Marine Models: Volume 7, Number 8 – November 1934

\ se Vi N\j Vol. VII, No. 8 Published on the Seventh of each Month November, 1934 EDITORIAL E are now settling down in our new home in Fetter Lane. At the time we produced our October number we were in the throes of moving, and, as readers will have noticed, also altered our outer jacket, type and general lay-out. We have also formulated plans for the development and improvement of our Magazine, but naturally are unable to do everya-thing at once. This month further innov tions are being made. We have now launcheds our Bonus Subscription Scheme, and reader interested are invited to write for particulars. In the present issue will be found particulars of our Monthly Photographic Competition. We have other schemes, which will be announced in due course, but readers can rest assured that nothing will be left undone to increase the attractiveness of this Magazine. An increase in size is also under contemplation, but must be governed by our circulation figures. As already announced, we are making great efforts to develop organised marine modelling by giving even more attention to the clubs us and societies that cater for the vario branches. At the same time we are not for- getting our duty to the designer, constructor and builder. We have a number of attrac we which end, this to view tive schemes in hope to announce shortly. Owing to our change in make-up we were obliged to go to press last month rather earlier than usual, and, in consequence, several items of club news, etc., were unavoidably held over until this month. In future, however, we shall adhere strictly to our advertised closing date for news, correspondence, and articles. | Everything must, therefore, be in our hands by the 16th of the previous month. In the past, by obliging correspondents and taking late matter, we have frequently made our Magazine late, but we now intend to keep rigidly to our publishing date of the seventh The co-operation of all of each month. club secretaries and contributors is invited accordingly. Ship modellers will be interested to hear that Mr. G. W. Munro has almost completed his set of drawings of the brig ‘ Daring.” These contain very full details which will enable the modeller to make a most accurate model of this celebrated vessel. The price of blue prints of the “ Daring” has not yet been fixed, but we hope they will be on sale early in December. Too many plans sold to ship modellers are woefully inaccurate, and therefore good plans are of great value. Every ship modeller should add Mr. Munro’s to his collection. 202 MARINE MODELS SIMILARITY AND WEIGHTS By C, O. LILJGREN, N.A. In this article the writer, a celebrated American naval architect, sets forward his views on the difference between the model and the full-scale yacht and the allowances which must be made in applying lessons from models to the full-sized vessel. HE use of models to foretell the behaviour of any full-sized body is based on the laws of Similarity, as first stated by the great Newton, and later, specially for ships, by Froude—although both were mistaken in some important points. In any structure, however, similarity requires that like materials are stressed in like manners, i.e., so many lbs. per sq. ft. If stressed less, larger weights and costs are unnecessarily incurred in the structure, and similarity disappears. If stressed more, breakage may occur in that structure. In ship and yacht work, similarity means that forces are proportional to displacements, or S*, if S denotes the scale. Moments are thus varying as S*.S or as S*, and from these data weights for similarity must be computed. Weights are estimated from the specific gravity of the materials, from their sectional areas and from their lengths. Let us take a simple example of tensional Other things stress—a shroud or a stay. being equal, its strength is proportional to its sectional area. If the forces that produce tension vary as the displacements in lbs., and the stress per sq. in. remains constant, it follows that the sectional area must vary Now the as the displacement or as S*. weight is proportional to area times length, hence as S*.S or as S*, or exactly as the moments, and this refers to the moment of stability as well, and all stresses in hull and rigging resulting therefrom. Hence, if the moment of stability were proportional to S*, then for exact similarity all hull and rigging weights must also be proportional to S‘, and consequently ballast weights must vary much less than S* or the displacements. In other words, unless the stresses and the weight of the rigging, etc., in the smaller yacht or model are very much less than those in the larger yacht, moments of stability can never vary as S‘. In this case, although there might be similarity between the towed model and the towed yacht, as regards resistance for instance, there can never be entire similarity between the sailed model and the sailed yacht—and the latter similarity is just what we want above everything else. All these facts are irrefutable, no matter what the textbook authors and_ professors all over the world might say. What has been said so far about shrouds or stays applies equally well to spars and masts, to frames and planking, in fact to every structural member, whether subject to tension, compression, or bending. Anyone familiar with strength of materials can make the computation by obtaining the requisite sectional area and multiply by the length of the member. But owing to misconception of the “experts,” all scantlings tables, whether for yachts or cargo ships, permit all weights to vary as S® or displacements, with a single exception. Since actually moments of stability vary more than S*, larger yachts are stressed much more than smaller ones, resulting in much greater breakage in the former. And the “experts” wonder, but never try a cure. The writer made an investigation of the masts allowed by the International Rule, and found that the mast of a 14.5-metre yacht is 70 per cent. too weak compared with a 6-metre yacht’s mast. Of course the rigging would be just as weak but for the introduction of costly metals and airplane wires, etc. The case is still worse in the largest class of racing yachts, and explains fully why these vessels blithely stay at their moorings whenever there is a fairly strong breeze. How different from the old days when no “experts” tried to meddle with the scantlings. Well the writer remembers the famous race at Cowes in August, 1894 (40 years ago, or was it 400?), when all the big racing yachts, “Britannia,” ‘* Satanita,” ** Valkyrie and others, carried full sails in a tremendous gale, and gybed just opposite the Royal Yacht Squadron, all standing. What a sight for sore eyes, spray flying sky-high as the mainbooms