The Model Yachtsman: Volume 4, Number 3 – June 1931

/ il Editorial … Model Yachting Association News … nad aan eae News of the Little Ships Scottish Page i With the Power Boat Clubs A Model Square Rigger A-class Design … A Beautiful Ship Model Wooden Hulls for Model Power Boats GOLDEN HOUSE, GREAT LONDON, PULTENEY W.1. STREET, —” Correspondence June 1931 The Model ‘ BOND’S 1-Metre Speed Yachtsman. 4 Boat Model Yachting Association GOSPORT Hulls REGATTA, ‘ 193] British A-Class Championship (SELECTION RACES). July 27th—30th, inclusive. International Races Bond’s New 1-metre Single Step Hulls are made of thin 3-ply wood and are very light in weight, weighing only 4lozs. -The profile and step have been carefully designed for high speed work and are ideal for fitting with a petrol engine or flash steam plant. (Entrants: Belgium, France, U.S.A. and Britain). August Ist, 3rd and 4th. Length 39”. Beam 12”. Weight 4lozs. Price £3 10s. Od. Carriage extra. Entries Petrol Engines suitable for above £6 10s. Od. Flash Steam Boilers … *Sun”’ Engines… v =A .- £5 2 5s. Od. \ ROAD, LONDON, as many boats as desired at a fee of 5/- per boat up to C. N. Force, Hon. Secretary, N.W.1. Phone; MUSEUM 7137 A-class June 29th. Later entries can be received up to July 6th, at 15/- per boat. Entries for this event should be sent to the Racing Secretary for the A-class, Mr. J. G. FELTWELL, 90, Church Road, Barnes, a BONDS’ o’ Euston Road, Ltd. EUSTON British Any recognised Associated Club in Gt. Britain, the Dominions, Colonies and Protectorate can enter 5s. Od. Send for Bond’s Catalogue, which is the Standard Reference Book for the Model Enthusiast, 6d. post free. 254, for Championship. 151, Lichfield Grove, London, N.3. a AS “Model Yachting” f y The ONLY Paper Published in the UNITED STATES Ship Model Makers’ Club on Building, INTERNATIONAL Designing, Founded by and Capt. E. Armitage McCann Racing Model Yachts. With an Official Magazine THE SHIPMODELER Subscription Price: Beautifully Illustrated Two Dollars a year. Informative Interesting Annual Subscription including Magazine and Sample Copies Free Certificate, $2.75 (11/6). Full particulars free. Address: “MODEL YACHTING.” Ship Model Makers’ Club, MELROSE HIGHLANDS, MASS., 55a, Middagh Street, U.S.A. Brooklyn Heights, N.Y. y, \. In replying to Advertisers, please mention THE MODEL YACHTSMAN. THE – – aw A = — MAGAZINE FOR MODEL MARINE ENTHUSIASTS. JUNE, 1931. No. 3. OK kK Ok Ok Ok In the present number we publish the second of the series of articles on “Wooden Hulls for Model Power Boats” by Atlantic. There is very little difference in methods of construction of wooden hulls for power boats and sailing craft except in details such as the fitting of engine bearers in the former and lead keels in the latter. Ship modellers too will find the methods used identical with their own. Consequently this series should be of almost equal interest to all our readers. rig on a vessel that is intended for serious deep-sea work. We remind readers that our September number is a Special Number, price 9d. Besides the report of the Gosport Regatta, it will contain features of interest to all classes of readers. ae Ge Sees | OC GeEde! Ome oem Ue GES FEE For the benefit of prototype modellers we shall next month be publishing the lines of the staysail schooner “John Williams V,” together with an article upon her design and rig including certain alterations that it -was found neccesary to make before the vessel gave complete satisfaction to her captain. This vessel with slight modifications would make an excellent mode] for sailing besides being of interest as showing a modern staysail schooner SRR other fin-and-skeg. OF, difference to be that one was a keel boat and the es been different. In order to really settle this question what is wanted is a series of trials between two models with identical hulls and rig, the only TF x so far are of no value whatsoever as the hulls have Oe In our pages will be found record of both model yachtsmen and power boat men carrying on through abominable weather and it says much for their keeness and enthusiasm that such is the case. So perhaps this spell of bad weather has been a well disguised blessing in that it has really proved that enthusiastic model-men will undergo considerable discomfort in order to enjoy their favourite sport. A spirited letter published in our Correspondence Columns on the great Kee] Controversy justly points out that all the comparisons that have been drawn ee E had not intended to write an Editorial this month but as the racing reports were rather shorter than we expected at this time of year. And talking of the time of year April and May certainly served us most unkindly this year. We were lunching in a City restaurant the other day and by chance happened to overhear a conversation between two of the other customers. One of them told his friend that he always got his car cleaned on Fridays and that he had noted in his diary the weather each week-end since the start of the year. He added that it had rained practically every one of them. ‘ee OR EDITORIAL. Oe + Vol. 4. MONTHLY 7 The Model Yachtsman 38 HOVE & BRIGHTON 10-RATER REGATTA. The next event on the M.Y.A. Fixture Card is the Hove & Brighton 10-rater Regatta. The race is being held on the Lagoon in Hove Park on July 12, and starts at 11 a.m. It is open to three boats per club at an entrance fee of 2s. per boat, and entries can be received up to June 28. After building a fine lake for model yachting, the local Council has taken the retrogressive step of letting the lake out to rowing-boat proprietors for the greater part of the week, so that facilities for model yachting are by no means as good as they should be. In spite of this local enthusiasts have formed a strong club and built a fine fleet of 10-raters. It is, therefore, of great importance that other clubs in this Association should support this regatta in order to make a good showing. It is, therefore, to be hoped that entries will be received from all the London Clubs as well as the other South Coast Clubs. GOSPORT REGATTA. This important event, comprising the British A-class Championship and International Races is being held on July 27 to August 4. Entries for the British Championship at 5/- per boat can be received until June 