- Description of contents
December 1981 60p (U.S.A. & Canada $2.75 Solarkraft’s new radio Marblehead Reviewed by D. Hackwood EA URCHIN (4) G.r.p. hatch cover, also in white, moulded to shape to fit recess in deck. (5) Pre-shaped lead ballast ready drilled and supplied with brass anchor bolt for attachment to fin. The lead supplied weighed Qlbs. (4.09 kgms.). (6) Mast Y2in. dia. aluminium in two parts complete with mast joiner to make mast 87in. long and one suit of sails. (7) Main boom Yin. dia. aluminium and one jib boom 3,in, dia. aluminium, cutto size and drilled as necessary. assembled to pre-marked position on hull; below Fin lead bolted into place with the two mounting screws (8) One set of chrome plated fittings, including: rigging, wire, bowsies, self-tapping screws, mast bands, sheet horse, shroud plates, rudder tube etc. HE Sea Urchin is the latest addition to Solarkraft’s highly successful fleet of model racing yachts. The Sea Urchin falls into the Marblehead class andisintendedto se. Thehull profile el SeaHor ll tothe run para shows that special emphasis has been placed on the design to give highly competitive performance in light and medium airs. The kit itself comprises as follows: (1) Glass reinforced plastic coloured hull with a white g.r.p. deck already bonded to the hull. The hulls are available in four different colours, red, blue, lime andorange. (2) G.r.p. fin in white. (3) G.r.p. rudder blade, also in white. 702 Model Boats (9) Cork bumper and backing block. (10) Detailed building instructions. | understand that the manufacturer Assembled rig prior to fitting onto deck foot and clew, the same as the main. The head of the jib is relatively simple, the luff wire is continued up through the jib s intend, as.with theirSeaHorse marketi ng, to make the Sea Urchin available in four units. attachment point and returned back downto (1) all g.r.p. parts i.e.: hull, fin, rudder and hatch cover; (2) lead ballast and anchor bolt; (3) mast and booms and all fittings; (4) sails i.e.: (1) high top; (2) working; (3) storm rig, all being 800sq.ins. measured area, or the front of the jib boom thus forming a jib kicking strap, keeping everything tight. The hatch cover is secured very simply by screwing down through the hatch into the deck recess and sealing round with silicone as supplied to me in adeluxekit form, i.e. 1,2, 3, rubber sealant (bath sealant is ideal and is available in clear state thus eliminating the risk of colour clash). 4, but with only one suit of sails, the other sails being available at extra cost. Now to the building. Because the hull and deck are supplied as one unit already joined Winch and rudder servo mountings were positioned adjacent either side of the centre line, thus giving equal balance. The hatch together, it is possible to progress immediately to the fitting of the fin. The deck and keel have the correct sized and shaped opening is of sufficient size to allow easy access. | used a clear plastic box 6in. x 3in. x aperture pre-cut in them and all that was necessary was a gentle touch up with a file to make sure that the fin slid directl y into position to the marks shown on the fin. With this being done ready for the builder it eliminates the possibility of not getting the fin into correct alignment. It was then a simple operation to follow the directi ons given in the building instructions tobondth e fin at the keel and deck level, thus ensuring that both joints were perfectly water tight. Following the instructions the next task was to fit the lead ballast anchor bolt to the fin. This was quite straightforward and after the final filling of bottom of the finwith some form of epoxy filler the lead could be bolted into position. Aremoveable lead isa decided advantage when transporting the model to regattas, etc. The next stage | found the fiddliest part of the whole operation, that was positioning some form of suppo rtfor the rudder tube through the aperture in the transom. Having fitted a Support board across the hull | then drilled out the premarked position on the keel the hole to take the rudder tube and extended it into the Support board. Then following the instruction, bonded it correctly into position . The rudder shaft was then positioned, asper detailed drawing, in the rudder blade and bonded into position, and because extrem e care was taken in aligning the rudder tubeto the fin when the rudder blade was slotted into position, it lined perfectly. The next stage involved the adding of the deck fittings. This was relatively easy as the main positions are pre-marked on the deck moulding and the remainder were obtained from the comprehensive deck layout drawing supplied with the building