struck the water, MARINE 203 MODELS and not a yarn snapped! Try to imagine ; the modern large class in such a blow The single exception in scantling tables mentioned above refers to the American Universal Rule, where part of the hull scantlings actually must vary faster than S* or displacements, but by far not fast enough to make a big yacht as strong as a small one. Even so, this was, of course, pure accident and nothing else, but a lucky accident for the owners of the biggest yachts. Yet their hulls must be built of costly metals to keep the weights low with the requisite strength. Ignorance of the law excuses no one, and this includes the laws of strength and weight for similitude. Yachts race in the same wind, producing the same pressure per sq. ft., and this fact is fundamental for weights. It all amounts to this—the moment of stability can never vary as S*, hence it is needless to make a large yacht as wide and as deep as a small one enlarged to scale. SCANDINAVIAN MODEL YACHTING R.N.L.I. HE Norsk Modellseilforening recently cele- T brated the thirtieth anniversary of its foun- dation by holding an international regatta. Fifty-four models from various parts of Norway and Sweden took part, and excellent sport resulted. The classes catered for were the 0.60-m., the 0.80-m., and l-m. Scandinavian, and the 1-m. International. The latter is the same as our 12-m. class. In the first series of races, Mr. Sam O. Berge, the well-known yacht designer, whose work is so familiar to readers of this Magazine, won the 0.60 event, with ‘* Prince Charming,’’ the 0.80 race, with ‘* Demona,’’ and the 1I-m. International, with ‘* Prince Charming II.’’ He was not competing in the l-m. Scandinavian. In the second series of races he was third in the 0.60, but repeated his success in 0.80 and 1-m. International classes. In the point sailing event Mr. Berge was successful in the 0.80 and 1-m. International classes. Seven firsts and one third out of nine starts is a very commendable record for one regatta, and Mr. Berge is to be highly congratulated thereon. It is interesting to observe that *‘ Prince Charming Il ’’ was built as an A-class model three years ago. Her lead keel, draught and sail area were cut to bring her into the l-m. International class rating. Sweden will have three A-class models next season, and it is hoped to arrange some races. One of these is Mr. Berge’s own ‘‘ Prince Charming II,”’ another an Australian-built model, from the lines of ** Mussolini,”’ with which Mr. Berge won our first Designing Competition. The third boat has been built at Kristianssand, from the lines of ‘* Mussolini,’’ slightly altered by her designer. It is not considered likely that many A-class boats will be built in Scandinavia, as they are more powerful than the 1-m. International (or 12-m.), which are considered really too big and heavy. Following these large models on open water, when there is any wind, is hard work in an ordinary skiff or rowing boat, and, therefore, kyaks have been brought into use. Practical yacht designers know this. Hence a sailed model and a sailed yacht, while both must be derived from the same parent design, must never have the same proportions for most accurate comparisons. Similarity is not possible in this case. A letter from Mr. C. O. Liljgren on this subject will also be found in our Correspondence columns. i HE Royal National Life-boat Institution has received an anonymous gift of £7,000. All it knows is that this gift comes from a lady in the West of Scotland. It is to be used to provide a new motor life-boat for the station at Broughty Ferry, Dundee, and at the donor’s wish, this boat is to be called ‘‘ Mona.’’ The boat is now being built, and should be ready to go to her station next spring. She is a cabin life-boat, of the Watson type, 45ft. 6in. by 12ft. 6in. On service, with crew and gear on board, she weighs She is divided into seven water-tight 20} tons. compartments, and is fitted with 142 air-cases. She has twin-screws, and is driven by two 40 h.p. engines. The engine-room is a water-tight compartment, and each engine is itself water-tight, so that it could continue running even if the engineroom were flooded. Her speed is 8} knots. She carries enough petrol to be able to travel 116 miles, at full speed, without refuelling. She carries a crew of eight, and, in rough weather, can take 95 people on board. She has a line-throwing gun, and an electric searchlight, and is lighted throughout with electricity. Broughty Ferry has had a life-boat station for 104 years, and since 1851 its life-boats have rescued 122 lives. The Watson type of motor life-boat was designed by Mr. J. R. Barnett, of Messrs. G, L. Watson & Co., Glasgow. We gave full plans and particulars of these boats in our issues of January, February and March, 1931, and a number of highly successful models were built from them. A few copies are still available at 2s. 7d. each, for January and February, and 2s. Id. for March. THE “ MONARCH OF BERMUDA” We recently received an enquiry from a reader who is building a model of this vessel from plans published in this Magazine, as to the type of davits fitted. These are gravity type davits made by the Maclachlan Automatic Boat-Davit Co., Ltd., 247. West George Street, Glasgow, C.2. MARINE MODELS SAVY ae) ree y oa a5 204 (Continued from page 182) HE engine in a prototype model does as the plant of a racing craft. It is, not always receive the same attention therefore, a great point in favour of an engine if it is built as far as possible of rustless materials. The engine on this sort of craft should not be run in the same way that a racing engine is. There is no need for it, as prototype models lose their attraction when run at speeds far in excess of their scale speed. Engines should run at much lower r.p.m. for this work, and everything can be sufficiently robust and well up to its job as the hulls have sufficient displacement to carry the weight required. Prototype craft, as a rule, have considerable top-hamper and weight in the bottom is useful ballast. Where circumstances entail the use of a small engine, running at high speed, it is usually advisable to use a reduction gear and a reasonable-sized propeller. If a small twobladed propeller is used on a heavy boat, cavitation must occur, and the result be entirely unsatisfactory from every point of. view. Boiler and engine should be carefully selected in relation to each other. In a prototype boat the objective is very different from, say, a racing hydroplane. In the latter the idea is to get as much steam as possible out of a lightweight boiler, and only short bursts of steaming have to be provided for. In a prototype model the object is to have a boiler that will keep a steady and sufficient supply of steam for a long