29, and late entries up to The term July 6 at a fee of 15/- per boat. “* British Championship” is somewhat misleading, as it is really the Championship of the British Empire, and is open not only to yachts from clubs in Britain, but those from our Overseas Dominions, Colonies and Protectorates. Some misconception appears to have arisen with regard to the conditions of this race. The trophy for the International Races is the celebrated Yachting Monthly Cup. This cup is the property of the Model Yachting Associa on, to whom it has been presented by the proprietors of the magazine whose name it bears, but the races are not under M.Y.A. jurisdiction but under the jurisdiction of the International nr Ee a ee rs Model Yacht Racing Association. By the conditions of this cup, each country may enter one boat only for the International races. This includes Britain and the British Empire, which, like every other country, is allowed a single boat. The method by which each country selects its representative is, however, nothing to do with the I.M.Y.R.A., and it is left to each country to arrange this matter in its own way. The British method is to take the winner of the British A-class Championship as representative. As pointed out above, the M.Y.A. is sole arbiter of the methods of sailing the British Championship, June 1931 and it is held under M.Y.A. Rule and subject to the Deed of Gift of the Cup, and is accordingly open to any club associated to the M.Y.A. only. I am inclined to think that the misconception which has arisen on this score is a confusion between the Yachting Monthly Cup conditions and those of the British A-class Championship—in fact, I have received letters quoting an article about the new Yachting Monthly Cup (published in 1926) and citing this in connection with the British Championship Races. An additional event to those usually staged at the Gosport Regatta will be provided this year by the series of three Open Water Races. These are the outcome of a challenge from the States to meet them in a series of races in open water under American rules, and the M.Y.R.A. of North America is providing a Cup for the occasion. Two of these races will be over to windward and return, and the other one round a triangular course of half a mile a leg. The entrants for the International Races proper are U.S.A., France, Belgium, and the British Empire. For the Open Water Races the competitors will be U.S.A., Belgium, and ourselves. France will possibly also take part as a good deal of French model sailing is done on open water. GOSPORT REGATTA FUNDS. As is usual, it has been decided to raise a special fund to defray the cost of the Gosport Regatta and entertainment of our foreign visitors. These will be rather heavier than last year as it will be necessary to build special skiffs for the competitors in the open water races. Open water racing is not seriously practised in this country, and in fact is only indulged in where there are no facilities for pond sailing, so that no suitable skiffs are available. With their great experience in this kind of sailing, the American boat should start favourite, but at all events it will provide an interesting variant to pond sailing and give British model sailers a chance to see an exhibition of open water handling by expert American modelmen. The expenses of the Gosport Regatta have always been considerable, and it is therefore to be hoped that British modelmen will respond generously to the appeal for funds. Hon. Secretaries of model yacht clubs are asked to bring the matter to the notice of members either orally or by means of a notice upon the club notice board. Subscriptions to the above fund should be sent as soon as possible to the Hon. Treasurer of the M.Y.A., Mr. H. C. Whetstone, 142, Station Road, Hendon, N.W.4. 39 The Model Yachtsman. Jane 1931 me =—— —- SS —a mae4a WisOsay? Ah 4 Edited by A. C. DAVISON, A.M.I.C.E. LONDON JOTTINGS. improved, and it says much for the enthusiasm of the competitors that racing was considered possible at all. In previous years this annual M.Y.A. event has filled to the tune of a dozen boats, but this year, as only two clubs entered, the field was restricted to six as only three boats per club are permitted. The idea of this race was to gradually build up an event that was worthy of the class. It is, therefore, a Heavy and continuous rain with heavy squalls of wind kept everyone on the move. Scoring was fixed at 2 points for each board and seven rounds were completed. “ Albion” was leading at the end of the day, being 2 points ahead of “Twinkle ’’ with ‘“‘ Gleam ”’ and “‘ Charis ”’ a further great pity—particularly in view of the handsome prizes that have always been given, that such a miserable response should have been made by the clubs that are interested in the class. two points behind. The race was sailed on the Forest Gate water on May 2. The day was overcast, but there was a moderate to fresh breeze from north by east that gave a close reach one way anda free reach the other. Right from the start there were only two boats in the race, “‘ Fly” and “ Kismet.” Some competitors appreciated by everyone, after such a gruelling day. seemed to have difficulty in keeping on the course, whilst another boat, though always on the course, the westerly wind gave a dead beat and run. Tea was taken in the Clubhouse, and the warmth of the house, together with a good meal, was much Conditions generally had not improved much when racing was resumed on the following Sunday, the wind now, however, was almost due west, squally, and knocking up quite a fair amount of sea. The scoring was still carried on, as 2 and 2, though The lake was well filled, and, as it has now been was trimmed in such a way that the whole of her lengthened to 910 ft., there was ample opportunity mainsail was never really pulling hard. for the well-sailed yachts to show their advantage. The race was a fast sailed one, and the eventual! ** Albion ’’ continued to do well; ‘‘ Miss 8. Africa ”’ was well handled, and, worked up to second place, Ist, “Fly” (H. G. Howard, Forest Gate M.Y.C.), 18; 2nd, “ Kismet” (W. Kingsmill, F.G.M.Y.C.), 14; ‘‘ Brunette” (Dr. Grenville, Highgate M.Y.C.), 10; “‘ Meteor” (H. W. Apling, F.G.M.Y.C.), 8; “Kestrel” (F. T. Webster, thoroughly Webster, H. B. Tucker, who had the able assistance of Messrs. Piper, Hodges and Harrison as umpires, whilst Messrs. W. R. Johnson and J. E. Cooper filled the offices of starters and scorers. The poor entry was a great disappointment, and it is to be hoped that the race, if held next year, will produce a better response. H.B.T, M.Y. 6-m. O.A.