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Class Rules for Hull, Spars and Sails

4.         Hull

 

(Rules 1-17, checked with the boat the right way up.)

 

Note. The construction of the MK. 3. G.R.P. version, with its hull shell taken from an official mould, with integral transverse and longitudinal bulkheads, and assembled with deck moulding also taken from an official mould, positively maintains the hull shape and the detail hull measurements 1-4 inclusive, 6-13 inclusive, 16 and 18-20 inclusive are not required to be taken. These measurement rules which do not apply to the Mk. 3., are marked with a marginal line.

 

 

 

 

+ or -

1.

Length overall

11' 0" (3353)

1" (25)

2.

Outside transom to forward face of aft bulkhead

1' 9¼" (540)

¾" (19)

3.

Outside transom to aft face of forward bulkhead

8' 11½" (2731)

¾" (19)

4.

Centreboard case; maximum internal width

1" (25)

 

5.

Weight of hull stripped of loose gear, including hatch covers, oars, rowlocks, rudder, tiller, spars, fendoff, etc., but including centreboard, and weight correctors (if any), not to be less than

160 lbs (72.5 kg)

 

6.

Outside transom to aft face of aft half frame

4' 8¼" (1429)

¾" (19)

7.

Measurements of outside transom;

 

 

 

(a) Beam at gunwhale to inside skin

3' 3¼" (997)

½" (13)

 

(b) Beam at angle of upper chine to inside skin

2' 10¾" (883)

½" (13)

 

(c) Beam at angle of lower chine to inside skin

2' 3¾" (705)

½" (13)

 

(d) Depth, gunwhale height to top of keel

1' 1½ " (343)

½" (13)

 

(e) Depth, angle of lower chine to top of keel

2½" (64)

½" (13)

8.

Measurement at forward face of aft bulkhead;

 

 

 

(a) Depth, upper edge to upper surface of hog

10½" (267)

½" (13)

 

(b) Beam to inside skin on upper edge

4' 0½" (1232)

½" (13)

9.

Measurement at aft side of aft half frame;

 

 

 

(a) Beam measurements under Rules 9a., 10a., and 16, shall be taken to sheerline (intersection of the lines of the upper surface of the gunwhale and the outside plane of the hull skin, projected if necessary.)

 

Beam to sheerline as defined above;

4' 8¾" (1441)

½" (13)

 

(b) Bean, inside skin at upper edge of upper chine stringer

4' 4½" (1334)

½" (13)

 

(c) Beam, inside skin at upper edge of lower chine stringer

3' 9" (1143)

½" (13)

 

(d) Depth, gunwhale level to upper edge of upper chine stringer where it joins the skin

10¼" (260)

⅜" (10)

 

(e) Depth, upper edge of upper chine stringer to upper edge of lower chine stringer, where it joins the skin

7" (178)

¼" (6)

 

(f) Depth, gunwhale to upper surface of hog

1' 8" (508)

½" (13)

10.

Measurements at aft face of forward bulkhead;

 

 

 

(a) Beam to sheerline as defined in Rule 9a

2' 9¼" (845)

½" (13)

 

(b) Beam, inside skin at upper edge of upper chine stringer

2' 4" (711)

½" (13)

 

(c) Beam, inside skin at upper edge of lower chine stringer

1' 8¾" (527)

½" (13)

 

(d) Depth, upper edge of upper chine stringer to top of hog

10½" (267)

⅜" (10)

 

(e) Depth, upper edge of upper chine stringer to upper edge of lower chine stringer

6⅝" (168)

⅜" (10)

11.

Foredeck;

 

 

 

(a) Length on centreline

2' 0½" (622)

1" (25)

 

(b) Stem head to extreme aft edge at gunwhale

3' 11½" (1207)

1" (25)

12.

At least one pair of rowlock sockets to be fitted to gunwhale

 

 

13.

The gunwhale construction shall not project outboard of the sheerline as defined above for Rule 9.a., more than 1⅛" (29), or inwards more than 2⅜" (60), measured horizontally at right angles to the tangent to the sheerline at any point

14.

