Black Book


This edition of the Black Book incorporates all revisions to the Constitution and Specifications through January, 2011. The Specifications section was reorganized to place all information on one item (e.g. "mast") at one location. Ml changes from the 1987 issue are identified with a "bar" in the fight margin. In general revisions can be made only once per year. The basic definition of the Thunderbird Class boat is fixed and further changes to this Black Book will not invalidate the measurement certificate of existing Boats. Revisions that are officially accepted since printing of this addition will be published in International (I.T.C.A.) newsletters. Update information is available by writing to:

I.T.C.A. P.O. Box 1033, Mercer Island, Washington, 98040-1033 U.S.A.

Acknowledgment and thanks is given to Jack Foster for providing the initial Specification draft and to Sandy Pratt, Bill Hurley and Roy Dunbar for coordinating updated Specification drafts for class acceptance. Thanks to Garth Wilcox for doing the Specification drawings.

SPECIFICATIONS

These specifications define the construction, equipment and measurement of the International Thunderbird Class sloop. Incorporated as part of these specifications are all of the Official Plans listed in the Reference Section below.

The issuance of an official measurement certificate and Gold Seal are dependent on the observance of these specifications, both in fact and spirit. Tolerances are specified to accommodate inaccuracies. However any boat measuring within these tolerances will meet the specifications regardless of the intentions or motives of the builder.

Specifications, however complete, cannot anticipate every possible situation which may arise. Anything that is not clearly covered in these specifications shall be brought to the I.T.C.A. Measurement Committee for a ruling.

These specifications shall be used in conjunction with the official set of plans. These specifications are requirements and the plans generally provide guidance, except where the specification requirement refers to the plans with such language as "as shown by" or "set forth in", in which case that part of the plans becomes a requirement. Where differences exist between the plans and the specifications, the text of these specifications shall prevail.

The builder shall supply a certificate to the Class Measurer stating that the yacht has been built to conform with the current International Class specifications and to the current official plans.

Table of Contents


1.0 References of Official Plans (Distributed by I.T.C.A.)

2.0 Arrangement 3.0 Construction 5.0 Rudder 6.0 Keel 7.0 Spars 8.0 Rigging 9.0 Sails 10.0 Weight Requirements 11.0 Instumentation

TIPS TO BUILDERS

These specifications define the construction, equipment and measurement of the International Thunderbird Class sloop. Incorporated as part of these specifications are all of the Official Plans listed in the Reference Section below.

The issuance of an official measurement certificate and Gold Seal are dependent on the observance of these specifications, both in fact and spirit. Tolerances are specified to accommodate inaccuracies. However any boat measuring within these tolerances will meet the specifications regardless of the intentions or motives of the builder.

Specifications, however complete, cannot anticipate every possible situation which may arise. Anything that is not clearly covered in these specifications shall be brought to the I.T.C.A. Measurement Committee for a ruling.

These specifications shall be used in conjunction with the official set of plans. These specifications are requirements and the plans generally provide guidance, except where the specification requirement refers to the plans with such language as "as shown by" or "set forth in", in which case that part of the plans becomes a requirement. Where differences exist between the plans and the specifications, the text of these specifications shall prevail.

The builder shall supply a certificate to the Class Measurer stating that the yacht has been built to conform with the current International Class specifications and to the current official plans.

REFERENCES (Official Plans distributed by the I.T.C.A) {Return to Table of Contents}

2.0 ARRANGEMENT {Return to Table of Contents}

For an alternate version to be considered for and receive approval. drawings shall be submitted to the Board of Governors prior to the start of construction. These drawings shall be accurately scaled and dimensioned plan and profile views, showing the entire deck. cabin with window layouts. the cockpit and the coamings. Section views at Bulkheads 2,3, and 4 and a bill of material shall be included on the drawings. Upon approval, the drawings shall be official plans and shall be the property of the I.T.C.A.

figure 1

ENVELOPE AVAILABLE FOR ALTERNATE CABIN CONFIGURATIONS

figure 2
Anchor Well Arrangement
3.0 CONSTRUCTION SPECIFICATION {Return to Table of Contents}
Traditional materials such as wood, steel, aluminum, bronze, iron, lead, lexan, Plexiglas, polyester, fiberglass, balsa cored fiberglass panels, foam cored fiberglass panels, paint and epoxies may be used. Carbon fiber and kevlar, shall not be used. Hull, deck, and house must be made from wood or fiberglass. Further material restrictions for individual items are located in their respective paragraph.Titanium will not be used on Thunderbirds after January 26,1994. Titanium installed on Thunderbirds prior to January 29, 1994 may remain.The use of materials not listed above as acceptable must be approved by the I.T.C.A. Measurement Committee.The selection of wood is at the option of the builder except as listed below but all woods must weigh in excess of 20 lb. per cubic foot (320 kg/cu. m) at 15% moisture content. All plywood is to be of Marine or Exterior type. It is expected that the yacht shall be constructed in accordance with materials and techniques normally considered sound for yacht construction.
4.0 HULL {Return to Table of Contents} 5.0 RUDDER {Return to Table of Contents}

Spade Rudder Diagram

figure 3

Notes: All measurements are in inches. (1 inch = 25.4 mm)

Measurement control point "B" is on Section B-B at 40% Chord.

Measurement control Point "C" is on Section C-C at 40% Chord.

The 5-1/2" rudder stock location shown is recommended, not required.

6.0 KEEL {Return to Table of Contents} 7.0 SPARS {Return to Table of Contents}

8.0 RIGGING {Return to Table of Contents}