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Optimum Pumping Techique |
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Topic: Optimum Pumping Techique Posted: 05 May 18 at 9:29pm |
Does anyone know of any published research into best pumping practise? I'm thinking particularly about the frequency and amplitude of the pumps. I think the combination of the frequency and amplitude should be such that the Strouhal number should be around 0.2 - 0.3 (Strouhal number being frequency x amplitude / apparent wind speed), but that still leaves a trade off between frequency and amplitude of the pump.
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iGRF
Really should get out more Joined: 07 Mar 11 Location: Hythe Online Status: Offline Posts: 6496 |
Post Options Quote Reply Posted: 05 May 18 at 10:11pm |
Well it's slower than we use when windsurfing, because the sail refresh rate is not as efficient.
Depending on the style of pumping action, I.e if you can combine rocking the boat to leeward in order to assist the refill or not I'd say pumping a dinghy is only about 60% as efficient as pumping a sailboard. This research is of course pretty anecdotal, since the natives don't actually like it up them, so peak efficiency can only really be achieved when races get abandoned. PS And don't even sneeze into the sail down the lake or the miracle mums will scream and rant about waving their arms in the air.. |
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Post Options Quote Reply Posted: 06 May 18 at 6:50am |
Thanks for that. That's a good point about combining with rocking - that forces the pumping frequency to coincide with the roll period. But on windsurfers do you just pump as fast as possible or is there a rate that feels fastest? And could you improve speeds by a fraction of a knot if there was proper research into it?
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423zero
Really should get out more Joined: 08 Jan 15 Location: United Kingdom Online Status: Offline Posts: 3406 |
Post Options Quote Reply Posted: 06 May 18 at 7:30am |
I understood that a sailing dinghy propelled is 6 times faster round the cans.
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Post Options Quote Reply Posted: 06 May 18 at 3:26pm |
That's a bit of a stretch - would mean sailing a Laser to a PY of around 180. Even an Albacore would struggle to keep up with that!
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iGRF
Really should get out more Joined: 07 Mar 11 Location: Hythe Online Status: Offline Posts: 6496 |
Post Options Quote Reply Posted: 06 May 18 at 3:53pm |
No, that's a common mistake just flapping as fast as you can, I'd say it's exactly like rowing technique if there's been any research into that it would be worth looking at. Calling it air rowing is pretty accurate, but obviously there are different techniques according to different points of sailing, in much the same way as there are in dinghies. It's obviously banned in dinghies so I've never seen anyone other than ainslie on film and I don't think his techniques is particularly special tbh. Pumping is a very defined art, it requires good timing, it also has to be in tune with any shifts or you lose out, it can also be very effective practised subtley in low wind conditions. It is obviously very reliant on the created wind refilling the sail since the actual 'pump' is replacing the true wind. Off the start line you live or die from your pumping ability and stamina, it's one place where pumping speed and pumps per second do count if you don't then you die in a maelstrom of disturbed air from everyone else flapping , but that rapid rate just cannot be maintained so once your either up to optimum speed and have generated enough apparent wind to hook in and lock down, or if it's too light you settle down to a rhythm of about 1 pump per second to keep momentum. It's very arduous, light wind races on windsurfing boards are so much more tiring than sailing in a gale of wind. |
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turnturtle
Really should get out more Joined: 05 Dec 14 Online Status: Offline Posts: 2538 |
Post Options Quote Reply Posted: 06 May 18 at 4:00pm |
It was pretty interesting getting a lesson in sailboard pumping from Graeme at Hayling a couple of years ago- it made a massive difference once technique was dialled in, it’s a whole-body exercise- not just in the arms
Edited by turnturtle - 06 May 18 at 4:03pm |
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423zero
Really should get out more Joined: 08 Jan 15 Location: United Kingdom Online Status: Offline Posts: 3406 |
Post Options Quote Reply Posted: 06 May 18 at 4:29pm |
Peaky,
Should have added in light winds. |
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Rupert
Really should get out more Joined: 11 Aug 04 Location: Whitefriars sc Online Status: Offline Posts: 8956 |
Post Options Quote Reply Posted: 06 May 18 at 7:12pm |
Windsurfers threw in the towel and allowed pumping, but sailing should back away from what the Olympic boys are allowed in the Finn before it is too late. I can see a time when it is permitted in any conditions, and light wind sailing skills are lost completely. As it is, all the squaddies I've raced against over the years have been pretty poor when thinking becomes more important than robot learned skills.
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Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686
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turnturtle
Really should get out more Joined: 05 Dec 14 Online Status: Offline Posts: 2538 |
Post Options Quote Reply Posted: 06 May 18 at 7:21pm |
It’s the age old chess on the water vs physical athleticism argument... truth is, at Olympic level, I reckon it’s pretty much both and too assume it’s no longer just as ‘tactical’ is at best naive, or worse; damn arrogant.
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