period. This means a boiler with large water capacity. The method of firing the boiler must largely depend on the size and type of craft. Many model powerboat men are inclined to look down on a model fitted with a methylated spirit burning lamp. Yet for many small, well-fitted models this is far more satisfactory than a blowlamp. In a small model the nipple becomes so small that the blowlamp requires most careful attention. On the other hand, methylated lamps have the reputation of being difficult in windy weather. This, however, is a difficulty that can easily be overcome by correct ventilation. If a methylated spirit lamp is used it must be a reliable pattern. One useful tip in any sort of steam plant is to arrange that the fuel supply gives out before the boiler runs dry. Thus, if you have a boiler that will steam 30 minutes at one filling, the amount of fuel carried should be just sufficient for 20 minutes’ running, or thereabouts. A cheap little plant for light work in boats about 30in. up to 36in., according to type, is Stuart Turner’s Twin-Drum Minor Boiler and Meteor Engine. The total cost of this outfit, including pressure gauge and syphon, is £2 6s. 6d. The only thing not included is the propeller and shaft. For a rather larger boat the Stuart Star engine is very satisfactory. The size of boiler used with this engine will largely depend on the size of propeller, If a big propeller is used the r.p.m. will be kept down, and a smaller boiler can be employed. Messrs. Bassett Lowke have just brought out a very neat little boiler, designed by Mr. Victor Harrison. This boiler is very suitable for prototype boats with elaborate superstructure, and will run a Star engine nicely. Owing to its construction this boiler uses practically every bit of heat generated. The lamp used with this boiler is a methylated spirit one of an excellent type. There are two spirit containers; the lower one on the level of the burners is very small, but the MARINE main tank automatically keeps the spirit in the lower tank at a constant level and so ensures a steady flame. The main tank is very readily accessible for filling. The automatic feed eliminates any risk of a flare-up, which would be detrimental in an elaborately fitted craft. This outfit would be most suitable to run the launch “ Brunhilde,”’ of which plans were published in the September number of this Magazine, and should give her a speed of about 5 m.p.h. Two other boilers suitable to steam the Star engine are Stuart’s Twin-Drum Major and Bassett Lowke’s No. | centre flue launch boiler. The former can be used with either a Duplex spirit burner or a blowlamp. The latter uses a blowlamp. Messrs. Bond have two very useful centreflue boilers. The smaller one is 54in. long by 24in. diameter, has four Zin. cross tubes, and weighs llb. 80z. The larger is 7in. by 3in. diameter, has six cross tubes, and weighs 2lb. 70z. They also make a flash boiler, complete with casing, 12in. by 33in. This weighs 4lb. and is fitted with safety release valve. The Twin-Drum Major with a blowlamp should generate enough steam to run a Star engine satisfactorily in a boat 48in. long. The Bassett Lowke centre flue is a heavier type of boiler, and suitable for a heavy model. The G.F. twin-cylinder single acting engine, marketed by Messrs. Bassett Lowke, used in conjunction with the Bassett Lowke No. 1 centre flue boiler, is quite useful in boats of about 54in. The Stuart B.B., used with a Bassett Lowke No. 2 centre flue boiler, will drive a somewhat bigger boat. An alternative boiler is Stuart Turner’s Babcock Boiler No. 501. The Stuart No. 10, with either of the above boilers, will drive most boats of, say, 66in. length, and the Sun is a little more powerful again. For large battleship or liner models there are still more powerful engines up to a triple expansion engine. These can be bought either finished or as castings. As finished engines, these cost a good deal, and to make them up from the castings is by no means a beginner’s job. Many of these engines are rather fast running for slower types of prototype models, and will have to be geared down for satisfactory running. Many of these engines need care, as obviously the steel parts will MODELS 205 rust if neglected. The most important precaution is to flood the cylinder and crankcase with oil immediately after running. Another range of engines very suitable for prototype displacement boats is made by Whitney, of City Road. They are finely finished, and many parts are gunmetal. These are double-acting single-cylinder and twin of the following sizes: 4in. x 4in., 4in. x 3in., and #in. x fin. They have also a compound of Zin. and Zin. bore. This firm’s boilers are made to order. Reference was made above to more elaborate outfits, and some of the plants turned out by expert modellers are really beautiful pieces of work, and many of their builders started with boats driven by commercially produced plants of a very modest type. The type of plant will very much depend on the individual’s taste. Some men are concerned mainly with the external appearance of their models. Others concentrate on their engine rooms. The third type like to have a beautiful model with an equally fine plant. Paddle ships make very interesting and effective models, and a fine example is shown in the photograph reproduced, which is of the “Crested Eagle,” owned by Mr. W. Poole, Snr., of the Victoria M.S.C. I should hesitate to say who built her, as nearly all Mr. Poole’s family seem to have had a hand in the construction. Mr. Poole himself was responsible for the very complete deck fittings. The hull, engines and boilers were made by Mr. Poole, Jnr. Mrs. Poole helped with the handrails. A lady friend was responsible for the ship’s pennant, with her name. Mr. Morss made certain fittings, including the steering wheel, binnacle, engine-room telegraphs and the ship’s bell, engraved with her name. This bell actually rings. The real ship had a hemisphere as a badge on each paddlebox. On the model these are made from Royal Marines’ badges, picked out with the appropriate colours. The size of the model is 68in. overall, and Qin. beam. The paddles have each eight feathering floats. She is fitted with inclined engines, double-acting twin-cylinders, 3 x 14. She is fitted with eccentric valve gear. The boiler is approximately 5in. x 7in., with a 2in. centre-flue and six cross tubes. . Its capacity is approximately one quart, which gives about half-an-hour’s running. This is 206 MARINE fired by a Max Sievert blowlamp, of pre-war vintage. There is a simple single control used when the boat is running, which can be operated without removing any deckwork. There is a hand-pump to the boiler and a bilge ejector, The prototype is the well-known pleasuresteamer running from