Forum menu
It requires significantly more engineering to have a pressure vessel with a penetration than it does to have an essentially sealed cylinder. All penetrations are weakness and thus cost and risk.
Sure, I just didn't think having an accessible hatch release of some kind (accessible bolt heads or something more complex, idk) would be a stretch given the general engineering levels going on.
I assume the need for it was seen as minimal, a situation where you're on the surface at the limit of the air supply is highly unlikely. Yet now they may well be snagged or having problems releasing ballast, short on time and if they can release themselves they could pop up some time after that 40hr point.
The simple answer is probably that opening the hatch on the surface would sink it ... the 'hatch' entry is that dome on the front isn't it? But at least you might have a chance of getting out and swimming for a bit.
Subs don’t explode, they implode.
Yeah sorry that was all covered above, its before 9am, but they still have been saying an implosion has not been heard.
Plus, how would you trigger them without creating any holes through the pressure vessel?
An earlier sub design had salt corrosion activated ballast release so whatever happened it would float up after a time. That kind of fail-proof release idea seems sensible. No idea what it could send up that would be of use for rescue and anything released would drift.
By the sound of it the people on board are quite pragmatic people. You would think if you were trapped attached to some wreckage with no hope of release you would realise that there is no point banging,
I think pragmatism would turn to desperation and trying anything when you realise you only have just over 40hrs to live. You'd bang on the sides just in case.
Plus, how would you trigger them without creating any holes through the pressure vessel?
Electro magnetic clamps, blue-tooth, differential pressure switches programmed to release from outside the hull once it gets back to 1bar after achieving a maximum or another button on the control panel. You don't need to drill holes. I bet that a military sub could launch a distress beacon without having to open any hatches.
Mercury space capsules had these back in the 1960's and they worked. Admittedly they weren't exposed to high pressure, but they still had a fairly rough ride and that was 60+ years ago.
Sure, I just didn’t think having an accessible hatch release of some kind (accessible bolt heads or something more complex, idk) would be a stretch given the general engineering levels going on.
Weight and cost. Properly designed releasable hatches are complex and heavy. That means you need more buoyancy. Carbon reinforced plastic is usually used in an attempt to reduce wet weight meaning you need less buoyance and can keep things smaller. All this is a cost reduction exercise.
I bet that a military sub could launch a distress beacon without having to open any hatches.
You'd lose that bet. They go out the submerged signal ejector and won't work at anywhere near that depth.
An earlier sub design had salt corrosion activated ballast release so whatever happened it would float up after a time. That kind of fail-proof release idea seems sensible. No idea what it could send up that would be of use for rescue and anything released would drift.
That's a neat idea. You'd think that they'd have bought some of the locator beacons used on aircraft flight data recorders and bolted them to the outside of the sub for such an eventuality. I imagine they would probably work from inside the sub if mechanically attached to a metal component.
I’ve just bought some electrical hull penetrators at work. They rated to a depth much less than than 4000m and each one cost as much as a half decent house. The mating connectors are over £12k each.
I'm guessing navy sub hull penetrators aren't any cheaper... And those subs only go to 300, maybe 500m.
So there's my answer on why they're sealed in. (edit, as @jonm81 says, weight and cost)
Electro magnetic clamps, blue-tooth, differential pressure switches programmed to release from outside the hull
Yes but these need power that would have to come from an external battery that would, again, be crushed well before it reaches the target depth.
I bet that a military sub could launch a distress beacon without having to open any hatches.
I'm sure it could..... But they only go down to about 300m!
Mercury space capsules had these back in the 1960’s and they worked.
Yes but that was in a vacuum - which is pretty simple - not at pressures that are constantly trying to make something ⅒ of its original size!
You’d think that they’d have bought some of the locator beacons used on aircraft flight data recorders and bolted them to the outside of the sub for such an eventuality.
Again...... Crushed!!
People really need to understand the pressures involved here 🤷🏻♂️
By the sound of it the people on board are quite pragmatic people.
One sealed cylinder. 5 people. Several days. Not much oxygen.
Won't someone think of the poo...
Its a really sh*tty situation however you look at it.
Again…… Crushed!!
People really need to understand the pressures involved here 🤷🏻♂️
ULB's fitted to aircraft are rated to 6000m....
This thing is equipped with external lights and thrusters that must have their own internal power supply as there are no holes in the hull, so they must have some sort of remote control over them from inside.
Could they have something similar that detaches and flashes?
What is the pressure rating on an aircraft flight data recorder?
You would have thought that it would have external dye cartridges, strobes and a beacon (maybe it does)
Nope. It's been lost before - for 5 hours, and they discussed putting a beacon on it, and decided not to, so it doesn't have any of that stuff.
ULB’s fitted to aircraft are rated to 6000m….
In height or depth? Not even comparable if you talking height
Won’t someone think of the poo…
They have a toilet
Mrs FD was saying they will want to pass out from Carbon Dioxide poisoning rather than lack of oxygen, as basically lack of oxygen will feel like suffocating, at least carbon dioxide poisoning will mean they just fall asleep
So that means when its getting to the end , they all need to fart - a lot
ULB = Underwater Locator Beacon.
