- Description of contents
A new double-chine Marblehea suitable for vane or radio Mike Harris: FIG.1 1/16″dia. HOLES at 1” SPACINGS. HIS design was originally produced for a member of my own club who wanted an existing design altered to one with ‘corners’. The first three attempts were consigned to the bin as the shapes turned out to be pretty awful. | then realised that it was not going to be possible to carry out this exercise of ‘cornerising’ an existing design. | therefore put a new piece of paper on my board and started from scratch. The result is Tricorn, a double chine 16lb displacement, 10.25in beam, M Class, suitable for free sailing or R/C. The Vic Smeed design Genie has proved thata simple single chine boat can be competitive. This concept has been taken further with 7ricorn by the addition of another chine and a similar displacement. Building There are two methods of construction | would recommend. One is to construct shadows, notched for the chines, inwales and backbone. Set the shadows up on a building board, fit the chines, inwales and backbone and fair in. Cover with 1/16in marine ply. Release shadows and complete hull as normal. Method two is to use the stitch-and-glue procedure as used in sailing dinghies. Method two involves constructing shadows notched for inwales only. Set the shadows up on a building board, fit the inwales and fair in. Fit bottom panel on shadows, having cut a veed slot in the forward end. It is suggested that a cardboard pattern be made as the slot will be curved, not straight. (See fig. 1.) Drill row of 1/16in holes at about 1in spacing either side of the veed slot, (fig. 1.) Fit bottom panel on shadows. Pin and glue to transom. Thread copper wire through 1/16in holes, and starting from the vee twist the copper wire to pull the panel into shape (fig. 2.) Fix panel to bow block. Clip off spare ends of copper wire and cover slot with fibreglass resin and 3in wide tape. Fit middle chine with copper wire, and cover with resin and BOTTOM WIRE’S | s+ DOWS L \— suione BOARD. FIG 2. BRACES. ] tape. Fit top chine by wire, and taping lower edge and pinning top edge to inwales. File off bumps in tape where there are copper wire twists, and recoat with fibreglass resin. Rub down until chines are smooth. Remove hull from building board. Tape all internal joints. Cut slots for fin and skeg. Araldite the fin and skeg into the hull. Fit braces between underside of inwale and fin (fig. 3.) Complete hull as normal. Using this method of construction it should be possible to produce a light, strong hull. When the boat is complete check it in a tank to ensure that it is floating on its correct waterline. If necessary adjust the position of the lead. The rigs as shown on the drawing have been used on other boats | have sailed, and are not extreme in any way. The important thing is to have the sails made of a good quality cloth. Well, there she is, 7ircorn — a boat | hope will give pleasure to beginners and experts alike. FIN. ime filha’ Newcomers to model yacht construction will find the following two publications useful: by R. Griffin, ‘Model Racing Yacht Construction’ published by Argus Books Ltd., 14 St. James Road, Watford, Herts.; ‘Model Yachting’ by Vic Smeed, see ad. in this issue. FULL SIZE COPIES OF THIS PLAN ARE AVAILABLE PRICE £3.65 (CODE J) POST FREE FROM MODEL BOATS PLANS SERVICE, P.O. BOX 35, BRIDGE STREET, HERTS HP1 1EE. QUOTE PLAN MM1298 WHEN ORDERING. OVERSEAS READERS MAY OBTAIN COPIES THROUGH THEIR LOCAL AGENT — DETAILS ON PAGE 66. Govignes by 00 MJ. HARRIS. copyrigat of 10-35 Bridge Street, Hemel Hempstead, Herts. 1/2″ BUMPER A Chine t “ TRICORN * Displacement LOA – 50:5″ Beam – 10:25″ LWL Draught CB WL + – 16/bs. Chine 2 – 505° – 15-25″ – 28-53″ IN. | SUIT [LUFF [FOOT [ROACH ist 6825141″ | 2° 2nd.| 60″ 141″ | 2 Sra [so [tar | 4tn| 44° 2 fier] Sth| x6″[rare] 7} 68] 2° ist. [507512 2nd|445″|128e| 2° 3rd] 3851288 2° an | 347 [eal _f 5th [29251266] 1 Pry Contrast in sail roaches, mentioned in text. K929 has a Fair curve’ roach, favoured by Naviga, while K980 has the modern ‘parallel’ roach which gains a square inch or two of unmeasured area. From our MYA Correspondent A interesting letter from Tim Fuller tells us that New Forest RCMY C has been lucky enough to be offered the use of five acres of a 50 acre lake owne d by the Kingfisher Country Club at Ringwood, Hampshire. Sailing membership costs £16, and as members of the Country Club all facilities are available, including the glass-sided club house which overlooks lawns and landscaped gardens down to the sailing area. With car parki ng, loos etc. it’s all super-luxurious comp ared with the previous ‘gorse-bush’ exist ence. There will be