—-THE SERPENTINE SPRING CUP. The number of entries received for this race held on April 19 and 26, were very gratifying to the Y.M. 6-metres Owners’ Association, whose officers worked very hard to make the regatta a success. In all fifteen yachts entered and all faced the 11 a.m. on the 19th, but the weather starter at conditions were so bad that the start was postponed until 2 p.m. Even then conditions had not up; ‘The Limit” (formerly her owner, Dr. Pooley, will be well up on future Mr. Howard thoroughly deserved his win as he only lost one board, and the remaining scores fairly represent the day’s form. The O.0.D. was Mr. tuned owned by Mr. Reg. Lance) also did well, and no doubt – occasions. “Twinkle” is a good boat and her owner, Mr. Emery, will do better with her as he gains experience in the class. Of the remainder, “Charis,” ‘** Venture,” ‘“‘ Gleam,” and ‘‘ Saracen’ did best. The conditions suited the A-class yachts very well, and the lake at times presented a fine picture with the numerous pairs, sailing tack and tack to windward. Luck occasionally decided the winner, but generally the boards were very closely contested. The final scores were :—‘‘ Albion ’’ 36, ‘‘ Miss S. Africa” 33, “Rhythm” 28. A handsome prize apart from the cup was allotted the winner, also second and third prizes were awarded. The following is a complete list of entries :— * Albion ” (L. F. Rudd, Y.M.6.M.0.A.), “‘ Rhythm ” (P. J. Levy, 8. London M.Y.C.), “* Twinkle ”’ (W. R. Emery, Long Pond, M.Y.C.), “ Miss South Africa ”’ (R. Perrin Cole, Durban M.Y.C.), ‘‘ Albatross ” (H. E. Andrews, Highgate M.Y.C.), “‘ Charis” (Dr. ee TS Ee ae W. San (F. ck aayeacagas-oosuneahaean kaw “Heron” H.M.Y.C.), 4 ee ae a ae § se = —- 4 . 5 ; ec aT 8 Wy St oa ee J = Se Lo The Section and Sail plans of this model will appear in the July issue of THE MODEL YACHTSMAN. The lines show a powerful model tha, would be at her best in heavy weather 47 48 A BEAUTIFUL = ee ewe a ee ede. MODEL. Southampton, and we hear that she is practically ago was in ill health. We heartily congratulate her builder on a magnificent piece of work. The story of her building isa proof of the excellence of model shipbuilding as an interest for those who find time hanging on their hands, and it also shows what patience will accomplish. Casting about in his mind for The vessel represented is a _ fully-developed “medium ” clipper of circa 1880 with a full midship section. She is, however, on absolute clipper lines as the run commences immediately abaft the greatest section. When completed the hull was tested afloat with a spirit level and floated dead true without any adjustments or corrections. The scale is }” to 1’, and this has been most scrupulously adhered to down to the smallest detail. The hull consists of four layers of yellow pine, glued and brass screwed together, and is fully hollowed out except the bottom layer. The model has a flying jib-boom, a long topgallant fo’c’sle (housing most of the crew), and a fully developed long poop with charthouse on top. She carries two lifeboats on skids on the forward deckhouse and two gigs on skids over the after hatch. A SHIP Pee builder of this perfect model ship, Mr. J. Copland, of New Milton, Hants, some two years something to occupy the long weary hours, he suddenly got the inspiration to build a model clipper ship. Although he knew nothing of the subject, this did not daunt him, and he went to work and studied clipper ships, and eventually got out working drawings. From these he laid off the hull for bread-and-butter construction and took out twelve templates for fairing. ———— June 1931 The Model Yachtsman. She is sparred nearly to the limit with double topsails and topgallant yards. She was not designed to bend a sail on the cro’jack. Mr. Copland made hull, masts and spars entirely himself, including deckhouses, hatches and covers {which open), skids, ladders, main and forecastle pumps, etc. The cast and turned metal fittings were bought, but are all perfect scale models. These include Downton pump, bollards, davits, fairleads, stanchions, steam windlass, steering wheel and ‘Thomson’s binnacle. Blocks and deadeyes were also purchased, but the builder made the sheaves for the sheets himself. There are over a thousand blocks, sheaves and deadeyes and about 1,100 yards of rigging. The painting (17 coats) and varnishing (4 coats), and the rigging were done under the instructions from an ex-ship-rigger, Mr. J. W. Foley, 16, Briton Street, Southampton. The actual dimensions of the model are 5’ 10” long from jibboom cap to taffrail, and 3’ 103” from keel to main truck. Her lower mainyard measures 1’ 9”. The weight of the hull unpainted was 42 lbs. Work on the ship was commenced in September, 1929, and she was completed in October, 1930, but during May, June and July of the latter year she was not touched. Her builder estimates that altogether 1,200 hours were spent upon her from start to finish, The model is on exhibition at the premises of Messrs. G. J. Tilling & Sons, Ltd., 82/3, High Street, sold for a very substantial sum. The dimensions of the masting and spars are as follows :— Length overall Bue Length between perps. er, – i ae … 240° oe Depth of Hold iat Length of fo’e’sle… Length of poop ox . sus ins ae at .-. on Beam .. esa ui Gross measurement tonnage site ow 35 6” 2)’ AB” 47’ a 200 tons MAsTs AND SPARS. Bowsprit—Knightsheads to cap … Jibboom—Outside bowsprit cap… soe sa ia BET Foremast— Lower mast (above deck) e.3 eee e tO” Topmast Se .. 52’ Doubling Doubling … … aes sy . oh ne nai aaa .. EY’ 10° 6’ To gallant mast and royal pole (in one)… 55’ Lower yard ai Lower topsail yard. tne co .. 76 wine oa -» 68″ Lower to’gallant yard… Upper to’gallant yard… ra oa we. w. =527 44’ Lower mast (above deck) Doubling … at en Top mast … a des Doubling … Ke Ke aoe .. ws . .. «74 28? 