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ae gereoe 4 ; THE SPECIALIST SHOP FOR THE SHIP SHOP move: LERS OF SHIPS AND BOATS NO. | regret | will not be at the Model Engineer Exhibition this year, but I’ll be glad to welcome you at the shop. For the sailing enthusiast — all 3 of the Hegi yachts are back under WEDICO name. INGA IV £140.95; SAUDADE £126.00 and MISTRAL Bermuda Rig 42” £82.00. Also a new yacht from Caldercraft COSMIC WIND. Price TBA. Also due from the Calder stable will be the TALACRE a raised quarter deck steamer. Price TBA. Scheduled release date is January 1984. We still have the largest selection of GRP hulls with one of the latest being the 67” Steam Drifter/Trawler at £67.50 In time for Christmas is a Unimat lathe operating at 6 volt — will turn wood and metal. Screw threaded tool slides; 3 jaw independent chuck. Can also be used as a vertical miller and driller. If it sounds un- believable it has the UNIMAT name and the MICROFLAME backing and it’s priced at £92.00. SAITO ship kits — STARLIGHT Coaster 1:50 length 900mm £215; KAMONE Victorian Steam Yacht 1:40 length 1350mm £400; CHIBA STAR Salvage Tug 1:50 length 1200mm £380; POLAR STAR Whalecatcher 1:50 length 1300mm £420; MINEGUMO Anti-submarine escort 1:100 length 1160mm. All with GRP hulls for steam operation. Boilers and engines also available. More of the HEGI kits are now becoming available: Helgoland Police Fairplay V 29′,” 41” Hydrofoil Tug £59.80, AVAILABLE Check with us first, we are ‘likely to have it in stock Contact us for all your marine requirements, we may be able to save you a lot of time. Have a Happy Christmas. Post and Packing is additional to all quoted prices and enquiries must be accompanied by S.A.—. or International Reply Coupons. Prices shown include V.A.T. | — Underhill 1775-181 Masting Ships & Mastmaking (Fincham) Sailing Ships, Rigs & Rigging Pes *£10.00 Plank on Frame Vol. Il — Underhill . *£8.50 Anatomy of Nelson’s Ships £15.00 Modelling Brig. of War Irene £28.00 Modelling Thames Sailing Barges .. *£3.50 Model Open Boats ; “£3.25 Steam Coasters & S/S Traders *£11.95 Old Time Steam Coasting *£10.95 The Steam Launch £19.95 . £9.50 £15.00 Cutty Sark Ship and Model Ship Model Builder’s Asst. The Built-up Ship Model . Search for Speed under Sail Schooners in 4 Centuries ……….. The Mary Rose . . Anatomy of Intrepid also Hood £15.00 1: Pe io “£8.95 “£8.50 “£7.50 “£7.50 £15.00 *£7.95 *£12.50 *£8.50 Destroyer Weapons ……………….. “£7.50 Steam Picket Boats .. ieee “£7.95 The Tea Clippers 1833-1875 *£14.00 Shipbuilding in Miniature “£8.50 King’s Cutters.. tees £10.50 British Steam Tugs…vee eee ieil =o *£12.50 Ship of the Line Vol. | . £20.00 US PT Boats of WWII i “£7.95 Spirits’l BargesThames & Medway *£12.50 Sdiling Drifters — March £15.00 Sailing Trawlers — March …….. £15.00 Scale Model Sailing Ships “£6.50 Scale Model Warships “£7.50 Flags for Ship Modellers . “£3.50 Lusci Ship Modelling Handbook .*£6.00 Handbook of Ship Modelling *£5.95 Masting & Rigging Clipper Ships *£11.00 Naval Gunnery 1855 £15.00 Sail & Oar BOOKS — (Part listing only) \(\! Za Maritime of plans boat kits — for details please send stamped addressed envelope. Working Boats of Britain SAX 45p; SAITO Steam engines, boilers and Ship Modelmakers Manual OPENING HOURS MON-SAT 9.15 am-6.30 pm Timber Fittings 45p; Hulls 85p. Send S.A.E. for listings cataloques available. Plank on Frame Vol. Police Launch £71.57, 27)” £45.57. LISTS Marorants gna Ships Sailing Shins of War 1400-1860 *£12.50 \ t . . £15.95 Books add 10% post & packing. Items * add £1.50 Goods will be despatched ‘Ai within 14 days unless Simeve otherwise advised. =a titPatt ‘ es Greenwich 7 Nelson Road, Greenwich London SE10 Telephone 01-858 5661 in T ae MAIL ORDER SERVICE THROUGHOUT THE WORLD: ACCESS : BARCLAYCARD : AMERICAN EXPRESS Groupner DISTRIBUTED BY RIPMAX Two fine yachts — for free sailing or R/C. They cut building time toa minimum, too, “with READY-FORMED impact plastic. hulls’ in Plus other plastic highmoul- dings, pre-cut balsa and ply parts. Sailcloth, etc. COLLIE (length 28”) is a compact scale- type model with a beam of 6/5″. Definitely a ‘quickbuild’ project from this excellent kit at £31.50. Fittings set available as an optional extra £6.35. OPTIMIST (length 41”) is a true 1/11 scale cruising yacht with fine hull lines and really seaworthy with 10%” beam and hydrodynamically designed round- bilge hull. Ample room to take