune part of the mainsheet and trim off the coarse part only. Whensailing upwind in flat water, the top telltale should be flicking (in and out behind theleech, vs. trailing. If the telltale is trailing, then the sheet is probably eased toomuch.). Don’t be afraid to carry the boom above the centerline with the mainsailtraveler car 228mm (9”) from the side of the cockpit. In choppy water, the top tell-tale should be flowing all the time, with the traveler dropped down 150mm (6”).The outhaul should be eased so there is 100mm (4”) of sag to leeward of theboom. The cunningham should be off.

MEDIUM AIR TRIM: To maintain speed, play the traveler con-stantly. Ease the fine tune of the mainsheet 150mm (6”) in the gusts. The boomshould now be just below center line most of the time. Use moderate boom vang,remembering to ease the vang at the top mark. The outhaul should be firm so thereis no sag to leeward of the boom. Cunningham should be on 100mm (4”).

HEAVY AIR TRIM: Keep the mainsheet close at hand ready toease. The traveler will be eased down to the cockpit wall (coaming), but be sure toplay the traveler in the lulls to maintain pointing. When the mainsail is sheeted tothe max, there is slight boom vang load. The outhaul should be tight, with a creasealong the boom. The cunningham should be set to maximum. Be ready to ease theboom vang and cunningham when rounding the top mark.

Light Medium HeavyBoom/Traveler Above center Just below center Ease to

coaming

Vang None Some MaxOuthaul 100mm sag Firm MaxCunningham None 100mm Max

MAINSAIL TRIM


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Set-Up 3DL headsails aresupplied with a tack clip (snap hook)which is placed on the bar directlybehind the stemhead fitting. Attach thesheets by tying very small bowlines orstopper knots through the clew ring.(This allows enough adjustment in the bar-berhaulers.) Run the sheet through thebarberhaulers, through the aft leadblock under the shockcord guide, thento the winch. Use the port halyard andset in the port groove. You’ll be onstarboard tack if you need to set-up aheadsail change. You’ve already marked the barber-haulers, (p.6) refer to the table at rightfor fast settings in various wind condi-tions and sea states.

Battens supplied with your3DL headsail are Bluestreak. Starting atthe top, place the top batten (tapered end forward) into the battenpocket. Use firm tension on all headsailbattens. As a reference, the table to theright details the type, size, length andwidth of headsail battens, helpful forreplacing battens or ordering spare sets.

Batten Type Length WidthPosition Bluestreak (meters & ft.) BluestreakTOP WR 2 85cm / 2’ 9-1/2” 15mm (5/8”)

Upper Mid OR 1 80cm / 2’ 7-1/2” 20mm (3/4”)

Lower Mid OR 3 80cm / 2’ 7-1/2” 20mm (3/4”)

BOTTOM OR 3 80cm / 2’ 7-1/2” 20mm (3/4”)

LIGHT AIR TRIM: Barberhauler is required. If the boat feelsstalled, ease the barberhauler and/or sheet so the leech is at the spreader tip. Also,ease the forestay 25mm (1”) to loosen the headstay. Leave the jib halyard on awinch for easy adjusting with increasing or decreasing wind pressure.

MEDIUM AIR TRIM: Some barberhauler is required. If the boatfeels stalled, or the headsail is backwinding the mainsail, ease the barberhaulerand/or sheet until the leech is at the second outside spreader mark. Take up theforestay 25mm (1”) to tighten the headstay. The halyard should be firm withsome wrinkles coming out of the headstay. It’s good to leave the jib halyard on thewinch until it’s time to lead the spinnaker halyard to the same winch at the topmark.

HEAVY AIR TRIM: No barberhauler required. If the boat is stalledor the headsail is backwinding the mainsail, ease the barberhauler and/or sheetuntil the leech is at the spreader tip. Take up the forestay 50mm (2”) to tightenthe headstay. The halyard should be tight with no wrinkles coming out of the head-stay. Again, it’s good to leave the jib halyard on the winch until its time to lead thespinnaker halyard and/or sheet to the same winch at the top mark.

BARBER HAULER SETUPTrue Wind Speed 0-5 5-10 10-15 15-20 20-25 25-30Adjust Headstay Length Ease 1” Base Tighten 1” Tighten 1 1/2” Tighten 2”

(25mm) (37mm) (50mm)

Barberhauler Mark #1 #2-3 #3-4 #5-OFF OFF OFF

Spreader Mark (Flat Water) #3-4 #3-2 #2 #2-1 #1 50mm (2”) Inboard #4, Outboard #1* inside spreader end

Spreader Mark (Rough Water) #3 #3 #2 #1 #1 50mm (2”) Inboard #4, Outboard #1 inside spreader end

*For distance races: Install a padeye outboard, just aft of the chainplates. Attach a snatch block onto thepadeye with the sheet leading to the cabin top winches.

