T-10 Class

One Design Rules and Amendments

Revised 3/12/02

 

Table of Contents Page #

    1. OBJECT 3
    2. PROTECTION OF ONE-DESIGN 3
    3. HULL AND DECK 4
    4. KEEL 4
    5. RUDDER 5
    6. MAST 6
    7. MAST RIGGING 7
    8. MAIN B0OM 10
    9. SPINNAKER BOOM 10
    10. ONE-DESIGN SAIL MEASUREMENTS 11
      1. GENERAL REQUIREMENTS 11
      2. ONE-DESIGN SAIL MATERIAL 11
      3. DEFINITION 12
      4. WINDOWS 12
      5. DOUBLE LUFFED SAILS 12
      6. MEASUREMENT BANDS 12
      7. INSIGNIA, LETTERS AND NUMBERS 12
      8. SIZE AND COLOR 13
      9. MAINSAIL 13
      10. ONE-DESIGN GENOA 15
      11. SPINNAKERS 17
      12. STORM JIB 17
    1. SAIL RESTRICTIONS 17
      1. SAIL INVENTORY 17
      2. SAILCLOTH WEIGHT LIMITATIONS 18
      3. SAIL ACQUISITION 19
      4. SAIL TRIM 21
      5. SAILMAKER’S INSCRIPTION 21
    1. DISPLACEMENT MEASUREMENT AND EQUIPMENT WHILE RACING 21
      1. STANDARD SAFETY EQUIPMENT 23
    1. AUXILIARY ENGINE AND PROPELLER 24
    2. GENERAL RESTRICTIONS 24
    3. REGISTRATION NUMBERS 26
    4. OWNER’S RESPONSIBILITY AND MEASUREMENT CERTIFICATE 26
    5. SANCTIONED EVENTS 26
      1. DESIGNATION 27
      2. REGIONAL CHAMPIONSHIPS 27
      3. REGIONAL CHAMPIONSHIP TROPHIES 27
    1. RE-MEASUREMENT 27
    2. TRANSLATION 27
    3. OFFICIAL PLANS 27
    4. CLASS RULES ENFORCEMENT 27
    5. AMENDMENTS 28
    6. PLANS A & B 29

 

    1. OBJECT

1.1 The specifications and official plans for the Class are intended to ensure that all T-10's, as designed by Sparkman and Stephens and built by Tartan Marine Company, are as nearly alike as possible as regards shape and weight of hull and decking, shape and weight of keel, shape of rudder, shape and area of sail plan including spars and rigging dimensions, displacement and any other matter which has an influence on the basic speed of the yacht.

2 PROTECTION OF ONE-DESIGN

2.1 The administering authority for the Class shall be the Board of Directors (Board), which shall cooperate with the T-10 Class Association and Tartan Marine Company (sole authorized builder) in all matters regarding these Rules.

2.2 Construction shall be of reinforced plastics and shall be in accordance with the approved general arrangement and construction plans and specifications. The builder shall construct the hull and install the stringers, bulkheads and floors in a jig approved by a measurer appointed by the Board. The hull and deck shall be assembled with the deck in a jig approved by the Board appointed measurer. The necessary support shall be given so that the sheerline is as shown on the plans.

2.3 Production molds for hull, deck and rudder shall be made from molds obtained from the one current set of official master plugs. The casting pattern for the fin keel shall be made from the one current official master pattern. The Board chief measurer shall measure and issue a certificate giving the dimensions of each plug, pattern and mold. Such dimensions shall be within a tolerance of one half the permitted building tolerances. The shape and form of the patterns, plugs and molds shall not be altered unless specifically authorized by the T-10 One-design Class Association. The primary control shall be by means of a single uniform source of plugs and molds to be administered by Tartan Marine Company.

2.4 Construction shall be checked in accordance with the official measurement diagram within the tolerance given. The yacht, before leaving Tartan Marine Company, shall be checked by a measurer appointed by the Board. The flotation of the boat, complete and in the condition specified in the schedule shall be measured and recorded.

2.5 Any attempt to depart from the design of these Rules in any particulars shall be reported to the Board, which shall revoke the certificate of the said yacht in question pending examination of the case or requisite remeasurement.

Class Vote 2002, Rule 2, Protection of One-Design

Yacht Dimensional Tolerance Rule

No yacht may be protested for a measurement that falls within the tolerances listed in the Class Rules.

 

3 HULL AND DECK

3.1 The hull and deck construction shall be in accordance with the official construction plans and specifications.

3.2 The weight of the cored hull shell completed to the laminate schedule shall be not less than 925 pounds. The weight of the cored deck completed to the laminate schedule shall be not less than 400 pounds.

3.3 The builder’s hull number and production date (month and year) shall be recorded on the transom.

3.4 The hull shall be fitted out according to the approved arrangement plan.

Chief Measurer’s Ruling: Hollows and indentation on the hull exterior as supplied by the builder may be filled in order to achieve a fair surface.

3.5 Prohibitions: The following are not permitted:

    1. Coring, drilling out, rebuilding, replacement of materials, grinding or relocating standard equipment in any way to reduce weight, to improve moments of inertia, or to change standard shapes.
    2. Reshaping of the full profiles or contours.

4 KEEL

4.1 Materials

4.1.1 The ballast keel shall be of molded lead and cast in a Class approved mold.

4.1.2 The keel may be over coated with any protective material and faired, provided it complies with dimensions in official Plan A.

4.2 Shape

4.2.1 The thickness of the keel section at the top of the ballast keel, defined as Section 1, shall be 6.125" +/- 0.125". The location of the thickest portion shall be 20" +/- 1" behind the leading edge. The chord length at this section shall be 52.5" +/- 0.5".

4.2.2 The thickness of the keel section located 20" below Section 1, defined as Section 2, shall be 5.875" +/- 0.125". The location of the thickest portion shall be 18" +/- 1" behind the leading edge. The chord length at this section shall 47.75" +/- .05".

4.2.3 The thickness of the keel section located 40" below Section 1, defined as Section 3, shall be 5.625" +/- 0.125". The location of the thickest portion shall be 16" +/- 1" behind the leading edge. The chord length at this section shall 43" +/- .05".

4.2.4 The leading and trailing edges between Sections 1 and 3 shall be straight within a tolerance of +/- 0.125".

4.2.5 The leading edge of the keel section between Sections 1 and 3 shall have minimum radius of 0.5".

4.2.6 The trailing edge of the keel section below Section 1 shall have minimum thickness of 0.25".

4.2.7 The distance measured from the junction of the transom and the hull at the centerline to:

    1. The trailing edge of the keel at Section 1 shall be 167.875" +/- 0.375".
    2. The trailing edge of the keel at Section 3 shall be 172.375" +/- 0.375".