Tower Bridge to Clacton. Some years ago the prototype used to come above bridges, and her funnel lowered accordingly. The model was similarly fitted, but when the steamer changed her starting place to below bridges her funnel was fixed, and that on the model was altered also. The deck removes in sections and all the machinery is easily accessible. This is very well arranged as it does not show and also is watertight. The ventilation is also very skilfully carried out, being high on the centreline of the ship. Air is admitted through the chartroom and paybox and deckhouses. All the ports and windows—seventy-four in number—are properly glazed with real glass, and watertight. The skylights are also A FINE THE MODELS properly glazed. In the saloon are seats and a piano, while the floor is covered with lino- leum. Two Trotman anchors are carried with proper.anchor davits. Four lifeboats are carried in davits that will turn outboard. In fact, the entire deck detail is very complete. One ingenious detail is the provision of a float in case the model is accidentally sunk. This is made in the form of the small deckhouse aft which, in the prototype, is used for lifebelts. If the model is sunk the whole deckhouse floats off and acts as a wreck buoy, being made of wood with a line attached. The mast is made from the top joint of an old fishing rod. This model is the successor to a model of the “Golden Eagle.” I should have mentioned that the hull of this model is made of tin-plate. The builder got his plans and details by frequent visits to the ship and from photographs, and afloat this model gives an excellent impression of the prototype. (To be continued.) MODEL PADDLER “* CRESTED EAGLE” 207 MARINE MODELS PETROL ENGINE and HYDROPLANE TOPICS By J. B. INNOCENT (Continued from page 185) ELL, here is the drawing of the “Bean’s” carburettor. It is made entirely from bits of brass tube and rod, silver soldered together. There is nothing at all complicated in it, and the drawing shows the construction closely enough to make further comment unnecessary. There is, of course, no main venturi choke, its place being taken by the variable strangler. The primary choke size is a matter for experiment, but keep it small at first or starting may be difficult; it must not in any case exceed the area of the lower set of air-holes which feed it. The drawing shows a variable jet, but a fixed one can be used and, in fact, was used for a long time on the “ Bean.” The adjustment of mixture is made by variation of the strangler setting—the lever of the strangler should therefore run against a marked quadrant. thirty miles an hour in about twenty-five yards!—no wonder it is a ticklish business getting a boat away. At the time of writing these notes I have just returned from Paris. Well, the visit resulted in a defeat, for M. Suzor won both races, and put up a record for the 1,000 metres. We were not far behind, a matter of a 4-mile an hour in the fastest race yet run. The speed was not so great as our own record of thirty-eight, made at Farnborough, but the first three boats put up better speeds than our own International was won at. This regatta was, by the way, the first fast run we have had since our disastrous visit to Wickstead, when both “Betty” and “Crackers ” suffered severe internal derangement. “Crackers” was our second string in Paris, and a very useful second string it proved for so new a boat, its third place was — ‘“ OLD BEAN’S “’ CARBURETTOR (SEE ARTICLE) well within hitting distance of the winner. The choke arrangement may be made comIn the kilometre race “ Betty” showed her airplete by placing a choke above the main to the unusual conditions, and objection the of centre the up g bringin holes, and taking the line. We managed to up tipped is primary choke as in the sketch. If this and barrel off and back again head the get for used be only should r done the strangle was M. Suzor’s day out, and it but time, in d adjuste the mixture should be starting, and by varying the jet. Once more, don’t forget that the float chamber must be forward of the jet. If this is not done you will find that your motor dies as you let go. The reason is, of course, that the petrol is left behind owing to the acceleration of the boat. Incidentally, this acceleration is really terrific, just think zero to he won by some three seconds. It is really remarkable how he does it, for The only there is no competition at all. French boat going at all fast apart from Nickie V ” is “* Baby II,” which has “* Nickie IV’s” motor in it, so he plays a lone hand. He may find a bit of support in future though, for M. Perrigue’s boat got away with 208 MARINE a really useful turn of speed, but did not last, which was hardly surprising as the engine was only finished five days before the regatta. Apart from the racing our visit was a great success, for M. Suzor looked after us and showed that his knowledge of hospitality is comparable with his knowledge of twostrokes. He did, in fact, give us a really good time. To return once more, we must now con- sider the ignition equipment of the motor, and here we find many snags. The Bosch plugs did well for a long time, but even their latest green ring type is now being com- plained of, and something better is needed. K.L.G. designed a special plug for “ Betty,” the 783, and it is really good, but, of course, rather expensive, as the demand is too small for mass production. Probably the best way out of the difficulty is to turn down and re-thread a standard 14 mm. motor cycle plug, of the semi-racing type. This may necessitate a new side electrode and, if it does, make the electrode of nickel or German silver, The 12 mm. thread, by the way, is almost 20 pitch, and if you use this pitch you will find the plug will fit. Of course, if you are oiling up your plugs, you must attend to this before using a hotter plug, or the oiling up will be worse. The cure is to alter the piston by undercutting the ring and drilling oil return holes through the piston walls; this is, of course, taking it for granted that your rings really fit all round the cylinder. Next the coil, and more trouble. I do not know a commercial coil I really like, though most of them will do the job. In choosing a coil the length of spark is not the only point to watch; in fact, a 4in. is sufficient if obtained when operating the breaker by hand. Other considerations are that the H.T. terminal should be sleeved; the short circuit current must not be too high, and the coil must be impervious to water. Of course, the coil must be capable of giving enough sparks a minute, but as quite a poor one, checked up at 16,000, there should be no trouble from this source. ‘ Betty” runs on a coil made from half the secondary of a Ford T type coil, with a new primary of 