Drafting

RE: Drafting

Former Member — Tue, 16 Oct 2007 16:34:36 GMT

He did all kinds of things and all are true. He was a great friend. I have been trying to reach him for the last 2 years but all the emails I have sent come back undeliverable. I hope he is still with us. www.geocities.com/.../

RE: Drafting

Former Member — Tue, 16 Oct 2007 16:26:34 GMT

One of the great drafters was Abdel Latif Abou Heif the great Egytian Marathon swimmer, he was called the "Crocodile of the Nile" I heard that Abdel Latif Abou Heif used to read the newspaper while kicking with fins on his back.

RE: Drafting

Former Member — Tue, 16 Oct 2007 10:18:02 GMT

Don't believe all those ones for sure. Abou was not a very fast swimmer and had quite a splashy stroke. It was easy to pull away from him at the start of a race but once you got up around the 10 mile mark he was very tough. He would catch onto some one and rest on the draft, then pull away rested then latch onto someone else, rest then catch onto someone else rest until he was closer to the lead. He did not win a lot of races in the USA or Canada. He used to come to our house for dinner often. He sure could eat, two or three T bone steaks in a sitting. A family sized chichen was like an appetizer to him.

RE: Drafting

Former Member — Tue, 16 Oct 2007 09:59:50 GMT

He did all kinds of things and all are true. I heard some other stuff about Abdel Latif Abou Heif too... Abdel Latif Abou Heif had extra skin between his fingers and toes that he could stretch into webbing while he was swimming.

RE: Drafting

Former Member — Tue, 16 Oct 2007 07:59:46 GMT

I started swimming again 14 mos ago, and really training this past June. Always by myself. Last night I swam with a girls HS team who needed the YMCA's pool space in an emergency (their pool was closed due to pump problem). So I swam in a circle of 6 as I used to do constantly as a kid. And I really got to thinking about how swimming in a circle impacts technique. Just the crowd alone makes technique concentration harder. And I was swimming fast w/ perceived ease, but since I've been practicing the EVF I've read about here, it was noticeably harder to feall, at least, the catch. My DPS changed for sure. Subtleties like hand placement were lost compared to still water workouts. So...back to drafting...has anyone seriously looked into how swimming directly behind others constantly effects stroke technique? Do we subconsciously adapt to swimming efficiently in that environment to the detriment of race times, etc.? Do elite swimmers train single lane?

RE: Drafting

Former Member — Tue, 16 Oct 2007 06:35:20 GMT

I think most swimmers are familiar with the principal that other things like weight, beam (width) and propulsive force being equal, longer vessels are able to go faster than shorter ones. It has something to do with reduced drag on a longer object. I wonder if two swimmers close together front to back can effectively replicate to some extent the properties of one vessel twice as long. If there is a reduction of drag, it would benefit both swimmers who are acting as one to some degree. This "new" vessel would have double the weight, but with the same beam and double the power and length (approximately, depending on body sizes.)

RE: Drafting

Rob Copeland — Tue, 16 Oct 2007 03:09:59 GMT

I wonder if two swimmers close together front to back can effectively replicate to some extent the properties of one vessel twice as long. No.

RE: Drafting

jswim — Thu, 12 May 2005 06:07:31 GMT

Originally posted by ande I don't think it does, other than it's annoying in a pool to have someone on your heels for a long set, cause you know they aren't working nearly as hard as you are. ande , but they also won't be reaping the benefits that you are either so you'll probably smoke em' in a race!

RE: Drafting

ande — Thu, 12 May 2005 04:23:37 GMT

I don't think it does, other than it's annoying in a pool to have someone on your heels for a long set, cause you know they aren't working nearly as hard as you are. ande , Originally posted by LindsayNB We all know that drafting off someone allows you to go faster with less effort, I am wondering if being drafted off of slows one down? Anyone know?

RE: Drafting

Former Member — Fri, 08 Oct 2004 16:43:59 GMT

Originally posted by knelson I think you're confusing turbulence with wave action, but I see your point! What you want to do is ride the other swimmer's wave, not get swamped by it. What the lead swimmer wants is to not have the drafters chop up the water that any part of his body is moving through, including hips and legs.

RE: Drafting

Former Member — Fri, 08 Oct 2004 16:15:51 GMT

Originally posted by knelson Turbulent flow actually decreases drag compared to laminar flow for a bluff (i.e., not streamlined) body because it reduces the size of the wake. A good swimmer tries to be streamlined, but we're still not exactly an airfoil! If swimmers benefit from turbulence projected at them from an outside source it would seem that getting rid of lane lines would help trim some time off those stubborn world records. :)

RE: Drafting

Former Member — Fri, 08 Oct 2004 14:23:52 GMT

Originally posted by GNITE The truth is that like cycling the person being drafted also gains an advantage. Same speed with less effort. Or if you wish greater speed with the same effort. If you have a person on each side of you even better. Add one behind better yet. Of course the benefit is not as great as the one drafting. And if those drafting on either side are creating waves and other turbulence that disrupt what might otherwise be more laminar flow along the lead swimmer's lower body, this works against the lead swimmer.