GENOA TRIM


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SET-UP Before you leave the dock...• Attach the guy to the headstay. • Run the guy through the jaw of the spinnaker pole and attach the pole to the

mast. • Set the spinnaker pole up so it is 460mm (18”) above the deck and sitting

beside the headstay.• Mark the point (black marker pen works well) where the guy is loaded onto the

cockpit winch.Photos show the tack set-up.

The Mumm 30 is a very fast, responsiveboat. We’ve found that smalladjustments in boat handling canenhance speed and overall performance.

Included is an additional sectioncovering standard boat handlingtechniques such as tacking, gybing, andcoordinating the crew for optimumweight distribution in varied sailingconditions.

Our techniques may differ slightly fromthe methods that you and your crew use.Your feedback is welcome, and weencourage you to practice both ways,and let us know what works best for you.

Diagram below shows sheet and guy leads for the asymmetric spinnaker. When gybing, be careful not to push the spinnaker polethrough the mainsail or between the D1’s and V1’s where the mainsail will gybe onto the exposed end. More information on boathandling and gybing are explained on page 12 of this guide.

ASYMMETRIC SPINNAKER TRIM


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SHEETS & GUYS • Run the spinnaker sheets through the barberhaulers (outside the lifelines), back

to the corner spinnaker blocks (outside to inside with the sheet), along the deckthrough the deflector blocks and up to the cabin top winches.

• Run the guys aft through the guy blocks outside the lifelines. This provides abetter angle to the pole. The guys then lead under the spinnaker sheets, andunder the headsail sheet on the port side, behind the genoa sheets on thestarboard side to the cleats on the edge of the cockpit coaming below thewinches. The tails go down below through the open window or into the tail bag.

• You have a choice of three downwind sails to choose from in the Mumm 30rules. A sail chart is included on page 24,which shows the overlap of allthe sails in the inventory for various wind speeds and angles. A set of polars arealso provided, courtesy of Bruce Farr and Associates, Inc.

• Install a piece of shockcord from thehounds to a small stainless ring thatthe spinnaker halyard passes through.When the spinnaker halyard is cast-off, the ring pulls the halyard to themast preventing the halyard fromgetting stuck behind the top battens inthe main.

• Prevent spinnaker sheets and guysfrom dragging in the water by placinga cleat on the edge of the cockpit bythe genoa winch.

• In moderate conditions (16 knots), thespinnaker luff should fly ‘straight’ orperpendicular to the pole. Use the guyfore & aft to position the spinnaker formax. speed.

• Always drop the spinnaker on the sideof the boat where you intend torehoist. Set the spinnaker out of thefront hatch unless there is a largeseaway running, preventing the hatchfrom opening without risk of flooding.

SYMMETRIC SPINNAKER TRIM


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TACKING INLIGHT AIRBowIf sitting to leeward, roll tacks by crossingto new weather side. If sitting on theweather side, stays on the rail, and leansover the rail to roll tack. Trimmer Casts off the headsail sheet, tails in thenew side (alone). As the boat speedclimbs, grinds sheet to final trim.Mainsheet May have to release the topmast backstayto clear the mainsail leech.HelmPushes the helm to leeward smoothly, cen-tering the helm 3/4 through the tack. Also,may have to flick the topmast backstay toclear the mainsail leech.

TACKING INMODERATE-HEAVY AIRBowCross the boat quickly and hike your heartout!Trimmer After final trim, move up to the weather rail& hike.MainsheetKeeps the mainsheet in hand, uncleated.Ease after the tack to keep the boat on itsfeet.HelmPushes the helm to leeward smoothly, cen-tering the helm 3/4 through the tack. Trynot to bear off too much creating moreheel, causing the boat to slide to leeward.

PREPARATION 1. Look ahead to be sure you will be sailing in clear air after you tack.2. Load the weather headsail (new) sheet onto the cockpit winch. Place three turns on the winch and take-up the slack.3. Be sure the weather sheet (new) is clear of the spinnaker sheets and leads over the pole, around the outside of the mast and

halyards.4. Be sure the leeward headsail sheet is clear to run.5. Try and tack in a smooth spot of water. 6. If you have to dip a boat after you tack, make sure the mainsheet is ready to ease.

