- Title. Author. Summary
- Title. Author. Summary
- Title. Author. Summary
- Title. Author. Summary
- Title. Author. Summary
7. a An Invitation to Model Yachtsmen oes od sel ct i Prepare Now for Our International Challenge Next Year R the past three years the Model Yacht Racing Association of America has sent challengers to Gosport, England, to race for the Yachting Monthly Trophy, emblematic of the world championship in model yachting. This past summer our challenger lost the cup by one point. Can we send a challenger over in 1928 to bring this trophy to the U. S. A.? The Model Yacht Racing Association of America invites all model yachtsmen of the United States to enter models in the elimination races to be held late in June, 1928. There are many details about rigging and steering gear that are necessary for equipping this type of model. Articles on these subjects will be published in YACHTING during this coming winter. These will enable everybody to equip their models with the very best and latest devices used for sailing under pond conditions. This class of models has been known as the Yachting Monthly ‘Six,’ but isto be called the International Model A Class in the future. Plans of this class have been published in YacuT1NnG for June and August, 1927. The measurements of the international challengers and defender this year appear in the September, 1927, issue. Further information may be obtained by addressing the Association’s Secretary, Mr. Wellington Rindge, 1717 Beacon Street, Waban, Mass. The following is a copy of the Yachting Monthly Cup measurement rule: The races shall be open to models not exceeding 6 metres (19.68 ft.) on the scale of 2 in.=1 ft. by the following formula: Rating = L+vS ‘ LVS above water level. (Any deficit in freeboard or excess in height of sail plan shall be added to the rating.) N.B. — The Donors retain the right to modify these conditions if thought advisable, due notice being given. In the event of a difference of opinion arising as to their intention in any direction, the point at issue shall be submitted to the Donors’ representative for his decision. LENGTH Before being measured, a yacht must have a “load water line _ plane” established and permanently marked at centre and at forward and after ends of L.W.L. The plane shall be, as nearly as = the plane of flotation when in racing trim. Each side mark shall consist of two equal equilateral triangles, whose apices touch at the established plane of flotation and whose bases are parallel to such plane. The total vertical height of each side mark shall be % in. on the model. The bow and stern marks shall be % in. long and ¥ the position of the established plane. hen in trim, under racing restrictions, the vessel floating on an even keel in sea water of usual density, both side marks must be cut by the surface of the water. ; “Load water line length” (L.W.L.) is the distance in a straight line between the points farthest forward and farthest aft in the established lane and likewise “load water line breadth” is the extreme breadth in the established plane. uarter-beam length (Q.B.L.) shall be measured in a line parallel with the middle fore and aft vertical plane, at a distance from it equal to one-quarter of the load water line breadth and one-tenth of this breadth above the load water line plane. The length used in calculating the measurement (L in formula) shall be the “load water line length” plus one-half the excess quarter-beam length over the percentage of the load water line length given by the formula, Percentage = 100 — VY L.W.L. No hollows shall be allowed in the surface of the hull between the L.W.L. and the sheer line. Any local concave jog or notch (curved or angular) at the plane of measurement of either end of the load water line length, shall be bridged by a straight line and the L.W.L. taken to the intersection of 12./D length of rating to be: L.W.L. + 3% any excess in “quarter beam” measurement—hull measurements and displacement being taken as by the Universal Rule and sail area as by the International Rule. — Limits and Penalties: (1) There shall be no limit on the actual displacement of models, but the cube root of the displacement, D, as used in the measurement formula, shall never exceed 20 per cent of L.W.L. + .5, but, in the event of its being less than 20 cent of L.W.L. + .2, an amount equal to such deficit shall be deducted from the actual cube root for use in the measurement formula. (2) Greatest draught = 16 per cent L.W.L. + 1.75 in feet. (Any excess . draught shall be multiplied by 3 and added to the rating. (3) Lowest average freeboard (taken at centre and at forward and after ends of L.W.L.) = 28 per cent WD + .5, the sheer to be a fair continuous concave curve. (4) Height of sail plan not to exceed twice the length of L.W.L. such lines with the established load water line plane. below the load water line plane. The load water fine (L .L.) shall be measured to intersection of this line with the established load water line plane. Centre-boards are prohibited. The round of beam must not exceed the Y.R.A. allowance of 4% inch to the foot. DISPLACEMENT The cube root of displacement, for the formula, will be found as follows: The cube root of the weight of the model in pounds will be multiplied by one and a half, this giving the cube root of displacement, in cubic feet, for full scale yacht — the weight of sea water being taken at 64 pounds to the cubic foot. For example, the cube root for the formula of a model weighing 27 Ibs. is 3 X 1.5 = 4.5. Salt AREA To be measured by Y.R.A. system, and models must sail with spars as measured. a iter ine | | Quarier Beam Length- Gl aa Centre Line: ie ee The method of measuring mcdels for the “Yachting Monthly” Cup. 78 Any concavity in the stem line shall be bridged by a straight line equal to one-third (34) of the greatest load water line beam, placed equally above and |geen Ban in. in vertical height so placed that the bottom of the marks shall indicate /div>