58’ 12’ Lower yard ne is .. BA’ Upper topsail yard sks Lower to’gallant yard… Upper to’gallant yard… Royal yard ee wee re as rr rie Upper topsail yard Royal yard aie wien oe se wie eee in BO” Mainmast— To’ gallant mast and royal pole (inin| one). ws) BF” as Lower topsail yard. vee Lea cae 76″ wwe a. .. w. 68″ 607 §2’ 44’ wa Ses .in 64’ 3” 1S Mizen— Lower mast (above deck) Doubling … al at Topmast Doubling a … “ae a ‘ w. ioc 45′ 3” 8 To’ gallant mast and royal pole (in one)… 47’ 6” Cross Jack yard … _ Lower topsail yard ews Upper topsail yard oe Lower to’gallant yard… a ae zy a5 — 68’ wae | OO vse G2″ w 44’ Royal Yard a wm. Upper to’ gallant acne sib Spanker boom… Spanker Gaff a we vise . ve Sas ane — .. 36’ .. Pee) 40° oo G Jane 1931 The Model Yachstman. Ag ——— Loap WaTER Line MEASUREMENT.—/f any part of the model yacht below the L.W.L. (except the rudder) project beyond the extremities of the L.W.L., such projections shall be added to the measured length. Any yacht having notches or hollows in the surface Gardens. Mr. Littlejohn has also been one of the Model Yachting Association’s Official Measurers. or profile intended to reduce length for measurement Miss McDuff is well-known to London modelmen as an enthusiastic supporter of the sport. Our best them both. wishes and hearty congratulations to a and the Model Yacht Sailing Association, Kensington Mr. A. W. Littlejohn designed the well-known and successful 10-rater “Silver Spray” specially for THE MODEL YACHTSMAN. : = 5 profile ~ underwater 7 the rule deals with the hollows in the profile. ae the builder wishes, but the following quotation from shall be refused a certificate. The 10-rater formula in full is contained in the M.Y.A. Rules, 1930 (price 1/-, postage 1d.), and the method of Sail Area Measurement in the J. Y.R.U. Rating Rules, 1929 (as applied to Model Yachts) (price 1/-, postage 1d.). We will be pleased to forward a copy of either, or both, to anyone, and those who have the least doubt upon any point about the 10-rater formula should purchase same, and study them carefully. 3 a number of highly successful models, both 10-raters and 36” Restricted Class. He also designed “ June ” (A-class) and a model from the same lines made a capital showing at the recent Bradford Cup Regatta. For many years he has acted as Hon. Secretary to barred from the 10-rater class. There is nothing in the rule that prevents the use of any style of fin ww ET OC eNOS THE 10-RATER FORMULA. We frequently receive letters asking whether the old-fashioned double finner with a bulb keel is AT WS HEARTY CONGRATULATIONS. We hear that Mr. A. W. (“‘ Bert *’) Littlejohn was married to Miss Lily McDuff on April 4. Mr. Littlejohn is known to London and South Coast model yachtsmen as a very successful 10-rater skipper, and he is also known to every reader of THE MODEL YACHTSMAN as the designer of TRS CLIPPER SHIP MODE BUILT BY MR. J. COPLAND. Reproduced by courtesey of Messrs. G. J. TILLinc & Sons, Lrp , Southampton. ee ee ee po ee OO eT so ie a — 50 The WOODEN HULLS Model FOR June 1931 Yachtsman. MODEL POWER BOATS. By ATLANTIC. Part II. The instructions given by Atlantic in this part of his article on preparing full-size plans for hull-building. HE worst of this ““To-be-continued-in-our-next”’ business is that only part of what one has to say appears in any one number of the magazine and one is liable to be taken up by some smart gentleman for a statement which one intends to qualify later on. In such fashion I have received two letters dealing with the first part of my article on the above subject, so before proceeding with Part 2, I will deal with the points raised. The first letter is from Mr. W. J. E. Pike, the well-known model yachtsman, and is as follows :— * T used to wonder why the Power Boat Association had found it necessary to allow a metre boat to have a displacement of 17 pounds. Now I know the reason— evidently they build them with the };” thickness of planking recommended by “ Atlantic.” I am well aware of the fact that the final smoothing processes will rob the planking of some of its original thickness, but there is no need to use thicker material than }” for a wooden hull up to 5’ overall length. When a specially light-weight hull is desired the skin can well be +” or even 4”. The bent frames }” by +” should be spaced not more than 2” centre to centre.” I may be wrong, but I seem to remember in the old days before the War a scarlet 10-rater of extremely light construction with a deck of oiled silk stretched over the deck-beams that was often sailing the Highgate Pond belonging to Mr. Pike ? Well, Mr. Pike is both right and wrong. Wood that starts #,” will be a very bare }” after being planed both sides. If it is planed one side only, it will be }” full. Now as the outside of a hull is rubbed down after planking until the skin goes smooth and the plank edges merge one into another, it is unnecessary to plane both sides of the wood down before starting to plank up. This means that a ,” board becomes 2” full before starting. If planking a metre launch hull of the normal displacement type, the planks would be }” or possibly 3” wide at their widest point. When the edges of the planks were rubbed down and the hull properly faired up the thickness would vary from a very bare }” (say #”) toa bare }”. Now the strains experienced by a sailing boat are very different to those experienced by a power boat hull where engine vibration is considerable, and unless very special methods of construction are employed, I do not consider it advisable to use wood thinner than #” unplaned or }” finished (i.e., finished wood not finished thickness in the hull). Mr. Pike proceeds to steal some of my thunder when he speaks of specially lightweight hulls as for these I advocate using wood 4,” finished in narrow planks of not more than 3” full or ” bare width on light, closely spaced timbers 3” by 7)” spaced as Mr. Pike suggests at 2” centres, or better still }” wide frames (which can be slightly thinner) spaced 13”. It will be observed that I call the bent ribs “timbers ”’ as I thus distinguish between these and the cut frames in speaking of them. Now my second letter received through the offices of THE MODEL YACHTSMAN was on the subject of the system of insulation for the plant that I suggested and queried the possibility of carrying it out, and whether even if carried out it would prove effective, especially whether the arrangement