• 5.1.1 The rudder shall be constructed as per the plans with the tiller head located above deck.

• 5.1.2. The rudder tube shall he located according to plan with the centerline of the rudder shaft 15' 8-1/8" (4.79 m.) +- 1/2" (12.7 mm.) aft of the after side of Bulkhead #2.

• 5.1.3 The original rudder shaft shall be of corrosion resistant material having a minimum yield strength of 55,000 psi (379.2 N/sq.m)and shall be 1" (25.4 mm.) minimum diameter. The spade rudder (see 5.3) shall have a shaft of 1-1/8" (28.5 mm) minimum diameter. A spade rudder may have a 1" diameter shaft provided the material has a minimum yield strength of 100,000 psi (689.5 N/sq.m).

• 5.1.4 The position or the shaft in the original rudder shall be as shown in the official plans. The position of the shaft in the spade rudder shall be no more than 3" (76 mm) from the location shown on the Spade Rudder Diagram.

• 5.2.1 The rudder shall be not less than 1-7/8" (47.6 mm.) thick for 75% of its vertical dimension at a horizontal distance 5-3/8" (136.5 mm) abaft its leading edge.

• 5.2.2 The rudder side profile must be within 1/2" (12.7 mm.) of the plan dimensions.

• 5.2.3 The rudder cross-sectional shape is optional. The recommended shape is as shown in the official plans.

• 5.3.1 The rudder shall not be less than 2-1/4" (57.2 mm.) thick at control section B-B and 1-1/4" (31.75 mm.) thick at control section C-C, as shown in the Spade Rudder Diagram.

• 5.3.2 Rudder side profile dimensions are to be within 1/2" (12.7 mm.) of those shown in the Spade Rudder Diagram. Corners may be rounded to a maximum of 1/2" (12.7 mm) radius, where not specified in the Diagram.

• 5.3.3 The rudder horizontal cross-sectional shape is optional, with a recommended shape shown in the Spade Rudder Diagram.

• 5.3.4 Rudder shall taper uniformly between control sections.

The keel shall be of cast iron or cast steel having the following minimum properties:

Tensile strength: 35,000 psi (2460.8 kg/sq. cm.)
Transverse bending strength: 2600-3000 lb. (1179-1360.8kg)
(1.2" dia. bar 18" centers) (30.48 mm. dia. bar 457 mm. centers)
Deflection: .22"-.34" (5.59 mm. -8.64 mm.)

Weight as specified by a certificate from the foundry shall be 1500 lb. (680.4kg.) minimum, 1560 lb. (707.6kg.) maximum. If no foundry certificate is produced, the keel must be weighed separate from the hull on a certified scale and verified by the measurer. Foundry weight for keels must be verified by a fleet measurer. For keels found to be over maximum weight, the additional weight must be removed by drilling holes at the bottom and sealed by welding. Holes must not exceed 6" (152.4 mm) in depth.

The keel drawing in Reference 1 shall be referred to when applying this Section of the Specifications.

• 6.3.1 Horizontal profile (Section "B-B" of the plans, Ref 1) shall be measured by half section templates produced from expanding the profile of the two B-B sections (bottom of flange radius and 1/2" (12.7 mm) above the bottom of keel) by 1/8" (3.18 mm.) from the profile shape. Allowable tolerances are : tight against the template to 1/4" (6.35 mm.) minus with the exception of the trailing edge. This overall dimension is controlled by section 6.3.5.

• 6.3.2 Vertical profile (Section "A-A" of the plans, Ref. 1) shall be within 1/4" (6.35 mm.) of the sections as shown on the plans.

• 6.3.3 Radius at bottom edge shall be 0" to 1/2" (12.7 mm.) maximum.

• 6.3.4 Absolute side profile dimensions as shown on the plans shall be 3'8" (1.12 m.) +- 1/2" (12.7 mm.) vertically and 48" (1.22 m) +/- 1/2" (12.7 mm) horizontally.

• 6.3.5 Location - The leading edge of the keel where it intersects the bottom of the yacht shall be 42" (l.06m.) +/- 1/2" (12.7 mm.) aft of the after side of Bulkhead #2. Boats with approved original measurement certificates which did not require recording this dimension are exempt from this measurement except if the keel is removed for other reasons. Re-installation of a keel shall be in accordance with this location specification

• 6.3.6 Keel Thickness - The point of maximum thickness at the bottom of the flange radius including port and starboard halves is to be 1-3/8" (34.9 mm) minimum and 2" (50.8 mm) maximum The point of maximum thickness at 1/2 inch above the bottom or keel, including port and starboard halves is to be 6-5/16 (160 mm) minimum and 6-7/8" (175 mm) maximum.