[ Follow Ups ] [ Post Followup ] [ TimeZone Public Forum ] [ FAQ ]
Posted by Mike Bilow on September 13, 2000 at
02:27:47:
In Reply to: To continue the water resistance debate.. posted by
Rp @ Tz on September 12, 2000 at 13:00:35:
Posted from Host: prov05-pm3.intap.net (208.131.219.197)
B. Hannigan and I were two of the main parties to the discussion on the Breitling Forum to which he refers. My view is exactly opposite to his.
First, depth meters used for diving are designed to discard rapid changes by integrating them over some period of time. Many instruments are designed to do the same, such as car fuel gauges. In a GM automobile, making ordinary left and right turns will produce variation of nearly a quarter of a tank, but, in a Ford automobile, there will be almost no such variation while turning. This is because the Ford system is designed to be slower to react, smoothing out occasional variations. Therefore, depth meters are not useful for making measurements of instantaneous pressure.
Entry into and exit from water, or any other action which causes some sort of abrupt change in medium, is as some have said the most likely opportunity for failure. The pressures can be enormous in such circumstances, sometimes even deadly. There are cases on record of people being killed by doing a "belly-flop" dive and landing the wrong way. Many people have been killed on impact after jumping off bridges. Hurling a watch at a wall could be expected to do considerable damage to it; hurling a watch at the water -- by, for example, jumping off of a diving board -- is capable of doing the same.
Force is not equalized in any rational way. As a practical matter, force is encountered at a point of impact, and something is usually going to deform severely, at least during the course of actual impact. Exactly what happens and in what sequence will tend to be complex and unpredictable. If it is a matter of life and death, as in the crash resistance of a passenger car, then you design a series of controlled failures and deformations, eventually working up to the airbags and safety belts.
-- Mike
: .Greetings,
: We had an interesting discussion yesterday on the forum that I think deserves another round...and maybe a permanent place on the classics..
: I started off the thread with a question about who really wears their non-divers watches rated to 30meteres in water...
: please add your input..