a grand open meeti ng to introduce all clubs to the water next April (details later) and the 1980 seaso n will include the Nylet RM, Wellworthy , Wilkin- son Sword and Model trophies, plus the Met. Boats Magazine & SD RM Cham- pionships. Any enthusiast in the Ring- wood/Southampton/Bournemouth area who would be interested in joining New Forest is invited to ring Tim Fuller on Southampton 766055 for full detail s. You notice that the foregoing says… “lucky enough to be offered… ” but in fact Tim approached no fewer than 47 owners etc. of water during 1979 in the search fora good sailing site. This bring s up an interesting point, as every one of the 47 widespread years ago than it is now. If the title is not to be changed, there seems no reason why there should not be modifica- tion by addition, which would not cause any upheaval. Most clubs have a vane sec- tion and a radio section witho ut the club feeling divided, so would it not be possible to allow clubs to use the same distinction after the main title? ‘Model Yachting Association (Radio Yacht Secti on)’ might seem an acceptable compr omise, retain- ing the proper Association name yet allowing the recipient to realis e that he may not have quite the right interpretation of ‘model yacht’. Similarly, ‘Vane Yacht Section’ suggests rather more thana bath- tub toy? This is a cosmetic idea only, and regarded as such there shoul d be no divi- sive effect. Publicity No visitor to Wembley for the Model Engineer Exhibition or Earls Court for the Boat Show can retain any doubt about what ‘model yacht’ means; this is perhaps especially important at Earls Court, where many of the visitors may not even have seen photographs of our models. It is next to his rubber duck. We all tend to rate description, and there was hope that amount of good in promoting the MYA yacht in the soapdish in the bathroom, think of the term ‘model yacht’ as an accuthe general public were becom ing aware of what it meant, but, Tim says, with so many people outside ridicu ling it because of their interpretation, would it not be to the Association’s benefit to consi der some amendment to the title? As a radio man, he puts forward the suggestion ‘Radio Racing Yachts’ or even just ‘Radi o Yachts’, yachting an immense generally, even though the performance of the yachts of pool available. The problems are in ing and two remaining on the stand) and two are needed at the same time at the types of model sailing, so that the intro- Sail Area Measurement There is still a slight divergence of opinion unacceptable. be There would objection to almost change on cer- the grounds that the Associatio n has operated under its name for nearly 70 years, and ignorance of the subject was far more January 1980 Aircraft wing areas are usually measured as projected area, i.e., effects of dihedral are taken into account, and the age is included, so the actual area is different from the measured, proje cted area. If a sail were to be pinned to a flat surface with three pins through the headboard and tack and clew eyes, the triangl e formed by the pins (and the approp riate perpendicular) could be what is meas- ured. It would be necessary to stipulate a maximum distance between eyes and edges of sail; the roach would be measured perpendicular to a line between the distances to measure, irrespective of mast bend or boom angles, so that it would model does 21801. tainly seem reasonable to check the sails off the boat. manning, since a comfortabl e minimum at the Boat Showis five (three demonstrat- and exposure and henceforth will be Chel tenham Radio duction of ‘Radio’ into the title would be Most of the trouble lies in people cutting to the absolute limit, so that an adjus tment in mast bend is enough to rever se the legality ofa suit, or even perhaps of the roach, and to obviate any fiddling with the rigging to gain or lose a square inch it would cannot be easily demonstrated in the size Such ME. There is still room — and time — for volunteers to spend a day talking about their favourite subject, and Roger Stollery would be delighted to tell you of any gaps Yacht Club. One difficulty is that the MYA cover s all for change seem to add more compli ca- tions. head andclew pins. It would even be possible to lay down a tension figure (40z or 100g, perhaps) under which the pins must be inserted, using an inexpensiv e spring balance and pinning ina prescribed order. If all this sounds involved, reme mber that it would replace existing metho ds of pointing out that the latter is apparently used by Leeds and Bradford club. It is noticeable that Basildon club, which changed earlier in the year to ‘Channels International’, has had secon d thoughts