200 turns of 24 S.W.G. wire, and a stalloy core, additional stalloy strips being placed between the secondary and the outer casing of paxolin The tube, to form a return iron circuit. secondary current on short circuit is under MODELS four amperes, and yet this coil will deliver twice as many sparks as we have any need of. Little need be said about condensers, for there is a really good one available in the Delco-Remy. Don’t use radio condensers, they are not good enough, and the other ignition condensers are not too clever, The last component is the contact breaker, and, here again, I do not advise you to make it yourself. Get a standard coil ignition breaker arm and mount it so that the spring gives the tension the makers intended, and then you do not need to worry about point bounce, as they are all designed for ‘over 12,000 r.p.m, on a single-cylinder four-stroke. No attempt should be made to make the breaker cam at all fierce, quite an easy action is all that is required. A fierce cam won’t give better sparks, but may break up the fibre pad it works against. When you wire up get rid of any scale ideas you may have, and use thick H.T. cable and decently heavy flex for the low tension side. If you don’t your sparks will wander off and your battery volts won’t get to the coil. The switch is best made with a blade going into a spring brass contact piece; this piece must be formed so that the blade once in is held there by the spring closing down. It is worth taking’ a bit of trouble with this component as they cause an endless amount of annoyance at most regattas, by either switching themselves off, refusing to. switch on properly, or by breaking. At the same time there is no point in using ebonite as insulation, as there is only four volts to insulate, and wood, varnished or painted, is quite good enough. When fitting the switch, remember that you must be able to knock it off whilst the boat is travelling fast, and preferably without hitting the exhaust pipe, or knocking the engine about. Now we must have a really reliable source of current and the only practical one is an accumulator. Dry batteries are too unreliable at the discharge rate required, and a high or low tension magneto absorbs power which is best put into the prop, All the available accumulators are disgustingly dear for their size, when compared with those used for wireless, but I am afraid we must put up with this. I have myself had experience of the “ Ever Ready ” and the Gamage “ Acorn” accumu, MARINE lators, and am quite satisfied with both; the Gamage put up with an amazing amount of misuse through motors stopping on contact with seven amps. running. MODELS 209 WITH THE ue. BOAT The troubles people have with accumulators are invariably due to bad charging, weak acid and excessive sediment. If you can, it is far better to charge your own batteries, and check the acid strength with an hydro- meter, putting in new acid if the old won’t come up to strength after a prolonged charge. The sediment must be washed out occasionally,. and, per accel thisis difficult with the “ Every Ready ”’ as “ Exide” type separa- tors are used, which ie little space to shake the sediment through. Jelly acid cells work quite well so long as water (distilled, of course) is put on the acid before charging. If the jelly once dries out and becomes hard, it won’t soften properly again. When you buy acid get it from a charging station, if possible, and at the full strength given on the battery label; if none is given, use 1-220 sp. grav. HEATON AND DISTRICT MODEL POWER BOAT CLUB This Club finished its competition season on Saturday, September 22, with a steering event, which was won by the motor boat*‘ Betty.’’ There are six competitions during the season, five of these being for steering, and one nomination. The highest possible points for each is sixty, and the leading score in five of them was 55, and in the other 50 points. In one of the steering events three boats scored 55 points, so that six boats scored this number once, and one boat twice. We think that this shows a very high level of performance when it is remembered that the boat has now to travel 90 yards before reaching the target. The divisions of the target being each 2 yards wide. The Watson Challenge Cup and the Gold Medal for the boat with the highest aggregate of points was won by Mr. J. Humpish’s steamer ‘* Emily,” FINEST SOFT PINE petition was won by Mr. Wallace’s motor boat ** Mary.’’ Mr. Hopper’s steamer ‘* Florence ’’ was second, and Mr. Wallace’s motor boat ‘* Helen “’ Model Boat Building. third. from The lake has been in very bad condition during most of the season, owing to weeds and fallen leaves, which has caused the withdrawal of two or three of the fast, open boats. The shower of water which pours over these boats when they pick up weed or leaves on the bow, puts them out 4” to 3”, widths up to 24” ALSO Prime Honduras of action by drowning the lamp in a steamer or Mahogany shorting the sparking plug in a motor boat. Let us hope that next season the powers that be will see fit to do something to kill the weeds and, if that is done, it will be easy to put the competitions further forward, so as to miss the falling CHETHAM TIMBER Co. Ltd., “at 70, FINSBURY PAVEMENT, LONDON Mr. W. The Smeaton Memorial Cup for the Speed Com- Specially selected for All thicknesses with 290 points out of 360° possible. Hepplewhite’s motor boat ‘‘ Betty ’’ was second with 240 points, and Mr. Hopper’s steamers ‘‘Irene’’ and ‘‘ Florence’’ tied for third place, with 195 points each. E.¢.2 METROPOLITAN 7418 leaves. It would the various tell us the target used be of great interest to the members of clubs in this district if the Editor could usual length of course and width of for steering competitions in the South. For J. HUMPISH, JNR., Hon. Sec., J. W. [We invite Hon. Secretaries of Model Power Boat Clubs to reply to the query contained in the last paragraph of the above report.—EpiToR, M.M.] ge 210 MARINE HOW TO MAKE — MODELS MODEL SHIP AND STEAMER FITTINGS (Continued from page 191) By A. P. ISARD, A.M.I.Mech.E. T the conclusion of my last article I had just started to describe the construction of goose necks, and the reader is referred to the drawings on page 189. There are several varieties. Some are made in two halves and _ bolted..