Openings into buoyancy tanks;

 

 

 

(1) Wood boats only;

 

 

 

(a) All hatches shall be properly secured and watertight when sailing

 

(b) One inspection port, of maximum internal diameter 4½" (114) and capable of complying with Rule 14.1.a., shall be permitted in each hatch cover

 

(c) Width of hatch openings

9½" (241)

1" (25)

 

(d) Depth of hatch openings

6" (152)

1" (25)

 

(e) Drain holes of ¾" (19) maximum diameter, closed in a watertight manner whilst afloat, shall be permitted in the buoyancy tanks as follows;

(1)   Not more than two in the forward bulkhead

(2)   Not more than two in the aft bulkhead

(3)   Not more than two in the transom

 

(2) G.R.P. boats only;

 

 

 

(a) All hatches shall be properly secured and watertight when sailing

 

(b) Two circular hatches are permitted in the forward bulkhead. Diameter of openings 6¼" (159) maximum

 

(c) In Mk.1 and Mk.2 versions only one circular hatch is permitted in the top of the aft buoyancy chamber. Diameter of opening 6¼" (150) maximum

 

(d) Drain holes of ¾" (19) maximum diameter, closed in a watertight manner whilst sailing, shall be permitted in the buoyancy tank as follows;

(1)   One in the forward bulkhead near the centreline

(2)   One in the aft bulkhead, near the centreline, in Mk.1 and Mk.2 versions

(3)   One in the transom, near the centreline or skeg of Mk.1 or Mk.2 versions

(4)   One in each longitudinal bulkhead, within 12" (305) of the transom in Mk.3 versions

15

Hull drainage;

 

 

 

Only the following drainage openings shall be permitted in addition to those mentioned in Rule 14;

(a) Not more than two self-bailers having a total effective opening area of not more than 2 sq. in. (12.5)

(b) Not more than two drain holes of ¾" (19) maximum diameter in bottom of wood boats and Mk.1 and Mk.2 G.R.P. boats.

(c) Not more than two drain holes of ¾" (19) maximum diameter in the transom or skeg of Mk.3 G.R.P. boats

16

Beam to sheerline, as defined in Rule 9.a., at 4' 8" from outside transom

4' 10½" (1486)

½" (13)

17

Centreboard slot;

 

 

 

(a) Forward end to aft face transom, measured along keel

6' 9½" (2070)

¾" (19)

 

(b) Aft end to aft face transom, measured along keel

3' 7½" (1105)

¾" (19)

 

(c) Rubber strips at bottom of centreboard slot not permitted. They may be used at top of slot.

18

Keel;

 

 

 

(a) Minimum exposed width on outer face from transom to 10' 0" (3048) forward

2⅜" (60)

 

 

(b) Minimum exposed depth

½" (13)

 

 

(c) Maximum thickness of keel-band to be fitted entire length of keel and stem

½" (13)

 

19

Bilge keels;

 

 

 

(a) Minimum length

3' 11½" (1207)

 

 

(b) Minimum width

⅝" (16)

 

 

(c) Minimum thickness

9/16" (14)

 

 

(d) Distance from keel measured on skin (minimum)

1' 5" (432)

 

20

Skeg;

 

 

 

(a) Minimum depth at transom

3" (76)

 

 

(b) Minimum depth at 1' 0" (304) from transom

1½" (38)

 

 

(c) Minimum width

¾" (19)

 

21

Rudder blade;

 

 

 

(a) Minimum thickness

7/16" (11)

 

 

(b) Not to be chamfered on lower edge of blade

 

 

 

(c) Chamfer not to extend from other edges more than 1" (25)

 

 

 

(d) The profile of the upper portion of the blade may be altered to permit the blade to be lowered to the extent that its leading edge is in line with the forward edge of the rudder stock. The blade may not be angled forward of this.

22

Tiller;

 

 

 

(a) Maximum overall length

3' 0" (914)

 

 

(b) No part of the tiller extension when folded along the tiller, shall be closer than 7" (178) from the aft end of the tiller

23

Centreboard;

 

 

 

(a) Minimum thickness

7/16" (11)

 

 

(b) Chamfer not to extend from any edge more than 1½ " (38)

 

 

 

5.         Masts and Spars

 

24

(1) Mast (Gunter rig only)

 

 

 

(a) To be solid with metal sail track

 

 

 

(b) Position of coloured bands (1) with upper edge not more than 2' 1" (635) or less than 1' 9" (533) above gunwhale in either mast position, (2) with lower edge 5' 7½" (1715) above upper edge of (1)

 

(c) The upper edge of the boom is not to extend below the upper edge of coloured band (1) when racing

 

(2) Mast (Bermuda rig only)

 

 

 

(a) May be metal or timber, but if jointed approximately in the middle, so that neither of the component pieces is more than 10' 0" (3048) long. Both component pieces, complete with fittings, must be buoyant. Metal masts may not be tapered.