being that current sail measuremen t rules are over-complicated. So far suggestions area nominally passing throu gh the fusel- always a pleasure to answer questions there, since they usually come from sailing enthusiasts who can get very interested — and often astonished ! appeared to think that Tim kept his model method of measuring them rigged on the yacht is preferred. As it happens, this is one of the main areas in which Naviga would like to see changes, the feeling he still has if you ring him on Godal ming on how sail area should be measured. Yachtsmen in the North seem to favour, in general, measuring the sails on a table, the sails being pinned out as flat as possible without stretching or pulli ng them in any way. In the South, the traditional measurement and would provide positive remove ambiguities and in fact simplify matters. Like the aircraft, it wouldn’t be actual area, but it would be consis tent. Also on sails, Naviga still uses the fair curve ruling for the roach and dislikes (so we understand) the accept ed modern practice of having about three quarte rs of the roach parallel to the headclew line, which of course gains an extra bit of unmeasured area. This would notseem an insurmountable obstacle to agree ment, though people do seem to get very fixed ideas on sails generally. Any views on this or other point s raised in this column are always welc ome, incidentally. It does offer an Oppor tunity to express opinions which might not other- wise get an airing! 21 7 Procedure on entering and leaving pits (1) Entry and exit to pits must be via pit lane. (2) Boats entering pits have priority over boats leaving pits. (3) Any boat leaving the pits which hits another boat entering the pits or causes a boat (4) entering the pits to take evasive action will be subjected to a time penalty of not less than 30 secs. and not more than 2 mins. 11 Entry (1) No pre-entry is required, enter on the day. Minimum recommended entry fee of £1.00. Entry to heats will be by card selection method. This is to operate as follows: (a) On booking in the competitor is to be given a race card and race number — the latter is dependent on radio frequency. The competitor then slots his race card into the master board in the heat in which he/she wishes to race. A competitor (2) (3) If any boat impedes or collides with another boat in the pit lane that boat will be subjected to a time penalty of not less than 30 secs. and not more than 2 mins. may run in as many heats as he/she wishes dependent on heats being avail- able. 8 Procedure whilst racing on the course (1) No deliberate obstruction of another boat or fouling will be permitted. (2) Overtaking must be completed in a manner not likely to impede or collide with the (3) The boat being overtaken has the right to take the best line but must not deliberately (4) overtaking boat, particularly at corners. this. Boats leaving the pit lane to rejoin the course must give way to boats on the course. Penalties for the above offences will be a warning for the 1st offence and a time penalty of not less than 30 seconds and not more than 2 mins. forthe second offence. Subsequent infringements will be subject to a 2 mins. penalty. 9 Start and finish procedure (1) There will be a 5 mins. interval between heats. (2) All engines must be stopped at the 30 second mark. Failure to do so will result ina time penalty of 1 min. being imposed from the start of the race. (3) There will be no restrictions however as to work being carried out on the boat up to the start time. Engines may only be re-started on the start of race signal. (4) At the start of the race boats may go straight onto the course through the pit lane marker buoys. Any claims of radio interference must be reported to the race officials within the time interval between heats, who will ensure that it is safe to proceed before starting the race. A competitor will be disqualified if his radio equipment is found to be causing interference on other frequencies. The start will not be delayed if competitors or boats are not ready to race. The starting area will be clearly marked to allow sufficient room for starting, and to space out transmitters to avoid interaction with other competitor’s equipment. Only the pilot, one mechanic and the lap counter to be allowed in the starting area. (8) At the finish of race signal, lap counters niust mark the lap sheets with the exact (9) At the end of each heat the pits are to be cleared immediately. 