4.2.8 Depth of the ballast keel from Section 1 shall be 47.5" +/- 0.5".

4.2.9 Keel measurement templates shall exist and periodic measurements will be taken.

4.3 Weight

4.3.1 The ballast keel shall weight 3340 pounds +/- 25 pounds.

Chief Measurer’s Ruling: A kelp cutter mechanism designed to clear debris from the keel or rudder while under way shall not be permitted.

5 RUDDER

5.1 The rudder shall be made according to the official pattern.

5.2 The rudderstock shall be located as per the official plan.

5.3 The yacht is to be steered by means of a tiller only. Tiller extension devices may be employed.

Chief Measurer’s Ruling: Auto-helm devices are prohibited while racing.

Chief Measurer’s Ruling: The rudder may be over coated with any protective material and faired.

5.4 The leading edge of the rudder section located 40" above the bottom of the rudder shall have minimum radius of 1.25".

5.5 The leading edge of the rudder section located 5" above the bottom of the rudder shall have minimum radius of 0.5".

6 MAST

6.1 The mast shall be placed on the supporting member and on the centerline. The forward side of the mast shall be located SFS (setback of forestay) plus J plus or minus .5 inches aft of the forward end of LOA as defined by 1977 I.O.R. Rule 301.

6.2 The upper shrouds shall meet the deck at 17-1/2 inches plus or minus .25 inches aft of the after end of J, and not more than 42.1 inches outboard from the centerline of the deck.

6.3 The lower shrouds shall meet the deck at 14-1/2 inches aft of the after end of J, and not more than 39.1 inches plus or minus .25 inches from the centerline.

6.4 The forestay shall meet the deck at 8 inches plus or minus .25 inches aft of the forward end of LOA as defined by 1977 I.O.R. Rule 301.

6.5 The mast shall be of an alloy extrusion with a minimum of 90% aluminum content.

6.6 The mast shall be of a constant section, whose dimensions shall be 4.6 inches plus or minus .125 inches athwartships and 6.4 inches plus or minus .125 inches fore and aft including the luff groove. The mast shall be deemed to be of constant section provided that no variation in fore and aft and athwartships dimension between any two points exceeds .25 inches. The sectional weight including the luff groove shall not be less than 3.0 pounds/foot.

6.7 The forestay attachment point is defined as the lower edge of the opening in the mast, which receives the forestay T-ball fitting. The forestay attachment point is measured from the butt of the mast and shall be 34 feet 6 inches from the butt of the mast. To accommodate the variances in the location of the forestay attachment point which have occurred, the allowable extremes are the minimum of 34 feet 3 inches and the maximum of 34 feet 7 inches from the butt of the mast.

6.8 From a point 30.5 feet below the forestay attachment point the luff groove may be cut away or otherwise modified.

6.9 Tapering or chemical milling of the mast extrusion shall not be permitted.

6.10 The weight of the mast, including all normal fixed fittings (including all standing rigging but excluding running rigging), shall not be less than 177 pounds and its center of gravity shall not be less than 17.6 feet above the upper edge of the band defined by Rule 6(14)(b).

6.11 The mast complete with all standing and running rigging and supported at the band defined in Rule 6(14)(a) shall weigh not less than 185 pounds when it is weighed at the band defined in Rule 6(14)(b). For the purpose of this measurement, the standing rigging shall be secured along the mast. The ends of the rigging below the band defined in Rule 6(14)(b) may rest on the ground or be removed as not to affect tip weight.

6.12 Holes may be made in the mast only for fittings and running rigging.

6.13 Permanently bent masts and rotating masts are prohibited. A set, due to distortion, of up to 3.0 inches between upper and lower bands shall be permitted.

6.14 One inch bands of contrasting color shall be applied to the mast as follows:

    1. With its lower edge 40.25 feet plus or minus inch above the upper edge of the band defined in Rule 6(14)(b).
    2. With its upper edge at the point of intersection of the mainsail tack, which shall be taken as the point on the mast directly forward of the center of the uppermost hole in the stock mainsail tack attachment hardware of the stock gooseneck fitting. The stock gooseneck fitting shall not be modified or repositioned.

7 MAST RIGGING

7.1 The standing rigging shall be of stainless steel wire construction and shall consist of only:

    1. Two 1 X 19 SS main shrouds of not less than inch diameter which shall be attached at 1.2 feet above the forestay attachment point.
    2. Two 1 X 19 SS lower shrouds of not less than 9/32 inch diameter which shall be attached at a point not more than 17.5 feet below the forestay attachment point.
    3. One 1 X 19 SS forestay of not less then 7/32 inch diameter.
    4. One backstay of not less than 3/16 inch diameter shall be attached to the masthead on a crane not less than 6.5 inches in length.

Class Vote 2002, Rule 7.1 Mast Rigging

Allow use of a Backstay Flipper

Allow the addition of a sail batten type of flipper to the top of the mast to support the backstay and allow it to clear the leech of the mail during tacks. There will be no revisions allowed to the material of the SS wire backstay from the Class Rules to make the flipper more effective.

 

7.2 The forestay and its attachments shall be subject to the following additional requirements and restrictions:

    1. The upper end of the forestay shall be attached at the forestay attachment point.
    2. The lower end of the forestay shall be attached to link plates. The link plates shall measure no more than 4.125 inches from centerline to centerline of the highest and lowest holes. The link plates shall be attached to the stock stem head tang. The stock stem head tang shall be positioned so that the centerline of the stem head pin hole is two inches above the deck (bow plate) at the stem. The stock stem head tang shall not be modified ore repositioned to increase effective headstay length.
    3. To control mast rake in light of variations in the location of the forestay attachment point, the following maximum forestay lengths are established:

    Distance from mast butt to forestay attachment point

    Maximum forestay length (plus " tolerance)

    34 feet 3 inches

    36 feet 3 inches

    34 feet 4 inches

    36 feet 3 7/8 inches

    34 feet 5 inches

    36 feet 4 5/8 inches

    34 feet 6 inches

    36 feet 5 1/16 inches

    34 feet 7 inches

    36 feet 5 inches

    Chief Measurer’s Ruling: The intent of this Rule is to provide the construction length for the forestay. One-half inch of tolerance shall be permitted in measuring, after installation, to allow for the stretching, which occurs after installation. Length of the forestay shall be measured from the center of the eye to the forestay attachment point, namely the lower edge of the T-ball fitting which rests in the forestay attachment point as defined above.

    Chief Measurer’s Ruling, July 1993: If the length of the mast is between two measurements the allowable length of the forestay is to the forestay length for the longer of the two mast lengths.