 

(b) The weight of the mast with fittings (exclusive of rigging) is to be stamped on it in the vicinity of the gooseneck and is not be less than 12.75 lbs (5.8 kg)

 

(c) Height of centre of gravity of mast with fittings (exclusive of rigging) to be stamped on it in the vicinity of the gooseneck and is not to be less than 8' 7" (2616) from the heel

 

(d) Position of coloured band (1) on mast with upper edge not more than 2' 1" (635) or less than 1' 9" (533) above gunwhale with mast in either position. The upper surface of boom is not to extend below upper edge of (1) when racing

 

(e) Position of coloured band (7) on mast with lower edge 8' 0" (2438) above upper edge of (1). The extended line of forestay and luff of jib must meet the mast below the lower edge of (7).

 

(f) Position of coloured band (3) on mast, lower edge 15' 1½" (4610) above upper edge of (1). No part of mainsail is to extend above the lower edge of (3) when racing

25

Gaff (Gunter rig only)

 

 

 

(a) To be solid, except for groove for sail bolt rope

 

 

 

(b) Position of coloured bands (3) with lower edge about 2" (51) from the head, (4) with the lower edge 9' 7" (2921) from the lower edge of (3)

 

(c) The head of the mainsail is not to extend above the lower edge of coloured band (3)

 

(d) The lower coloured band on Gaff (4), is not to be above the upper coloured band on mast (2) when the mainsail is hoisted

26

Boom (Bermuda or Gunter rig)

 

 

 

(a) Of wood or metal, but if of wood to be solid, except for groove for sail bolt rope

 

(b) Position of coloured band (5) with inner edge 7' 2" (2184) from aft side of mast, when assembled on gooseneck

 

(c) The clew of the mainsail is not to extend beyond the inner edge of coloured band (5)

 

(d) In Una-rigged boats prior to No. 199 an additional red band (6) is to be positioned on boom with inner edge 8' 5" (2565) from aft side of mast, when assembled on gooseneck. The claw of a Una-rig mainsail is not to extend beyond the inner edge of this red band (5)

 

6.         Sails

 

27

Mainsail (Bermuda or Gunter rig)

 

 

 

(a) The maximum width of the headboard, measured at right-angles to the mast or gaff, shall be 3" (76)

 

(b) The measurement of the leech along a straight line from the centre of the head cringle to the centre of the clue cringle shall not exceed 16' 3" (4953) in Bermuda sails of 16' 1" (4902) in Gunter sails

 

(c) Not more than three battens shall be permitted, dividing the leech into four approximately equal parts. The maximum length of the top batten shall be 1' 6" (457) and the maximum length of the two lower battens shall be 2' 0" (610)

 

(d) The width of the mainsail at three-quarter, half and quarter height shall be determined as follows: The sail shall be dry and smoothed out on a flat surface. To find the half luff point, the head cringle shall be placed over the tack cringle, with the two halves of the luff coinciding; the fold so formed indicates the half luff point (and should be marked for convenience). This fold is then placed over the head and tack cringles together, thus forming two further folds indicating quarter and three-quarter luff points (which should also be marked). A similar method shall be used to determine the half, quarter and three-quarter leech measurement points, the head cringle being placed over the clew cringle to form the half leech fold, and this fold then being placed over the two cringles together to form the quarter and three-quarter leech folds.

The sail is then unfolded and width measurements taken through the corresponding points on luff and leech, over the entire width of the sail, including bolt rope, with sufficient tension to remove wrinkles across the line of measurement. The maximum width at three-quarter height shall be 2' 10" (864), at half height 4' 9" (1448) and at quarter height 6/ 3½" (1918).

 

(e) The mainsail foot shall be attached to the boom for its entire length between tack and clew cringles

28

Jib;

 

 

 

(a) The jib halyard block shall be suspended from a point on the mast not more than 2' 4½" (724) above the lower edge of coloured band (2) on the gunter rig mast, (see Rule 24.2.e. for Bermuda rig mast)

 

(b) The centre of the head, tack and clew cringles shall not be more than 1" (25) from the adjacent edge of the sail

 

(c) The maximum dimensions of the measured between centres of the eyes at tack, head and clew shall be:

(i) Small jib,  ( Original Class jib)

Luff 8' 7" (2616), Foot 4' 2" (1270), Leech 7' 3" (2210)

 

(ii) Large jib ,( Modification with the Gull Spirit building adopted by the class)

Luff 8' 7" (2616), Foot 4' 2" (1270), Leech 7' 11" (2210)

 

 

(d) The mid point of the foot shall be determined by placing the centre of the clew cringle over the centre of the tack cringle, tensioning both halves of the foot equally to form a fold. Then with the sail unfolded and sufficient tension on the sail along the line of measurement to remove wrinkles across the line of measurement, the distance from the centre of the head cringle to the mid point of the foot shall not exceed 7' 11" (2413)