10 Format for heats, semi finals and finals Heats to be of 5 mins. duration. Semi-finals to be of 15 mins. duration. position of the boat when the race ended. Refer to drawing of course for part positions of lap. (1) (2) (3) (4) (5) (6) (7) Finals to be of 30 mins. duration. A maximum of 12 boats per race. The 8 drivers with the highest number of laps (from their best heat) will qualify for the final. To decide for the remaining 4 places in the final, the next 12 drivers with the most number of laps (from their best heat) will compete in a semi-final. All finalists to receive an award. The boat completing the most number of laps in any one heat shall receive an award. “A room with a bath, please!” = al 12 Rescue (1) Rescue service to be provided by organising club. Hitting the rescue boat will result in disqualification, in that race. Rescue boat has right of way at all times. (2) (3) 13 (1) General rules All boats when initially entered in the competition must be neatly finished and complete. (2) (3) (4) (5) (6) Boats will display MPBA numbers on both sides of hull or deck. Numbers will be at least 1in high in black on a white background. All boats must be fitted with a vertical plate minimum size of 6mm high and 65mm wide. Race numbers as supplied by organisers must be affixed to both sides of plate. The recircling of missed buoys will not be allowed and that lap discounted. Cutting across the course is not allowed for any reason and the competitor will be disqualified from that race. Drivers must supply their own lapscorers. | hope you have read through the rules more than once and try to picture in your minds what exactly | am trying to achieve. By having a hull restriction you will not have to pay a fortune on the best racing engines to make it go fast. The fuel system is restricted to 125cc which should give you between 6-7 mins. running time. If you make the final which is of hr. duration you will have to come in for refuelling to complete your time on the water, which should tax your pit mechanics brain, working out how far your fuel will stretch to eliminate that last fuel stop. Format of heats, semi-final and finals have been introduced to allow a sit out. If after one or two heats you think you have attained sufficient laps to allow you to go straight through to the finals, you do not have to race in any more heats if you do not wish to do so. | have started giving out rule sheets which | have had printed with the help of Norman Dickinson from the Bexley club, who is also willing to help in getting this class of racing going. Already | am getting a feed back of information on improvements to the written rules as printed above. Rule 2(5) Various hull manufacturers have moulded lips which increase the size of the boat so the measurements will be taken along the waterline. Rule 6(1) It would seem that most people would prefer an oval keen interest. With the help ofa few people, | will only be to pleased i ull! ay Onthe completion of each heat the race official will mark the race card with the course rather than M shaped to allow for faster racing and less smash ups. With this healthy attitude towards improving these rules, already before there has even been a race, there seems to be \\ is Race cards for each heat will be removed from the master board 5 mins. priorto the start of the race. Only cards removed from master board will be accepted for that heat. number of laps completed and sign it, it is the competitor’s responsibility to collect their race card from the race official. He may then again enter his card on the master board in the heat of his choice. Fouling is defined as bumping and boring where there is adequate water to avoid > (6) (7) (c) manoeuvre so as to baulk the overtaking boat. (5) (6) (5) (b) it f to become a central information point, for the south only. | am hoping to get enough clubs interested to run some competitions for 1980. As this is a new type of event there might be a few problems in the first year at organising Team Sprint 3} events, i.e. — masterboard, race cards, race sheets, rules etc. Well| can solve that problem by loaning the various clubs my own masterboard, and to take advantageof the printing | have had done, | could supply race cards, race sheets, rules etc. for a small fee to cover printing costs, until such time as clubs feel it is worth while building their own masterboard and providing their own printed matter. | would also like clubs to return race sheets after every meeting so that Norman Dickinson can keep a record of all events in his computer and we can have information at hand such as possible overall championship prize, possible handicap system, novices results, etc., which are but a few possibilities. In the short time WUDINGJanuary 1980 since we have developed this class there are already a few models finished and running. More Team Sprint 33 news in March ‘Model Boats’. 49
