I have been replaced by glass idol! Now I know why you do a hiatus from hv projects so can do like Lara Croft AGAIN now this time for sunk treasure! I said you are the radiation bug now I want thank you for prove it! Careful now! I never forgive you if drown I say fresh water size of Indiana totally creepy like unnatural My opinion says storage at pressure is ok but suck in only if powered so glass gets hot.

 

Go for it HP! As you say the downside is the loss of a week's work plus a lot of broken junk. On the other hand You'll be kicking yourself if the content's of the hold are successfully raised and you have no part it it. It appears to be a unique opportunity for you. I say go for it!

 

Now I know why you do a hiatus from hv projects so can do like Lara Croft AGAIN now this time for sunk treasure!

You might laugh - but remember the true value of an item is not what you can get for it - but, rather, what you might reasonably expect to pay to acquire it! -- That said - I'm happy the IRS doesn't share my views on the subject

I said you are the radiation bug...

Indeed you did -- and, as you may recall, I agreed!

I say fresh water size of Indiana totally creepy like unnatural

Sounds like a nasty case of hydrophobia, Aleph!

To my mind the truly uncanny aspect of the "Saint Lawrence Lakes" is their extreme 'youth' (Ca 10,000 years) --- The fact that humans (well-nigh as we know them today) walked the Earth prior to the lakes' existence is beyond incredible to me!

Careful now! I never forgive you if drown

I'm sure glad you said that! -- Should self-preservation reflexes fail - dread of your condemnation will buoy me up (pun intended)

My opinion says storage at pressure is ok but suck in only if powered so glass gets hot.

While vacuum sucks - loss of same sucks much, much more!

Well, hey! Seriously -- Thanks for thoughts!!!

Best regards
HP

 

Go for it HP! As you say the downside is the loss of a week's work plus a lot of broken junk. On the other hand You'll be kicking yourself if the content's of the hold are successfully raised and you have no part it it. It appears to be a unique opportunity for you. I say go for it!

My sentiments exactly! I've certainly more to gain than lose -- Moreover, I'm heartened by the consensus that my prospects of a gainful venture appear promising!

Best regards
HP

 

Why not do some experiments, 36m of string is not hard to obtain so you could try lowering old tubes or even light bulbs to that kind of depth and see what happens. You could also attach bulbs or whatever at 10m intervals and lower them to say 100m to see at what depth (if any) they fail. I know the tube in which you are interested is a different beast but it would give you a feel...

 

@sirch2

The idea of determining the 'crush depth' is intriguing! I've a couple 'dud' RAs (fractured anodes but intact vacuum) for use as 'test subjects' and ready access to ~ 250 Fathoms (1500 ft) ~ 650 PSI (I'm guessing that should do it) --- The 'tricky' part is preforming the experiment in such a way that the tubes remain out of contact with the water (i.e. remain under elastic force) -- an inverted drum might 'do the trick' though excessive buoyancy may become an issue...

It's tempting to merely attach a tube to a length of polyfilament then lower it until disruption occurs -- Maintenance of 'good standings' with the MNRF/DNR, however, will require retention of debris - meaning I cannot use abrupt loss of tension (weight) as an indication of breakage --- Well hey! Thanks for your considered suggestion! -- It is certainly easier (and, I might add, less hazardous) than my pressure chamber idea!

Very best regards
HP

 

I don´t see any problem with weighting the drum to make it sink. Just beware that the air will compress so you need to have enough initial volume to keep the tube inside the air pocket. Also note the boyancy will fade away as the drum descends, so the tehter needs to be strong enough to hold the counterweights.

 

I don´t see any problem with weighting the drum to make it sink. Just beware that the air will compress so you need to have enough initial volume to keep the tube inside the air pocket. Also note the boyancy will fade away as the drum descends, so the tehter needs to be strong enough to hold the counterweights.

While I don't have time to try this prior to the salvage operation --- I'm definitely going to do this and report the results here (as Photonicinduction is wont to say) 'in the name of science'!

Thanks @kubeek and @sirch2 !!!!

Best regards
HP

 

I have to say I am struggling to see that elastic force is different to hydrostatic in this case, as long as the force applied is genuinely triaxial which it would be in water. To catch the debris you could use a bag or net, indeed placing a sample in a thick, sealed plastic* bag may achieve both aims without adding too much buoyancy.



*One made from something like butyl pond liner or a car inner tube may be better but harder to see what has occurred without opening.

