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AYRS NWLG Autumn Meeting, Saturday 8th September 2018

Posted: Mon Jan 07, 2019 9:52 pm
by AYRSWebAdmin
The meeting commenced with Mark outlining the development of a suitable sail system for his Proa. He is now on the third development. He passed around a drawing showing the general layout of the sail plan. The main sail is a Bermudan sail which wraps around the mast. This eliminates much of the drag generated by a conventional mast section. The twin trailing edges (leech) are attached together with Velcro in the region of the conventional short sail battens. The sail can be slab reefed which then enables the upper potion of the mast to telescope within the lower mast. This feature reduces windage and lowers the centre of effort and the centre of gravity of the rig. To avoid the use of excessively large diameter tubes, the upper mast is stayed. The mainsail is supported at its lower edge by a wishbone boom which extends forward to carry the tack of a small self trimming jib sail. A strut between the mast and boom, which is angled upwards, acts in the same was as a kicking strap. Much discussion surrounded this subject with opinions being sought and given in equal measure. Mark seemed delighted with the interaction.

Colin then gave a presentation of his development of a radio controlled kite which he intends to use to tow his hapa. Much of his talk surrounded the theory of flight, the advantages of the dihedral wing configuration, control surfaces and the use of a radio control module and servos. A separate discussion took place on the use of carbon fibre to reinforce or stiffen existing structures. The consensus was that it was an expensive, difficult material to handle and it was probably better to use Kevlar for general stiffening purposes.

After a break for tea, coffee and cakes (thanks Col), Mike informed the meeting that he had written to the AYRS Chairman, Fred Ball, suggesting a change of tack on the way the Annual General Meeting was conducted. As reported in CATALYST magazine, only eighteen members had turned up at Thorpe Village Hall on the 21st January 2018. Mike had pointed out that it was impossible for someone living in the North of England to attend the all day meeting and the AGM without an overnight stop. The cost of hotel accommodation (not everyone knows someone who lives near London) rendered it an expensive outing. Mike pointed out that he had suggested a central London venue, to be held on a Saturday, with the AGM being held at midday followed by a general meeting. The idea was discussed with at least one member stating it was within driving distance, but Mike pointed out that he, personally, was not prepared to drive that distance during potentially severe Winter weather. The meeting was generally in agreement with Mike’s proposal and urged him to write to Fred Ball stating that the members of the NWLG were in agreement with this proposal.

A further subject discussed during he above session was the question of voting for proposals put forward at the AGM. Some of those present felt that members should be able to vote online. Mike pointed out that not all members were computer literate and that two years ago he had proposed a fact finding questionnaire be sent to every member to try and discover if digital communications could be used more effectively by AYRS. The questionnaire had been modified slightly and recently trialled amongst members attending a Thorpe Village Hall meeting. The results were certainly not representative of the general membership as the more active members of AYRS tended to be computer literate.

Mike also pointed out the difficulty in recruiting members to sit on the AYRS Committee. Currently, the positions of both Treasurer and Secretary were in the caretaker hands of Simon Fishwick, who was still acting as Editor. John S stated that he belonged to an organisation where a steering committee had been setup to handle specific projects. This reduced the rhetoric and helped to move things along at a steady pace without having to indulge in the cumbersome practice of leaving all the decisions to the full committee.

James made mention of a dissertation he had undertaken as part of his Marine Engineering Degree course. He had investigated shape versus lift for a variety of foil shapes when used as daggerboard, centreboards or rudder blades. He had commenced with a simple rectangular cross section and progressing through several stages to a full airfoil section. He stated he had been surprised at the apparent huge jump in efficiency by simply rounding the nose of the foil. Incremental increases then occurred as he first rounded the trailing edge, tapered the trailing edge and then finally produced a completely symmetrical airfoil section. This led to a discussion about foiling Moth class dinghies and their unusual cranked boom. The engineers present explained why this shape was more efficient that a straight boom. Further discussions on Renolds Numbers, Froude and boat speed led Mark to offer the following rule of thumb which is used by the wardens on lake Windemere.:
Time in seconds between stern waves x 3 = boat speed in knots.

Several members, having enjoyed days out during the Summer, outlined places of interest. These included Ironbridge and Blyth Village; both in Derbyshire, Beamish Steam Museum in Northumberland; the DANIEL ADAMSON, a Merseyside based restored steam powered Tug/Tender, which carries out tours of the river Mersey, Manchester Ship Canal and river Weaver. Mike recited a brief history of the ship, the only steam powered Tug/Tender in working order in the UK.

John Alldred mentioned the LEIGH CANAL FESTIVAL which is taking place on the weekend of 15th/16th September. He also mentioned a visit to the National Waterways Museum at Ellesmere Port, organised by his local Rotary but open to all comers, which is on the 10th October.

Finally, Mike stated that he had purchased a Selway Fisher STORNOWAY dinghy. He showed photographs and a brochure of this dinghy. The dinghy is just the finished hull and so is a blank canvas. Mike hopes to turn it into a sailing dinghy, using his stock of spars, sails and fittings. The meeting concluded at 5.30 pm.

Present: John Alldred, John Shuttleworth, Colin McCowen, James Nielson, Mark Hillmann, Steve McKenna, Brian Shenstone, Mike Howard.
Apologies: Adrian Denye, Colin Weir.