Sounds like they could have fitted kit. But didn't.
Misquoting the cost of operating the boat perhaps? I’d not be surprised if you wanted to charter a boat that size if the price wasn’t £100k/day?
That heap of junk will be nowhere near £100k a day. It's a 60 year old buoy tender. You would get a half decent construction vessel for that price.
there are no holes in the hull
There are. The hull has titanium end pieces. This is where they have the penetrations and the hatch. There are no penetrations in the composite sections.
In height or depth? Not even comparable if you talking height
Underwater: https://www.skybrary.aero/articles/underwater-locator-beacon-ulb
Yes but these need power that would have to come from an external battery that would, again, be crushed well before it reaches the target depth.
not necessarily - i have successfully hydro tested and deployed batteries for RFID and pressure sensing equipment - albe it Batteries that cost as much as a car mind. Deeper than the subs rated for. - small vessels are not so bad to get to depth (4/6 inches in diameter)- but big vessels for humans with windows - No thanks
ULB = Underwater Locator Beacon.
Sounds like they could have fitted kit. But didn’t.
Reads like an aircraft ULB is activated by water contact. Perhaps they'd need a ULB that transmits full time during the dive on a different frequency that is only for the Titan, not interfering with other systems, if that were possible/allowed.
there is plenty of mature, stable, commercially available technology that could of (should of?) been fitted to make this vessel safer.
why and who made the decisions not too, I'm guessing will be a matter for the lawyers.
So, is there technology to transmit a distress signal already existing or that could have be adapted?
Would extra weight/kit have meant one less paying passenger or pushed the price up too far? Hence not using it.
Submersibles have gone deeper than this. Were they similarly equipped?
there is plenty of mature, stable, commercially available technology that could of (should of?) been fitted to make this vessel safer.
why and who made the decisions not too, I’m guessing will be a matter for the lawyers.
I'm guessing that it's a lot to do with keeping weight as low as possible, which then allows the sub to operate from smaller, simpler ships. This keeps the operating cost as low as possible.
I can't see that the composite hull build cost would be less than more traditional materials but it avoids the need for very expensive buoyancy.
I think they were trying to do it as cheap and as simple as possible.
This article gives a good insight into their mindset. They are innovative pioneers who know better than the rest.
https://oceangate.com/news-and-media/blog/2019-0221-why-titan-is-not-classed.html
Mrs FD was saying they will want to pass out from Carbon Dioxide poisoning rather than lack of oxygen, as basically lack of oxygen will feel like suffocating, at least carbon dioxide poisoning will mean they just fall asleep
Unfortunately there is a significant amount of evidence that carbon dioxide poisoning does not involve peacefully drifting off into oblivion, instead being painful and triggering a stress response on a biological level. If that's how they go they will almost certainly know that it's happening.
https://journals.sagepub.com/doi/pdf/10.1258/0023677053739747
Submersibles have gone deeper than this. Were they similarly equipped?
A quick google seems to suggest that most submersibles with similar (or better) operating depths aren't built on this sort of shoestring budget. They're either military/government funded or James Camerons toy. (Or don't have people in them, so effectively disposable).
I’m not sure why people are struggling with this…whilst there are a very few commercially built submersibles which are capable of descending to the depths we are talk about, they are extremely expensive to build and operate safely. So rather than go down this route, a business man and inventor with a plan has conceived and built a backyard special on a budget much smaller than actually needed. Then through his sales pitch and personality he has pursueded those with more money than sense to buy tickets.
A cursory examination of the design and a few conversations with those in the industry would have made its shortcomings obvious enough to anyone with the ware with all to pay for a ticket let alone two. Even if I was brave or stupid enough to take on those odds because of the rewards (or bragging rights) of seeing the Titanic for real, there is absolutely no excuse for taking a 19 year old along who probably had no idea of the risk or even possibly a choice in going, knowing the dominance and certainty of a successful businessman in his chosen decisions.
The pilot and other scientific guy knew the risks, the business man should have worked them out and I feel very very sorry for the young lad who was in the wrong place at the wrong time.
"The people that have been mentioned several times already just in this thread?"
"I suspect he was referring to the efforts of the navy, coast guard and other private organizations…and yes I agree it’s pretty distasteful"
Correct - I'm not talking about this thread, but the efforts from navy, coastguards etc but also more specifically the massive press coverage.
Mrs FD was saying they will want to pass out from Carbon Dioxide poisoning rather than lack of oxygen, as basically lack of oxygen will feel like suffocating, at least carbon dioxide poisoning will mean they just fall asleep
Other way around. Lack of oxygen causes hypoxia, which leads to a euphoric state and then unconsciousness. CO2 poisoning is an exceptionally unpleasant way to go.
@whatgoesup that's fair, I'm absolutely with you there.
