Brent, If you can find someone to place some strain gages on critical areas of you hull, the readings would be invaluable in determining how strong your hull and viewports actually are. While this might be an expensive idea, you might contact a local college that offers mechanical engineering degrees as taking the measurements and processing the data would be an excellent class exercise and provide practical experience. R/Jay From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of ShellyDalg@aol.com I gotta believe anybody building a sub must be smart enough to test the damn thing "empty" before going down in it. By "testing" I don't mean just sending it down once or twice to see if it leaks. You're putting your life out there on a very small branch. Tests before it even gets wet are first. Then dunk testing while attached to a cable so you can be popped up quickly if there's even the hint of a problem. Like I said, you're looking for way more than whether it leaks or not. Instruments that collect real data must be included, and a thorough analysis of the results carried out so you know exactly what happened and why. I'm a ways off from this stage of my build but I've spent a fair amount of time researching and trying to educate myself on what is prudent before I go down in it. Still have a long way to go before I'll be satisfied with the safety factor thing but sure as hell won't be "hot dogging" my boat into the great beyond before I'm sure it's safe. That Seeker sub obviously wasn't tested empty to twice it's operating depth or they would have seen how fragile it was. After dunking mine and doing all the shallow tests etc. I'll be sending it down empty real deep a few times to collect the data I need. As I said, not there yet, but SOME of the things I've planned are onboard video,( of the inside), sound recording, ( listening for creaks and drips ), stress deformation on the hull and windows, ( got some little devices designed to measure what moves ), recordings of gage readings for the plumbing/air systems,( the onboard video ) and a cable to bring it back up if it screws up. I've talked to the guys at the harbor with the crane barge and they've got more than enough capacity to drop it down to 800 feet. It may seem a little expensive to go through all this but it's a lot cheaper than being DEAD! I'm really aiming for 1000 feet but I'll never get it in water past 600 feet manned and don't expect to actually drive it any deeper than 300. This of course is all subject to change depending on the test results. I'm still researching what kinds of things will give me a thorough picture of exactly what happens when it goes down. This is all part of the fun in building it. I see where most subs being advertised have a fail-safe system built in so the sub can't go deeper than it's operating depth. That's deserves a little discussion on how that might work. Anyway, as psub guys, it's up to all of us to "promote safe design and operation" of these things and anything less would be reckless. Better get off my podium now......Frank D. |