of ventilators suggested would really induce a cool current of air between the machinery space and the hull. In answer to this gentleman, I may say that though I have never tried it out myself, I saw it installed in a model of a naval steam pinnace made by an E.R.A. on one of H.M. sloops where I served nearly a year during the War. She was a very fine little model and in spite of having been a number of times under steam, her finish was unimpaired. * * * * Now to get on with the business in hand: As I stated at the end of my first article, the first job is to enlarge the drawings to full-size. If the boat is to be built on the bread-and-butter principle, we require a profile drawing, waterline plan and a certain number of the sections enlarged for making templates. As all of these have to be taken to the outside of the hull, we have no allowance to make for thickness of shell. Let going which issues it be assumed that the model which we are to build is R.N.L.I. Barnett Motor Lifeboat, appeared in the January, February, and March of THE MODEL YACHTSMAN. This is a most suitable vessel for modelling, as she is a robust type of craft and will make a picturesque, interesting and satisfactory model. Moreover, the prototype being a small vessel, she can be built on a reasonably big scale, and consequently the detail work will not be too small to be effective in the model. The lines reproduced in the magazine were on a scale of 1 inch=—4 feet, so if we decide to make our model 1 inch=1 foot, the plans will have to be enlarged four times. This will give a model 45.5 inches long. To make the enlargement a suitable sheet of cartridge paper is required, and this should be pinned on a drawing board or table top. It is best to put a sheet of cheaper paper underneath in case of holes or slight irregularities in the board. The drawing instruments needed are an engineer’s pule, calibrated to some fine division of an inch— fiftieths—or sixty-fourths, a four-foot straightwie. a five-feet batten (or spline) for drawing the ‘eee curves, a celluloid spline for short sharper emrves, a hard pencil (say H or HH) and a good peneil eraser. In order to keep the splines in Pesition weights are wanted. For the purpose proper ship designer’s weights are best, but at a pamch the domestic flat-irons, weights from the bitchen scales, etc., can be made to serve. With regard to the rule mentioned above, I have beard it contended that one cannot work wood to eme hundredth of an inch nor even a sixty-fourth. True, wood does not permit as exact work as metal due to the material. But remember that every measurement taken is going to be enlarged—and eme sixty-fourth inch error is one-sixteenth inch if enlarged four times. So not only is a finely ealibrated rule an essential, but great accuracy is ealled for to take the measurements to enlarge from. At this stage of the proceedings, before the actual drawing is started, it might be as well for the benefit of those who are not familiar with ship plans to give a short explanation of the various lines that appear im the various plans. The elevation of the boat is shown on a plan known as the “ Sheer plan ” and takes its name from the sheer. The sheer plank is the top plank in a boat’s side and its elevation (or side view) is known as the boat’s “Sheer.” Unless the plan shows also the centreline of the deck, this line will form the top line of the sheer plan. 51 The Model Yachtsman. 1931 Now all ship plans are drawn to show one side of the vessel only, as if both were shown one side would merely be a repetition of the other. If one imagines a model of a ship cut vertically down the middle from stem to stern, one would have two half-models, and the plans are those of a half-model. If the half-model were It will be noticed that in designing this Lifeboat, Mr. Barnett calls the L.W.L. the ‘* Datum Waterline.” The probable reason of this is that a lifeboat carries a varying load according to whether she is proceéding or returning from her errand of mercy, and her displacement varies accordingly. The calculations on which her design was based were presumably taken out on the Datum Waterline. The cross (or transverse) sections are shown in the “Section plan’’ and represent the boat cut across at right angles to the centreline. Obviously the Transverse Sections will appear as curves in the section plan, and as straight lines in the sheer and waterline plans. Similarly the Buttocks will appear as curved lines on the Sheer plan, and as straight lines in the Section and Water- line plans. The Waterlines also appear as curved lines in the Waterline plan and as straight lines in the Sheer and Section plans. A point of importance to note is that the intersections of the exactly coincide. crosses the lines in the various plans must Thus the point where the L.W.L. greatest section must be the same distance from the centreline on the sheer plan and the waterline plan, and so on. There are other lines used in ship designing, but the reader who is interested in building only need not worry his head about diagonals, curves of area, etc. For the sheer plan, first rule a line to represent the L.W.L., and then put below it parallel lines at the correct intervals to represent the other waterlines shown on the plan. The first one will be }’, the second }?”, the third 3”, and the fourth 2”. The waterlines above L.W.L. are not shown on the published plans so we shall have to get them out for ourselves from the section plan. They can be placed on a sheet of paper and a pencil run round her, we should have her profile. spaced }” apart up to the top of the sheer, as shown If we took our half-model and again sawed her down parallel with the centreline a short distance next but one below it will then be of $” wood and out we could again take off her shape at this point. a small piece to the bottom of the lowest layer to This line would be what is known as a “ buttock line.” Several buttocks are usually taken out. If reference is made to the plans of the Lifeboat, it will be seen that her inner buttock was taken out 2’ 6” from the centreline, the second one at 3’ 9”, and the third at 5’ 0”. on section plan, or }” may be found more convenient. The layer immediately below the L.W.L. and the the remainder }?”