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PAISLEY’S LEGGAT TROPHY HIRTY-ONE boats entered for the Paisley M.Y.C. Leggat Trophy race this year, from all over Scotland, but three boats scratched owing to their respective skippers’ ill health; 28 boats there- fore came under starter’s orders at 2.30 p.m. on Saturday 18th June. A good top suit wind made for fast and exciting sailing, and most yachts managed to use a spinnaker. Sailing in general was of a very high standard, most boards being won or lost by a matter of a boat length. Outstanding performers for the day’s sailing were the Sunkiss design Stardust and the Elusive design Blue Belle. Points of interest in these two yachts were the Sunkiss’s fibre glass hull and the sliding rig, both owner made, and the Elusive having a portion sliced off her bows and added in the form of a hollow transom. ane Sunday’s sailing commenced at 11 a.m., but the wind did not behave so well, however, and fortunes were won and lost as it completely changed direction. A large element of luck entered into things, and the less fortunate could be found muttering to themselves in some secluded corner. Nevertheless, general opinion was that it had been an excellent two days’ sport, when the O.O.D. called a halt to proceedings at 7 p.m. The final results were announced by the scorer after the skippers had satisfied their obvious hunger on the tea provided by the ladies of our Catering Committee. First place went to E. Bruesh of Victoria West Club, Glasgow, with his Saida design Solveig with 71 points. Second A. McMillan of Paisley Club, with his altered Elusive design Blue Belle 68 points. Third R. Gillespie of Victoria West Club with his Sunkiss design Kelpie with 65 points. Fourth place T. Dodd’s Pye design Yochabel of Miniature Club, Glasgow, with 55 points, this being the result of a sail off between Yochabel and R. Greig’s Mithras design Yokatana, Yochabel winning by a short nose. The winning Saida was a perfect example of the art of model making. Her fittings were mainly of stainless steel and the vane gear had such refinements as top and bottom balance on the make and break arms and a spring bobbin device for guy adjustment. The only thing not produced by her owner were the sails; a really first-class model and deserving winner. Other models of interest were the two Ducks: their keels had been reduced an inch and a half on the trailing edge and they carried a narrower rudder than as designed. Their owners assured me that these modifications had increased performance, but thought the lack of sliding rig had prevented them from attaining the best results from this type of hull; “over to the experts”. I would like to extend our invitation for next year’s race. We will be only too pleased to see anybody from over the border.and accommodate them over the week-end’s racing. Top picture shows Blue Belle leading Mistral to windward, Kelpie (background) seems to have lost her opposition. Top left: Solvieg and Blue Belle, Left: Yokotani and Emu, another Sunkiss 505 Hi OCTOBER, FTER almost forty years experience of the rule, it may be of interest to compare the dimensions of “Crusader ’ (designed by W. J. Daniels), winner “Y.M.’’ Cup 1924 and 1925, with those of the sister_yachts, ““Moonraker’’ and “Moonraker II’’ (designed by the late Eng. Admiral A. Turner), which won the cup in 1955 and 1959 Tespectively. L.W.L. ““Crusader’’ ““Moonraker’’ 45.0in. 53.5in. Displacement 37.0lb. 63.0lb. S.A. 1,936 sq. in. 1,630 sq. in. THE HISTORY OF THE ‘A’ CLASS Part 3 (Conclusion) Under all previous rating rules, later boats have tended to be much larger than earlier ones, but in the A-Class this tendency has been aggravated by the introduction of Terylene, with its smooth, almost non-porous surface, in place of union cloth for sails. Originally the ‘Class was intended to be one-sixth size models of 6-M. yachts, and I feel that in drafting the rule, Major M. Heckstall-Smith had in mind boats nearer the size of ‘Crusader’ than the ‘‘Moonrakers’’. 1960 H. B. Tucker Apart from this, and the fact that the rule stresses displacement overmuch, the formula is the best that has been framed to date. pad Cannes, Monaco, etc., but of rather smaller size than the 6-Metres So, when in 1957, the I.Y.R.U. launched the new 5.5 Metres Class Rule, many model yachtsmen thought that our rule had been adopted for full-sized racing yachts, as at first sight it would appear to resemble the A-Class Rule superficially. A closer examination, however, reveals that the learned pundits of the I.Y.R.U. Council have not only ruined the formula itself by the method used to ascertain L (length for rating formula), but also added a number of pernicious restrictions that cramp the designer and prevent him from developing the best types he can under the rating limits. The formula is as follows :— Let us next examine the limitations referred to above as (a) Maximum Draught and (c) Fin Keel and Rudder. These two restrictions LVS 1223VD + Be ws 4 = Rating (which is not to exceed 5.5 metres). ass. in combination give us a long, shallow full-keel with the rudder hung on its after end. Very obviously if the maximum permitted draught was 6 feet instead of 4.34 feet, it would have given a far better boat in every way, and as the yachts are not intended for places where they ground at every low tide, there was no practical objection to this. Briefly summarised, the advantages of a greater draught would be:—(i) Greater power and sail-carrying ability due to a lower C.G. (ii) A longer leading edge to the fin making for greater weatherliness. (iii) A more efficient shape of lateral plane, enabling its area to be somewhat reduced, and thereby reducing wetted surface, making for a faster boat. (iv) The rather shorter lateral plane would make the boat quicker in stays, more sensitive on the helm and manoeuvrable. L=Length measured at a height