all the R/C gear you want in the scale cabin. Deluxe kit£79.50. Cast keel £21.00. Fittings set £36.00. You can’t be wrong when you build a Graupner boat kit FROM YOUR LOCAL MODEL SHOP. January 1984 13 formance. Such alterations may well have been introduced by very experienced STARTING IN SAILIN skippers who also design yachts and thus make a shrewd assessment of present performance and potential improvement. A simple case in point is the Bamb/ Marble- head design which is a better performer if the lead bulb is moved aft by nearly an inch. If the yacht is an own design, or the first off Vic Smeed takes a look at displacements. and offers some general guidelines ACHTS in model form, as mentioned a issues ago, are essentially dis- few the recent a new plan, it is better to ask a recognised expert for an opinion if the performance is not as expected. By ‘recognised’ is meant America’s Cup Liberty was lightened by 1000lb for the last race, and placement craft, i.e. they move through the whether or not the resulting shorter water- water rather than their motion generating line was used to set sails of larger area, dynamic lift to raise them to plane over the surface. If driven very hard some lift is such a marked alteration would have been created and planing does occur, usually in short bursts, although the factors of hull shape encouraging planing are likely to reduce the potential speed at lower wind reasonable grounds for a protest. The classes which limit overall length rather than waterline (M and 36R) are not so critical, but are covered by the rule that ballast shall not be changed during a race strengths if carried to extremes. ‘Displacement’ is the term used for the or series of races. total sailing weight of the yacht, since (by Archimedes) it displaces a volume of water having detachable fins or leads of varying equal to its own weight. There are skippers who believe that depths and/or weight offers advantages. For example, in light winds a lighter fin If you can establish the volume of the hull allows the yacht to heel to its sailing angle in cubic inches and divide this by 27.7 the result is the weight in pounds; if worked in metric, the volume in cubic centimetres accelerate better because of lower wetted divided by 1,000 is the weight in kilogrammes. This applies to ship hulls as well, of course, or indeed any floating object. an increased speed. When the wind pipes A yacht is normally designed to a definite displacement and if built accurately will be carried longer. In view of the rule about changing ballast (really only applicable to then float on its designed waterline, so that the M or RMclasses) the skipper is required all to the other calculations in the design should work out correctly. Yachts which need to be made lighter (or heavier) than the design weight in an attempt to improve performance are obviously not fulfilling the but, because of lower overall weight, it will area (less hull immersed) and should have expertise, or will be diffident about their status, but they will be pleased to offer an opinion if asked. What happens during building can affect the total displacement considerably, and any discrepancy in all-on weight can usually be corrected by adjusting the amount of lead. We have seen the same design varying by as much as 20 per centin displacement because the hull and rig have been built ‘heavy’ but the standard ballast has been fitted. Some builders will build, or reinforce, a hull till it is like a tank, others will build so light that a brush with another yacht will hole them. The latter will lead to better performance (while the boat lasts!) but an eye should be kept on weight throughout construction and steps taken to correct any severe deviations. How does one know what weights should particular design? Well, if the up, a heavier-or deeper fin would restrict be for a heeling, thus allowing top suits of sails to designer has not put some guidance on the plan and you are not a club member who assess the probable weather over a series of races andchoose the fin or bulb he thinks best suited. There are two points worth mentioning on this subject. Firstly experience has designer’s expectations, and changing the displacement ofa model yacht is often quite frequently shown that it is the heaviest an awkward job, since normally the ballast is one cast lump of lead, the volume of performance which has also had to be calculated