Aside from the affected meet hosts, the real losers of this dilemma are the swimmers from the two affected SCM meets who stand to lose their placing in the USMS Top Ten. In short order, R&T will release the 2001 SCM Top Ten and we’ll discover who was denied placement on the list because their worthy performances were conducted in pools they believed were legitimate for sanctioned competition.
I do not yet know if I will be one of those people, but I expect to be. You might remember the story of my 1500m Freestyle that turned into the 1550m Freestyle (or rather the 1498.7m Freestyle that was the 1548.68m Freestyle) at the NWZ meet. My time was 19:04.76, a 50-second improvement from my previous lifetime best. (The 19:55 swim as well as a 20:05 swim both put me into the SCM Top Ten in those years)
Many folks in the discussion forums have sounded off about how important they view the Top-Ten rankings. I’ll simply say that in my case, if I had been told by the meet director before my 1500m Freestyle that the pool was less than 25m long, I probably would not have swam the event. There was no other swimmer in my age group at the NWZ meet. My “competition” was the other 30-34-year-olds nationwide.
The impending ruling by the EC could very likely demand that I and other swimmers at the affected SCM meets make a sacrifice for the betterment of USMS. Honestly, I do not know what greater good is supposed to result from locking out certain swimmers from the Top Ten. I do not even know if this sacrifice is even necessary.
The EC certainly is considering the relationship between USMS and its swimmers in making its judgment. It is inevitable that some swimmers will be affected negatively by whatever “final” decision the EC renders. My contention through all of this has been that (1) deserving swimmers ought to be appropriately recognized for there outstanding achievements, and (2) that if we must do harm to swimmers and strain the USMS-to-swimmer relationship, we affect the least amount of harm upon the least number of swimmers. I’m glad that we are soon to be bringing this matter to a close, but I do think that this decision does harm to more people than necessary, as well as to the wrong people.
If it turns out that the 10th place 30-34 swimmer went slower than 19:04.76, I will be happy to congratulate him publicly and acknowledge that he earned his position. If there is any kind of positive outcome from all of this that I can guarantee, this is it.
Former Member
Michael Heather is Chairman of the SPMA subcommittee on pool measurement. Along with Steve Schofield they have measured pools within SPMA for over a dozen years. Perhaps we can call upon Michael to write up a procedure for measuring pools using steel or fiberglass tape measures. We can call this a "Guideline for pool measurement" and along with laser measurement our LMSC's can begin to fix this problem and make masters swim meets a level playing field.
There are so many variables in a swim meet, such as pool depth, lane line size, starting block height, even water purity that I think we have enough rules to cover everything. We just need to clarify and close any loop holes. If we do our job as a governing body the swimmers will never know, nor need to know all the rules and tolerances for pool design.
And those who swam in 24.98 meter pools can have solace that they will allways have the world records for that distance. SPMA has a swimmer who will always hold the 300 meter backstroke record.
Wayne McCauley
SPMA Chairman
That is a cool tape. One way it could work is that at the appropriate tension, the 'mis-measurement' as a consquence of the sag is a constant fraction of the total length. Then the marks on the tape are made slightly farther apart than the nominal length of meters. If one person can hold the zero position of the tape I doubt that the tape will stretch much.
That would mean that Michael's tape could not be used if it were supported (or laid on the ground.) I wonder how much its measurements differ from that of a regular steel tape.
In our LMSC the approach to measurement, rightly or wrongly, has been to assume that, since all the pools we use are regularly used for USS and/or college competition, they are the correct length. In the only instance I'm aware of that a Masters-motivated measurement has taken place, it was done, years ago, "by the (USMS) book" - that is, by rank, though responsible, amateurs with a fibreglass tape usually used for measuring track and field courses. That tape was chosen over a similar steel tape because there seemed to have no appreciable sag compared to the steel tape. The pool was judged to be within the required specifications.
Most of what I learned in math class in yesteryear has become Edgar Allen Poe-esque "forgotten lore" but I do remember that the shape of hanging lines is the so-called catenary curve. This is different from parabolas, but how it varies, I have no idea. Anyhow, someone who understands the mathematics of catenary curves should be able to compute the fudge factor inherent in any degree of sagging, I would think.
For a different thread I was thinking about sag when measuring a pool. I remembered from high school geometry the pathagorian theorem (If I spelled it correctly it is only by luck). I assumed that the sag would be close to a straight line (I think it is really a curve). Assume that you have a 10mm sag, create a right triangle, one side is 10mm one leg is 12500mm and from that compute the hypotenuse (if I spelled that correctly I have hit the daily double). The length of the hypotenuse is barely longer than the 12500mm leg and so small as to be not measurable. (I think the co-efficient of expansion or the stretch of the tape would be more significant, but I will wait for the engineers to let me know).
As I said this was 10th grade geometry, by 12th grade I was more interested in getting a date on Saturday night than studying and really forgot analytic geometry. Rob Copeland wrote back "a true 25 meter pool is measured with a 0.1 meter sag, in the tap, the length on the tape would read 25.001066663 meters"
According to Rob, the formula used to calculate the segment of a parabola is
s = sqrt+* ln)/(c/2)]
Where: s = tape distance, h = midpoint sag and c = true pool length.
To Mike Heather who measures the SPMA pools and would not compete in a pool that was one Angstrom short. "You da man." I once made a telescope lens where the lens was configured to a 1/10 wavelength of light or somewhere around 500 angstroms (as I recall). I know what it took to get the right interference pattern to be that close, but to get it an even smaller distance, I doff my hat. :-)
michael
To Jim
mea culpa!!
I sent the calculation of the parabola to the Rules folks only as an example of how little the sag would effect the total calculation for measuring a pool. I should have invoked the catenary curve calculation instead. However, without knowing the weight of the tape and the tension at the end points, I did not know how best to calculate the exact sag, so I sort of winged it and used the next best calculation.
And in case anyone is interested in knowing the difference between a parabola and a catenary curve (yea right) there is a good explanation at:
www.nas.com/.../hanging.htm
In , our next lesson we will discuss the differences between electrical currents and ocean currents, and which one a wet swimmer should stay away from.
To Mike Heather:
You Said:
"When I was in high school, there were two schools in the conference that were 100 feet long"
Either the schools were really wide or they didn't have a very large student body. By the way, how long were the pools? :)
Leo
To Michael Moore,
Thanks for holding me up as a pillar of righteousness, but I didn't say I would not compete in a short pool. I'll compete anywhere, almost. But if it (the course) is not a legal length, I would not think of submitting any times for official recognition.
When I was in high school, there were two schools in the conference that were 100 feet long, and our times for a 50 (really 66 2/3 yds) were dismal. So were the 100 and 200 IM times. And they were all recorded as official, as far as I know. Ugh.
I yam what I yam
I honestly mean no offense to anyone, but this business about
steel tape sag vs fiberglass sag is pretty anal.
Just lay the tape on the side of the pool edge (or both sides
and divide by two) and that would be plenty close for me.
No sag if the tape is supported by concrete.
Fascinating thread here!
Just to pick up on something Wayne mentioned, how does the depth of a pool have an effect? I have wondered about this.
At my old swim club in Austin, the 4 foot deep pool got a couple of inches more shallow in the center, and I would often scrape my hands on the bottom which was no fun, but otherwise I am clueless what effect pool depth has.
Tom.
