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{ o co = Le 0) N oO THREE SHILLINGS . & CANADA U.S.A SEVENTY CENT S HOBBY MAGAZINE MODEL BOATS PERHAPS the introduction to this little model can best be made in the form of a brief anecdote. When it was built, it brought to four the number of yachts built by keepers at Puysegur Point Lighthouse, on the South Island of New Zealand, and it was felt that it would be a good thing to stage a race. With no experience of model yacht racing, it was decided to make a no-holds-barred trip from point A to point B – 24 miles across Preservation Inlet, in a 25 knot north-westerly breeze. One boat sank and was lost, one, a catamaran, was dismasted, and two finished, this one, Shearwater, 10 mins. 43 sec. ahead of the other, which was a nice model built by an ex-professional boat-builder. In several races following this, the little sloop has walked away from other boats, and since it is simple to build, it was felt that other modellers might be interested in constructing one for pleasure sailing. The building procedure is a little unorthodox for a yacht in that the first item is the deck. Trace this on to % in. balsa ( a 4 in. and a 3 in. sheet butted together), cut out, then mark and glue in place the ply patches shown. Mark and cut out the } in. sheet frames and the pine bow and stern pieces (spruce or obeche could be used for these). The mast, beam, and rudder can be cut at the same time and pine is really preferable for these if it can be obtained. Pin the deck down, upside down, with packing A 332 MASTHESD __ a beneath it to give the correct sheer curve. Cement and pin all frames in position, then cut the keel from + in. ply and glue and screw the joints. When dry fit into frame notches and glue thoroughly, and again leave to dry thoroughly. Remove the assembly from the plan and fit the + in. dowel rudder bush and the bracket and nut for the hatch retaining bolt. Fit all stringers in the frames and sand all planking. The original model a smooth shape for was planked with 1/16 in. balsa, which after undercoating and painting was quite adequate in strength, but no doubt 3/32 in. or even % in. sheet could be used if preferred. The cabin and hatch cover are made from + in. sheet, the celluloid windows being cemented in after painting. Fix all rigging eyes, mast step, tiller plate, etc. in place, then paint the fin only, ready to fit the lead ballast. Make the keel torpedo by casting it in a preheated length of } in. copper tube. After cooling, tear off the copper in a spiral, a method used by electricians in removing copper sheathing, and easier than it sounds. Shape the torpedo, drill and countersink. Fit the lead sheet either side of the fin, then screw the torpedo at the base. The whole model can now be undercoated and painted. If preferred, the balsa planking can first be covered with tissue or thin nylon, and the usual undercoating and rubbing down carried out before finish coating. SLOOP SHEARWATER designed by Wemesseh, Opytight : _ MM 1057 —o DRESSHOOKS The Model Maker Plans Service IS over to provide Bridge Street. Heme! Hempstead. STITCHED TO SAILS “ SSS SOLDERED HERE THREADING e 1/16″ BRASS PLATE DIAGRAM i 1} DRILLED WITH |5/32″ DRILL |i es << | i BRASS WASHER CUT FROM SHEET ORILL & DOWEL GLUE IN (F7) TO TAKE LEAD AT — 6) PINS e PLACE “7 = = UPL. ; SOLDER PINS IN PLACE a =a ; = See oe a t or “- ad os Se al 2) ~ oe a JOINTS AND p DERED ON KEEL SHAPE 7 TOTAL LEAD WEIGHT 418. CORNER DOUBLE THICKNESS MATERIAL EYELET FITTED TRANSOM END VIEW = TE TWLER PLATE FROM GAUGE BRASS PLATE THIN ae ee SCREWES GLUED V8" LEAD SHEATHING SEAMS TORPE! KEEL WITH = zm SECTIONAL VIEW OF THIS Sail PIANO | | ‘= — TO GWED 8 BOM Boarps iat —— { To f- pat) | aie TH CORNER 80mm THIN GAUGE pm 100KS. —F2 BE CS THIN GAUGE PIANO WIRE nr con TT == PLY STITCHED |B ——— NYLON 6 of = Her esc ete Pal gn d 1/8" PLY. APRIL 1970 SHEARWATER A simple-to-build 313 in. semi-scale sloop which sails extremely well. Would no doubt take light radio gear. Designed by a New Zealand lighthouse-keeper, W. P. RUSSELL Full-size copies MM1057, Service, of the plan below