  1. The forestay may be fitted with a foil or grooved device. The owner is required to provide a section of the foil used on the yacht for the measurer’s use in measuring the class genoa. See Rules 10.10. and 10.10.2.a.
    1. Turnbuckles or other tension adjusting devices on the forestay shall not be allowed. Turnbuckles are the only permitted tension-adjusting devices on the shrouds, and they shall be located below decks immediately above the chain plates.

Class Vote 2000: Above deck shroud attachment: Turnbuckles are the only permitted tension adjusting devices on the shrouds. They either shall be located below deck attached to the chainplates or above deck attached to class approved deck tangs.

 

7.4 The spinnaker shall be suspended (i.e., maximum hoist point) from a point not more than one inch above the forestay attachment point.

7.5 The spreaders shall be attached to the mast 1.25 feet plus or minus .25 feet above the lower shrouds.

7.6 There shall be a fixed boom gooseneck. The stock gooseneck shall not be relocated from its position at the time of manufacture of the mast.

7.7 The jib halyard shall meet the mast at a point not more than 1-1/2 inches from the forestay attachment point.

Chief Measurer’s Ruling: Only two foresail halyard sheaves may be rigged with a halyard during a race. It is immaterial whether they are both above the forestay, both below, or one above and one below. If the use of a halyard is lost while racing, the lost halyard may be replaced, but not by using a halyard rigged through a third sheave. A messenger may be rigged through a third sheave, but pulling a halyard through a third sheave is prohibited. A messenger may be rigged through a sheave with an active halyard in use, such as through a sheave designed for a wire-to-rope spliced halyard, and a replacement halyard could legally be pulled through that first or second sheave while racing.

8 MAIN BOOM

8.1 The main boom shall be of a light alloy extrusion.

8.2 Sectional dimensions shall be 2-3/4 inches +/- 1/8 inch in width and 4-1/2 inches +/- 1/8 inches in height including a groove, except that for a distance not exceeding one foot from the aft edge of the mast t the groove may be cut away or otherwise modified. The sectional weight shall not be less than 1.675 pounds/foot.

8.3 Tapered or permanently bent booms shall be prohibited. A set due to distortion of up to 1-1/2 inches between band and mast shall be permitted.

8.4 A one-inch band of contrasting color shall be applied to the boom with its inner edge not more than 13.75 feet from the inner face of the luff groove on the after side of the mast extrusion.

9 SPINNAKER BOOM

9.1 No part of the spinnaker boom including fittings shall be capable of extending more than 12 feet from the centerline of the mast athwartships.

9.2 The attachment of the spinnaker boom on the spar shall not exceed 8.75 fee measured up from the sheer line (26.25 feet below the forestay attachment point).

Chief Measurer’s Ruling: The spinnaker car and track may be changed from stock track and car, so long as the foregoing rules regarding the spinnaker boom length and maximum attachment place are not thereby violated.

Class Vote 2002, Rule 9. Spinnaker Pole

Vote to allow the use of a carbon fiber spinnaker pole and two similar (but carbon fiber pole compatible) end fittings in addition to the continued use of the current aluminum spinnaker pole and its two current aluminum end fittings. To avoid potential injuries to crew, any carbon fiber pole utilized must be of adequate section and have a minimum breaking strength and rigidity equal to or greater than the current spinnaker pole. The end fittings must be of similar function and strength to those used on the current spinnaker pole.

 

10 ONE DESIGN SAIL MEASUREMENTS

10.1 General Requirements: Sails shall be measured in a dry state laid on a flat surface with adequate tension to remove wrinkles across the line of the measurement being taken. All measurements shall be taken as a straight line. Sails shall be made to measure to the recommendations of the I.Y.R.U. except where varied herein. It is the responsibility of the owner of the yacht to arrange for the measurement of new sails or newly acquired used sails in the sail acquisition year in which the sail is to be used for racing.

10.2 One-Design Sail Material: The body of one-design sails shall be so constructed of woven fabric, that it may be folded flat in any direction, other than in way of window and corner stiffening as defined below, without cracking or otherwise permanently damaging the sails or their reinforcement. Normal tabling at the edges of the sails is permitted provided that it shall not be stiffened. The only material permitted in a one-design spinnaker is nylon. The only material permitted in the main is Dacron. The storm jib may be constructed of nylon, Dacron or cotton.

See 11.2) C for cloth weight restrictions

Chief Measurer’s Ruling: No Kevlar, Dimension DI 65/75, Mylar, tri-axial or other exotic materials are permitted. Only cotton, Dacron, or nylon are permitted as sail material except as specifically provided otherwise with respect to the one-design genoa.

Chief Measurer’s Ruling: All one-design sails shall be constructed of a single layer of such fabric except for permitted reinforcements, construction seams, tablings, reefings and anti-chafe patches, camber lines, numbers and repairs to damage. The material used in one-design sails shall be such that when the material is torn it shall be possible to separate the fibers without leaving evidence of a film, except that a one-design genoa may be made of or may include polyester substrate Mylar film laminates, including Dimension DI 65/75 laminate material.

Chief Measurer’s Ruling: Dimension DI 65/75 material used in mainsails constructed prior to the National Championship Regatta in August 1990 are "grand fathered" from the application of this rule.

Chief Measurer’s Ruling (March 1994): Sobstad’s Genesis sail making technology may be used in the construction of the one-design jibs provided that the sails meet all class requirements for materials and material weight.

Chief Measurer’s Ruling: The one-design genoa shall be made of either woven polyester or polyester substrate/polyester film laminate.

Class Vote 2002, Rule 10.2 One Design Sail Construction

Allow the use of a UK Tape Drive sail construction for the Class Jib.

This issue concerns discontinuing the exclusion of the UK Tape Drive construction method for the Class Mylar jib--not the materials used to construct this sail. The UK Tape Drive Class Jib is required to be constructed using the same minimum sail material weight as is any other Class Jib, including the Class allowed Dacron, Mylar and North 3DL and Sobstad Genesis Jibs. The currently allowed 3DL and Sobstad Genesis sails are constructed using essentially the same sail construction methods as the UK Tape Drive Jib.

10.3 Definition: The term "sail" shall be taken to include the headboard, tabling, bolt and footropes or tapes. It shall not include cringles, slugs or rings, which are wholly outside the sail.

10.4 Windows: Not more than two separate unwoven transparent windows shall be permitted in any sail, the combined area of which shall not exceed three square feet in each sail.

10.5 Double Luffed sails: Sails passing around a stay or spar and attached back on themselves by stitching, zipper, or similar device, shall be considered to be double luffed sails, and shall not be permitted.

10.6 Measurements Bands: Where sails are set on spars, measurement bands shall be marked on the spars, so that they are clearly discernible while racing. The inside edges of these bands shall define the limits to which the sails may be set. These bands specifically limit the P and E dimensions of the mainsail taken from the point of attachment on of the mainsail tack at the boom gooseneck. This Rule will be enforced. With maximum outhaul, the clew of the mainsail shall not exceed the black band.

