- A-Class Yacht Windjammer. By H.B. Tucker
VOLUME 4 NUMBER 39 New 0-6-0 0 Gauge Steam Loco Miniature Stern A Goods Wheel Jetex Yard Paddle Powered Hydroplane ** Genevieve ” Model Human Interest “Windflower” Lamps Steamer on Continued © the A-Class Line ~ Yacht A New Look for Model Cars? Choice of Make This Profile A a Loco Outline Model Prototype Four-Way Toolpost Model J-Class Cars Destroyer FEBRUARY De 1954 MODEL MAKER) 4a C HLORIS was designed in the winter of 1934, and published in Marine Mode/s in the spring > A-CLASS YACHT of 1935. At the time I had a personal fancy for double-enders, and also there was a fashion for ood ane By H THIS TUCKER DESIGN FROM ACKNOWLEDGED BEING giving boats long pointed snout and tails to gain overall length, regardless of wheth er this was usefully employed or not. Both feature s were embodied in Chloris, and she had an overall length of 84 ins. on a L.W.L. of 52.0 ins. In other THE BOARD MASTER BUILT FOR THE IS respects, she was a normal, health y boat, and as a matter of fact, very advanced for her day. OF AN ALREADY Recently, a London model yachtsman asked me about this design which he found in an old number of Marine Models, and sugges ted bringing 1954 NATIONALS. PLANS ON THREE SHEETS ARE AVAILABLE FROM MODEL MAKER THESE % OFFICES, PLANS PRICE SERVICE I5/- POST AT her right up-to-date. As a result, I ; FREE sy designed ment, her, entirely re- increasing her L.W.L . and displace revising the profile SHEET ! OF 3. for use with “WINDFLOWERTM “A> CLASS YACHT c——_-2 (Ma) H.B. TUCKER. DESIGNED Wee ee BY WLiI6 COPYRIGHT OF Noe | 2 : Xi W.L.14 38, CLAREN RO WATER DON ERS) wi 3 4 vane APPROX. POSITION FOR M 5 E x, = WL. 13 | W.L. II W.L.IO 560° MAX. BEAM 14-875, ae | W.L.9 28 ie W.L.8 DIMENSIONS. LOA. 78-4 —LWL lo 5 st Ee 8g SE WhPe o ee LEAD LINE W.L. 6 ———___\— —— Wia of 12-25 SA 1479 SQINS _/S_ 38-5 DISPLACEMENT 57-25 LB = 1545 CU. INS. = 2c on cs WL.2 WLI “is = NC = ¢ ; NOTE*C.B. MOVES AFT O-|” AT x- E oT . Poa ay a Se BE inte e ries 3 fe) oA RP WLI WL.I3 ace PA << \A \ Va Us: soa 9 iL. 20 I I ae I == 1 1 aoe _—— 1 ae, i ; = wig LWL f ghee 4 a WL.8 WL.7 wi be rN Eee eNs ge Sern Z 1) 2o- HULL TABLE OF WEIGHT TABLE _OF WEIGHTS -DECK WITH BEAMSs& HATCH PAINT & VARNISH FITTINGS oie 2 2 VANE WL.4 WL.3 GEAR RIG TRIMMING © 0 8 WL.6 WL.5 6 BALLAST L rete ai 43 14 a7 WL.2 WL. WLO 92 I Se) = SRS eyr cee 4 ia oe 8 Sse | —___— = 4 fet - ye > BURVES OF AREAS CANOE BODY ONLY. —~ = “SN PPRIGHT >Sie AND ne Sve ee |HEELED eee 20°-7—— eee = eee GREATEST BEAM LINE DECK | LINE r FEBRUARY Windflower is very different to Lynx and the other “Cats,” though she embodies many of the same ideas and principles. She is a very powerful craft and should revel in strong winds, though I should also expect her to give a good account of herself in light weather. She has a moderate beam and round, easy section. Now there are certain hoary fallacies that are like old soldiers. One is the belief that a fine entry ensures real performance in rough weather, while a flat run gives the best results running. As a result, inexperienced designers often try to marry a V-bow and a U-stern. As long ago as 1915, Mr. W. J. Daniels, a doyen of model yacht designers, published a series of three articles in the Model Engineer, on Model Yacht Designing. In these he pointed out that for good all-round performance, bow and stern must match exactly. It is true that scow types, which have a full U-bow sometimes pound in a seaway, but this is mainly attributable to their light displacement. Such boats lack weight and power to carry their way against a choppy head sea, and in consequence, lose speed and pound. Actually, a moderate U-bow makes a better steering gear, and abolishing her excessive overhangs and canoe stern. Superficially, this revised design bears little or no resemblance to the original Chloris and as a matter of fact should be capable of sailing rings round her. Yet the new design is a direct descendant of the old. Before the war, I often took names for my designs from the Classical Dictionary, so wanting a name for the new boat, I look Chloris up again to see whether she had any daughters. Now Chloris “was another name for Flora, Goddess of Flowers, and wife of Zephyrus, God of the West Wind. There seems no record of her daughters, but the daughter of Flora and Wind God obviously had to be called Windflower. Another pointer, was that during the First World War, I was loaned to H.M.S. Windflower and acted as her First Lieutenant for several months. I z A ) 12 ED o 1p ee ai seaboat than a V-entry, as it rises easily and rides the waves. It may throw spray about in the case of a fast boat driven hard into it, but solid water does not come aboard, as it does when a Vsectioned boat is similarly sailed. The V-sectioned boat is at its best in light winds, because it has less wetted surface and also offers less head resistance. But whether we decide to make our bows V- or U-section, it is most essential that the character of the sections be maintained throughout the full length of the vessel. What leads many young designers astray, is that they think one can embody in a model yacht features seen in successful 14 ft. dinghies, ““Flying Fifteens”’ and the like. These light, crew-ballasted craft alter their shape as the crew trims them. For example, when the crew moves aft, the boat cocks her nose up, her entry becomes steeper and shorter, and her run longer and flatter, and the C.B. moves a long way aft as the C.G. has also done. The model yacht is a pure “displacement” type and her C.G. cannot move in a fore-and-aft direction. Hence, the problems are entirely different and have to be treated on entirely different lines. The model yacht is akin to the 6-metres R.O.R.C., boats and other displacement type yachts. Another fallacy occasionally heard, is that one can afford to design an unbalanced boat with the ends that do not match, because any steering ———— RATING \ PARTICULAR Q.BL.ALLOWED WITHOUT P 52 8. SKEG 0-375 THICK Q.BL ACTUAL 53:15 — P. MIN. 3/p PENALTY iI % +035 – 563 LFOR FORM JO ACTUAL 11°56 -~P O04 1 1:56-0:04 -11 52 3/D FOR FORMULA X. DRAUGHT _WITHOUT_P. 1246: MIN” PREEBOARD WITHOUTP ‘ \\ 0) FREEBOARD 2124.02 4-00. 