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I don't think that definition fits, Vance. A divers operating depth one day could be 30 feet and 300 feet the next day. Neither of those data points is effective in communicating the maximum safe operating depth of the sub. Likewise, Phil used "working depth" in his reply, but working depth is just as generic as operating depth. To me, your working depth is what ever depth you happened to be working at in a particular moment of time. "Hey, I dove in a DW2000 today" "No kidding. What was your working depth?" "Oh I was just checking out some underwater pipes at 100 feet" That seems like a very logical conversation that could take place after a dive, yet it in no way communicates the operating limit of 2000 feet that the vessel could have been taken to. In the home-builder arena the term use becomes significant because there are likely instances when even "rated depth" could be used in the wrong context. I think there are three data points that home-builders need to be aware of. The first is crush depth, failure depth, design collapse or whatever other term you want to call it. It is, however, the theoretical failure point for the vessel determined either by calculation or FEA, which I believe ABS appropriately termed "design depth". The ABS definition is faulty however because they mix the words "designed and approved to operate" which introduces confusion by interpretation. Other references to design depth by ABS in their rules document make it more clear that they mean failure depth. Perhaps "Failure Depth" is the term we should use here since it should not cause the same confusion as does design depth. The second data point is either safety margin or MAX operating depth. The third data point is the "rated depth" which is the deepest depth the vessel has been tested to. With these three data points the home-builder and PSUBS enthusiast has all the performance data they need to make reasonable interpretations about the safe diving parameters of a particular vessel. The failure depth is the most important data point however since everything else is a factor of that depth. Jon On 12/10/2010 2:25 PM, vbra676539@aol.com wrote: You guys have fallen head over heels in love with a logic trap, heavily basted with semantics. Give it up. Design depth is your operating depth PLUS the percentage required for testing. It means the depth to which the pressure vessel may be taken repeatedly without incurring irrecoverable damage. |