 

Actually if I have my orders of magnitude right 36m is about 3.6 bar and could probably be achieved with a decent foot pump, so I am now thinking something put together from solvent weld plastic pipe (you may be able to pick up a short off-cut) with a screw-cap fitted with a car tire valve. Anyway, enough idle musings...

 

I would try it in the lake with a 5 pound anchor and a standard Edison bulb. Lower the anchor with 3 to 5 bulbs attached to rope and lower to 40 feet and monitor for any slight change in weight as bulb breaks (buoyancy loss). I am willing to bet a standard 60 watt bulb survives. If so, I am certain that a tube will survive.

As mentioned above, potting compound is just bonding the connector to glass, the glass is fused around any metal anode exiting the glass and it will not be a source of leakage unless you have corrosion issues.

 

I would try it in the lake with a 5 pound anchor and a standard Edison bulb. Lower the anchor with 3 to 5 bulbs attached to rope and lower to 40 feet and monitor for any slight change in weight as bulb breaks (buoyancy loss). I am willing to bet a standard 60 watt bulb survives. If so, I am certain that a tube will survive.

Sort of thing I had in mind but I'm not sure that with 40' or more of rope there will be any chance of detecting weight changes - 40' of rope probably weighs a lot more than the displacement mass of a light bulb; drag, buoyancy, currents, entrained air, etc. etc. will confuse the "weight" measurement.

 

Sort of thing I had in mind but I'm not sure that with 40' or more of rope there will be any chance of detecting weight changes - 40' of rope probably weighs a lot more than the displacement mass of a light bulb; drag, buoyancy, currents, entrained air, etc. etc. will confuse the "weight" measurement.

If you are not able to feel a half pound water displacement difference (10%), this paper suggests that 25 to 100W standard A19 bulbs have unique resonance frequencies as they break underwater. Fortunately, they have done the experiment for us and determined that glass A19 Edison bulbs can break on their own down to 200 meters.

http://saund.stanford.edu/saund1/Light_bulbs.pdf

Note that some bulbs were broken with a mechanical bulb breaker and some allowed to break on their own at depth. The point is, @Hypatia's Protege, bulbs are easily survivable to 100 meters, a vacuum tube (valve) with thicker glass will likely do better.

 

I am struggling to see that elastic force is different to hydrostatic in this case, as long as the force applied is genuinely triaxial which it would be in water

Shock fronts and and corollaries thereof (e.g. cavitation) from remote sources - and, on a different while relevant 'tack', thermal effects, come to mind -- Granted! Probably not important in this case - still, the closer the experiment is to 'reality'...

Actually if I have my orders of magnitude right 36m is about 3.6 bar and could probably be achieved with a decent foot pump, so I am now thinking something put together from solvent weld plastic pipe (you may be able to pick up a short off-cut) with a screw-cap fitted with a car tire valve. Anyway, enough idle musings...

I too was contemplating employment of a pressure chamber -- Though I've now 'just gotta' see how much a tube will take! --- Then too the 'immersion approach' has undeniable safety benefits

I would try it in the lake with a 5 pound anchor and a standard Edison bulb.

Well.. The bulb has a rather poor vacuum -- but, on the other hand, is fashioned of much thinner glass... --- What the Hey! I've two 'sacrificial dud' tubes! --- FYI - There seems to be some misunderstanding the tubes are at 120' (as opposed to 40')...

Sort of thing I had in mind but I'm not sure that with 40' or more of rope there will be any chance of detecting weight changes

It should be a simple matter to implement a "pinger" (i.e. underwater 'acoustic transmitter') 'rigged' to change its 'modulation' pattern in response to tube breakage...

Further complication will likely owe to the the omnipresent, sporadic and utterly unpredictable 40+ knot undercurrents - seems nothing's ever easy!

Many thanks for your ideas, interest and assistance!!!

Best regards
HP

 

A little dive music for you -

 

I was but a scant 3 months of age when Big Fitz went down! -- How truly time flies!

 

I was but a scant 3 months of age when Big Fitz went down! -- How truly time flies!

Were you already living on the shores of the Great Lake?

 

Were you already living on the shores of the Great Lake?

Yes indeed! That predated my sojourn in dear old blighty --- though, needless to say, I really don't recall

 

HP, would have guessed you about twice older, judging by the archaic choice of words

 

HP, would have guessed you about twice older, judging by the archaic choice of words

--Emphasis added --
Not archaic - just formal Tho - If you insist on SMS Speak - cn do dat 4U2