10.7 Insignia, letters and numbers: Class insignia, national letters and racing numbers shall be displayed on the mainsail according to I.Y.R.U. specifications. Racing numbers shall be displayed on both sides of the spinnakers according to I.Y.R.U. specifications. No numbers, national letters or class insignia are required on the one-design genoa.

10.8 Size and color insignia, letters, and numbers

    1. The Class designation shall be a distinctly contrasting color and the configuration of the scimitar "T" on a shield 20 inches horizontal by 21.15 inches vertical.
    2. Letters and numbers shall be of the following minimum dimensions:

      Height: 15.0 inches Thickness: 2.5 inches Width: 10.0 inches

    3. Space between adjoining numbers and letter shall be three inches. Color selection is open. This paragraph is subject to the I.Y.R.U. Rules effective May 1, 1989.

Chief Measurer’s Ruling, July 1993: Numbers must be of uniform and distinctly contrasting color.

10.9 Mainsail

10.9.1 Definitions

    1. Head: The head shall be taken as the highest point of the sail projected perpendicular to the luff or its extension.
    2. Clew: The clew shall be taken as the straight-line intersection of the leech and foot boltrope, ignoring any cutouts to accommodate outhaul fittings. Any sail constructed prior to July 5, 1989 with cutouts such that the clew point is in "mid-air" below the clew hardware may have its clew taken as the bottom of the sail at the clew hardware, provided the maximum distance from the front corner of the headboard to a point on the foot of the bolt rope which passes through the mid-point of an imaginary line between the luff at the tack fitting and the leech at the clew fitting is 42.5 feet.
    3. Tack: The tack shall be taken as the straight-line intersection of the luff boltrope and foot boltrope.
      1. Reinforcement: Mainsail reinforcement shall be in accordance with the I.Y.R.U. Sail Measurement instructions except that it shall be permitted only within a vertical distance of not more than 11.5 feet from the clew and 7.5 feet from the head. Cunningham or reefing eye reinforcement is limited to 3.0 feet.

Class Vote 2002, Article 10.9.2, Mainsail Reinforcements

Revise the allowable mainsail reinforcement to read: Mainsail reinforcement shall be in accordance with the I.S.A.F Sail Measurement instructions. Delete the 11.5 foot, 7.5 foot and 3 foot reinforcement limitations and update the name of the governing body.

 

10.9.3 Measurement

    1. Leech: Leech length is to be measured from the forward upper corner of the headboard to the clew intersection. The maximum dimension shall be 42.58 feet and the minimum dimension shall be 42.08 feet.
    2. Cross Widths: 1. The maximum three-quarter height width between the leech and the nearest point on the luff, including the luff rope, shall be 5.25 feet. 2. The maximum half height width between the leech and the nearest point on the luff, including the luff rope, shall be 8.58 feet. 3. The maximum quarter height width between the leech and the nearest point on the luff, including the luff rope, shall be 11.5 feet. 4. The point on the leech from which the cross measurement is taken shall be determined by bridging any hollow in the leech with a straight line. 5. The points at which the cross width measurements are taken shall be determined by folding the forward upper corner of the headboard to the clew intersection and making a mark at the fold in the center of the leech for the half-height width point, and then by folding the headboard corner and the clew to the half-height point and making small marks in the center of the leech to determine the quarter-height points.

10.9.4 Attachments: The mainsail shall be attached along the entire length on both the luff and foot of the sail, exclusive of reasonable cutbacks for attachment of the head, tack and clew hardware. The foot shall be secured to the groove at the outhaul point by an adjustable fitting, which is to be attached to the boom while racing by means of the groove in the top of the boom. The luff may be secured by slugs spaced at reasonable intervals (not to exceed approximately three feet) from head to tack. "Reasonable cutbacks" shall mean cutbacks sufficient to receive the tack and clew hardware.

Chief Measurer’s Ruling, 1992: The customary "slug in the groove" fitting attached to the clew of the mainsail may be replaced with a shackle attached to a car sliding in a track permanently affixed to the groove in the boom (such as the Harken batcar arrangement);

Class Vote 2002, Rule 10.9.4, Attachments

Allow use of a Loose Footed Mainsail

Allow the use of an optional loose-footed mainsail. All of the current mainsail material and measurement requirements will remain unchanged except for the addition of a 1 foot maximum mainsail foot round dimension that will assure that the loose footed main will not extend below the boom. This new foot round dimension is consistent with what is allowed on the current mainsail. The current mainsail dimensions will not be affected. There is no performance advantage expected with either mainsail design other than improved durability of the optional loose-footed design.

 

 

10.9.5 Battens: No more than four battens shall be permitted, spaced at even intervals along the leech plus or minus .25 feet measured to the center of the batten pockets.

Class Vote April 1991: The top batten may be of any length, and the maximum length of the remaining three battens shall be in accordance with the IMS batten length rule as of January 1988 without penalty, namely the second and third batten shall not be more than 4.67 feet in length and the bottom batten shall not be more than 3.44 feet in length. No batten shall be more than 2.5 inches wide.

Class Vote 2002, Article 10.9.5, Mainsail Battens

Revise the mainsail batten length rule to allow the lower batten to be the same length as the two mid battens, i.e. a maximum length of 4.67 feet long.

 

10.9.6 Cunningham tackle: Cunningham tackle is allowed on the luff only.

10.9.7 Headboard: Maximum breadth of the headboard measured perpendicular to the luff shall not exceed 6 inches. The aft corner of the headboard shall not be higher than the forward corner.

10.9.8 Reefing: No more than three sets of reefs are allowed. These reefs shall be parallel to the foot at intervals of 4.5 feet, 9 feet, and 13.5 feet (plus or minus .5 feet in each case) above the tack. A flattening reef not more than 1.5 feet above the tack is permissible. These measurements shall be perpendicular to the boom.

Chief Measurer’s Ruling (May 1994) A fourth reef point may be added to satisfy ORC Category 2 requirements (ORC 10.21.1) for long distance races such as the Mackinac Races. This reef must be located according to the ORC rule and may not be used in class races.

10.10 One-Design Genoa

10.10.1General: The one-design genoa shall be measured to the outside edge of the cloth, including for example tabling, foot skirt, and luff rope; in the case of a one-design genoa fitted for a grooved forestay, the width of the groove device (headstay foil) shall be included as part of the sail. Hardware not included within these edges is to be excluded from measurement. Head, clew and tack boards are not permitted. Cunningham tackle is permitted on the luff only. Any permitted roach must be a fair curve.