4: = —— = Same: SS em, \\ %& 1 ZZ ae Sie ee RATING = – 56-35+38:5 39:37 4 56-35X385 12 X 1-52 | | | = 1954 et 93 MODEL MAKER] effect thus produced, can be countered by jugglery with the “fin root.” It is perfectly true that steering effects can be induced by the position of the fin under the hull, by the angle of its leading edge, etc., but why create another energy wasting fault instead of curing the original one. I wonder what any motorist would say if he went to a garage with his off-side brake binding and pulling his steering to the right, and the mechanic immediately suggested pulling up the near side brake to bind and thus compensate the steering? I use this simile deliberately, because any steering tendency acts as a brake on a boat’s speed, and absorbs energy that should be devoted its power. Her sail plan is modern with reasonably large headsail. | As regards rig, I recommend a metal mast to minimise windage, and the use of runners in addition to a preventer backstay. The mainsail should be loose-footed. I strongly recommend the use of a radial jib-boom with the “Guy Blogg” type fitting. In this, the gooseneck for the jib-boom is mounted on a kingpost stepped on the keel, and coming about 2in. above deck. The kingpost must be raked so that its line, if produced would cut the head of the jib. This rake is most important, as otherwise in light winds, the boom may stick up due to the kicking to forward propulsion. Perfection in design consists primarily of a perfectly balanced hull with no steering vices at any normal angle of heel, and under this a fin (or keel) appendage likewise free from steering vices, thus leaving the rudder to do its own proper work. Then, since there will be no inherent steering vices to counteract, the yacht will be more amenable and sensitive, and require smaller rudder area and lesser helm angles. Strap tightening as the boom swings off. Being 2 in. above deck, there is plenty of room for a kicking strap underneath, and I recommend the wire rod type with knurled nut adjustment. By this means the foot of the jib will be given increased flow as the sheet is eased off, but the after leach of the sail will always be kept under control, thus preventing the head of the sail winding and spilling. There is one more point in this connection. In order to get every ounce of power possible to steer unhandy boats, many carry the tops of their rudders upward immediately under the backbone (keel). While this may possibly give a little extra punch to rudder action, it also produces a steering effect by impeding the free escape of the garboard stream. This makes for back pressure, The excessive snout of Chloris has been shortened, and her long tail lopped into a small neat transom. Her fin closely resembles Lynx and /0-I/. It is kept reasonably thin and the garboard angles only lightly filled, in order to make for good windward work. The rudder is a little more forward than is usual for vane steering. This places the rudder in water clear of the hull and increases with As regards the vane steering gear, this boat will resultant loss of energy and speed. Please do not think I am laying down the law or theorising, I merely repeat principles enunciated by far cleverer men than I am, and the embryo designer should accept them, rather than repeat the mistakes others made years ago. Let him accept these principles as the art student accepts the primary colours, and devotes his energies to learning how to use them. In model yacht designing there is plenty of scope for originality, and experiment, without the handicap of faulty technique. As regards the ordinary model yachtsman, who does not go in for designing, I hope the above may prove of service in helping him to select designs to build from. Let him eschew designs where the forward and after sections show entirely different characteristics, and look for those where the shoulders and quarters are harmonious and matching. He will then steer clear of many troubles. In transforming Chloris into Windflower, I have not embodied any untried features. Her bow is slightly foreshortened and a blunt stem is used, just as in Lynx and a number of other designs. Steer easily with small angles of helm, but owing to the rush of water, these angles of helm will need holding firmly so a minimum linkage of ratio 23:1 will be essential. This should be kept in mind when selecting a steering gear. Owing to her easy lines, Windflower should be a nice boat to plank, I have allowed generously for the hull, etc., in her Table of Weights. The lead keel is arranged to cast somewhat overweight to allow for trimming up, and adjustment of fore-and-aft balance. I have also provided a small amount of Trimming Ballast. All these things make the builder’s task easier. As the dimensions on the plans reproduced may be difficult to read on account of the scale, I repeat them here, and also give the yacht’s Rating Particulars. DIMENSIONS L.O.A. 78.4 in. L.W.L. Beam Max. Beam Draught Displacement Sail Area 142 in. 142 in. 124 in. 57: Ib. 1,479 sq. in. L.W.L. 56.0 in. RATING PARTICULARS Q.B. Penalty Lfor Formula 4 — 39.37 94 0.35 in. 56.35 in. Displacement Penalty 0.04 in. 3/D for Formula 11.52 in. RATING 56.35+ 38.5 56.35 « 38.5 12 11.52