TACKINGSEQUENCESTEP 1HelmGives the command to tackTrimmerComes off the rail, crosses cockpit toleeward side and uncleats the headsailsheet.MainsheetEases mainsheet fine tune 75mm (3”)

STEP 2HelmPushes the helm to leeward smoothly,centering the helm 3/4 through the tack.TrimmerAs the headsail is luffing, cast off the oldheadsail sheet by casting the turns off thewinch, cross the cockpit and grind in theheadsail sheet. TailerTails in new sheet from the weather side.Mainsheet Uncleats old traveler line, picks up the newtraveler line on the other side of thecockpit.BowCrosses the boat by going under the boomvang.

TACKING

Sail your heart out!


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GYBING: LIGHT-TO-MODERATESTEP 4BowOnce clew is past the headstay on thenew leeward side, connects the new guyto the spinnaker pole, pushes the poleout on the weather side of the headstay,connects to mast.PitEases the bobstay out following the tackof the asymmetric to the pole end. Thenreadjusts the bobstay once the pole isback from the headstay. Old TrimmerEases out the asymmetric sheet until theclew is near the headstay, holds thesheet until the slack is taken up by thenew sheet, then releases and helps oldsheet to run free. Sets up the guy on themarks around the cockpit winch oncethe pole is connected to the mast andtrims the tack to the pole end.New trimmerTrims the sail, easing the sail to followout to the pole, paying attention toincreasing speed by working with thehelm for optimum sheeting angle.

STEP 5HelmSails a slightly high course until theboat speed is optimum, then adjustshelm to sail to correct wind angle.

TIPS1. Best times to gybe the asymmetric are:a) The beginning of a puffb) Up the back of the wavec) When the boat is going slow.

2. When dropping the asymmetric alwayspull the sail by the luff or the tack area.

PREPARATION 1. Look behind your boat to be sure you will have clear air after you gybe. 2. Load the weather asymmetric sheet onto the cabin top winch. Place two turns on the

winch and take-up the slack.3. Be sure the weather sheet (new) is around the inside of the asymmetric and sitting

on top of the spinnaker pole, leading around the outside of the forestay, between thesail and the headstay.

4. The starboard guy is attached to the tack ring of the asymmetric. The bobstayand port guy are attached to the eye in the starboard guy snap shackleon the outside of the forestay, clear of the pulpit. This gets cleated.

5. Give the foreguy 600mm (2ft.) of slack so the bowperson can take the spinnakerpole off the mast.

BASIC GYBINGSEQUENCESTEP 1New Trimmer...is on the guy. Releases the guy quicklyso the weight is taken up on the bobstay.

STEP 2Bow1. Releases the spinnaker pole from the

mast.2. Moves pole aft until the outboard end

jaws are over the deck. 3. Trips guy out of jaws.

STEP 3PitTails in slack of the new sheet as theasymmetric comes across the bow,hands off sheet to new trimmer. Youcan’t run the old sheet fast enough oncethe bow has passed 180 degrees.

NOTE: Be careful not to push thespinnaker pole through the mainsail orbetween the D1’s and V1’s where themainsail will gybe onto the exposed end.

GYBING: LIGHT AIRBowWatches the sail to be sure sheets runsmoothly.PitPulls in the bobstay as the boat turns,until the luff of the asymmetric is tight.Old trimmerBlows off asymmetric sheet while stillloaded, allowing the clew to fly awayfrom the boat (like a flag). Sets up theguy on the marks around the cockpitwinch once the pole is connected to themast and trims the tack to the pole end.New trimmerTails the new asymmetric sheet as fastas possible.HelmThe helmsman controls the gybe. Gybesare easiest when the apparent windspeed is the highest.

GYBING THE ASYMMETRIC


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GYBING: LIGHT-MODERATE AIRSTEP 4BowMoves aft to the new leeward side and col-lects the new lazy guy ready for anothergybe.

PitSets the barberhaulers 1/2 way down,and eases sheet to the headstay slowlywhile trimming the new sheet

Sheet trimmerTrims the sail, paying attention to increas-ing speed by working with the helmsmanfor optimum sheeting angle.

STEP 5HelmSails a slightly high course until the boatspeed is optimum, then adjusts helm tosail to correct wind angle.

TIPThe best times to gybe the spinnaker are:a) The beginning of a puff. b) Down the front of a wavec) When the boat is going fast.

