quote:

Originally posted by Fly-Sig:
Maybe pilots are just wired differently, but I can't imagine anyone thinking it was a good idea to be bolted inside a sub. They must never have engaged in what-if brainstorming.

Thinking back on my flight training, it seems like a high percentage of it was on the many things that can go wrong and how to deal with them. The attitude often seemed like it isn’t a question of if an engine will quit, but when, and how will you respond when it does.
Perhaps as a result I tend to think in terms of my options for safe completion of the flight. Are they numerous and varied? Great, rock on. Are they limited? Crap, it’s already late, but get busy coming up with a better plan. Are they narrowing? Change something NOW!, because I never want to be in the position where everything has to work or I’m in trouble.

quote:

Originally posted by HRK:

quote:

’ll ask again, what difference does it make if the submersible could be opened from the inside?

Well underwater not so much, but if it resurfaced, you could open it, get air, shoot up a flare, call someone with a Sat Phone, Fire up an EPIRB, launch an inflatable raft, crawl outside and take a leak in the ocean.....

As your means of staying afloat sinks 12,000 feet into the abyss, but ok, whatever floats your boat.

quote:

whatever floats your boat

Sorry, but that did make me chuckle, especially after the context.

They say the pressure is immense. Just remember your ears at 15 feet underwater.

I think it has to be strong, bolted closed.

I deal with quick opening hatches/closures for piping and vessels in high pressure flammable and explosive liquids and gases. Granted the pressure for us is on the inside not the outside.

Quick opening closures get rarer and rarer as pressure increases. 1480 psig is very common, 2220 psig is less common, and 3705 psig is a rare bird. Typically switching to bolted connection. For example, the 10000 psi vessel we designed and built a few years ago was a bolted connection and used specialized running gear to bolt/unbolt it.

Rough comparison of pressure vs depth assuming 1.05 SG for seawater:

1480 psig = ~3600' in seawater

2220 psig = ~5400' in seawater

3705 psig = ~9000' in seawater

5180 psig = ~12,566' in seawater (i.e. depth of Titanic)

10000 psig = ~24200' in seawater

Too soon?

https://twitter.com/HDontMiss/...469224135389185?s=20

I just read where this sub was ‘rated’ as being good for a depth of 13,120 feet deep?

If so, seems kinda close to the limit to be diving down to 12,500 feet? Only 620 foot margin?

I realize these limits are partially theoretical, but they are at least guidelines.

quote:

Originally posted by sourdough44:
I just read where this sub was ‘rated’ as being good for a depth of 13,120 feet deep?

Rated by who?

quote:

Originally posted by Rightwire:

quote:

I suspect much of this is hype created by the media to keep people watching unfortunately.

I agree. I also bet if a member of this forum who perhaps had served on a submarine in the Navy called a news agency and told them there was a new angle on this and made something up utilizing elements of the turbo encabulator we'd see him on the 6pm News tomorrow.

In my opinion, the older marzel vane encabulators are not the right ones for this application. The versions where the waneshaft is directly linked are much more effective in damp environments and not subject to noncoptic variations in ionometric flux. That can be important when you need to minimize surges in the "up" direction.

Link

Titanic submersible LIVE: US Coast Guard 'hopeful' in search as 'banging' noises continue
Story by Adam Chapman, Jacob Paul, Paul Withers, Aurora Bosotti • 5m ago

The US Coast Guard has said it remains "hopeful" in the search for the Titanic while revealing the underwater "banging" noises first detected yesterday have continued today.

Captain Jamie Frederick, the First Coast Guard District response coordinator, told a news conference a Canadian P3 aircraft has continued to detect the noises.

He said teams are continuing to search the area in question in the hope of locating the missing titan submersible with five people on board.

Captain Frederick added: "You need to have hope but I can't tell you what those noises are. However, we are searching where those noises are.

He later added: "The noises were heard by a Canadian P3 and that was this morning and some yesterday. I don't know specifically about the 30-minute intervals."

I just read where this sub was ‘rated’ as being good for a depth of 13,120 feet deep?

[/QUOTE]

Rated by who?[/QUOTE]

I’d take it as ‘designed for’, but very loosely. Kinda like the guy with balloons attached to his lawn chair ‘self-rated’ for 8000 feet or whatever.

No, it wasn’t ‘rated’ by Lockheed-Marten or whoever.

quote:

Originally posted by sourdough44:
I just read where this sub was ‘rated’ as being good for a depth of 13,120 feet deep?

I read that the guy fired found out the viewport section, was rated by the manufacturer at only 1300 meters, yet the craft was going to go down 4000 meters. And to my knowledge, the boat as a whole was not classed or rated by any independent entity based on industry standards. If it was "rated", it must have been by the company itself.

quote:

Originally posted by tatortodd:
I deal with quick opening hatches/closures for piping and vessels in high pressure flammable and explosive liquids and gases. Granted the pressure for us is on the inside not the outside.