are available reference price 8/- including post, from Model Maker Plans 13-35 Bridge Street, Hemel Hempstead, Herts. MEASURING SHIPS (continued from page 159) When L.B.P.’s is used the breadth and depth are given as Moulded Breadth, which is the widest breadth be- tween strakes or plates, and Moulded Depth, which is measured from the underside of the deck to the top of the keel. Here are the particulars of H.M.S. Bulldog, built MATERIALS _ LIST. MED SHEET BALSA SQUEEZE -¢ AFTER HOOK CLOSED INSERTING SSS fess BOOM WITH PLIERS}; EYE ea Se Sr CLOTH -5/8"SO.x2-7"P ae PLY 8-1/8" DIA. BRASS vex 6x6 20FT. BOLB. FILAMENT FROM PIANO IN WRE ALL PLACE RIGGING SOLDERED (MAST | -3/e"x(3/4"43" © (TRANSOM Ve" 2 14/2" 3.1/2" PINE (RUDDER cf 1=16"x 2"4 3" & SOLOER |-30"SO LIGHTWEIGHT TERYLENE | 1-1/2" SO. 20" PINE (BOOM) 4"x | 1-1/4" « 8.1/2"2 15" HANDLE | . 6x4 8 B.S 7-DRESS 9” NYLON FISHING LINE MONO- SCRAPS 225WG. iS EYES WIRE HOOKS (FOR SAIL THINWALL 3/4"0D COPPER OF THE PIANO BRASS TUBE FORLOWING:- WIRE, BRASS SHEET, WIRE TO BRASS SHEET. recently. Length between perpendiculars Moulded breadth ab) ni Moulded depth Draught “ 168 ft. 6 in. 37 ft. 6 in. 19 ft. 9 in. 11 ft. 6 in. The marking of the safe loading level on a ship’s sides became compulsory by Act of Parliament in 1876. The line is marked by a Lloyd’s agent, and it is called the Plimsoll Line, named after the member who introduced the Bill. The line alters according to the prevailing density and provision is made for this by a series of lines to which the ship can be loaded for various densities. See Fig. 4. I conclude this short article, which may clear some doubtful points for those interested, with a diagram (5) which indicates very accurately a waterline. Racing yachts generally display it on their topsides amidships, because the length of the waterline is fixed for certain classes; it is exceedingly accurate and also indicates if the yacht has a list either to port or starboard. Ship measurement is an extensive subject and the measurements are made by ship surveyors and H.M. Customs; now, no fortunes are made by overloading, for the Plimsoll Line makes this too obvious and the penalties are severe. I can only think of one attempt at legitimate evasion which I know of, and_ this occurred in this century when turret ships were built; they were ugly and soon dropped. Fig. 6. Turret steamers were cargo tramps evolved by Doxford’s shipyard at Sunderland to avoid a portion of the Suez Canal dues which were on deck area. The cross section I have drawn clearly shows how this area was considerably less than that of normal types. This advantage was soon nullified by altering the method of fixing the dues on net tonnage only, and this sealed the doom of turrets. No replacements were built when their normal lives ended. When com- ” BOW. END VIEW MMIO57 pletely loaded with a bulk cargo such as wheat, turrets became very ‘tender’ and some of them overturned completely. Hatches in the deck were very narrow and in harbour decks were nearly impassable. APRIL 1970 p.s.i. Readers Write... A wallet of chrome-vanadium spanners in the small of letters offering something new or interesting to say. M.Y.A. AND R/C Dear Sir, _ | refer to your correspondent N. D. Hatfield's comments on the M.Y.A. image, and as he has referred to me | feel | should reply at least to get the facts straight. He tells us of all the good things the M.Y.A. have done for R/C yachting; may | remind him that the sailing rules were compiled and _ issued by R. Skeates of London R/C Models Society and C. Brazier of Gosport M.Y.C., some two years before the M.Y.A. asked for them. (Incidentally, these rules are now badly out of date and need revision.) The recognition of the ‘R’ class was a mistake from the beginning and had the MYA had any knowledge of the subject they would not have considered the adoption of this class. The M.Y.A. proudly announces it stages the ‘Q’ class chamionship; it does nothing of the kind. This event is staged by the Y.M.6, Gosport, and Poole clubs in rotation. | will cite two instances of the M.Y.A. efforts in this hg connection. that it