-:agether round the mast, but, if fitted with a socket, this socket is usually part of the end of one half; others are made in one piece and split at one side, as illustrated in Fig. 65, with a bolt for tightening up when in position round the mast. The writer would make this fitting by cutting, drilling and filing from the solid. The belaying pins would, of course, be separate, removable fittings, and present no difficulty. It should be noticed that the gooseneck is a form of universal joint, as it allows a horizontal radial movement together with a vertical movement. Chuck in the lathe a piece of round brass rod with a diameter large enough to include the belaying pin sockets, turn down to this diameter, centre and drill out to the required inside diameter, and part off to the desired width. Saw, cut and file away, forming the six projecting lugs roughly, four for the belaying pin sockets, one for the joint, and the last for the gooseneck socket. Mark out and drill holes for the belaying pins, drill hole for gooseneck pin. Finish by filing to size all round, using these holes as your guides. Drill hole at right angles for bolt through the clip lugs and carefully split these by sawing with the hacksaw. The clearance made by the saw-cut will be sufficient to clip your band quite tight round the mast, provided that you have worked correctly up to this point. The fittings should be finished off by polishing, like the others. Alternatively, the belaying pin sockets may be made separately in the form of clips, and pinned and soldered into position. It must be here stated that the boom or whatnot is fitted to the universal spike; to make this spike, either turn up in the lathe or file to shape, the fork being filed afterwards. Using the spike as a centre guide, drill hole for pin. The gooseneck pin can be turned and its lug filed up to suit the spike fork, into which it should just fit nicely. These fittings can be used for the cargolifting jibs on merchantmen as well as for boom and spar fittings on sailing craft. When these bands are plain and fitted with belaying pins they are termed spider bands, but when fitted with hinges or sockets for boom fittings they are named goosenecks and mast bands. Belaying pins, Fig. 66, are easily turned up in the lathe to the shape. Two different kinds are shown. They should be slightly tapered to fit comfortably in their sockets. Racks of belaying pins are also fitted inboard of the bulwarks under the shrouds or other convenient places. These pins are all interchangeable. Sheet horses (Fig. 67) for main sheet or jib sheet use. Two shapes are shown in the sketch, with the method of fixing to the deck. They are easily made from brass wire and bent to shape. The ends should be screwed far enough to allow for a tapped ring being run on to form a_ shoulder against which the nut on the underside of the deck will pull. Always insert a thin washer between the underside of the deck and nut, otherwise the nut will work loose and sink into the wood and so loosen the – horse. Fig. 68 illustrates travellers for either masts or bowsprits. They consist of merely a ring to which is attached an eye-hook and a link the shape of which is similar to an harp shackle. They may be bent from good brass wire. These travellers are hauled up or down the mast, or inboard or outboard, in the case of bowsprits, by means of suitable tackle. (To be continued.) MARINE MODELS 211 me an KeBy aN.2 Munro. (Continued — page 179) HE topsail yards are the next to be swayed up into position. A pair of large single blocks, about 15in. long, are stropped and hung at the topmast head, the strops going round the mast-head above the shrouds, etc., with the blocks hanging down at each side between the cross-trees. Stropped to the yard, there is another single block of similar size to the other two. This is called the tye-block and has its swallow looking along the yard instead of across, as it should do in the case of the jears on the lower yards. When the stropping is done, provision must be made for stropping two small blocks to its upper end. These small blocks are for the buntlines. The topsail tyes are wormed, parcelled and served in the usual way for three-quarters of their length in the middle and, after being reeved through the large blocks just mentioned, have a double block turned in at each end. The latter are called fly-blocks, and are for the halliards, which are set up with a lufftackle purchase at the channels, the single block being stropped to an eye-bolt there. The size of the halliard is about 3in. To keep the yard to the mast as it is being raised or lowered, parrals are fitted. They are made by taking two lengths of rope, each with a thimble turned in at one end. The end is made fast to the port side of the sling cleats on the yard, one rope hanging from the top of the yard and the other from the bottom. The free ends are reeved through a number of ribs and trucks, generally about five ribs and eight trucks going to complete the parral. A rib is made by taking a piece of wood in length the diameter of the yard and one-third this amount wide. The edge which goes up and down the mast is left straight and the outer corners are rounded off with a curve, the radius of which is the width of the rib. The middle of the outer edgeis hollowed with a reversed curve, so that the result is very like a wing-nut. A_ hole is « d through the flat, one at the top and one ‘at the bottom. Trucks are shaped like a large wooden bead, and the proportions are :—Diameter one-third the width of a rib, length one-third more than its own diameter. Starting on the port side of the mast, the parral rope is reeved through the top holein the first rib, through a truck, through the top hole of the second rib, and so on round the after-part of the mast, until the starboard cleats are reached, where it is hitched. The lower parral rope is worked the same way, but through the lower holesin the ribs. A pair of quarter blocks are stropped to the yard, just inside the cleats one either side of the tye-block. Just outside the cleats are a pair of clue-line blocks. All four blocks are about 10in. long, and are stropped similarly to those on the lower yards. At the yardarms, the eye-splice of the footrope is put on first, and the inner end hitched to the further sling cleat. The bightis supported along its length by three stirrups. | notice that I spelt “stirrup” with an ‘“e” last month, as was sometimes done in the old text-books. I wonder if this is the old form, or purely a parochial version of the unschooled practical shipbuilder. The brace-blocks are next to go on the yardarm. They may, or may not, have a short pendant. The lifts are stropped round the topgallant sheet block as was described for the topsail sheet block on the lower yard. Towards the outer end of the yardarm, a sheeveis fitted, with the swallow looking up and down. Thisis for the reef tackle, which is workedin the following manner: the end of the tackle is made fast to the reef-cringle on the leech of the sail. The upper end is 212 MARINE passed through the sheeve-hole just mentioned, and up to the upper sheeve in the sister block, set up in the shrouds, and from here. down to deck. There is one other fitting peculiar