PREPARATION 1. Look behind your boat to be sure you will have clear air after you gybe.2. Load the weather spinnaker sheet onto the cabin top

winch. Place two turns on the winch and take-up the slack.3. Be sure the weather sheet (new) is on top of the spinnaker pole, leading around the

outside of the forestay.4. Make sure the spinnaker barberhaulers are set for the existing wind pressure.5. The lazy guy should be off & ready to go forward (Bow).6. Give the foreguy 600mm (2ft.) of slack so the bowperson can take the spinnaker

pole off the mast.

BASIC GYBINGSEQUENCE

STEP 1PitReleases the foreguy as the spinnaker poleis trimmed aft as the boat turns down.Guy trimmertrims the pole aft.

STEP 2Sheet trimmerTakes up on the new spinnaker sheetbefore the spinnaker pole trip is called.Eases the old spinnaker sheet out to theheadstay, while tailing in on the newspinnaker sheet, as the boat is turned.

STEP 3Bow1. Has the new (lazy) guy in hand ready to

place into pole. 2. Trips guy out of jaws.3. Releases pole from mast and connects

lazy spinnaker guy, pushes pole out andforward underneath spinnaker sheet andattaches to the mast again.

PitEases foreguy 150mm (6”). Releasesspinnaker tweaker all the way.

GYBING: LIGHT-MODERATE AIR

Sheet trimmerQuickly eases the old sheet to the headstaywhile trimming the new sheet, then sets thebarberhaulers 1/2 way down, and easessheet to the headstay slowly whiletrimming in the new sheet.

Guy TrimmerWhen the trip is called, quickly releasesthe guy from the winch, making sure thesheet trimmer has taken up the new sheet.Changes to the new side of the cockpit totail new guy with 2 turns around the winchonce the spinnaker pole has been connect-ed to the mast.

HelmThe helmsman controls the gybe. Thehelmsman turns the boat when the clew isnear the headstay. The turn should besmooth maintaining medium speed coming out of the optimum VMG angle.Full rotation of the spinnaker is key to alight air gybe.

GYBING THE SYMMETRIC SPINNAKER


15

CREW WEIGHTCrew weight, when used effectively, is apowerful tool on any boat. In level racingand one design classes, the optimumdistribution of crew weight can have alarge impact on overall sailing performance. Besides keeping the boaton its feet, and reducing heeling angle,weight distribution can change the sailing characteristics of the boat. Forthe Mumm 30, the optimum heel angleis 15-20 degrees.

SAILS When sailing upwind in light air;• Have the headsails flaked into the

turtle, rolled up and tied.• Position sails around the base of the

mast.• Place downwind sails forward on the

bunks.

SAILING TIPS:• Optimal windspeed for practicing

asymmetric spinnaker gybing for thefirst time is 7-10 TWS

• When reaching with either asymmetricor spinnaker, be sure to ease the leeward barberhaulers.

• When adjusting sail trim, count thenumber of ratchet clicks, this helps torepeat fast settings.

UPWIND:0-7 KNOTSPosition the crew forwardand to leeward to induceheel or down below if seasare choppy. In puffy con-ditions, nominate one ortwo of your most agilecrewmembers to be‘moveable ballast’. Adjusttheir body weight acrossthe boat to maintain heel.

REACHING:0-7 KNOTSPlace some of the crewdown below to leewardand/or the middle of thefloor. The remaining creware forward on the rail or around the leeward shroud.

In light air, you shouldn’tsail directly downwind. Usethe asymmetric as a VMGsail.

CREW WEIGHT IN LIGHT AIR


16

SAILS When sailing upwind in moderate air; • Have the headsails flaked into their

turtles, rolled up and tied. • Position sails forward around

the floorboards.• Place downwind sails on the

middle bunks.

In heavy air; • Have the sails flaked, rolled in their

turtles and tied.• Position the sails aft behind the main

hatch on each side of the steps.

TIPS• When the mainsail flogs upwind, the

center of balance is transferred to theheadsail. Adjust your helming technique to account for this. Makesure that you have firm vang on.

• When overpowered upwind, try easing the mainsheet 150mm (6”) onthe fine tune adjustment.

• If you feel that you are going slow,drop the traveler down, ease the backstay and mainsheet.

• When you adjust the jib halyard, threethings change:1) head depth2) draft position3) vertical curvature

• When crewmembers shift their weightin response to puffs, do four things:1) adjust outhaul2) adjust mainsheet3) adjust backstay and4) adjust jibsheet.

