Titanic submersible confirmed destroyed with loss of all five souls onboard.

When I read that this thing was made of composite I assumed they would change it out every time, or that they have a process to ensure there's been no leftover damage to the hull.

I work in an industry where we make aircraft interiors and the use of composite is fairly prohibitive anywhere that a passenger is retained (I.e seats, it's used extensively in galleys, furniture etc) . We test for crash landing and if there's composite on the primary load path, you have to conduct further testing following a crash landing event test, to ensure there's enough load carrying capability within the structure. And that's for a one off event... Nevermind reusing the same material time after time.

We also have to conduct coupon testing of the material as composite manufacture can vary, to derive a material variation factor and apply it on top of load factors. I've seen first hand how the same material and process can result in variation in strength and stiffness just because it's made at a different location, different people, etc.
 
Feek said:
This is the kicker for me. If it’s genuine, it would have been reported to the coastguard straight away.
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That's the thing, we know they waited 8 hours before they reported it missing. The transcript reports depth readings of when they released the weights - you can work out from them that it would have taken a little over 8 hours to return to the surface. Either it's a convincing fake that someone went to lengths to fit to the known facts at the time, or it's real.
 
chaparral said:
Why was the whole pressure hull not made of titanium like the end caps ?

Was it due to the Cost or weight or something else
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I think it's more cost, it wouldn't be economically viable to build a titanium hull large enough for taking passengers to the deepest parts of the Ocean, there's a reason nobody else is doing it
 
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chaparral said:
Why was the whole pressure hull not made of titanium like the end caps ?

Was it due to the Cost or weight or something else
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The whole thing would have to be thicker to account for the stresses placed on the cylindrical portion. Normally these things are, as near as makes no difference, perfectly spherical to evenly spread the load around the object. I know this because I watched a couple of YouTube videos about how to build a proper deep ocean sub.
 
if you watch Mrk's video on victor and deapsea challenger the forging of a titanium sphere to accomodate 5 alone, would probably need a new press, beyond current tech.


sounds familiar
www.thetimes.co.uk

Climber blames Nepalese firms for deaths on Mount Everest

Record holder Kenton Cool urges western companies to intervene on safety standards
www.thetimes.co.uk www.thetimes.co.uk
Cool said that there had been an explosion of operators, some of whom were “there one year and not the next”. He added: “There’s not the level of accountability that we would expect in the West. If these companies lose clients there doesn’t seem to be any vested interest by a governing body to find out why or how.

..
He said that he was told of one operator that had less than half of the number of oxygen cylinders they needed for all of their clients to reach the top. “What does that say? Are they hoping for a drop-out [at lower camps]? That sort of behaviour is not conducive to a reputable operator.
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Submarine expert says it went into freefall after losing power and "fell like an arrow vertically" for 3000 feet before "popping like a balloon" :eek:
metro.co.uk

Titanic sub victims 'knew their fate' before implosion

'Imagine the horror, the fear and the agony. It must have been like a horror movie.'
metro.co.uk metro.co.uk

Minusorange said:
I think it's more cost, it wouldn't be economically viable to build a titanium hull large enough for taking passengers to the deepest parts of the Ocean, there's a reason nobody else is doing it
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Exactly you can't stuff five fee paying passengers in a spherical object a tube is better for that. And cheaper. In other words its all about maximising revenue (the father and son on the trip were really worried about safety and the CEO personally flew over to britain to assure them it was safer than crossing the street. :()
 
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Makes no sense either. Losing power has to be the most plannable failure imaginable.

I know other submersibles would automatically drop ballast and rise like a cork if power failed as a failsafe.
 
Hotwired said:
Makes no sense either. Losing power has to be the most plannable failure imaginable.

I know other submersibles would automatically drop ballast and rise like a cork if power failed as a failsafe.
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Given how much he seemed to hate convention and doing things safely, it wouldn't surprise me if the sub was designed to eject the passengers on power loss.
 
Blackjack Davy said:
On an interview with previous passenger they asked what the safety and emergency procedures were and why they hadn't been given any and the CEO just laughed and said if anything goes wrong they'll all be dead anyway, which doesn't sound like forward planning was his strong point. Or any real planning at all.
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It's realistic though, if there's a leak on any submersible at that depth, there's no way out.
 
Feek said:
It's realistic though, if there's a leak on any submersible at that depth, there's no way out.
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With safety critical items you should either:
-have sufficient mitigation/redundancy to ensure it never happens, or
-have provisions in place to ensure a level of safety if it does happen.

In the case of this sub at those depths, mitigation/redundancy would be the preffered approach I imagine as you are right, if it leaks at that depth you are done for.
 
Blackjack Davy said:
On an interview with previous passenger they asked what the safety and emergency procedures were and why they hadn't been given any and the CEO just laughed and said if anything goes wrong they'll all be dead anyway, which doesn't sound like forward planning was his strong point. Or any real planning at all.
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Feek said:
It's realistic though, if there's a leak on any submersible at that depth, there's no way out.
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M1k3H said:
With safety critical items you should either:
-have sufficient mitigation/redundancy to ensure it never happens, or
-have provisions in place to ensure a level of safety if it does happen.

In the case of this sub at those depths, mitigation/redundancy would be the preffered approach I imagine as you are right, if it leaks at that depth you are done for.
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I recall watching an interview with James Cameron where they stated the reason they didn't have a hull monitoring system on the pressure vessel for traditionally designed DSVs is simply that, these elements were designed and constructed not to fail. Titan's acoustic hull monitoring was only viable in shallow depths and a major red flag that carbon fibre construction required it.

Hence 9" or thicker titanium alloy spheres and 7" or thicker glass on viewports on traditional DSVs.

Rush was right, at depth, safety systems don't help. Sounds like a leak at depths of 200m or more in the pressure vessel of small DSVs is potentially fatal due to increased water reducing natural buoyancy but the PV won't collapse. Thus a small window of opportunity where dropping ballast may allow ascent. With leaks once reaching preasure vessel material crush depths (c>1000m on the carbon fibre) resulting in implosion, nothing helps.

However, it's evident (since 1960s) you can 100% successfully design and build the risk out of the DSVs as others have done. MIR1 & 2 (80s design/build) used by Cameron for the Titanic exploration also always worked in pairs so there was redundancy and support. It sounded like entanglement in wreckage was a real issue in the early days of Titanic exploration and 2 DSVs ensured the other could be freed.
 
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