of 1.5 per cent. of class rating above L.W.L., plus the difference between the girth at the bow ending of this length, measured to points 5 per cent. of rating above L and twice the vertical height from L to these points, plus one-third of the difference between the girth measured from top of covering board to top of covering board at the stern ending of this length, and twice the vertical height of the yacht at this point. Likewise, we know that the most efficient form of rudder is the balanced rudder. It is superior to the type enjoined by the Rule in the following respects :—(i) It gives a more sensitive control and is quicker in action. (ii) It has greater power per square foot of area so can be of smaller size, and this further reduction of wetted surface area makes for a faster boat. We are not dealing with a cruiser, or even an ocean racing cruiser, but a comparatively small day-boat intended for pace rae is no reasonable objection to using a balanced rudder Where S=Actual Sail Area. Where D=Displacement (Volumetric). There are a host of limitations, restrictions and prohibitions attached to this formula, but I will single out only three for comments:— There is one fatal objection to the use of a balanced rudder on model yachts. All our lakes suffer to a more or less degree from weed and the balanced rudder is a champion weed-trap. The’ usual model yacht type of skeg and rudder is the best substitute for a balanced Where (a) Maximum Draught.—1.35 metres (=4.43 feet). (b) Stern Angle.—“The angle of the after profile with the waterline not to be less than 1 in 54, this to be checked afloat in measurement trim.’’ (c) Fin Keel and Rudder.—‘The after edge of the fin keel shall be straight and be formed to receive the forward edge of the rudder and to it the rudder shall be attached and shall extend the whole rei a the fin keel except for a reasonable rounding up at the heel.’’ Dealing first with the formula, the constant “.9’’ merely allows this so-called 5.5-M Class to measure one-ninth more—i.e., 5.5-+0.6=6.1 metres. As the equivalent of 5.5 m. is 18.04 feet, would it not have been simpler to call it a ““20-footer’’ and omit the constant? When, however, we consider the manner L is found, we see that the pundits of the I.Y.R.U. have perpetuated the worst features of the 1920 I.Y.R.U. formula in the bow and stern taxes, and the measurement of a length at a height of 1.5 per cent. of rating above L.W.L., in lieu of L.W.L. or D.W.L. or the 5.5’s. rudder we can find. Hence its practically universal use on models. On a full-sized yacht the balanced rudder is preferable. From the above summary, it will be realised that the 5.5-Metres Rule is ill-conceived and half-baked, and cannot possibly produce desirable yachts, It is infinitely inferior to our own well-tried A-Class Rule. In fact the late Major M. Heckstall-Smith in 1923 evolved a far better Rating Rule than the pundits of the I.Y.R.U. have in their recent effort! We need not follow their retrogressive mistakes. If model yachtsmen find the A-Class a little large and heavy, as well as expensive, and desire something rather smaller either for Vane or R/C, there is nothing to prevent the formation of a B-Class to our own rule. In writing this history of the A-Class, I found it impossible to separate the purely historical aspect from the technical side of the rating rules involved. In the case of the latter, however, I have merely cited the formulae and summarised a few of the more salient restrictions. Any reader wishing to have further information should, therefore, study the official rule books for the various classes concerned. It is true that the principle of a two-part formula has been accepted but the advantages have largely been negatived by the imposed Limits on Hull Sizes, Weights and Sail Areas. The Bow and Stern Taxes, method of Length Measurement, and the restriction on Stern Angle, referred to above under (b), rigidly control L.O.A. and overhangs. Now the purpose of overhangs is to provide additional sailing length and reserve buoyancy, but if they are overlong they are detrimental because of the useless windage and weight at the extreme ends of the vessel. Again, if they are too Vsectioned, the boat will be wet and have insufficient reserve buoyancy, and consequently lack power and sail-carrying ability. On the other hand, if the overhangs are too U-sectioned, the ends of the boat will smack in a seaway, causing the sails to shake and loss of speed. Moreover, the two ends of the vessel must match each other and the middle of the hull; otherwise the rhythm of her pitching and scending will be adversely affected. The main object of a Rating Rule is to measure boats fairly and balance the elements of speed so that close racing is assured. Experience has shown that Q.B. (Quarter Beam) Measurement, as used in the Universal and A-Class Rules, is a better method of ascertaining L for the rating formula than the clumsy system employed in the 1920 I.Y.R.U. Rule. and now repeated in the 5.5-M. Class. Further, it gives the designer more liberty to create the best and fastest yacht he can for the required purpose. In this case what was wanted was a half-decked, day racing yacht of the displacement type with a fixed keel, suitable for international racing in such waters as the Solent, 513 R/C EQUIPMENT Reptone Unitone Tritone… E.D. Black 4 E.D. Black 6 AND £15/8/0 £16/10/0 £20/13/0 £28/5/6 £32/9/0 ACCESSORIES £7/18/4 O.S. 35 R/C Merco 29 and 35 R/C Sextone $5 Octone £7/12/6 £31/17/0 £50 0/0 Instrument soldering iron, 220-240 v., 25 watt 24/- Escapements and Servos by R.E.P., E.D., Remtrol-Olsen, Bonner, etc. Extended pa yments from 20% deposit: e.g., R.E.P. Octone £50/0/0 cash. £10/0/0 instalments over 6 months 8 months £7/0/0 _ £5/7/0 deposit with 12 months £3/10/8 Prompt mail order service from K. M. GREAVES, 24 and 26 Garbutts Lane, Hutton Rudby, Yarm, Yorks