to the topsail yards. This is the flemish-horse, which is a short length of rope fastened at the one end to the outer part of the boom iron, and the other end brought in to the yard, about the length of the yardarm within the cleat. Another method is to eye-splice this end round the foot-rope. On the boom iron, beyond the flemishhorse, is a small block, called a jewel-block. This is used to hoist the stunsail into position. The bunt-lines and leech-lines lead up through the blocks on the yard, and from there to blocks under the trestle-trees, and then down to deck. The braces of the three topsail yards are rigged in the normal way, but I will go over the procedure in case the reader is not familiar with this. The fore topsail brace is hitched to the collar of the main topmast stay, and leads down to the brace-block, and then to a block some way up the main stay, then to a block onthe collar, about level with the trestle-trees, and then down to deck at the side. The main topsail brace is rigged the same as for the fore topsail. However, there is an alternative method to this. The standing end is hitched to the mizen stay at the mouse, and the other end, after reeving through the brace block, is led back to a block just below the mouse, on the mizen stay. The first method is the more sound mechanically, as it does not put a downward strain on the topsail yard when it is hoisted. The mizen topsail braces are rigged similar to the alternative method above, except that the end and the leading block are stropped to the end of the gaff instead of a stay. The leading block is a double one so that it takes the topgallant braces as well. The fore and main topsail braces are both made of 3in. rope, and the mizen is 24in. Before going on to the topgallant yards, perhaps I should describe the spritsail yard. This is exactly the same size and shape as the fore topsail yard. It has foot-ropes, stirrups, clue-line blocks, etc., like this yard. The lifts are rigged like those on a lower yard. The braces are hitched to the fore stay and then reeved through the brace block at the spritsail yardarm and then led back to the underside MODELS of the fore top, where there are two blocks, one at the fore end and one at the after end, so that the brace leads down to deck at the side abaft the shrouds. Equally spaced at about the length of the yardarm, in from the yardarm cleats, are two large thimbles. These are for the jib-boom guys. They are placed on top of the spritsail yard, and will be mentioned in their proper place. The spritsail yard is secured to the bowsprit just a little forward of the fore stay. To keep it in position, a saddle or pair of stops are nailed to the top of the bowsprit, and a collar or parral used. This is done by taking a length of rope, which has a thimble in each end and is wormed, parcelled and served all over. It is taken round the yard, within the cleats, and passed over the bowsprit, and the longer end passed round the yard, and the two ends seized together. Seizing is put on at each side to hold it to the yard. Topgallant yards are simpler than the topsail yards, but are rigged on the same principle. There is only one stirrup to each side. The brace blocks may, or may not, have short pendants. Lifts are fitted to the yardarms and led up to a single block stropped to the shrouds, and then down in the usual way. The clue-line blocks are stropped just without the sling cleats. A pair of buntline blocks are dispensed with, and a thimble takes their place. It is stropped to the tye-sling on the fore side. The buntline has a bridle from the foot of the sail to about half-way up the sail, where a thimble at the end of the buntline holds it in position and itself goes up through the thimble at the yard to a single block at the mast head. Within the sling cleats are three thimbles; the one to starboard has a short span, the one in the middle is close up to the yard, and the one to port has a long span. The two outer ones are passed round the back of the mast to form a parral, and the middle one is to take the tye, which is a single rope leading up the after side of the mast to a sheeve in the mast head, through and down the fore side to the yard, where it is made fast to the thimble with a midshipman’s hitch. The lower end is set up at the channels like a backstay, and on the opposite side to the topsail halliards. (To be continued.) MARINE MODELS 213 EWS! NG = = 0: OE —— = il 3 HE Quarterly Meeting of the Council was held on September 20, when the sad news of the death of Mr. A. E. Tucker, Secretary of Cardiff M.Y.C., was received in silence. He has been a strenuous worker for the Club for over 40 years, and was highly respected by all. Will correspondents please note that Mr. Pete Paterson, -of 85, Inverness Place, Roath Park, Cardiff, has taken up the duties of Secretary. The Minutes of previous meeting were read and confirmed, and included the election of a new Club —South-Western M.Y.C. (London). Fleetwood Regatta (British A-class Championship and the International) was the subject of a detailed report by the O.0.D., Mr. Wm. Carpenter, on behalf of the Regatta Committee. The actual racing has already been ably reported in these pages. The accounts, in spite of a slightly smaller balance of £55 10s. 7d., indicate a healthy position—when allowance is made for certain non-recurring expenditure. The above balance is made up of £27 ls. Ild., in hands of Mr. Carpenter, and £28 8s. 8d., in the hands of M.Y.A. Treasurer. At an informal gathering during the Regatta Mr. F. L. Pigeon; the American Challenger, referred to the fact that they had come here for 10 years for this Cup, but there was a growing feeling on the other side that, unless the European countries came into the scheme, the event had become AngloAmerican—and it might be in the interest of both sides and of the sport if this Regatta were staged alternately in Britain and America. This was merely a hint. On the other hand, a definite preparation is being made by yet another special fund expressly created for the purpose of fetching the Cup back —should such occasion arise. In connection with the Regatta Committee, the question was raised as to the complete omission of any reference to the M.Y.A. from the Committee’s letter paper—which tends to create the impression that the Committee is a completely separate body, instead of a Committee of the M.Y.A. Mr. Carpenter admitted that he had not seen it in that light, and would bear it in mind. The Council were unanimous in a hearty vote of thanks and appreciation to the Mayor of Fleetwood, to Mr. Carpenter, and to all who had assisted in bringing a big job to a successful issue. The Open Water Race was not carried out as provided, and therefore leaves the Cups and two prizes in the hands of Mr. Carpenter for 1935. A PROPOSED INTERMEDIATE CLASS.