 

 

 (e) A transparent panel, not exceeding 16" (406) in width, and 9" (229) in height, shall be permitted in the jib, provided that no part of the panel is less than 6" (152) from any edge of the sail

 

(f) The jib stick shall not exceed 3' 6" (1067) overall length. When in use the inner end must be attached to the mast

 

29

Spinnaker;

 

 

 

(a) The spinnaker halyard shall be external to the mast. If the halyard leads through a block, the block shall be suspended from a point not more than 1" (25) from the foreside of the mast, and not more than 2' 5½" (749) above the lower edge of coloured band (2) on the Gunter rig mast, and more than 2½" (63) above the lower edge of coloured band (7) on the Bermuda rig mast (see Rule 23.e.).

If the halyard leads through an eye, the bearing surface of the eye shall not be more than 1" (25) from the foreside of the mast and not more than 2' 5½" (749) above the lower edge of coloured band (2) on the Gunter rig mast, and not more than 3½" (89) above the lower edge of coloured band (7) on the Bermuda rig mast (see Rule 23.e.)

 

(b) The spinnaker shall be made of any woven cloth. No artificial stiffening is permitted at the corners or along the edges, other than fabric hems or patches required for reinforcement

 

(c) Spinnakers shall be three-cornered and symmetrical about a line joining the head to the centre of the foot

 

(d) The measurements shall be according to the sail plan, with the sail dry and laid on a flat surface. Measurements at the corners shall be taken to the centres of cringles, which shall not exceed 1¼ " (32) diameter. Each measurement shall be taken with the sail pulled just taut enough along the line of measurement to eliminate all creases across the line of measurement

 

(e) Each luff AB shall be measured individually and shall not exceed 10' 2" (3099)

 

(f) The centre measurement AC shall not exceed 11' 0½" (3366)

 

(g) The width measurements shall be taken with the sail folded in half along the centreline and laid on a flat surface with both halves coinciding. Points D, F, H shall be marked on the centre fold at 2' 7" (787) and 7' 9" (2362) from the centre of the head cringle and points E, G, I shall be marked on the luffs at 2' 7" (787), 5' 2" (1575), and 7' 9" (2362) from the centre of the head cringle. The half width of the sail between D and E shall not exceed 2' 2" (660) nor be less than 3' 0" (914), and between H and I it shall not exceed 4' 0" (1219). The half width of the foot BC, from the centre fold to the centre of the tack or clew cringles shall not exceed 3' 10" (1168)

 

(h) The registered sail number shall be on both sides of the spinnaker in figures not less than 12" (305) high

 

(i) The overall length of the spinnaker pole shall not exceed 4' 9" (1448)

 

7.         Miscellaneous

 

30

(1) Wood boats – Class number

To be carved on the inside of the transom, above the stern buoyancy tank in figure not less than 1" (25) high, or  on the hog in figures not less than 1" (25)

 

(2) Reinforced plastic boats – Class number

To be permanently displayed in figures not less than ⅛" (3) high on a plate mounted on the forward face of the transom beam or centreboard case capping

 

(3) In all boats:

Class number to be displayed on mainsail below class insignia (a symbolic flying Gull) in figures not less than 9" (229) high

 

31

Buoyancy;

 

 

 

(1) It is not practical fully to test the buoyancy compartments by total immersion owing to their large volume. Officials Owners are to check all watertight joints and satisfy themselves that they are efficient and that the hatches are adequately watertight. In addition, the boat is to be floated in a waterlogged condition, with the water overflowing the top of the centreboard case. After 20 minutes in this condition, the boat is to be bailed out and the tanks inspected for leakage. This test must be carried out annually and the certificate endorsed by a club or class official. Certificates without current endorsements cease to be valid. Additional buoyancy bags apparatus may be carried.

 

(2) Mk.1 and Mk.2. G.R.P. boats shall have solid foam buoyancy units permanently fastened to the hull to provide 52 lbs. (23.5 kg) minimum lift in the forward buoyancy compartment, and 58 lbs (26.5 kg) minimum lift in the aft buoyancy compartment. Mk.2. versions shall in addition be fitted with one solid foam buoyancy unit of 50 lbs (23 kg) minimum lift under the side bench on either side

 

(3) Mk.3. G.R.P. boats shall have one solid foam buoyancy unit providing 40 lbs (18 kg) minimum lift permanently fitted into each side buoyancy tank and solid foam buoyancy units providing 20 lbs (9 kg) minimum lift permanently fitted forward of the main bulkhead