Quick opening closures get rarer and rarer as pressure increases. 1480 psig is very common, 2220 psig is less common, and 3705 psig is a rare bird. Typically switching to bolted connection. For example, the 10000 psi vessel we designed and built a few years ago was a bolted connection and used specialized running gear to bolt/unbolt it.

Rough comparison of pressure vs depth assuming 1.05 SG for seawater:

1480 psig = ~3600' in seawater

2220 psig = ~5400' in seawater

3705 psig = ~9000' in seawater

5180 psig = ~12,566' in seawater (i.e. depth of Titanic)

10000 psig = ~24200' in seawater

I was taking a physics course in college around the time the movie Titanic came out. Our professor was nuts over that movie and one of the things we did was calculate the speed the water would rush into a sub if something ruptured the hull at the depth the Titanic was at. I don't recall the numbers, but essentially the water would be coming in at well past the speed of sound. The basic takeaway was that if something catastrophically fails at that depth the crew would never know it. They would be crushed before the sound of whatever broke reached their ears.

It’s been since Sunday, near 12 hours +/- of O2 reportedly left. At this point, still listening for noises trying to LOCATE the sub. These handful of days, still trying to get an exact location.

The actual attaching then pulling it up is the biggie, but it’s not even been located yet!!


I just don’t think the slow opening hatch is going to be a player in this.

quote:

Originally posted by jhe888:

quote:

Originally posted by Rightwire:

quote:

I suspect much of this is hype created by the media to keep people watching unfortunately.

I agree. I also bet if a member of this forum who perhaps had served on a submarine in the Navy called a news agency and told them there was a new angle on this and made something up utilizing elements of the turbo encabulator we'd see him on the 6pm News tomorrow.

In my opinion, the older marzel vane encabulators are not the right ones for this application. The versions where the waneshaft is directly linked are much more effective in damp environments and not subject to noncoptic variations in ionometric flux. That can be important when you need to minimize surges in the "up" direction.

Hopefully they weren't using a foreign sourced encabulator or, God forbid, one 'off the shelf'. Critical that these components are carefully matched to the application and we all understand what a failing purvis bearing will mean.

For everyone who believes that there should be a way of opening the exit way from the inside, what would be capable of permitting that while also withstanding the enormous pressures at depth? Bolt heads on the inside? How would entrance be made from the outside if necessary? Two portals?

quote:

Originally posted by sigfreund:
For everyone who believes that there should be a way of opening the exit way from the inside, what would be capable of permitting that while also withstanding the enormous pressures at depth? Bolt heads on the inside? How would entrance be made from the outside if necessary? Two portals?

If the hatch were bigger than the opening and it was placed on from the outside, water pressure would press it tight as the sub descended. A mechanism attached to the inside of the hatch could rotate out and then snug it in place.

There would be no mechanism on the outside to open it, thus there would be no mechanical bits having to pass through the hatch that could leak. The ring it attaches to could have bolts on the outside for emergency use in case the occupants could not open the hatch normally.

At depth, if the hatch is 24 inches in diameter it has approximately 384,530 pounds of pressure pushing it onto its mounting. I expect that is a lot more than the bolts are applying.

I expect the decision was made to go with a simpler, cheaper design with the logic the occupants would never have to open the hatch because the support ship would always be there.

quote:

Originally posted by DanH:

quote:

Originally posted by Fly-Sig:
Style is one thing, actual design and construction is something completely different.

Is that Logitech controller built with mil-spec parts and construction? Or is it commercial grade?

How about all the connectors in their system? Are the mil-spec? Are they accessible by the crew while submerged? Connectors develop high resistance over time due to oxidation, and solder joints or wiring fails. I cannot count how many times maintenance swapped boxes in an airplane or just unmated and rejoined connectors due to connector problems. And that's with high quality mil-spec hardware.

No, it's an off the shelf XBox controller. The Captain of the USS Indiana explains this in the tour of his Virginia class SSN:



Mind you, the XBox controller is only controlling what passes for the periscope, not navigational control of the sub.

I expect there is a USN specification on that controller. It will detail the values +/- some % for the electronic interfaces. Voltage, current, resistance, etc. There will be a test requirement for each unit, possibly over an extended temperature range. There may be revision control, meaning that the supplier must make it per their own specifications of a particular date, so they can't just change stuff the Navy buys.

I have the question out to my step son who spent 10 years on nuclear subs and now consults with the USN on training sub crews.

Not including how terrifying it must be to be stuck in that metal tomb with no idea if rescue is a possibility, they've been down there long enough for most of the passengers to have to...answer the call of nature. That must also be almost unbearable given the cramped area they are in.

WAG bags...