• When the boat is up to speed andsailing comfortably, have the main-sheet trimmer turn around and hikewith legs positioned over the side.

UPWINDIn moderate air, all thecrew will be on the rail.The first crewmember willbe situated against thewindward stanchion whichis located 60cm (24”) backfrom the shroud.

HEAVY AIRIn heavy air (13-22 knots)the crew should be hikingas hard as possible, withone person sitting behindthe helmsman.

REACHINGConsolidate the crew in themiddle of the boat, hikingas hard as possible. Inheavy air, the crew shouldbe sitting well aft, and hik-ing hard. Sailing downwind, balancethe crew evenly across theboat. In heavy air, the crewshould be across the backof the boat, especially insteep seas. If sailing deepangles, place the entirecrew on the leeward rail.

Reaching 7-12 knots

CREW WEIGHT IN MEDIUM - HEAVY AIR

Upwind 13-22 knots


17

True Wind Speed: 5 knots Top: 12.88 of cord length @ 41% draft position MIddle: 13.32 @ 45%Bottom: 10.27 @ 44% Notes: Set-up for maximum power, more twist is required using the top mast backstay.

True Wind Speed: 15 knots Top: 8.30 of cord length @ 46% MIddle: 9.50 @ 50% Bottom: 7.90 @ 46%NOTES: The sail luff is just beginning to lift.

MAINSAIL SHAPE

NOTE: In the following sail photos, depth is listed as apercent of chord length. Draft position is measured as apercent of chord length from the front of the sail.


18

TWS: 20 knots Top: 5.35 @ 57% MIddle: 6.99 @ 55% Bottom: 6.04 @ 47% NOTES: Maximum flattening on all adjustments.

TWS: 25 knots Top: 5.16 @ 61% MIddle: 6.90 @ 58% Bottom: 6.42 @ 52%NOTES: In this photo, we are driving off the lower leech only. It would be best to change to a heavy air jib.

MAINSAIL SHAPE


19

TWS: 6 knots Top: 14.89 @ 45% MIddle: 18.23 @ 47% Bottom: 14.64 @ 47% NOTES: This sail is set up very full and open, looking for power.

TWS: 9 knots Top: 13.64 @ 41% MIddle: 15.52 @ 43% Bottom: 12.67 @ 43% NOTES: This sail is at the top end of its range, the boat needs the medium headsail.

LIGHT HEADSAIL SHAPE


20

TWS 15 knots Top 16.60 @ 39% MIddle 16.00 @ 41% Bottom 12.00 @ 40%NOTES: Sail is well set-up with the draft forward and the leech open.

TWS 23 knots Top 16.68 @ 35% MIddle 16.03 @ 38% Bottom 13.88 @ 34%NOTES: The front end of this sail is lifting as the boat is feathered in this windspeed.

MEDIUM HEADSAIL SHAPE


21

TWS: 25 knots Top: 8.46 @ 38.5% MIddle: 12.5 @ 33.3% Bottom: 10.3 @ 37% NOTES: Under high load, this sail fits the rig perfectly.

TWS: 30 knots Top: 9 @ 46.15% MIddle: 13.89 @ 34.7% Bottom: 11.11 @ 34.8% NOTES: The sail is smooth under extreme load with progressive linear twist.

HEAVY HEADSAIL SHAPE


22

Cloth Weight: .6 Poly TWS: 16 knots AWS: 11.2 knots TWA: 135° AWA: 97.3°

BROACHINGCONDITIONSThe Mumm 30 is fast, responsive andaccelerates quickly, especially on areach. Keeping the boat balanced andmaintaining speed is a delicate mix ofknowing when to push the boat, andwhen to back-off to prevent a broach.When sailing in moderate breeze (12-16knots), if the boat begins to broach, thefirst rule is...don’t panic! Each memberof the crew should stay in their positionand follow-through the steps listedbelow to keep the boat on its feet andmaintain speed, without surrenderingprecious real estate on the race coursespinning out on a broach.

1. Move crew weight aft and out.2. Ease mainsheet.3. Ease vang.4. Ease asymmetric spinnaker.5. Ease barberhauler.6. Sail a lower course.7. Change to a smaller sail.

ASYMMETRIC SPINNAKER NOTES

30/20 AsymmetricWith 9 vt. the tested cross-over, thissail was proven before the fleet grew to34 boats. At a crowded mark, theasymmetric sail stays in the bagallowing the tactician time to positionthe boat downwind allowing moregibing options and choice of fastlanes.