Chief Measurer’s Ruling: In the case of a one-design genoa fitted for a grooved forestay, the width of the groove device (headstay foil) shall be included as part of the sail for the length perpendicular (LP) measurement.

10.10.2 Definitions

      1. Head: The head shall be taken as the straight-line intersection of the luff and the leech ignoring any round or hollow of either. In the case of a one-design genoa fitted for a foil device, the luff shall be taken as being at the tape.
      2. Tack: The tack shall be taken as the straight-line intersection of the luff and the foot, ignoring any round or hollow of either.
      3. Clew: The clew shall be taken as the straight-line intersection of the leech and the foot, ignoring any round or hollow of either.

10.10.3 Measurement: The one-design genoa shall be laid flat and held at the head. The head intersection is the starting point for all measurements, except LP.

    1. Luff: Measured from the head intersection to the tack intersection. The maximum dimension, with the luff stretched to eliminate wrinkles, shall be 35.75 feet.
    2. Leech: Measured from the head intersection to the clew intersection. The maximum dimension shall be 33.0 feet.
    3. Foot: Measured from the clew intersection to the tack intersection. The maximum dimension shall be 13.7 feet.
    4. LP: Measured from the leech to and including the width of the foil. The maximum dimension shall be 12.67 feet.
    5. Battens: No more than three battens shall be permitted, spaced at even intervals along the leech (plus or minus .5 feet). The width of the battens shall not exceed 2.5 inches and the length shall not exceed 2.5 feet, except that the top batten may extend to the luff of the sail. The battens may be removable to facilitate storage of the sail. No adjustment of the battens shall be made while racing.
    6. Foot roach: The distance, measured on the surface of the sail, between the med-point on the foot and the mid-point on the luff shall not exceed 55% of the length of the leech.
    7. Genoa reef: The one-design genoa shall be permitted to have one shortening reef. The reef shall be installed four feet (plus or minus three inches) up the luff from the tack between 5.5 feet and 5.75 feet up the leech from the clew (in order to facilitate sheeting on the one-design track).
    8. Mid-girth: The maximum mid-girth measurement of the one-design genoa shall be 6.85 feet.
    9. Leech Roach: No positive leech roach shall be allowed on the one-design genoa.

10.11 Spinnakers

10.11.1 General: A spinnaker shall be symmetrical about its centerline in both shape and construction. Attachment hardware shall be limited to head and clew corners of the sail. A center patch for a spinnaker dousing line is permitted.

10.11.2 Definitions

    1. Head: The head shall be taken as the straight-line intersection of the two luffs ignoring any hollow or round in the luffs and head hardware.
    2. Clew: The clew shall be taken as the straight-line intersection of the foot and luff ignoring any round of the foot and clew hardware.

10.11.3 Measurement

    1. Luff and leech length: Measured from the head intersection to the clew intersections. The Maximum dimension shall be 35.15 feet and the minimum dimension shall be 33.40 feet. Luff and leech shall be of equal dimension.
    2. Foot length: Shall be the distance between the clew intersections on a straight line on the surface of the sail. The maximum dimension shall be 21.6 feet and the minimum dimension shall be 20.52 feet.
    3. Minimum mid-girth: Measured from the mid-point of one leech to the mid-point of the other leech. The minimum mid-girth dimension shall be 75% of the foot dimension.
    4. Maximum girth: Measured from any point on the leech to the equivalent point on the opposite leech. The maximum spinnaker girth dimension shall be 21.6 feet at any point.
    5. Center line length: Measured from the head intersection to the center point on the foot. The maximum centerline dimension shall be 39.25 feet.

10.12 Storm Jib

10.12.1 The storm jib shall not exceed 100 square feet in area (LP x hoist x .5).

11 SAIL RESTRICTIONS

11.1 Sail Inventory

11.1.1 The phrase "one-design sails", or words of similar effect, as used anywhere in these T-10 One-Design Rules shall mean the mainsail, one-design genoa, 1.5 ounce spinnaker and ounce spinnaker.

11.1.2 No more than one (1) one-design mainsail, two (2) one-design genoas, and two (2) one-design spinnakers (maybe oz or 1.5 oz) plus one storm jib as defined in Rule 10.12, may be measured and carried aboard by a skipper in any T-10 Class Association race or sanctioned event (Such as the North American Championship). If two (2) one-design genoas are measured and carried on board the genoa that is used to start the race, as defined by the starting gun, must be used for the entire race regardless of changes in wind strength or damage to the genoa. Also, when changing genoas between the preparatory signal and the starting gun only one genoa may be flown at a time; Class Vote, April 1993, effective immediately.

Chief Measurer’s Ruling: To change from one one-design spinnaker to another, the spinnaker in use must be lowered and the same halyard attached to the next one-design spinnaker to be used. Double sets of sheets and guys may be rigged and used. A changing strop may be rigged and used. See Rule 7.7 regarding sheaves and use of foresail halyards.

Chief Measurer Ruling, August 1993: The sail acquisition rules are meant to apply to apply to all races where T-10's sail as one designs. The sail acquisition and usage rules may not be modified by local fleets or for regattas with out the written permission of the Chief Measurer.

11.1.3 In the event of unrepairable damage of any sail, a replacement sail may be measured and used at the discretion of the Judges or measurer present.

11.1.4 Any one-design sail used must be measured and approved by an official Class measurer, and shall not be altered during the event, nor shall any repair be made to it which constitutes an alteration during the event.

11.2 Sail Cloth Weight Limitations

11.2.1 Minimum cloth weight for the mainsail shall be 5.7 ounces (161.88 grams) per U.S. sail maker yard.

11.2.2 Minimum cloth weight for one-design Class genoa (except the Mylar genoa) shall be 5.5 ounces (156.2 grams) per U.S. sail maker yard. The one-design genoa must be of single ply construction in accordance with Rule 10.2.

11.2.3 Minimum cloth weight for Mylar (or DI 65/75) one-design Class genoa shall be 4.5 ounces. The Mylar (or DI 65/75) one-design genoa must be of single ply construction as provided by Rule 10.2, except as specifically provided in this paragraph.

Reinforcements for Mylar (or DI 65/75) genoas cannot exceed 5.5 feet from any corner. These reinforcements must be capable of being folded. Mylar (or DI 65/75) one-design Class genoa reef point reinforcement cannot exceed three feet from the center of grommet. Two ply leeches are permissible provided (1) the extra layer of material is of the same weight Mylar (or DI 65/75) as the genoa and (2) the extra layer of material shall not extend into the body of the sail further than 18 inches from the sail’s leech. The extra layer of material must be pliable and in no way is to be used to simulate the use of battens to add positive roach to the genoa. (References to DI 65/75 added by Chief Measurer’s Ruling.)