instruct ions. The most important fittings, the shroud plates, sheet horse and jib attachments required bonding securely to the hull, otherwise all the other fittings just required screwing to the deck. The mast step screwed to the deck requires some support between the deck and the keel anda piece of dowel is supplied and needs bonding inside the boat directly underneath the mast step toprev ent the deck flexing under pressure when fully rigged. The sheet lead supplied also needed bonding at the bow to take main sheet from below deck to above deck level. The sheeti ng from the winch is kept to the simplest level using one main run of cord which is kept in tension by the use of elastic attached at the stern. The mast and booms are Yin. dia. and ¥gin. dia. aluminium tube and require a small amount of work to enable the boat to be fully rigged. The mast needed joining using the epoxying in joiner, the mast head plate position and the goose-neck fitting epoxying into the end of the main boom. The mast bands used are attached to the mast using self-tapping screws and all relevant positions for these parts are shown in detail on the drawings. The rigging wires were made up as per the instructions and then transferred to the mast band eyes. A forestay and backstay were then added using the cord and bowsies supplied. With the mast mounted on the mast step and shrouds and fore and backs tay secured it was then possible to bolt the goose neck on to its mounting on the mast. The kicking strap arrangement was made up as per details, which was quite simple buteffective and was then fitted, completing the main boom area. The jib aluminium tube and boom was %in. its attachment was very simple indeed, but very effective, the pivot being a simple cord attac hed to the boom through a ring of Bowden tube, which in tension grips the tube and when slack allows movement to the other required positions, then passes throu gh the eye on the deck and the end being attached to the forestay eye. At this point one can attach the sailstothe mast and booms. The head of the main simply hooked to the mast head plate by means of the hook suppli ed, andsimilarly on the foot of the luff of main to the eye onthe goose-neck. The clew adjustment is made by means of a hook attached to pre-drilled holes in the main boom. The luff of the main could be attached tothe ma byst either using a jack line down the mast and hooks orsmall eyelets in sail stainless steel rings to clip around the mast. In this insta nce | chose the eyelet and ring method, which | have found works very satisfactorily in the past. The jib foot is hooked into the jib boom at the luff 3in. to house the receiver, amplifier and battery pack, and this | mounted just off the bottom of the boat in front of the winch and rudder servo. The linkage between rudder and servo wasa simple length of straigh trod onto the rudder horn supplied. |useda 1 Yin. dia. winch drum on a Jackson Mk3 winch, making 3/, turns to control the sheetin g. The final parts were now ready tobe putinto place i.e.: cork bumper and plastic adhesiv e covers for the apertures in deck transom. and The bow required the piece of pre-shaped balsa-wood trimming and bonding into the bow and the cork which is over size needs Cutting to size and shaping, then sanding smooth prior to final attachment, using any type of contact adhesive. This then completed the building of the Sea Urchin, all that remained was to clean and polish the g.r.p. hull; this must be a major attrac tion to the absolute beginner, not having to paint anything, as we are not all perfect painters . The self-adhesive panels, three in total, were then placed in position, two on the deck and one on the transom. Thetwoonthe deck cover the access holes used when fitting the jib attachments; the transom covers the rudder post and rudder horn access. That completed the buildin g of the Sea Urchin, a very enjoyable boat to build. The criticisms were minor, mainly arising from personal preference and experie nce. All that remained was to see how she performed on the water. At the lakeside the boat was eas and ily quickly riggedand when she was launched for the first time in relatively still water she lay as near to balance as | could have hoped, and moved away gracefully. The weather at the time was overcast with little or no windata ll and the way she moved away seemed very en- couraging. Later sessions were run in “moderate winds and excellent results were obtained, her beating to windward was very pleasing indeed and downwind acceler ation was more thandarebe expected, as was acceleration out of the calms. | hope the photographs taken of the Sea Urchin do her justice and that