. It will be found necessary to add complete the keel. At the ends of the sheer also pieces will have to be added to the top complete layer to make up the requisite height. Having ruled in the waterlines—the vertical lines for the cross sections. It will be noticed that those in the centre of the boat are spaced wider apart than The next plan is the ‘Waterline plan.” If one looked straight down on top of a vessel one would see the shape of the deck in plan and this forms the greatest line of our waterline plan. In this case the baseline of the plan is the centreline. Now if one sawed the at the ends and this is accounted for by rapid changes in the boats form at these points. The spacing of the waterlines was similarly decided. model through horizontally on her line of flotation, lines. we could trace the shape of her waterline plane. Other cuts made parallel to the waterline plane above intersection of section and waterline. and below it would give the boat in plan at each of these levels. The plane of flotation is known as the L.W.L., and the other waterlines are numbered or lettered to identify them. the stem, the keel, and sternpost are straight lines and can, therefore, be ruled straight in. This leaves merely the turn of the stem to be drawn in to complete the outline. The next step is to carefully spot in the points where the profile crosses the section lines and water- These points are measured from the nearest is obviously to put in the profile. The next step The upper part of a ee ee ee eee ere PPE ey. 52 The Model It will be seen that this extends from a point above the L.W.L. to Section 2, where it joins the straight run of the keel. The points of intersection with the Yachtsman. June 1981 complete the lines. It will be noticed that the section plan is shown on a scale of 1 inch=2 feet and the measurements will, therefore, only have to be various waterlines and Sections $ and 1 have been multiplied by 2 instead of 4. spotted in and therefore it remains to draw a curve that is a fair line through the spots. For this purpose the celluloid spline must be used and it must be bent round using the weights and also the fingers of the left hand until a line can be drawn that passes exactly through the required points. Great care is needed to make this line “‘ teach” (i.e., blend into) the straight lines of the stem and keel. measurements for the breadths of the sections on Having drawn in the profile, the sheerline can next be drawn. The heights are spotted in carefully on each section line. The long batten (or spline) is then bent and held in position with the weights, care being taken to arrange the spline so that the line when drawn passes exactly through the spots. It will be seen from the section plan that the planking makes an angle with the keel in the garboards, and also with the stem and sternpost. The point where the planking runs into these is known as the “ rabbet line.” This line is shown on the sheer plan and can be put in on the plan we are making in a similar manner to the profile. As the model under construction is having a bread-andbutter hull, it will be best to build the hull without keel, stem and sternpost and put these on after the carving of the hull is complete. The reason of this is that in this way an absolutely clean angle will be obtained and, moreover, it simplifies construction considerably. If the garboard was “ padded” at all (i..e, curved) it would be easier to build all in one rather than apply afterwards. Our _ bread-andbutter hull will accordingly have the rabbet line as profile during the earlier stages of construction. As a bread-and-butter hull is under construction, the buttock lines will not serve any useful purpose in the construction, but the detail of deck fittings, etc., can be drawn in elevation on the same plan to save making a separate one. Before doing this, however, it would be as well to complete the lines.of the hull proper and the next plan to draw will be the waterline plan. The centreline of the ship forms the base for this, and the first lines to put in will be buttocks and section lines as these are the straight lines on which the plan is based. Once again great care must be exercised to get these absolutely accurate—in fact they are almost more important than the curved lines. The deckline is the first of the curved lines to be spotted in, and to draw it the long spline is used. The best splines are made of lancewood and are rather expensive to buy, but a good spline can be made of red pine—}” by ¥” will be quite suitable for size. It should not be tapered, but straight from end to end. A tapered spline may, however, be found useful in drawing the ends of waterlines where the curve is too steep for the straight spline. The waterlines are drawn in the same manner, end it only remains to draw the section plan to If preferred, the each waterline could be taken from the section plan, but, as explained, in any case the measurements in each plan must tally exactly. They should, accord- ingly, be carefully checked over before the plan is considered finished. If on drawing any line through the spots, it is found that an unfair curve results, all measurements should be carefully gone over and corrected. As the lines were absolutely fair in the original, there must be an error in the enlargement if the curves are not fair. An exactly similar enlargement has to be prepared for building a planked model, but as will be explained later on mould patterns have also to be prepared. In the case of a bread-and-butter boat, however, the next step will be to prepare templates out of thin cardboard for the layers. A more experienced builder might be able to transfer his lines direct to the wood, and also a glance at the plans would enable him to decide which layers can come out of the middles cut from the larger layers. In explanation of this, a few words as to the principles of bread-and-butter building might not be amiss. This system is really a more modern application of the old ‘‘ dug-out” method. By the latter a hull was carved out of a solid block of wood. For a hull of any size this meant an immense block of wood, heavy, hard to obtain without knots, and entailing an immense amount of labour before the hull was finished. Moreover, except by the method of testing on the sections with