Devon, should in July, be insisted and held as in one there adamant. The result was no was a 100 per cent boycott of the event that year. When our local club organised the event we asked the M.Y.A. for an official to act as Officer of the Day. They nominated an _ individual, and when he was contacted it was the first he had heard of it, and anyway he was to be on holiday at the time. Since Mr. Hatfield is so proud of the M.Y.A. efforts, perhaps he will tell me and other interested readers of Model Boats when he or any other M.Y.A. official last attended one of these events, and what the M.Y.A. has done for us in the past five years. Highcliffe on Sea. C. Robert Jeffries IT’S RACING Sir, As an elderly, but still a novice, skipper, may | reply to some of the charges levelled by various denigrators at 1, the M.Y.A.; 2, Yacht Classes and Radio Control; 3, Secrecy and the ‘PotHunters’. 1. The M.Y.A. exists to further the sport of Model Yacht Racing. To sizes is sent to writers to go unchallenged. The top skippers become Top by careful and systematic thinking and plenty of practice sailing. They all sail to win, just the same as | do, and are not going to give away the results of years of patience, acquired skill, and sailing knowledge to any ‘Tom, Dick or Harry’. However, if our friend from ‘Brum’ will give his club assistance at the regattas, and act as mate to a top skipper, he will learn how it is done. During the 1969 season, | inspected the boats and talked to most of the top skippers. At all times, | met with cea and good humour, even when the skippers were under the strain of championship racing. | would like to thank all those who have helped me, namely the members of Fleetwood M.Y. & P.B.C., Kai Ipsen, Fred Shepherd, Chris Dicks, Ken, Wally, and Colin Jones, Bill Poole, and that paragon of model yachting, Roger Stollery. Hoping to see and sail against most of you in 1970, who knows, | might even give one or two a fright! Altrincham. George Burgess year Paignton, local participation, knowledge, or facilities, together with the impossibility of travelling to that venue at the peak of the holiday period, they were advised by all likely competitors of this, but remained B.A. that end, the M.Y.A. controls the sport by means of regulations approved by, and intended to further the aims of, associated member clubs, i.e. to provide a sufficient number of class permits and suitable rules to satisfy the majority. If anyone wishes to have an extra class recognised then the way to do so is to ensure that a sufficient number of working models exist to warrant recognition by the M.Y.A . Mr. Jeffries, and others, wish to establish a R/C Class either within or without the authority of the M.Y.A. | suggest that the ‘Marblehead’, a recognised class, fits all the necessary requirements of a R/C boat, if modern lightweight R/C equipment is used. To gain recognition for such a class all that the M.Y.A, require is proof that enough boats exist to justify the issue of a permit. . As a novice | cannot allow the charges of secrecy by the ‘Pot-Hunters’ ON OUTCLASSING Dear Sir, Your comment in the March Tideway on rapid outclassing in model yachting is exaggerated. There was a danger 2 or 3 years ago that the 10 rater would develop very rapidly because of loopholes exposed in the rule.- However, the MYA fully realised this tendency and went to considerable lengths to modify the rule, so that rapid outclassing would not occur. The M class has improved its performance most in the last decade, but all this improvement has taken place quite naturally without the rules being read any differently to 10 years ago. The crucial factor contributing to the performance change was the introduction of the bulb keel to the class. Lots of skippers realised the logic behind this idea and the interest created by this new feature has stimulated the sport a great deal. While admittedly the older boats were outclassed by its introduction, this did take place over a period of 4 or 5 years. Instead of giving up, most skippers have welcomed this change and have reacted in a most keen way as illustrated in the