she will prove to be a popular model for the produce rs, Solarkraft. | certainly enjoyed building this kit and look forward to sailing her in competition. December 1981 703 years ago, and 3 is formal inclusion of the |.M.Y.R.U. Marblehead rule 13(c) defining the the M head of a sail. Since the committee revising rule is due to report, this inclusion will possibly be of a temporary nature, as itis naturally hoped that the rearranged M rule will find international and thus national acceptance; one of the main objects of the revision is to lay down a clear method of measuring sails. Motion 4 is an addition to the 36R rule limiting how far aft of the hull a rudder may be carried, and 5 covers the addition of more precise definitions of Start and Finish lines in radio sailing, as out- lined in this column previously. Interestingly, following a protest at Cowes, the R.Y.A. may well be taking steps to define the lines more exactly, and a copy of the I.M.Y.R.U. definition has been passed to the appropriate quarter. for A, 10r The new !.M.Y.R.U. rating certificates and M classes and their radio sisters are the subject of Motion 6. All clubs will have received copies from which future certificates can be photo-copied, thus reducing costs, postage, and correspondence. This not inconsiderable aspect added to the obvious advantages of a universal international certificate should ensure a fair passage for this Council-made proposal. (Inci- dentally, for those who prefer printed rather than photo-copies, a supply of these certificates is now held by the Publications Secretary, Vic Smeed, P.O. Box 6, Rickmansworth, Herts. WD3 4RE, price 12p per copy plus post or £1.30 per dozen plus post, mixed if required). The last two motions, 7 and 8, simply ask fora mandate for Council to investigate the possibilities of recognition/adoption of, respectively, the Mickey Finn and Duplex 575 yachts. The former is already unofficially recognised (regattas are included in the fixture list) while the latter enjoyed temporary recognition but lost it over a misunderstanding. Although it is not possible to give any amendments which may be received, the above may be of interest to M.Y.A. members who have not seen the list sent to their secretaries on Sept. 23. New Zealand Crossing our recent reference to the current scene in New Zealand was a letter from Harry Short, President of the N.Z.M.Y.A., asking us to mention that they are attempting to establish model yacht clubs in the following areas: Mana- wetu, Taupo, Timaru, Napier/Hastings, Hamilton Bluff, Gisborne, Marlbourgh (sic), New Plymouth and Westcoast. Indeed, they’d like to hear from anyone anywhere in N.Z. who is interested in model yachting. Harry’s address is 17 McLeod Street, Upper E MY.A. A.G.M. will be held for the first time in Manchester this year, on Dec. 5 in the Princes Suite of the Grand Hotel, Aytoun Street. There are eight motions, though the Secretary may receive amendments to any of them up until Oct. 31. Motion 1 isa revision to the Constitution mainly modifying the right of the M.Y.A. Council to vetoa motion from a club. In the past, Council has rarely exercised this right except in cases where a motion is worded in a confusing or inconclusive manner: usually this means that such a motion would be deferred, but where the basic idea isa good one, Council has occasionally put forward the gist of the motion in suitably adjusted wording, as a Council-moved proposal. The new motion is that if three clubs in unison propose a motion, it must go on the AGM agenda, ie., Council cannot veto it. Council, of course, consists of four or five elected executive officers (elected annually) and District Councillors (elected annually) from all 704 M.Y.A. Districts, giving up their time to interpret to maintain the wishes of clubs and endeavouring a cohesive and improving Association. The combined experience, both in terms of sailing all types of yachts and in reconciling the apparently ir- reconcilable, is pretty impressive and most matters discussed (exhaustively, often) achieve near unanimity in decisions taken. The chances of such a representative body, able to take a broad view, vetoing any sensible or constructive motion are, to put them at their highest, slight, and one t electing different officers that might havethough rather than changing the Constitution might have been a simpler course if there is any dissatis- faction with the way matters are handled. In fact if three clubs supported a proposal, it would ob- viously have some merit and, provided it was clearly worded, it is highly unlikely that Council would be other than delighted to have a meri- torious motion to put on the agenda. Motion 2 