11.2.4 Minimum cloth weight for the one-design spinnakers shall be .090 ounces (25.56 grams) per U.S. sail maker yard.

11.3 Sail Acquisition

11.3.1 No registered yacht may acquire in any manner, whether by purchasing, receiving as a gift, leasing, borrowing or otherwise, more than two one-design sails during the period beginning with the day after the last race of the North American Championship Regatta in one year and ending on the conclusion of the day preceding the first race of the North American Championship Regatta, except as hereinafter provided in this Rule 11.3.

11.3.2 A newly constructed or newly acquired yacht may acquire a total of six sails in its first two such years, but no more than four one-design sails in any one defined year. Nevertheless, a newly acquired yacht may, in addition, acquire one one-design genoa and one mainsail from the prior owner which were acquired by him no more recently than the second previous acquisition year, provided that the measurer is satisfied that such two-year-old sails were in fact used for racing for two seasons. "Banking" new sails is therefore not permitted, it being the intent of this rule to give parity to the newly acquired yacht with respect to older but competitive sails.

Chief Measurer’s Ruling, 1991: To be classified as a "newly acquired yacht", the yacht must be registered in the name of a new owner under state or federal registration laws, and the effective date is the date of issuance of the registration in the name of the new owner.

Chief Measurer’s Ruling 1996: To be classified as a "newly acquired yacht" for purposes of sail acquisition, there must be a complete change in the ownership of the yacht excluding the previous owner.

Chief Measurer’s Ruling 1992: A chartered yacht is a "newly acquired yacht" so long as the charter is (i) long-term, such as seasonal, (ii) there is a written charter agreement on the usual commercial terms, (iii) the chartered yacht is regularly raced in Class events and (iv) the charter arrangement overall is bona fide in the judgment of the Fleet Measurer. A chartering skipper may not acquire another yacht within a reasonable period of time so as to establish another six-sail acquisition right.

11.3.3 A new sail is deemed to be acquired on the date that it is originally measured and accepted by a Measurer. In order to enforce the renunciation of newly acquired used sails by the owner of a newly acquired yacht, any such used sail shall be acquired by its new owner on the earlier of (1) the day when it is accepted by a Measurer upon presentation for measuring by the new owner of the sail and (2) the date when first used by the new owner in a T-10 Class Association race. It is assumed that a new sail shall not be used in a T-10 class race prior to measurement and acceptance by a Measurer. A sail used in one sail acquisition year and not measured until a subsequent such year shall be deemed acquired in the year which is least advantageous to the owner, unless written proof of date of delivery of the sail is produced or the Measurer was not able to measure the sail in the year of actual acquisition due to the fault of the Measurer.

11.3.4 Any sail recutting resulting in an alteration to a sail requires remeasuring that sail, but such recutting and remeasuring does not constitute acquisition of an additional sail.

11.3.5 A "replacement sail" shall not be counted as a new acquisition in any case when the sail maker has agreed that the replaced sail was defective and the sail maker replaced the sail at no cost to the owner. The measurer shall be furnished such evidence as is satisfactory to him, such as an opportunity to inspect the replaced sail, and an invoice rendered in the normal course of business showing full credit for the replaced sail.

11.3.6 Unexpended sail acquisition rights applying to a particular defined year shall not be carried forward to any subsequent years.

11.3.7 Should the Board of Directors find that this Rule has been violated, it shall have the authority to prevent participation of the offending yacht and its owner in sanctioned events for one year.

Chief Measurer Ruling, August 1993: The sail acquisition rules are meant to apply to all races where T-10's sail as one designs. The sail acquisition and usage rules may not be modified by local fleets or for regattas with out the written permission of the Chief Measurer.

11.3.8 A sail that does not meet the minimum weight requirements of Rule 11.2, or that otherwise fails to satisfy the requirements of these Rules, shall not be a legal sail for racing. Any such sail which was deemed to have satisfied a prior Rule with respect to, for example, minimum weight requirements, or any other requirement which has or may have a performance advantage, shall not be "grand fathered".

11.4 Sail Trim: Unless otherwise specified, sail trim methods and restrictions shall be in accordance with I.Y.R.U. Rules. The genoa shall not be reattached and used as a staysail.

11.5 Sail Marker’s Inscription: Each sail submitted for measurement shall have inscribed in indelible ink of contrasting color at the head of the sail (i) the date of construction, (ii) the sailcloth weight(s) and (iii) the name and location of the loft and (iv) the signature of the sail maker. Effective for sails manufactured after May 1, 1991.

12 DISPLACEMENT MEASUREMENT AND EQUIPMENT WHILE RACING

12.1 Displacement of the yacht shall be determined as follows:

    1. A T-10 in commission with all factory installed equipment required by these Rules, with a single suit of class sails and in compliance with the safety equipment specifications of these Rules with water and fuel tanks empty, shall weigh not less than 7100 pounds. Adjustment shall be made for the weight of any water or fuel, which may be in the tanks.
    2. To assess displacement, flotation marks shall be placed forward port and starboard at the stem and on the rudder’s trailing edge. The marks shall be positioned to appear above water if the yacht’s displacement is less than 7100 pounds. The measurement and marking shall be made as follows:
      1. Forward: stretch a steel tape down the centerline of the stem from the bottom of the stemhead lip sixty-five and five-eights inches to the stem mark location. (Alternatively, if a screw impression is found in the stem at the centerline just above the boot top, measure down fourteen and one-quarter inches to locate the line to be scribed in the gel coat.)
      2. Aft: measure down from the counter at the center line along the trailing edge of the rudder three and one-quarter inches to locate the line to be scribed in the rudder.
      3. At each location, scribe a line in the gel coat three inches long and parallel with the water, port and starboard. Affix contrasting color tape (or paint) one-half inch by three inches to the underside of each line. The yacht will rise or sink one inch with each 756 pounds of displacement.
    3. Any yacht indicating a displacement of less than 7100 pounds is subject to weighing by a certified load cell scale. A yacht weighing less than 7100 pounds must be brought up to the required displacement by the installation of trimming ballast on a neutral axis, that is, lead weight at hull side port and starboard above the main cabin bunk level.
    4. It is the intent of this Article to provide minimum displacement for each yacht, not a particular plane of flotation.

12.2 Each yacht must be raced with all standard equipment on board and in a normal functional or stowed position. The stock boom lift shall be attached to the mast crane while racing. The table is optional equipment.

Chief Measurer’s Ruling, April 1993: Standard equipment shall include by not be limited to all bunks, including cushions, hatch covers, companionway slide, one main boat battery, lower bunk boards, port-a-potti, the cabinets above the chart table and galley and other equipment that is an integral part of a T-10. The intent of this ruling is to allow boats with different standard interiors to compete on an equal basis. The final arbiter in determining standard equipment will be the Chief Measurer.