—A resolution by Mr. R. S. Momber was down for consideration, the purpose of which was the introduction of a new class somewhere between the 36in. L.O.A. and the 6-m. and 10-Rater—to suit those confined to smaller waters, and yet on a sound scientific rule, leaving eS : SS =o =: = scope for design and experiment, from 48in. to 50in. L.O.A. The Formula suggested is giving a boat : SF’ =Rating Blin.). 15 L+/s L is the average of L.W.L. inches is square root of S.A. LEYSR.U. and Q.B.L. in measured as per The whole was discussed at length, and a Technical Committee appointed to examine and report; and a questionnaire is being sent out to ascertain the probable support for such a class. This will reach all concerned in the near future, with full details for consideration and reply. Mr. H. B. TUCKER AND THE COUNCIL.—Circumstances have compelled the production of MARINE MODELS to be placed on a commercial basis, which involves the Editor, Mr. H. B. Tucker, being commercially and financially interested. The question for the Council was, whether Mr. H. B. Tucker could or should continue to take part in the government of the M.Y.A., and whether he should still act as proxy for another. The Council decided that the position of Mr. Tucker in the M.Y.A. shall remain in status quo till otherwise decided. A, L. TWO NEW CLUBS JOIN THE M.Y.A. The Mottingham M.Y.C. has just affiliated to the National Authority. The Club has a fleet of 6metres, 10-raters, 36in. and 30in. Restricted Class The membership is 27 Seniors and 7 models. Juniors, and sails at the University Lake, Highfields. The Hon. Secretary is Mr. A. E. Marrow. The other new Club is the Blackheath M.Y.C., which sails only the 36in. class, so far. There are nine members to date. ANOTHER MODEL FAR YACHT EAST CLUB IN THE We hear that a Model Yacht Club is likely to be formed in Rangoon, and hope to have full particulars in due course. The strong Calcutta M.Y.C. has been represented several times in the British Empire Championships (A-class). We hope that the new Rangoon Club may progress similarly. 214 MARINE MODELS YORKSHIRE i] NTIL recently the type of vessel known as the “ Keel’? was much used for cargo carrying on the Trent, Ouse, upper reaches of the Humber, and canals connecting with these waters. Gradually, however, these picturesque craft are becoming extinct, their place being taken by fussy motor barges, which can never have the same interest. Whilst the keel usually confined herself to her home waters, she occasionally made a dash along the coast to Bridlington or Boston Deeps. An old yarn, told by keelmen, is that one of their number once voyaged as far afield as London. The Port Authorities had never seen her like before, and were greatly puzzled how to classify her. The difficulty was eventually solved by entering her as a “‘ one-masted brig.” The keel is a strictly utilitarian craft, her dimensions and form being governed by the conditions under which she works. The dimensions are arranged to carry the maximum of cargo on a shallow draft, the length and beam being determined by the size of the locks on local canals, Consequently keels have flat bottoms, with slightly rounded bilges. There is a long, parallel middle body, and the bows are uncommonly bluff. Leeboards are used for working to windward, and, considering their form and rig, keels are remarkably close-winded. The rig of the keel is designed for easy working in their own environment, and these large vessels can easily be handled by a crew of two men, or a man and boy. Often the captain’s wife acts as mate. Early keels were very heavily built of oak, the bottoms being tarred, and the topsides bright varnished. Later, keels were built of iron. The keelman was invariably proud of his ship, and kept her very smart. He was fond of decoration, and all rails and timberheads were gaily painted in light colours. The stem is very stout and the stemhead is flush with the deck. On each bow are large oak knightheads, and five stout timberheads a-side, without bulwarks. The stern has six projecting timbers (threea-side) supporting a heavy oak rail, with short KEEL timberheads between each. The rail itself is unsupported across the stern, thus giving free play to the tiller. With the exception of narrow side decks (or “waterways ”’), the whole of the amidships space is occupied bya large hatch, with well – cambered hatch covers. In the model illustrated there are eighteen (nine-a-side) of these. When the covers are in place the whole is covered with a dressed tarpaulin cover, securely battened down with bars and wedges, There is a short foredeck on which is a large wooden windlass, of ancient type, to handle the anchor chains. This can be worked with handspikes through the ends, or, as is more usual, by a two-sided pump handle arrangement, worked by two men. It should be mentioned that below deck the vessel is divided into three compartments by transverse bulkheads situated forward and aft of the cargo hold, The fore end sometimes acocmmodated the crew of one, when the after compartment was given up to the captain and family. The most notable feature of the keel is the number of deck winches. These are known as “rollers” and practically everything aboard is handled by this means. In all there are nine steel winches, each having its separate purpose. All ropes, chains, etc., are wound round the barrels of these rollers, so that no coiling down is required. The mast roller is situated at the fore end of the hatch, and serves to raise and lower the mast. This is fitted with multiplying gear. It is about 3ft. 6in. long and 3in. diameter, and set 8in. to 12in. above the hatch end. It also serves to warp the vessel. The tack rollers are about 18in. to 2lin. long and 3in, diameter. These are also at the fore end of the hatch, under the mast rollers, but are set fore-and-aft at right angles to their work. The tacks are usually chain, but sometimes wire. The sheet rollers are set at the after end of the hatchway, and are used for winding in the sheets, which are either cotton or wire rope. They are about 2ft. 74in. long and 4in. diameter, and also set fore-and-aft. (To be continued.) Lines re-drawn from Humber Yawl Club’s Yearbook a | x 1835 Pe ‘ILA “10A SIZE. ] 603 8 “ON SHEFFIELD KEEL. OL INaWaTddNS ‘pIZ ased avy OF HUMBER Mainsaiw Torsaic Heap Foot 22’9″ 3q4’o” 22’9″ 263″ Leacnes 31’6″ J1’6″ peeru 23’6″ «tt’o” iN CENTRE (mo Sait Dimensions. SUPPLEMENT TO VoL. VII, No. 8. : “ JOYCE” 6-metres (14ins.=1 foot). Scale: one-sixth of full-size. ee “Se te Qe Ree PARTICULARS 56-85″ LOA ae =i : 38:0 ° Lwe Extreme Beam DRAFT DISPLACEMENT (Satur Warer) RATING 24° 5 css nae 8:8 Dech 4 FITTINGS Sais SPARS Ere: LEAD KEEL ToTaAL 2tss CREW WEIGHT Mas fe) le =