in order someone who is pointed out to you rather than a self-styled expert; most really knowledgeable model yachtsmen will not claim boats that have the better light weather largely because the lighter the wind the more erratic it is likely to be in direction and, particularly, strength. A can ask other members, the only thing is to read as much as possible — everything you and your librar can find — y to builda picture of what components of other yachts of similar class or size weigh. Experts will be able to make things lighter often because they know where the stresses are likely to come and therefore which areas need not be so strong, where weight can be saved. Any attempt to lay down figures will thus inevitably show wide variations, anda component falling outside the figures given would not necessarily be dud. that it should weigh the right amount. The most significant effects of lightening will a yacht are evident in classes where the direction through a lull much better than a waterline length and sail area are closely interconnected — ten-rater A, and six lighter yacht. Thus after a few seconds of metre — since if enough weight is removed and heading in the right general direction to allow the hull to rise, say /,in., the waterline length, because of the shallow angles while a light boat may have stopped and even paid off. This is possibly less notice- involved, could shorten by perhaps 4in. or more. To take a theoretical example, 3¥,Ib mast and able in radio sailing, but is a factor just the calculation removed from a 60in. waterline heavier boat has rather more inertia and carry way and, frequently maintain lull the heavy boat is still likely to be moving same. 10Or The second point is that none of the top (1250sq. in. of sail) would easily reduce the waterline to 56in. allowing about 1340sq.in. of sail, or more than seven per very top commented that he had trouble cent increase. lf, because of the shallow hull angles, the new waterline came out at 55in., the sail allowed would be increased alone confusing the issue by varying this skippers uses the idea; in fact one at the enough learning and remembering the sail- ing habits of a yacht with a single fin, let important element in sailing. by nearly ten per cent. This is a primary reason why a yacht’s rating certificaté is important and why major changes entail remeasurement. In January 1984 Advice from a builder is therefore to stick to the other designed boats to ballast, the unless design have Apart from the lead bulb, the heaviest part of a normal yacht will be the hull, probably followed by the fin, rig, deck and fittings, although the fin could work out lighter than the rig. It is, however, fairly easy to weigh material for the fin, deck, booms and, of how by doing a much rough material is required, get a fair approximation of final weights. However, for a real beginner, who “is going to be interested in a reasonably strong and practical yacht rather than the ultimate racing machine, let us stick our necks out and try to tabulate some general guidelines. All weights in pounds or decimal parts. See table on page 45. several clearly proved that an alteration can improve per- (continued on page 45) 43 Transom windows. The framing is made from three layers of masking after, it may be sanded back to whatever odd shape is required. | was presented with some proper mould- tape. ing plaster for the in-filling of the prow which in factfills out the area on the proto- type which is the forged casting. This heavy iron knee casting in real life gave the ship some problems of sailing trim; her inclination to nose dive, porpoise-style, had to be corrected in later life by the addition of a weighty poop-deck (1872); fighting ships abandoned later the iron- style of clipper-bow which served no real purpose, other than convention, in favour of the ram, which enjoyed a considerable come-back panes, rather than try to cut out each little square. Put more simply, the frames of the or any other kind of paste or plaster, by its as a practical fighting weapon. absorption of the material, which, as it dries panes are made by using thin strips of masking tape; this has the effect of being out, locks itself on the reverse side. There- | Next month: covering the hull. | ‘built-up,’ rather than ‘cut out.’ Amongstall the ‘outdoor work’ which the main part of the hull requires, this is a great change of scene and somewhat of a foretaste of detail yet to come. My only hope is that when the process for GRP lay-up comes about, this work doés not prove too delicate to survive intact. Marrying the galleries to the stern of the ship is a case for plaster and wire — some might say a meshy job altogether — (sorry — that won’t happen again — | promise). Expanded aluminium wire mesh in its bona Stern gallery references – Science Museum model and Scott Russel’s body plan in ‘Ships of War’. fide role is much used in the motor trade for the repair of difficult holes in awkward places, and has the ability of holding resin STARTING IN SAILING well outside the suggested range, but at (from page 43) 15% Ib all-on it still sails quite happily. Now all these weights are achievable Adding weight is a lot easier. At an absolute pinch it can be laid in the floor of What to do if the yacht comes out sig- the hull or, better, in the top of a hollow fin, with conventional materials, but of course nificantly they could vary depending on what is used. A Formica deck for an A boat could weigh twice as much as one of 16in. ply, which in plugging them with dowels, cutting off the fore and/or aft ends and epoxying on wood lead simplifies things, since a thin sheet of blocks and reshaping, or planing off the fin each side, but sheet lead can be added to would be needed with the heavier deck, although additional beams would not sides. the outside. necessarily add Tufnol fin would be heavier thana ply one, it or not, using turpentine or paraffin as a from lubricant, but it is nota quick job to take off a and often ply ones are heavier than need be. A short, wide fin might well be of much weight required. Roughen the existing bulb pound or more of lead. Sawing lead is not and the inside of the sheet and epoxy it in too easy, either, unless the bulb can be very place, tapping lightly all over with a small turn would be around twice as much as Y3oin. ply. However, fewer deck beams up to the difference. overweight? The lead can be filling up the fin with polyurethane foam reduced, but if it is already fitted this can afterwards, but clearly the best place is at only be done by drilling holes through it, the position of the bulb. Again, a two-part ‘Planing’ can be with a rasp or Surform, or with an iron jack-plane, believe A lead can be introduced between lead and Obtain a some new sheet builders’ lead flashing merchant and cut the thinner ply than a deep, narrow one of the firmly same area, or abalsacore/glass skin might frequently. show a the shape and then binding or sticky-taping If the lead has not been finally fitted the job is somewhat easier, simply because holding it is easier, but beware of using while the epoxy sets. It is possible to drive in power tools unless you are expert, since necessary. When set, tap down the edges considerable saving in weight. Variables are infinite, but the figures given check out by and large with existing boats. As an example, the weight range of an M, less lead, comes out from the table as between 3.2 and 4.5lb, so a lead of 6-10lb secured and the saw_ lubricated hammer or mallet to induce it to conform to short stiff pins holes are if required, drilled first, especially if but not really lead has a nasty habit of snatching. A two- gently piece lead is the best, as surplus can be repeated gentle tapping, and use car body would give (with .8lb for radio) an RM of 10- (it is possible to thin them by 15.3lb, which is pretty much the envelope removed from the flat faces or lots of holes filler to fair the patches in. Sanded well and drilled in which modern RMs are found. The writer painted, either to cast or buy a lighter lead and save the existing one for the next boat! has a glass RM with a hull/deck of 4/,Ib, Yacht Length Beam Hull Hull (ins.) (ins.) (wood) (grp) — 25 — 30 M 80 c10 1.5-2.5 72 c12 2.5-3.5 72 c14 3-4 36Rq 10r A 36 = January 1984 5 6 9 5-9 6-1 1-18 internally, but the real answer. is it is possible to produce an undetachable result. If large patches are needed, they should be cut into strips and applied individually, Fin Rig Deck Fittings 5-.8 2 4 1 1 joints; the filler will cover the cracks. If alot 5-.8 3 2 2 8-1.2 3 6 3 Zi of strips are applied, covering with a patch 2-2-2 S 8 4 3 2-3 8 1 6 4 the lead will be as good as a one piece 5-3.5 1 1.2 8 5 casting. 5 trimming to achieve reasonably close of glass cloth and resin is advisable, when (to be continued) 45