ASYMMETRIC SPINNAKER TIPS


23

Sail Type: .6 Nylon Runner TWS: 18 knots AWS: 8.7 knots TWA: 146° AWA: 113° Notes: The spinnaker pole in this photo needs to belifted at the inboard end of the pole. The spinnaker barberhauler is set at maximum.

.75 oz. Spinnaker(photo not available)This sail is more of an All Purposedesign than the light spinnaker forbetter helm control in a breeze. Usingthe .75 oz. in the upper wind ranges issuggested so you don’t overtax the .5.

SAIL TRIM TIPS• Have a pair of trained eyes looking

behind for downwind pressure, toposition the boat into the fast lanes.

• Use a snap-in block for the spinnakerbarberhaulers.

• When running with the spinnaker,make sure both spinnaker barber-haulers are set between 3/4 and full.

SAIL CARE: Congratulations on the purchase of yourNorth Sails inventory. Included aresuggestions to assist in general sail careand maintenance. Keep a sail repair kitonboard for ‘fixes on the fly’. Contents should include:• Scissors • 10’ x 3” sticky-back Kevlar • 20’ x 3” white insignia• Pre-waxed twine • 4 hand sewing needles & a palm. You can purchase a kit through yournearest North Sails loft, or put onetogether on your own.

Spinnakers...On the final spinnakerset of the day, have one or two peoplecheck over the sail for any small holesor tears. Any tear over 4” should besent to your nearest North loft forrepair. DO NOT place sails into aswimming pool - chlorine will damagethe sails. When folding an asymmetricsail on your lawn, stay away from dogpoop. If you have any Dacron sails,

MASTHEAD SPINNAKER TIPS

immediately. The longer they are left on,the harder they are to remove.Remainingsmall sections can be removed with ablow-dryer set on LOW. Glue can beremoved with an acetone wipe. Headsails... If the head of the lufftapesplits open, use some ‘Krazy Glue’ or‘Loctite’ to reseal the trouble areas.Periodically check the battens forbreakage.

spray Lysol into the bag to preventmildew. Taking care of your sails willextend the life of your sail inventory.

Mainsail... If left on the boom for anextended period of time, remove thebattens to prevent warping or breaking.Always ease the outhaul to relieve theload. If any sponsor logos are placed onthe sail, they should be removed


24

How to use this Chart: Select True Wind Speed (TWS) on the vertical bar and True Wind Angle (TWA) on the horizontal bar.Where the two intersect will tell you what sail should be used. If this point falls within one of the overlap areas, there will be littleor no speed difference between the two sails.

SAIL RANGE CHART

7

21

3

654

7060

8910111213141516

9080 110100

171819202122232425262728293031323334

130120 150140

No M

ans L

and

170160 180

20/20 MastheadSpinnaker

.75 MastheadSpinnakerBo

th S

ails

Light Headsail

Asymmmetricor SymmetricSpinnakerOverlap

Overlap

MediumHeadsail

Overlap

Overlap

Heavy Headsail Frac.Asy.

FractionalSpinnaker

TWS

– Tr

ue W

ind

Spee

d

TWA – True Wind Angle

30/20 MastheadSpinnaker

25


RUNNING RIGGING LIST

HalyardsMAINSAIL Tapered Technora® with captive D-shackle

GENOA Tapered Technora with snap shackle

SPINNAKER Tapered Spectra® with snap shackle

SheetsGENOA 100% Spectra core/Polyester cover with J-Lock Jr. shackle

SPINNAKER Tapered Spectra with snap shackle

ASYMMETRIC CLEW STRAP Eye-to-Eye Spectra

AFTERGUYS Tapered Spectra with snap shackle

• In Spectra and Technora rigging, chafe is your enemy. When the covers wear, exposing the core, the breaking strength of the halyard or sheet isgreatly reduced.

• After a windy series, double-check all sheets, guys, and halyards for chafe. As aquick fix, tape over worn areas, and replace as soon as feasible.

• Teflon tape works extremely well, and is available from North Sails Rigging. Thetrade-off between performance and weight means the rigging is not ‘overbuilt’ forthe loads onboard the Mumm 30.

• On most boats, the halyards and sheets should be replaced every year. If youhave a busy racing calendar, spare halyards and genoa sheets are recommended.


26

• Keep a disposable camera onboard. You can build up a libraryof fast sail shapes to study later.

