Missing sub

[GB]

US journalist Michael Guillen recounts his harrowing experience of being trapped in a similar vessel during a dive in the same spot back in 2000.

"I was the first correspondent ever to report from the wreck of the Titanic. So, naturally, I was excited," Dr Guillen, who at the time was science editor at America's ABC network, told BBC Radio 4.

He recollects that - together with diving partner Brian and Russian pilot Viktor - they went down in a small Russian submersible lowered from the Akademik Mstislav Keldysh research ship.

After touring Titanic's bow where "everything had gone well", the crew decided to head to the stern area some distance away.

The Titanic sank on 15 April 1912, after striking an iceberg. Before going down, the British passenger liner split into two parts.

"As we approached the stern area - flying over what's called the debris field - we were caught up... in a very fast-moving underwater current. So we ended up getting stuck in the propeller," says Dr Guillen, describing it as "huge".

"All of a sudden, there was just a crash. We just felt this collision, and all of sudden debris... just huge chunks, rusted chunks of the Titanic started falling on top of us."

'I had said my goodbyes in my mind' Dr Guillen, a physicist and now a best-selling author, remembers that "it was pretty clear to us almost immediately we were stuck".

He says the pilot, who used to fly Russian Mig fighter jets, was trying to jostle the sub out.

"It's like you get your truck, your car stuck in the mud: you try to go forward, backward, forward, backward. Just to try to dislodge yourself.

"We all fell silent. We didn't want to disturb or distract Viktor. And we knew we were in a crisis. So we just kept quiet."

The sub eventually managed to get out "through the skill of Viktor", says Dr Guillen.

"We were just fortunate. There was a better part of an hour we were stuck. And I already pretty much had said my goodbyes in my mind.

"I'll never forget this thought that came to my head: this is how it's going to end for you.

"But in the end, we sensed that something changed... there was a sense that we were floating."

The journalist recollects that all this was happening in complete darkness, as the pilot turned off the spotlight.

"We didn't want to say anything. I was like 'My gosh, is it possible that we are out of this?'

"Then I turned to Viktor, and I said: 'OK?' That was all.

"He only spoke broken English. And I'll never forget [how] he said this in a very low growling Russian accent: 'No problem.'"

[Paul]

The news has come in, they've been "squashed flatter than a bug".

Implosion.

The implosion was picked up on hydrophones. And the info passed to the rescuers, who continued on anyway, just in case the noise was not associated with the incident.

Paul

[Jethro_uk]

I did find myself wondering what happens at those depths.

Mythbusters did a bit about when an old fashioned diving suits pressure supply fails at 100m? Not pretty.

[Chris Hogg]

Thankfully, they would never have known anything about it. The implosion would have flattened them quicker than their brains could register it.

[Tim Streater]

At Titantic depths, pressure is 400 atmos.

At the bottom of the Marianna Trench, it's 1200 atmos, and water is about 4% denser.

[Rod Speed]

Or the brain could well still be working fine and experiencing the immense pain being flattened would produce.

[Tim+]

Front window looks a bit drafty.

Tim

[John Walliker]

Indeed, but I'm not that proves anything. It would have been designed to resist external pressure and might easily have popped out if the failure was elsewhere. I'm sure they will be looking for it if it has not yet been found.

John

[GB]

The bits of wreckage should have been left where they were, so future tourists would get BOGOF.

[Tim+]

Wouldn’t argue with that, but…

Tim

[jon]

The US Coast Guard (USCG) said it received debris and evidence from the sea floor at the site of the deep-sea vessel’s fatal implosion, which killed five people.

Medical professionals will formally analyse presumed human remains recovered from the debris which was quickly covered in large tarpaulins before being lifted by cranes on to lorries.

[Spike]

Although largely covered up by tarpaulins, the parts of Titan that have so far been recovered seem to be the metal components, such as the front dome (without its viewing port), the metal shields surrounding the composite pressure-hull, and the stern section with the batteries and electronics. Perhaps the hull’s composite structure is more difficult to locate.

[Tim Streater]

Perhaps those items, being lighter, might have tended not to just go straight down and may be some way off. What depth had they reached? Were they actually close to the Titanic?

[Chris Hogg]

I wonder how they raised them. OK, so they had a robotic sub capable of working at those depths, but did it somehow attach a cable from the mother ship and they hoisted the pieces up, or air-bags that they then inflated and they floated to the surface complete with a piece of wreckage which was then recovered, or what?

[SteveW]

There was definitely at least one ship (French IIRC) carrying a cable capable of lifting the whole sub. Other ships there may have had their own.

[GB]

Possibly, the simplest would be for the ROV to grab the wreckage and then be hoisted up to the surface. It's a 4 km trip to the surface, but there are no issues about decompression, so could be done at say 2km/hr.

[Sn!pe]

Air-bags being collapsible, I don't think you could inflate them in the enormous ambient pressure.

[Paul]

One of the reports, rated various parts of the device for their potential for a maximum depth. And the comment there, was that the window wasn't even remotely close to being rated for that depth. The body of the machine, can take the depth, but it degrades on each dive, so the performance (max depth) is variable. It means the machine is "biodegradable" with respect to continuing to give adequate performance. Maybe it really did have margin... on the first dive only.

I suspect the fun part of the forensics for this one, will be tracking down the "engineering documents". They seem to have interviewed various parties, who said "we didn't design this". I've not seen concrete evidence of who did design it. Someone wrapped that hull. Someone else told them how much material to use.

Paul

[Chris Hogg]

I think you're right. A quick search for the pressures at the level of the Titanic says ~400 bar

. But e.g. a nitrogen cylinder is pressurised to about 230 bar, so trying to inflate a flotation balloon from say a nitrogen cylinder at that depth would simply have failed.

[Jeff Layman]

The maximum pressure of standard cylinders of compressed air is 150 -

250 bar. So if you opened a valve of one of those cylinders at the depth of the Titanic, seawater would enter it rather than gas escape. Once that pressure had equalised, and assuming the valve was at the top, gas would escape due to it remaining a gas and being well above its critical temperature of around -135°C, and of much lower density that the seawater.