templates, it was impossible to get any reasonable accuracy. The bread-and-butter system consists of building up a laminated hull out of layers that have been previously sawn out to nearly their final shape, so that the hull is governed as to-its ultimate shape on every waterline. Further, as the greater part of the centre of each layer is sawn up before glueing the layers together, the greater part of the labour of shaping and hollowing out is avoided entirely. The name “ bread-and-butter ’’ presumably comes from the wooden layers with glue between. (To be continued.) JOURNAL OF COMMERCE BRITISH FLAGSHEET. We have received a copy of the Journal of Commerce Flagsheet. This new and revised edition contains illustrations of House Flags and Funnel Markings of upwards of 400 British Shipping Companies. These are printed in colour, and the low funnels of companies owning motor vessels are also shown. The sheet should be of great interest to those interested in our merchant, marine. It is published in two forms at 1/9 and 3/9 respectively, and can be had from the Journal of Commerce and Shipping Telegraph, Liverpool. June 1931 The Model 53 Yachtsman. The Editor accepts no responsibilty for opinions expressed by Correspondents Letters intended for publication must be brief and to the point. They should not exceed 400 words in length and must be written on one side of paper only. Correspondents are requested to read our note on this subject which appears elsewhere in this issue. LINE THEORIES to-day we have made such strides in fast The shape of the Curve of Areas is not, however, of paramount importance and may be varied within considerable limits, provided that in the operation due and proper regard is paid to the fairness of the curve and that the length of the Water Line entrance is not materially curtailed. This elasticity of the Area Curve applies particularly to the afterbody where the buttock lines are of most importance. The Author is referring to really fast launches. Mr. Humphrey mentions that a Troichoidal Curve may be as low 0.5. Surely this is a slip of the pen as a true curve of versed sines carries the same figure. These Wave Form and Wave Line theories are, nevertheless interesting, even if they have no scientific value. They are attempts to achieve the impossible. Yours faithfully, P. TURNER. “Dolfryn,”’ Rhos Road, Colwyn Bay. AN APPRECIATION FROM THE STATES. Gentlemen, I’m a new subscriber to your little wonder and I wish to congratulate your staff for the April issue. A little item in this issue states that the book sold out. I can’t see why this is unusual for a dandy “‘mag’’ like yours. Yours ete.. J.M. model will be a success. That the keel, whether fin or prototype, is of secondary importance. That the form of hull—which we hear so little about—is of primary importance. That there is little to choose between two well-designed models (fin and proto- type) the personal element, of course, being assumed similar. The possession of a particular type is for many people the deciding factor in favouring that type. So bear in mind that a good deal of what you read in the correspondence under the above heading is bunk. To compare two dissimilar models on the basis of their keels alone is absurd. For example, in the October issue, 1930, page 148, Mr. Stewart states that ‘‘ both models were fin and skeg—one 14” fin and small skeg, the other 18” fin with larger skeg. The shorter fin was certainly no disadvantage.’’ Now a glance at the photo on the preceding page shows that these two models have dissimilar hull forms. Therefore his comparison is worthless. He continues: ‘‘ Viewed from the weather side, the water stream from the lee could be seen boiling through the gap between the after edge of fin and small skeg. This stream certainly did not retard the boat. The stream was following its natural course under the boat and returning to the surface. Why try to hinder it by large skegs or long keels?” In point of fact, water that boils through a gap ceases to be a stream—in the sense of “stream line flow,’’ and becomes what is known as “turbulent flow.” Its effect is revealed by a small wave about a foot long, on the weather side, travelling approximately in the same direction and at the It is both visible and same speed as the model. Without going into the theory of wave audible. res 2 ee But launch design that both these theories go “‘by the board,’ as the following extract from Mr. G. 8. Baker’s work on “Ship Form, Resistance and Screw Propulsion’”’ proves. On page 120 we read: A little advice to the newcomer about to build or buy a model will not, I hope, be out of place here. Bear in mind that to possess a fin keel model does not necessarily mean that you possess a successful model. That its success will depend upon the opposition met with, whether in the form of another fin keeler or prototype model, which in turn depends upon sailing conditions. That the finest shape, area, and disposition of fin keel is no guarantee that the SL Your correspondent refers to Scott Russell’s “Wave Line Theory.” I understood only about a dozen vessels were built to conform with same. From a scientific point of view, Colin Archer’s “Wave Form Theory” has a much sounder basis. KEEL FORMS. Sir, 2S WAVE FORM AND WAVE Sir, I was pleased to read Mr. Humphrey’s letter in your January number on the above subject. 