Class Vote 2002, Rule 12.2 Displacement Measurement and Equipment while Racing

Optional Topping Lift Material and Usage Requirement, Optional Boom-Support

Allow 3/32 inch multi stranded Kevlar with an appropriate UV protective cover (or an equivalent multi stranded synthetic material with equivalent breaking strength and a UV protective cover) as an alternate topping lift material to the currently required stock plastic coated stainless steel topping lift. An adjusting mechanism may be used on either the synthetic or current SS wire topping lift to adjust the effective length of the topping lift. Which- ever topping lift material is used, for recognized ORC crew safety reasons, the topping lift must remain attached to the aft end of the boom. This is to prevent possible personal injury and damage to lifelines in the event of a sudden main halyard failure or release, and to assist the crew while reefing.

An alternative solid mechanical boom vang may be used in place of a topping lift of either design.

Chief Measurer’s Ruling: Boats manufactured with cabinets above the mid berths (Hull numbers above 200) shall be raced with these cabinets in place.

12.3 Standard safety equipment for sanctioned events on the following list shall be the minimum amount of safety equipment to be carried on board while racing. The Chief Measurer may modify this list by written notice to members of the Class Association mailed prior to May 1 of any year to be effective for the twelve-month period beginning May 1. Compliance with this rule shall not absolve a yacht from complying with safety requirements imposed by the United States, any state or local authority, or by the organizing authority of any racing event.

Standard Safety Equipment for Sanctioned Events

1 Companionway board secured to the yacht by lanyard or equivalent means.
2 At least one horseshoe life ring (Lifesling or equivalent acceptable) marked with yacht’s name and equipped with self-igniting waterproof light having a duration of at least 56 minutes within reach of helmsmen and ready for instant use, but the light must be in the sling’s pocket.
3 One manually operated bilge pump permanently installed in working order.
4 Two charged fire extinguishers readily accessible mounted in different parts of the yacht.
5 Marine radio transmitter and emergency antenna if regular antenna is mounted on the mast.
6 Weather radio receiver.
7 Lifejackets with whistle attached for skipper and each crewmember.
8 Safety harnesses for skipper and each crewmember.
9 Distress signals in waterproof container(s): minimum of three read hand flares.
10 50’ heaving line.
11 Soft wood plugs or various sizes, tapered, and mallet or engine crank handle.
12 Two two-gallon buckets each with lanyard.
13 Suitable drinking water container.
14 One anchor with rode securely fashioned.
15 Emergency navigation lights.
16 Two flashlights, one suitable for signaling, water resistant, with spare batteries and bulb.
17 First aid kit and manual.
18 Foghorn
19 Radar reflector.
20 Shutoff value on fuel tank.
21 Leadline or depth sounder.
22 Tools and spare parts including adequate means to sever standing rigging.

 

    1. A plaque showing the hull number, date of measurement and certifying that the boat has met the stipulations of measurement indicated above will be set in epoxy inside on the forward bulkhead of the hanging locker.

Chief Measurer Ruling 2000: Mooring cleats: Two bow cleats and two stern cleats as supplied by the builder.

Chief Measurer Ruling 2000: Replace the existing water tank with a 5 gallon portable tank: A five gallon water tank, securely attached and discharging through a pump.

Chief Measurer Ruling: Marine Compass 2000: A marine compass, permanently installed and properly adjusted.

 

13 AUXILIARY ENGINE AND PROPELLER

13.1 The engine dry weight (EW) shall not be less than 175 pounds.

13.2 The engine location shall be according to the official plans.

13.3 The propeller shall be as specified on the official plans.

14 GENERAL RESTRICTIONS

14.1 Hydraulic tensioning devices shall not be permitted.

14.2 Electronic instruments shall be limited to the following:

    1. One device transmitting data relative to 360 wind direction and/or speed and one device transmitting boat speed and distance by electronic means are permitted.
    2. Depth sounders, transistor radios, a RDF (not automatic) and any radio transceivers are permitted.

Chief Measurer’s Ruling, 1992: Electronic compasses (such as SailComp), LORAN, GPS and instruments which directly integrate boat and wind speed velocity made good (VMG) (such as the Ockam system) are allowed even at the North American Regatta. Multiple displays of information (repeaters) are permitted.

    1. Deck Hardware

Class Vote 2000: Lifelines: The deck shall be fitted with three stanchions on each side, port and starboard, as detailed in the official plans. Taut lifelines of wire not less than 3/16 inch diameter shall be attached to the bow pulpit and either stern pulpit or adequately braced stanchions and pass through the stanchions. The height of the lifelines above the sheerline when measured vertically shall be not less than 24 inches. The stanchions shall not extend outboard of the sheer in plan.

Class Vote 2000: Companionway Handrails: The deck along the companionway shall be fitted with a handrail on each side of the opening. The handrails shall have minimum length of 62 inches and minimum height of 4 inches.

14.3.1 Winches are restricted to six in number of any configuration, save that no cross linkages are permitted.

14.3.2 Tracks for inboard sheeting of the one-design genoa shall be limited to those installed by the builder as per the official plans. Continuously adjustable jib cars are prohibited. Additional holes may be drilled in the one-design genoa inboard sheeting track to receive the pin of the jib car.

Chief Measurer’s ruling, 5/93: The genoa sheet must lead through a block directly attached to the standard one-design genoa track. Any device or hardware that allow adjustment under load and/or continuous adjustment are prohibited except to rig a barber hauler led to the toe rail.

14.3.3 Through the deck blocks or fittings, which allow water to enter the hull, are prohibited.

14.4 Sanding and/or the application of paint coatings is permitted provided that no part of the yacht is thereby caused to lie outside the measurement tolerances specified in these Rules, the official measurement diagram and the official plans.

14.5 The jib tack fitting may be altered in design but not relocated.

14.6 The location and types of blocks, cars, stoppers, cleats, halyards, headsail sheets, backstay, Cunningham, outhaul, spinnaker pole lift and downhaul, and reefing may be changed consistently with these Rules. The material is optional in replacing sheets, halyard and other lines.

14.7 The main traveler shall not be relocated but may be replaced by similar arrangements of other manufacturers.

    1. Unless otherwise prohibited or restricted by the I.Y.R.U. Rules or by the Race Instructions of an individual fleet or event, crew torsos are permitted outside the upper lifelines only on that part of the yacht, which is equipped with double lifelines. No part of the toe rail as provided by the official plan shall be removed or reduced in size or otherwise modified. Hull #84 may carry a teak toe rail from her aft-most stanchion post to the aft end of the rail at the stem pulpit, provided the same is of the same height as the stock toe rail.