Unfortunately there is a significant amount of evidence that carbon dioxide poisoning does not involve peacefully drifting off into oblivion
It's not lack of oxygen that causes the panicky 'must breathe' reflex - try holding your breath as long as possible, it's the build up of CO2 that isn't getting exhaled and the build up in your blood that causes it. If the CO2 is slowly building up I would imagine it's really not nice.
As others have said, low oxygen without the CO2 build up causes the blissful ignorance effect - as they say on aeroplanes, fit your mask before helping others because even in the time taken to put your kid's mask on, you might then become all giggly and incapable. Put yours on and who cares if they start to become incapacitated, as long as you can then get their mask on in 2-3 minutes they will recover as quick as they went giggly.
Portillo did a TV program on the death penalty, where he was effectively executed with nitrogen. That will displace the oxygen in the air, but you can still breathe out the CO2 and it doesn't reach that level of panic before you become unconscious and eventually die. Sadly (! 😉 ) they then brought him back but it would be very effective and humane (as humane as state sanctioned murder of its citizens can be) One of the arguments against seemed to be whether witnesses seeing their child's killer depart the world in a euphoric state of bliss was appropriate.
http://news.bbc.co.uk/1/hi/magazine/7183957.stm
Back to the sub. If I was in such a situation, I think having a smallish cylinder of pure nitrogen or helium or whatever as a suicide 'if all else fails press here' would be a relief.
The banging thats been heard. Do you think its from the sub?
Last year David Pogue, from US TV network CBS, joined an OceanGate expedition to the Titanic and was told the submersible had seven safety systems to help it return to the surface.
Triple weights: three lead pipes that can be dropped using hydraulics to gain buoyancy
Roll weights: if the hydraulic systems fail those inside the sub can tilt the sub by moving to each side of it releasing weights held in place on each side by gravity
Ballast bags: motors can be used to release bags full of metal shot hanging beneath the sub
Fusible links: bonds that disintegrate after 16 hours in seawater to drop the ballast bags if the electrics and hydraulics fail
Thrusters: to push it to the surface
Sub's legs: the pilot can jettison the sub's legs as dead weight
Airbag: the crew can inflate an airbag to provide buoyancy
Seems it does have a lot of the features being discussed
The banging thats been heard. Do you think its from the sub?
If it's every 30 mins and has a rhythm or pattern (expect it would) it must be? Either that or a newly discovered species, the Atlantic Drum 'n' Bass Shark. Or something else entirely, that we'd prefer to stay down there..
Presumably if they get to the surface they would be able to use a satellite phone and handheld GPS given that they're inside a carbon tube (not metal)?
Just appeared on the BBC.
A submarine search and rescue expert in Australia, Frank Owen, tells the BBC his “confidence went up by an order of magnitude” when he heard reports of banging being detected by floating sound detectors.
“There's a couple of reasons for that,” he explains. “Firstly, on board this craft is a retired French navy diver. He would know the protocol for trying to alert searching forces… on the hour and the half hour you bang like hell for three minutes.”
He says the sound signal being picked by a buoy close to the surface also suggests that the sub itself could be near or at the surface.
“Below about 180 metres, the water temperature drops very rapidly,” he explained. “That creates a layer that the [sonar signal] bounces off. But if you’re in the same depth water it tends to go quite straight.”
Even if Titan is at the surface, it will be difficult to spot. Very little of the small, white vessel sits above the water.
But using an array of sound-detecting buoys to triangulate the signal could narrow down its position.
If these poor sods die because they can't be spotted bobbing about on the surface then it really is a tragedy.
The banging thats been heard. Do you think its from the sub?
I recon the musicians on the actual Titanic have long stopped playing their music. So unless it's Nessie on her holidays...
Where is Muskman?
Normally he’d be all over this.
I know, he's even got a wildly-unsuitable sub he could offer to send, then he could call the search organiser a 'paedo' when the offer is rebuffed.
Is it heated? Must be pretty cold down there - just wondering whether a potential noise would indicate it's more likely to be at or near the surface?
This long thread on Twitter from John Scott Railton is essential reading - looks like everyone in the industry knew this was a bit of an overreach.......Worth reading to the end and some whistleblower testimony
https://twitter.com/jsrailton/status/1671087361755697154?s=20
If these poor sods die because they can’t be spotted bobbing about on the surface then it really is a tragedy.
if they are on the surface and can’t get out then that really is a lack of contingency planning from the company. Not sure if a satellite phone would work from inside the sub, but if not surely some kind of way to open it up from inside would be a bare minimum…even a drill and a saw would be better than nothing!
also, why on earth is it painted white. Surely to god someone would have done a risk assessment and realised if this eventuality occurred, painting it orange would be a far better option
the whole operation appears to be run by amateurs
"Reasonable" is doing an awful lot of heavy lifting in that mission statement.
It's like a group of people have spent a night buying someone endless very expensive drinks in a bar and then asked them for a lift home.
As obviously unwise things to do it's right up there. This really doesn't need hindsight does it.
, why on earth is it painted white.
White is more visible underwater.
If it's on the surface surely a SAR aircraft with heat cameras could find it quite easily. They could cover quite a distance in a fairly short time.