54. The Model Yachtsman. formation it will be enough for our purpose to state = that to form a wave energy must be expended. In this particular case none of the energy is recovered. Therefore it is called “‘ wasted” energy. © This wasted energy might have been usefully employed in overcoming the hull resistances with a possible increase in model’s speed. Therefore it can be said that it certainly did retard the boat. It may be that this wave is due in part to model’s leeward speed (for it appears on the weather side only) and the remainder due to abrupt or quasi-abrupt changes of form as associated with fin keelers. The best that can be done is to avoid all items, as far as possible that favour its production. If that is so, the question asked by Mr. Stewart, “ Why try to hinder it,” etc., is answered by stating, Why have it at all? I hope letters. to take further examples from other Yours sincerely, HENRY CHALMERS. SPINNAKERS. Sir, There is a slight error in your reply dealing with spinnakers. It is the length of the spinnaker boom, which is measured and this length must not exceed the length of the base of the fore-triangle, or the spinnaker boom length will be taken as the length of the base of the fore-triangle. The spinnaker must be set within the fore-triangle and the sheet must also be made fast there. Your correspondent J. A. 8. mentions enveloping spinnakers and states that new regulations allow the spinnaker to be carried round the forestay. The M.Y.A. rules do not at present permit either of these practices, although the Y.R.A. do. While on the subject of spinnakers, I should like to know what the spinnaker gye is and in what part of the ship it is to be found. Guy, sir, is good English, and any seaman can tell you what it is. A little reflection will also serve to show you further uses of the word. Yours truly, W. J. E. PIKE. Re Racing Reports.—If you will read the report I sent of the 10-rater regatta you will find there the correct scores.—W. J. E. P. [Our correspondent finds fault with our answer about spinnaker booms. The M.Y.A. Rule referring to Spinnaker Measurement is as follows :— “I. The hoist I. shall be taken from the deck up the foreside of the mast to where the line of the spinnaker luff cuts the mast. “J. The base J. or length of perpendicular shall be found by setting the sail taut with the heel of the boom pointing towards the mast, and measuring along the June 1931 top of the boom where it is cut by the line of luff to the centre fore-and-aft line of the mast. * * * s oe . must not be so set as to increase the measured area of the fore-triangle. * * * * “ Note.—Should the spinnaker hoist or boom as measured exceed the dimensions of the fore-triangle, any such excess shall be added to the dimensions of fore-triangle for calculation of area.” Our correspondent no doubt bases his objection on the second portion of the above quotation. We cannot, however, see any reference in the method of measurement to any particular angle at which the spinnaker boom must be when measured and the owner would be perfectly at liberty to have it fore-and-aft in the position to which the sail was let fly in the Query published last month. Neither does the rule say that the tack of the sail must be within the area bounded by the jib-stay. What is said is that the sail must not exceed either in hoist or boom the measured dimensions of the foretriangle unless such increase is taken into calculation of area. The sentence upon which our correspondent bases his objections is, to our mind, intended solely to imply that the spinnaker must not be used as an additional headsail with its boom lashed out ahead of the tack of the jib. Further, when let fly the sail is not set. It was set before it was let fly, but as it was no longer functioning to advantage it was let fly in order to stop its drawing. Our correspondent proceeds to refer to the vld “Gye” and “Guy” controversy. We prefer the spelling “* Gye,” and reserve the ‘‘ Guy” for Nov. 5th. Referring to our correspondent’s postscript, may we say that for the first time on record we received no less than three accounts of the race at Eastbourne. The jirst had already gone into type before our correspondent’s excellent report arrived. As the other was set wp, we compared with his account to see the facts were the same, but we must have omitted to notice any discrepancy in scores. If Mr. Pike cares to let us have a note of the error with a correction we will be pleased to publish it.—Editor, The M.Y.] THIMBLES FOR MODEL SHIPBUILDERS. Sir, In the May issue of this journal you were good enough to publish an appeal from me as to where I could obtain model thimbles. You will be interested to hear that within a few hours of publication I received three very courteous letters giving the required information. For the benefit of others I pass on the address— Mr. Stevens, 112, Beresford Road, Green Lanes, London, N.8. Yours faithfully, W. H. BAUER. Printed ard Published for the Proprietors by H. G. StTonF, Town Green, Wymondham Norfolk, ihe Model Yachtsman. June Lv¥dl ees ‘ W. Cains, 36inch. L.O.A. Models Model to M.Y.A. Rating Yacht Sailmaker, uses the Best Union Silk Fabric the most suitable for Model Yachts. ORDER Planked Pine with or selected Mahogany. Finished either Enamel or plain’ Varnished, *‘Rylard.”’ 82, St. Edmunds Rd., Gosport HANTS. ~ y ‘ G. J. TILLING & SONS, Ltd. Yacht Eyes, Rack Makers, Sets of Spars, Sails and and Gunwhale Jib Sail SOUTHAMPTON. Plated Fittings including Pulleys EARLY. Rigging and Rigged 27in. Mast Slide. for Bermuda Model Cutter, Yachts 23s. 6d. Catalogue of Model Fittings on application. . Suit of Sails by Daniels including Spinnaker. 4 Cold Best Rig and a “TEST,” Water Waterproof. Finish. Glue Heatproof. The best CASEIN GLUE for Model Builders Sample Tin 8d. post free. 36inch. L.O.A. Sharpies to design in The Model Yachtsman. Trade J. g 326, enquiries invited. TREVOR, Dollis Hill Lane, ane, London, London N.W.2 5 > All Models to order only First-class Vancouver WANEY A. J. CHILD, 80c, THE PINE For Model Yacht Building. 4in. for Decks, and any thickness up to 24ins. wide. This wood is without a blemish. T. CHASE, MARCHANT, LTD., Timber Merchants and Importers, Clapham Common, S.W.4 — Verney Road, Rotherhithe New Road, .. LONDON, S.E.16 In replying to Advertisers, please mention THE MODEL YACHTSMAN. y, June 1931 The Model Yachtsman. sige oa “W.H. BAUER SAILS S.M.M.C. Model Best Union Silk in 3 Grades and Repair any size and design. for all Classes. SAIL CLOTH Drown, Built S.E.27. 6 The To order only. and Restored. Workshops: Norwood, a Service. Becorative, Water-Line & old-time Ship Models 8, Ullswater Rd., West Fit-out Spars, Sails, Fittings and Accessories Flags & Pennants Chas. Yacht ¥ L 237, Goldhawk Road, London, W.12 99 RY LARD,”’…: World’s best Marine “MISS Tested and Varnish and ENGLAND. Enamel. IL.” : proved in all Reduces climates the surface friction to a minimum. most perfect marine varnish and enamel. ‘*“MISS ENGLAND II” finished with ‘‘RYLARD”’ Varnish and Enamel. IDEAL FOR ALL MODEL CRAFT. Sole Manufacturers : LLEWELLYN sand eS Ei RYLAND, ie a ae Sa LIMITED, SR ae BIRMINGHAM Ee In replying to Advertisers, please mention THE MODEL YACHTSMAN. a