USSA Racing Rules Change 2000: Hiking out per the USSA RRS 1997-2000: No member of the crew shall station any part of their torso outside the lifelines, except briefly to perform a necessary task. On boats equipped with upper and lower lifelines of wire, a competitor sitting on the deck facing outboard with his waist inside the lower lifeline may have the upper part of his body outside the upper lifeline.

 

14.9 No change can be made, the intent or the effect of which is to alter the distribution of weight or decrease the amount of weight in the hull or the weight aloft.

14.10 A man overboard pole storage tube may be glassed into the transom.

15 REGISTRATION NUMBERS

15.1 The registration number shall be obtained from the Class Board of Directors.

16 OWNER’S RESPONSIBILITY AND MEASUREMENT CERTIFICATE

16.1 The owner shall be obliged to satisfy himself that the one-design principle has not been violated and to do nothing during the course of ownership to cause the principle to be violated.

16.2 No yacht shall be entitled to race as a bonafide T-10 unless: (i) the owner, including a new owner of a previously owned yacht, holds a valid certificate endorsed by a Measurer (or if not available by a member of the T-10 Class Association) in the owner’s name that the yacht conforms to these rules and (ii) the annual dues have been paid to the Association.

Upon payment of dues, the T-10 Class Association shall issue to the owner of the yacht a decal indicating that dues have been paid for that year. This decal shall be affixed to the starboard aft end of the boom. In order to participate in a North American Championship, the participant must be a member in good standing of the T-10 Class, with dues paid, thirty days prior to the day of the first scheduled race. In order to participate in other sanctioned events, this time shall be seven days. The portion of this Rule dealing with measurement certificates shall not be enforced until the issuance of certificates has been completed by the Chief Measurer. All requirements of these Rules shall nevertheless apply and violation of any of these Rules is grounds for disqualification from class racing.

17 SANCTIONED EVENTS

17.1 Designation: The Board may from time to time designate regattas it considers of particular importance as sanctioned events. Such events are run under the terms of the North American Championship Regulations.

17.2 Regional Championships: Each of the four regions designated in the Association by-laws may hold annual regional championships. These regional championships are sanctioned events and the winner of each such regional championship shall be entitled to entry in the North American Championship in the year that such regional championship is won.

17.3 Regional Championship Trophies: There shall be perpetual trophies, each the property of the T-10 Class, for each regional championship as follows:

17.3.1 Eastern Regional Championship Trophy: Consisting of a 7" x 12" stainless steel plate of a T-10 surrounded by 30 individual winner plates and mounted on a 17" x 14" walnut plaque. This trophy shall be presented to the Eastern Regional Champion each year, to be held until a successor champion is named.

17.3.2 Lake Erie Regional Trophy: Consisting of a Yellow "= 2’ scale half-model of the T-10 mounted on a wooden plaque 12" x 24". This trophy shall be presented to the Lake Erie Regional Champion each year.

17.3.3 Great Lakes Regional Trophy: Consisting of a Black "=1’ scale half-model of the T-10 mounted on a wooden plaque 12" x 24". This trophy shall be presented to the Great Lakes Regional Champion each year.

18 RE-MEASUREMENT

18.1 Any certified yacht may be re-measured at any time on protest, or at the direction of the Board or Race Committee, or at the insistence of any Measurer.

19 TRANSLATIONS

19.1 In case of dispute arising from the translation of these Rules into other languages, the English text shall prevail.

20 OFFICIAL PLANS

(To be published by the builder upon approval by the designer when building standards are documented).

21 CLASS RULES ENFORCEMENT

21.1 The official plans and specifications, and these Rules, however complete, cannot anticipate every possible situation, which may arise. It should be assumed that anything, which is not specifically permitted, is specifically prohibited until a written ruling by the Chief Measurer has been obtained.

21.2 Where there is any question of the permissibility of any proposed detail of design or construction of the yacht or of one-design sails, or of the rigging of the yacht, a specific request shall be made to the Chief Measurer for a ruling.

21.3 When a request for such a ruling has been made, the Chief Measurer shall approve or disapprove of the proposal within 90 days. Failure to disapprove within 90 days shall constitute approval.

21.4 Such rulings, once made, become a part of the official plans and specifications, and of these Rules, and may be changed or repealed at a later date only in accordance with the Class By-laws covering changes to the plans and specifications and these Rules.

21.5 A boat built in accordance with a Chief Measurer’s ruling may not be challenged at a later date because of approved methods of construction, except in the same manner that any boat built before a change in the official plans and specifications may be challenged after a change has been made. Such a challenge would be permitted only if an official change had been made in the plans and specifications in full accordance with the Class constitution.

21.6 In making such rulings, the Chief Measurer is to follow the intent of the existing Rules, and is not to be concerned with the literal construing of the wording of the existing Rules. The Chief Measurer is to follow the basic philosophy that the T-10 is intended to be one-design class in which no differences in design, construction, or rigging which affect boat speed are to be permitted.

22 AMENDMENTS

22.1 Unless otherwise expressly provided in any proposed amendment, no amendment to these Rules relating to sails shall be effective until the first day of the sail acquisition year following the year in which the amendment is adopted.

PLAN A

KEEL PLAN

Keel Sections

1

2

3

 

Location distance

From top of lead down:

0 20 40
Design chord length (x) 53.725 47.875 43.906
Section chord length 52.750 47.875 43.000
Leading edge radius 0.5 0.5 0.5
Section width, y,

At distance from leading edge:

     
0.005x 0.481 0.464 0.446
0.0075x 0.580 0.559 0.538
0.0125x 0.733 0.709 0.684
0.025x 1.010 .0982 0.953
0.05x 1.396 1.362 1.328
0.075x 1.684 1.646 1.607
0.10x 1.922 1.877 1.832
0.15x 2.293 2.235 2.178
0.20x 2.569 2.497 2.425
0.25x 2.770 2.684 2.598
0.30x 2.908 2.807 2.707
0.35x 2.986 2.868 2.750
0.40x 3.000 2.866 2.733
0.45x 2.935 2.796 2.657
0.50x 2.806 2.668 2.531
0.55x 2.625 2.493 2.361
0.60x 2.403 2.280 2.156
0.65x 2.147 2.034 1.920
0.70x 1.863 1.762 1.661
0.75x 1.561 1.474 1.388
0.80x 1.251 1.182 1.113
0.85x 0.942 0.890 0.838
0.90x 0.632 0.597 0.562
0.95x 0.322 0.305 0.287
(Trailing Edge) 0.98x 0.125 0.125 0.125
1.00x 0.013 0.012 0.011
  • Between Sections 1 and 3, the surface of the keel shall be fair in every plane. Extension of lines connecting corresponding offsets of Sections 1,2, and 3 shall define the section shape below Section 3. Keel tip profile and base veeing shall be per the keel design drawing.
  •  

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