RE: Drafting

knelson — Fri, 08 Oct 2004 12:35:28 GMT

I think you're confusing turbulence with wave action, but I see your point! What you want to do is ride the other swimmer's wave, not get swamped by it.

RE: Drafting

knelson — Fri, 08 Oct 2004 11:59:29 GMT

Turbulent flow actually decreases drag compared to laminar flow for a bluff (i.e., not streamlined) body because it reduces the size of the wake. A good swimmer tries to be streamlined, but we're still not exactly an airfoil!

RE: Drafting

Former Member — Fri, 08 Oct 2004 08:56:42 GMT

Lat night, I swam wiht the Unerv. of Ill. masters team. We did Indian Swimming. It used drafting by having us swim in a close line and sprinting. It was a lot of fun but drafting is a big no-no. Also, when you listen to peole after they've just swam a really fast time, thye will almost always mention that what was the best thing was that the water was either quiet or smooth. If you can get still water & move through it, you will swim faster. At least that is what I've always been told. Isn't that why you skull? So that your hand moves into still water through the length of the pull. Wave action is very tricky, it seems to me. Trying to move into & then stay in some one else's wave can be very deceiving. I don't know about all of this. When I think about it, it makes sense. But when I try it, I use a lot of energy trying to stay in the wave coming off of another person. Who knows? Some of this is talked about in Swimming Fastest. Physics is so confusing ot me, I was an Anthropology major. I could go on forever about the social and ecomonical dymanics of the division of swimmers in lanes

RE: Drafting

Rob Copeland — Fri, 08 Oct 2004 01:15:35 GMT

Turbulence increase speed?? So that’s why the announcers are always asking for us to cheer on the swimmers! The increased commotion and turbulence decreases drag. I always wondered why we swam faster with a cheering crowd. Thanks! And back to the subject of drafting, I think USA-Swimming did some extensive studies a few years back. For those who are really interested in this, they should contact USA-Swimming to see if they can get the scientific results.

RE: Drafting

Former Member — Thu, 07 Oct 2004 12:07:45 GMT

Originally posted by GNITE The truth is that like cycling the person being drafted also gains an advantage. Same speed with less effort. Or if you wish greater speed with the same effort. If you have a person on each side of you even better. Add one behind better yet. Of course the benefit is not as great as the one drafting. Are you aware of any research that bears this out for either swimmers or other surface penetrating moving objects?

RE: Drafting

Former Member — Thu, 07 Oct 2004 12:04:05 GMT

The truth is that like cycling the person being drafted also gains an advantage. Same speed with less effort. Or if you wish greater speed with the same effort. If you have a person on each side of you even better. Add one behind better yet. Of course the benefit is not as great as the one drafting.

RE: Drafting

Former Member — Thu, 07 Oct 2004 11:53:38 GMT

Originally posted by knelson Actually that is exactly what we are looking for. It tells us that a swimmer passing through the quiescent water will accelerate that water in the direction he/she is swimming. All it tells us is it's possible to draft, though. It tells us some of that swimmer's (or hand's) energy has been transferred into moving the water forward. It doesn't really help answer the question of whether the lead swimmer is helped or hindered by a drafting swimmer, though. I took it as obvious that the swimmer has accelerated some water. What the confetti is entirely unable to show us is how that accelerated water now affects another, similar size/mass, object that is placed in that space. The lone Nascar IS "pulling" air along behind it - which costs some energy. When the draft car tucks in behind that car the drafter now "pulls" a large portion of the tail air instead of the lead car pulling it. This shifts the work (fuel consumption) of pulling that air onto drafter and frees the lead car from that portion of the combined work. In return, the drafter is relieved of much of the frontal resistance which the lead car still labors under. Because the trailing end of a swimmer is quite tapered, the amount and nature of the tail eddys and turbulence is quite different than that of the rather blunt ended cars. A bit like the difference between the tail end of a Kayak vs the tail end of a rowboat. While a swimmer can get close enough to benefit from lower frontal resistance, I think the swimmer cannot get close enough to shift the tail resistance away from the lead swimmer.

