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The GOSSIP

Number 132 / April 2002

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Published by the Open Canoe Sailing Group

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Swing Rig (JohnB)

From an article in 'Open Canoe Sailor International' (an online newsletter for canoe sailors - now defunct).
A few weeks ago the AYRS (Amateur Yacht Research Association) published in their journal 'Catalyst' No. 7 an article by David Duncan on what he called the 'swing rig'. In essence the idea was to set the sail at an angle so that the overturning forces were reduced. Such a rig could have obvious attractions for the canoe sailor - lots of power and no overturning moment!! Not surprisingly this search for the Holy Grail is not new, and we ourselves have considered a number of possibilities over the years. As far back as '91 we published in GOSSIP a description of this type of rig. The essence of the swing rig was to align the centre of effort of the sail with the centre of gravity of the boat, thus eliminating the overturning moment. Nobody took the bait we cast, but the idea did not go away. In 2000 PeteH and I each produced a design for something similar, again the interest being in reducing the overturning moment. These would not have been as good as the swing rig, but every little helps. Again nothing happened, until now.

The winner of this year's AYRS John Hogg Prize was David Duncan who has constructed a full size swing rig fitted to his Wayfarer dinghy. The results are good enough to warrant further consideration of the idea. The sailing canoe's biggest problem is the tenderness of its hull. The normally negative, overturning forces become positive, lifting forces on the swing rig. Duncan points out that on a conventional rig something like 75% of the force on the sail is producing negative heeling forces, so reducing the effect can only result in a better performance. No sooner were these words printed than PeterH came up with the obvious next step. Incline the sail at 45 degrees; it will develop lift on either tack. On port it will pull up, on starboard it will push down, much like an aerodynamic Bruce foil. The line of the sail force acts through the C of E of the foil, hence no overturning moment. This would allow much higher aspect ratio sails with considerably lower induced drag and higher lift.

 

Low Wray - Joyce Afloat! (WalterG)

Low Wray was definitely a high point in last year's sailing. Beautiful autumn scenery, mild weather and perfect winds. A good time to improve my handling of my recently acquired trimaran and maybe get Joyce afloat? I found my new mast and sail that DaveP had brought for me and set about rigging the boat, whereupon Liz arrived to rig up the twin outriggers on her boat. I winced as I hauled my boat along the rocks into the water to give some room. There was going to have to be a better way! Out on the water I was at peace once more and sailed past two haughty swans that spoilt their regal appearance by dipping for weed and showing their bums.

Down south I could see a flotilla of OCSG sails and set off towards them, only to find that they were sailing towards me. I joined them and had a chat with Bernard about our respective boats. I was having to spill wind to stay with him, which surprised me for he had a mizzen up as well. Later, when he caught us up with a fine turn of speed, he told us that he found he had been dragging a large raft of weed on his daggerboard.

We all sailed about Ambleside bay like a gaggle of happy geese, until a roseate dusk drew in around us, the wind fell light and a little paddling was needed to get ashore. A trio of able-bodied sailors assisted me in getting my boat ashore and out of the way. I need a launch and recovery trolley if I'm to do this on my own. Bernard had such a trolley made for him by the two Daves, so a sketch was done and I have since made one. Whether I will achieve full independence or not, I don't yet know. The trolley can be carried on board to assist in landing on most beaches.

Sunday morning - light winds and the twittering of birds, ah so, I hadn't gone deaf! It was so noisy in the King's Head last night I couldn't hear what people were saying. Joyce volunteered to go for a sail in such a gentle wind, hey ho and off we go! She not only handled the main sheet well, but also became the ship's radio operator by calling friends and family on her mobile with messages like: "Guess where I am? I'm sailing in Wally's boat on Windermere". Information such as "Our position is 54 degrees 25 minutes North, 2 degrees 57 minutes West" did tend to be missing from the conversation but it's early beginnings.

The wind picked up after lunch so Joyce stayed ashore and I went out for some exhilarating sailing. We tore up the lake somewhat, with not a little competitive sailing going on and rather cheekily mobbed a Mirror dinghy, poor chap. As the early dusk came the wind fell light and the fleet sailed into Pull Wyke bay where we usually launch when we come to Low Wray. JohnS and myself sailed on into an adjoining bay with large numbers of coots paddling in and out of the reed beds; two small cottages were situated in this idyllic spot with vistas across the lake. Lucky them, and lucky us, for in our little boats we too could enjoy this tranquil spot. Back ashore Martin told us that the meals at Brockholes were good and cheap, so, as we were staying on a couple of days, weather permitting we would sail over for lunch on Monday.

Monday was fine with a force 2 so we set sail for Brockholes, a nice broad reach across the lake. When we finally found it, never having been before, we found the cafe shut. Still, it was nice to walk round the autumn garden. Back on board and feeling peckish we set sail for Waterhead, down wind

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