is a simple proposal to reduce cham- pionship entry fees to what they were a couple of Hutt, or you can write to the Sec., Mark Rundell, 32 Seavista Drive, Pekerua Bay, Wellington. R/C Rules No, not yet more on Class 2, but some cogent queries from a recently-formed club, members from which have now attended about a dozen races. All of them are rather concerned about the way the sailing rules are enforced, or, more correctly, not enforced. It appears (the letter says) that a lot of O.0.Ds. and most skippers (and they include themselves) are very hazy over the rules and that as a result, after an incident those who shout loudest are not penalised and many incidents are ignored. (Does this sound familiar?). Recurrent problems include boats on a reach at the start forcing their way past the mark and fouling other boats which are close-hauled, and, on a free leg, boats quite blatantly sailing below their proper course. Is the official line to ignore small infringements, or should the rule book be enforced? Model Boats Three main causes appear to be (1) lack of ap- competitors know what to expect from the outset . preciation and knowledge of the rule book by skippers; (2) lack of knowledge, or lack of ability or desire to enforce the rules strictl y by O.0.Ds.; (3) skippers being allowed to follow their boats round the course, placing themselves out of earshot of the 0.0.D. and then arguing their way out of an incident because of the time lapse since it occurred. The club suggests that if the answer is education, then how about month ly articles in M.B. explaining aspects of the rules? And isn’t it desirable for skippers to remai n adjacent to the 0.0.D. for the duration of the race, and thus within earshot of someone who, hopefully, is knowledgeable on the rules? What do we think, and what do other readers think? Well, Model Boats did run some illustrated articles explaining basic rules, some years back, and would no doubt be happy to do so again if an expert skipper would make time to write them. Also, until a couple of years ago skippers were obliged to stay near the control position; the distance they could move was determined by the 0.0.D. but was not /ess than 15 yards either side of the central position. We always thought that this should be not more than — certainly races seemed to run better when all skippers were limited in movement. It may have been coincidence, but this year’s RM Champ ionship seemed to go better than usual, and there the skippers Which, coincidentally and uninten tionally, brings Us to a position very close to Class 1 and Class 2 racing, which would recogn ise the inescapable fact that some people like formal racing and others prefer a more easy-going approach. Scale Yachts A Mr. Sacree of Twyford, a recent convert from aircraft, writes to say that he built a model of one of the top Admiral’s Cup yachts and gets great pleasure from sailing it on a local gravel pit, where it attracts much admira tion, but he has never been able to sail it in competition as thereis no class for it in either the M.Y.A. or the M.P.B.A. He goes on: “‘It now seems that even Logbook is not really aware of the curren t status of models that would interest those with aesthetic tastes in yachts.” Taking the most obvious point first, one would hardly expect the Model Power Boat Association to have classes for yachts — they already have something like 30 classes of mechanically-pro- pelled boats to cope with. As far as the M.Y.A. is concerned, they will recogni se a class formally proposed to them only when it can be shown that the class has reasonable support — the criteria are 50 boats registered from at least four Clubs. Instigating m number of classe s in the hope that someone will be interes ted in building a model to were more or less oblige dto standin one spot,i na one of them would be a bit cart-be fore-horseish. Itis faintly possible that someone else is sailing was a known), but if so the chances of it being the same line like in power boat multiracing. So, as a personal opinion, yes, the old Rule 15 good one and limiting the skippers seems to us better than movement of letting them roam about. One argum ent for movement is that it offers a better chance for those with poor visual depth perception, but on the other hand if they have impaired hearing, itcan make the race much more difficult all round. At a distance, there are some people unable to distinguish certain sound s (like “wa-ter’’ and “o-ver-lap”) until their yachts are in a favourable position and their concentration eases. Howev er, many skippers prefer walking about and they vote to approve rules, or if there is one that they dislike a proposal for change