RE: Drafting

Former Member — Thu, 07 Oct 2004 08:01:38 GMT

Originally posted by Conniekat8 Here's an experiment that may answer some of your questions: Go to the bathtub, fill it up with water. Take your 3 hole punch and empty the confetty over the water surface. Put your hand in the water (slowly and carfully, to disturb the surface as little as possible) then pull your hand in a fast liner motion in one direction, as if it is a swimmer going in that direction. Watch what happens to the confetti. Do it again, at variable speeds and variable hand depth and cross section. I don't think that what happens with the confetti relates in any significant way to the drafting effects we are talking about. It just shows where the tail eddys and turbulence and, perhaps how it moves. The confetti is simply reacting to water that has already been accelerated by the passing of the hand - they are not significantly changing the water flow. Actually my question about how the phenomena experienced by birds and nascar drivers might relate to swimming regards the interplay of the leader swimmer's wake with the drafter and, in the case of the drafter creeping up along side of the leader's legs/hips, the effect of the drafter's wake on the leader. I also question whether the drafter actually gets close enough to the lead swimmer to mimic the Nascar paradigm (where the two cars effectively act as one long car as far as air flow is concerned). If not, then drafting will not necessarily be a boon to the lead swimmer. If so, then drafting is almost certainly a boon to the lead swimmer - though not as big a boon as it is to the drafting swimmer.

RE: Drafting

Former Member — Thu, 07 Oct 2004 06:06:37 GMT

Originally posted by geochuck I will gladly share some of my experiences, and some of the stuff about my older brother Tom and some other guys that swam in my time, like Dennis Matuch the Chicago cop, Cliff Lumsden. George Young, the Black Shark Earnest Verkotter, the hunan windmill Gambi the Italian who stroked 100 strokes a minute from an earlier time. You do understand that Canada was where Marathon races started and some of the greatest marathon swimmers came from. George My understanding is that the lead goose tires not because he is "pulling" the others along, but because the others are benefitting from the draft and he is not, so he tires more quickly.

RE: Drafting

knelson — Thu, 07 Oct 2004 05:07:15 GMT

Originally posted by emmett I don't think that what happens with the confetti relates in any significant way to the drafting effects we are talking about. It just shows where the tail eddys and turbulence and, perhaps how it moves. Actually that is exactly what we are looking for. It tells us that a swimmer passing through the quiescent water will accelerate that water in the direction he/she is swimming. All it tells us is it's possible to draft, though. It tells us some of that swimmer's (or hand's) energy has been transferred into moving the water forward. It doesn't really help answer the question of whether the lead swimmer is helped or hindered by a drafting swimmer, though.

RE: Drafting

knelson — Thu, 07 Oct 2004 05:02:19 GMT

One thing is certain: the lead swimmer is NOT "pulling along" the drafting swimmer. The draftee may affect the leaders wake, but as emmett suggested, if anything it might add a fairing effect and actually aid the lead swimmer. Here's a simple experiment we did in a fluid mecanics lab in college. We had two cylinders of equal diameter one directly in front of the other in a wind tunnel. We measured the drag on each cylinder as the trailing cylinder was moved further back. Basically the trailing cylinder got the best draft benefit very close to the the front cylinder (maybe 3D or so?), but I don't think the lead cylinder's drag was affected much if at all.

RE: Drafting

Former Member — Wed, 06 Oct 2004 15:31:04 GMT

Here's an experiment that may answer some of your questions: Go to the bathtub, fill it up with water. Take your 3 hole punch and empty the confetty over the water surface. Put your hand in the water (slowly and carfully, to disturb the surface as little as possible) then pull your hand in a fast liner motion in one direction, as if it is a swimmer going in that direction. Watch what happens to the confetti. Do it again, at variable speeds and variable hand depth and cross section.

RE: Drafting

Former Member — Wed, 06 Oct 2004 13:09:08 GMT

My understanding of the physics of drafting in motor racing is that both the drafter AND draftee experience fuel savings as a result of drafting. The leader experiences less back end "suction" from air masses that would normally collapse in behind his car (creating eddys and other turbulence) are now shunted to the the rear of the drafting vehicle. The drafting vehicle experiences even greater fuel savings than the leader because he is spared the larger frontal resistance that is still the leader's to bear. But, BOTH experience fuel savings due to drafting. Same in cycling, though to a smaller degree. An ornithologist friend who dabbles in physics indicates that roughly the same is true of birds flying "in formation" - all including the leader benefit from the drafting process, the leader just gets less benefit than the rest. Same for fully submerged bodies in water. I can't tell you precisely how this translates to swimming though as there is a huge added variable because swimming is performed at the surface. How turbulence/waves/eddys etc are created and dissapated at the air/water boundary are entirely different than underwater.