• Warmer waters encourage bottom growth, make surethe bottom is cleaned just before every race.

• Keep a toolkit onboard - it should include an adjustable wrench,vise grips, screwdriver(s), serrated edged knife, and rigging tape so you can change the tension on the diagonalsbetween races.

• Between races, always check that the mast partnersare still in place.

• Use a piece of shockcord to hold down the tack slug on thegooseneck fitting.

• Add a retainer bracket across the top of the travelercleat to hold the traveler line.

• Install a piece of shockcord from the hounds to a small stainlessring that the spinnaker halyard passes through. When thespinnaker halyard is cast-off, the ring pulls the halyard to themast preventing the halyard from getting stuck behind the topbattens in the main.

• If the jib hits the spreaders in heavy air, use theforward luff groove.

• Install a spreader window in the main for easy viewing of the jibleech.

• When you hit a velocity header, let the boat glide to weather until the new target speed is suited to thenew wind speed.

• If you are forced to sit below in light air, make sure you have agood newspaper and cookies!

• Back down 6 minutes before the start of the race.

• Use Kevlar or Spectra for jib barberhaulers.

• In moderate air, try cross-sheeting the jib.

• Keeping the crew on the rail is a number one priority.

• Keep the spinnaker within easy reach, attach a sail tieto the spinnaker bag and duct tape to the main hatch.

• Below 8 knots of wind, don’t be afraid to carry the main boomabove the centerline.

• Prevent spinnaker sheets and guys from dragging inthe water by placing a cleat on the cockpit edge by thegenoa winch.

• Cover the outboard end of the top batten with stickyback. Thishelps the backstay clear the mainsail in light air.

• Sight up the back of the mast when sailing upwind tobe sure the mast is straight side-to-side.

Note: These are just a few ideas we’ve thought of. Youmay have more. In future versions of the Mumm 30guide, we will update these sailing tips for newer ones.Send in your suggestions by calling your Northrepresentative for fax us this page with your additions.(phone listings appear on page 24). We look forward tohearing from you.

TIPS & TECHNIQUES


All targets supplied courtesy of Bruce Farr & Associates, Inc.,Farr International & Grant Spanhake, North Sails PRG

1997 PERFORMANCE TARGETS

DOWNWIND

TWS Boatspeed AWA TWA

4 3.81 73.7 139.8

5 4.56 77.8 141.6

6 5.32 81.9 143.3

7 5.79 89.9 146.0

8 6.26 97.9 148.7

9 6.55 106.4 151.0

10 6.84 114.9 153.2

11 7.11 120.0 154.3

12 7.38 125.1 155.3

13 7.53 132.9 158.2

14 7.68 140.7 161.1

15 8.61 127.5 154.0

16 9.55 113.8 146.8

17 10.14 114.4 147.1

18 10.73 115.0 147.5

19 11.32 115.5 147.8

20 11.92 116.1 148.1

25 15.23 121.3 152.1

30 17.41 131.4 156.7

UPWIND

TWS Boatspeed AWA TWA

4 3.79 23.3 45.3

5 4.50 23.2 44.5

6 5.22 23.0 43.2

7 5.60 22.9 41.7

8 5.96 22.7 40.5

9 6.15 22.7 39.5

10 6.22 22.7 38.4

11 6.30 22.9 37.5

12 6.34 23.0 37.1

13 6.39 23.4 36.7

14 6.41 23.6 36.5

15 6.45 24.0 36.5

16 6.48 24.4 36.4

17 6.49 25.0 36.4

18 6.50 25.4 36.5

19 6.52 25.7 36.6

20 6.55 26.0 36.6

25 6.60 28.3 38.0

30 6.61 31.1 40.2


28

At North Sails, we view each sail purchase as the beginning of a long andrewarding relationship. We base this expectation on a strong servicecommitment that includes preventive maintenance, sound advice, educationand expert repairs. Your nearby North loft offers a wide range of servicesincluding...

� 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 andworldwide reach also means North has the world’s most expansive sailmakingdatabase. It would be hard to find a sailboat for which we cannot make a fast,durable and long lasting sail.