can be submitted, so in the absence of any proposed change it must be assumed that walking the bank is the wish of the majori ty. Ignoring minor incidents or enforcing the rule book is a tricky area. There is no doubt that a large Proportion of model yacht smen want to sail for fun and feel that formal debate , penalties, etc. for trivial infringements are pettifogging and, for them, take the pleasure out of sailing. To enforce the rules, on the other hand, calls for an 0.0.D. with expert in-depth knowle dge, sufficiently respected by competitors and with the confidence and positive personality neede d to lay down the law without brooking (or giving room for) argu- ment. There aren’t many fitting this specification, certainly not enough to go round. Some clubs hold races informally and come to accept technical transgressio ns without thinking, so that when they hold Open races they tend not to see, or take action on, breaches of the rules such as Our Correspondent instances and which even in club races elsewhere would bring a penalty, or at least a warning, to the offending skipper. Of course to be fair the rules should be Strictly fol- lowed, so that everyone knows where he stands and virtually all circumstan ces are embraced by the set of rules evolved over very many years of racing. The constraints and discipline involved do lot, however, appeal to a lot of people who just want to relax and enjoy informal racing. The only answer is for race organisers to state n advance whether an easy or strict attitude to he rules will be adopted at any regatta, so that december 1981 a scale Admiral’s Cupper (though none are scale as Mr. Sacree’s are several to one. He does not give any indication of his model’s dimensions, but if the hull will fit in a box 36x 9x 1 lin.andthe displacement is less than 12Ibs. the yacht is eligible for the 36R Class. If the hull length is The appeal of scale sailing yachts can be judged from our heading picture, and below: taken at a recent Primrose Valley Model Week, and from the Popularity of the Panache plan, above, a semi-scale ocean racer, presented in December 1980 MB. 50in. plus or minus Yin. and he is prepared to equip it with a top suit not exceed ing 800sq.in. it could compete in the Marble head class. It could rate as a 6mif around 40in. waterli ne, The snag is that even if it did rate in any of these, it is most unlikely to be competitive against yachts designed to be built and sailed at the rule size, as Opposed to scaled from anothe r size. Aesthetics? Well, there are people who think that some of the Admiral’s Cup designs are pretty gruesome-looking! The fact that tastes chang e indicates that they are modifi ed by experience and acquired knowledge; unders tanding the function for which something is designed is a major part of aesthetic appreci ation. All this being said, we believe that there isa case for the M.Y.A. at least to lay down guidelines for a scale category, even if it is only to recommend a maximum sail area to which scale could be adjusted. A race for any scale model having a sail area of under (say) 600sq. ins. (or 900sq.ins. or? Perhaps ¥sq.m., which is about 775sq.ins.?), sails measured as simple head-tack-clew triangles, would perhaps influence scale enthusiasts and over a period indicat e which scale subjects offer the most reward ing performance. Note that no actual class is propose d, simply a semi-official recommendation which would encourage scale builder s to produce yachts with at least one major common factor, from which a class could possibly develop some years hence. It might be wise to limit deviat ion from scale, to, say, 5% on any dimension. The suggestion of 600sq.ins. is made because a lot of people interested in a scale yacht do not want a big one, something between three and four feet being a maximum. At Y%;-scale 600sq.ins. represents a full-scale sail area of only 67sq.ft., but at 1/10th scale, 417sq.ft. and at 1/20th, 1,667sq.ft. Dividing 600sq.ins. (4.17sq.ft.) into the full-size sail area gives the Square of the scale factor, if you want to play with some examples. Apart from the 6m, which has scale connections through its rule, and the A, which has even more tenuous connect ions, there has been nothing consistently approaching scale modelling in yachting. What potential members would like to see is some sort of class for scale models of existing yachts, rather than models designed as yachts in their own right to rules adapted from full-size practice. Sufficient people have shown enough interest to write letters on the subject to indicate that a growing area remain s neglected; some sort of semi-official encour agement would surely be worth a try? 705