previous mentioned race. The future is unlikely to show the same change because the bulb keel has such a fundamental effect on a boat's performance that any further such drastic development is_ difficult to foresee. Woking. Roger Stollery. STEAM TROUBLES Dear Sir, | am sorry to hear of Mr. George's trouble with his ‘Lion’ but the information he gives is not really sufficient to enable one to help very much. However, One can clear a few points up. First, Methylated Spirit. This can be, and has been, used successfully for small (up to thirty-six inch) boats of modest performance but for a boat of this size and power it is quite out. You cannot ‘force’ a meths flame. It is clear from what Mr. George says that with steam at sixty p.s.i. his engine will do the job he wants. But he can only keep up a pressure of thirty 169 Either his boiler is not supplying the steam or his engine is wasting it. It is practically impossible to test his engine at valves or this range but there is one thing | can suggest. If he turns steam on to the engine and runs it, under load, dead slow, how does the exhaust sound? Does it come out in four equally spaced lumps—Chunt, Chunt, Chunt, Chunt, or is there a steady background hiss of escaping steam? A good engine should have four exhaust beats quite even and distinct —if they are not the valve setting requires adjustment. Also, in between the exhaust beats there should be no escape of steam whatever; if there is, either the slide the pistons are badly fitted. Either of these faults will waste a lot of steam, but unfortunately so will other things which cannot be detected except by expert examination. A properly desianed single flue launch boiler of the right size and with the right burner will produce enough steam to keep a Stuart Double Ten running at sixty p.s.i. Unfortunately, Mr. George does not give the size of his boiler, nor the layout, nor do we know whether the boiler is fed by a pump or carries the water supply for the whole trip — without details it is hard to advise, but this can be said. First, a boat in water tends to be cold. The boiler, and particularly the steam pipes should be lagged so as to prevent them acting as hot water radiators and to make sure that as little heat as possible is wasted. Secondly, Mr. George should make sure that the heat from the burner is getting to the right place. It is only too easy to put all the heat into the uptakes or out of leave the the top of the funnel and boiler itself comparatively London, is cold. Thirdly, and perhaps most important, is Mr. George superheating his steam? lf he is taking it direct from the top of the boiler to the engine then when it gets there it will not be steam but a hot water emulsion and it will have lost most of its kick. He ought to lead the steam pipe into the flue and seuss the actual blowlamp flame if he really wants to get the power out of it. Finally, with regard to three drum boilers these, in model sizes, suffer badly from scale effects. Whereas in a full-size job the height of the tubes is measured in feet, in the model it comes out in fractions of an inch and the pressure to circulate the water drops accordingly. In consequence, you do not get the brisk circulation of the prototype and, while the advantage of large heating area to volume continues there is a tendency for the steam to come, not in a steady flow but in gulps from each tube, this leads to serious priming troubles. | am sorry not to be more helpful. However, there are, as we know, a number of active Model Engineering Societies in South Africa, and | am sure that, if Mr. George could arrange to visit them sometime, though | appreciate the distances that may be involved, he would get an on-the-spot diagnosis there. T. W. Pinnock M.E. SPEEDBOAT COMPETITION Dear Sir, The Model Engineer Speed Boat Competition started in 1902 and served a very useful role in creating interest in speed boats and the records attained. It should be remembered that speed events were few and far between prior to the nineteen thirties, and also that travelling to distant regattas was more difficult. (Continued opposite)