North Sails LoftsUnited States

Atlanta . . . . . . . . . . . . . . . . . 770-945-2800Cape Cod . . . . . . . . . . . . . . . 508-778-6550Carolina . . . . . . . . . . . . . . . . 252-728-7481Channel Islands . . . . . . . . . . 805-984-8100Chesapeake. . . . . . . . . . . . . . 410-269-5662Colorado . . . . . . . . . . . . . . . 303-694-2345Detroit . . . . . . . . . . . . . . . . . 810-776-1330East . . . . . . . . . . . . . . . . . . . 203-877-7621Ft. Lauderdale . . . . . . . . . . . . 954-522-8840Gulf Coast . . . . . . . . . . . . . . 727-898-1123Hampton . . . . . . . . . . . . . . . 757-722-4000Hawaii . . . . . . . . . . . . . . . . . 808-591-9192Huntington Beach . . . . . . . . . 714-898-1234Long Island . . . . . . . . . . . . . . 631-673-5700Marina Del Rey . . . . . . . . . . . 310-827-8888Midwest . . . . . . . . . . . . . . . . 773-489-1308New Jersey . . . . . . . . . . . . . . 732-528-8899New Orleans . . . . . . . . . . . . . 504-831-1775Newport Beach . . . . . . . . . . . 949-642-7238Northeast . . . . . . . . . . . . . . . 978-745-1400One-Design East . . . . . . . . . . 203-877-7627One-Design Central . . . . . . . 614-418-9410One-Design Chesapeake . . . . 410-269-5662One-Design West . . . . . . . . . 619-226-1415One-Design Zenda . . . . . . . . . 262-275-9728

Oregon . . . . . . . . . . . . . . . . . 503-282-4282Puerto Rico . . . . . . . . . . . . . . 787-863-3761Rhode Island . . . . . . . . . . . . . 401-683-7997San Diego . . . . . . . . . . . . . . . 619-224-2424San Francisco . . . . . . . . . . . . 510-522-5373Seattle . . . . . . . . . . . . . . . . . 206-632-5753South Carolina . . . . . . . . . . . 843-744-7245Texas. . . . . . . . . . . . . . . . . . . 281-334-7559Vermilion. . . . . . . . . . . . . . . . 440-967-9576

CanadaAtlantic . . . . . . . . . . . . . . . . 902-634-3343Toronto . . . . . . . . . . . . . . . . 416-259-9644Vancouver . . . . . . . . . . . . . . 604-271-2111Quebec . . . . . . . . . . . . . . . . . 514-748-8368

EuropeAustria . . . . . . . . . . . . . . . . . 43-7666 7997Benelux . . . . . . . . . . . . . . . 32-3-325 67 20Denmark . . . . . . . . . . . . . . 45-39-20 40 90Espana (Pontevedre) . . . . . 34-98-654-8132Espana (Palma) . . . . . . . . . . 34-71-725-752Finland . . . . . . . . . . . . . . . 35-82-247 10 00France . . . . . . . . . . . . . . . . 33-297-53 78 58France-Mediteranee . . . . . . 33-493-36 66 17Germany . . . . . . . . . . . . . . 49-40-745 77 78Germany-Bodensee . . . . . . . 49-7543-16 89

Greece . . . . . . . . . . . . . . . . . 30-1-417-4669Italy . . . . . . . . . . . . . . . . . . . 39-0185-3526Norway-West . . . . . . . . . . . 47-66-79 89 14Norway East One-Design . . . 47-67-53 77 29Sweden . . . . . . . . . . . . . . . . 46-8-765 15 30Sweden-Gothenberg . . . . . . 46-31-29 11 52Sweden-Kalmar . . . . . . . . 46-480-41 12 99Sweden-Malmö . . . . . . . . . . 46-4-015 4101Switzerland . . . . . . . . . . . . . 412-278-23222Switzerland (Schweitz) . . . . . 417-168-68525Turkey . . . . . . . . . . . . . . . 90-212-696-99 15UK . . . . . . . . . . . . . . . . . . 44-2380-453109UK One-Design . . . . . . . 44-1703-45 52 20

InternationalArgentina . . . . . . . . . . . 54-1-147-250200Australia-Melbourne . . . . . . 613-953-40363Australia-Sydney . . . . . . . . . 612-999-75966Brazil . . . . . . . . . . . . . . . . 55-12-472-2607Chile . . . . . . . . . . . . . . . . . 56-32-970-504Guadeloupe . . . . . . . . . . . . . . 590-908044Japan (Kanagawa) . . . . . . . 81-45-770-5666Japan (Kansai) . . . . . . . . . 81-79-826-7771New Zealand . . . . . . . . . . . . 649-359-5999South Africa, Capetown . . 27-21-511-2154South Africa, Durban . . . . . 27-31-332-3624

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