at the time i was inspecting this type of vessel in Hawaii it was for Scripps or hawaii research corp for their underwriters. The only available regulatory data (guidelines) available at that time was a book published by the SNAME which had good guidelines for upkeep and maintenance, as i recall, and the only thing it brings to mind were there were certain fixtures such as windows / ports which would have to be replaced after so many pressure cycles.
DNV / Germarcher (sp?) Lloyds would be the only class society that i would know of which MAY have the expertise to inspect vessels with passenger for pay operations. The USCG in Hawaii at the time showed no interest in the research institutes. UNOLS had a few guidelines, but they were an association. MBARI for instance in Monterey Ca. was Getty funded and went their own way. however, they did not have subs they had ROV’s most of which were autonomous. drop them in and pick them up in week:)
From NYT right now. Unfortunately confirms something: the waters are so deep that not even submarine rescue systems can work at the depth. Can robots attach a cable to the sub if they find it in time? Over two miles of cable would be extraordinarily heavy. I’m sure experts on here can comment…
Britain’s Ministry of Defense, which hosts NATO’s multinational submarine rescue capability, said it was monitoring the search. British officials say that the depth of water in the search area greatly exceeds that in which the NATO Submarine Rescue System — which is based in Scotland — can safely operate, but that its team is available to offer expertise and guidance.
France is sending a research vessel equipped with an exploration robot to help with the search, according to Hervé Berville, France’s junior minister in charge of maritime affairs. The Atalante, a ship operated by a French maritime research institute, was about 48 hours away from the Titanic’s site, he said in a statement.Berville added that a French team is expected to arrive in Canada on Wednesday before heading to the site to operate the robot, which can dive to over 13,000 feet.
Desecrate a grave site for monetary gain, and karma bites you.
If you were inspecting Pisces IV or V, they were the boats manufactured by my employer. I piloted PV for a couple of years in the North Sea when it was leased to Vickers Oceanics. One of my frequent diving partners was Roger Mallinson who was the pilot of Pisces III when it sank in the Irish Sea.
I was in San Francisco for 40 years only Pisces I ever worked with was the high speed ferry for WETA.
What was “this type of vessel” then? The discussion is about manned deep submersibles. The only manned deep subs in Hawaii are operated by HURL. The tourist subs were designed and operated by Atlantis, a company started by former engineers of International Hydrodynamics, my former employer.
When obscene insurance costs put an end to commercial deep sub operations, we shifted to ROV operations and the founder of Atlantis built upon the design of a “submarine ride” designed for a shopping mall in Alberta.
“Rush’s company began to advertise in 2019 commercial trips in the Titan to see the famed Titanic wreck, touting an experimental design whose carbon-fiber hull was considerably lighter than other vehicles.”
There are plenty of airplane builders who feel stifled by rules and regulations and do not try and get their airplanes “classed”. Such airplanes have a warning to let passengers know they are experimental and it is illegal to take paying passengers in them.
I am sure carbon fiber is nice and light, but it is also very hard to do any NDI on it.
Thank you for the info. You are mistaken- greatly mistaken, my intent is not to “paint” anything. I have an extensive background in the area of steel structures and their survey and repair with regard to displacement hulls. Many years experience. My area of expertise is not in the area of submersibles or semi-submersibles; not something that interests me. Standard Naval Arch stuff and operational stuff.
Remember that classification society rules have evolved greatly in many areas- including that of submersibles and semi–submersibles in recent years. You mention that you are a Pilot oof these type craft- you hold some form of a credential? Also- Tech Rep- do you have any formal training in Marine Engineering (the Engineering Design part)?
No, right now I think that all of our Prayers and Hopes are revolving around getting these people rescued and the vessel recovered so that failure analysis might be carried out to prevent recurrence.
Whether or not I choose to “go for a dive” is irrelevant.
Many years ago they had a bad battery related fire 
n an Atlantis sub. All I remember
I also did a few things for DOERS. Silvia Earls daughter Elizabeth Taylor
Nice people I learned a lot
I just found a drawing of the Titan, it doesn’t have a “hatch” in the conventional sense. It is made of a carbon fiber cylinder with titanium hemispheres at each end. The front hemi with viewport is clamped and bolted to a mating surface at the forward end. It looks like it is hinged to allow access before closing and bolting.
So, yeah, once occupied and ready for diving the passengers and crew are there until recovered and the forward hemi unbolted. It does seem a bit sketchy for that size of pressure hull but that is just my opinion based on experience with spherical hull vehicles and heavy plug hatches and conical viewports. Our shallow boats used cylindrical hulls with hemi ends and one large viewport forward with a small vertical cylindrical “conning tower” with a slightly domed hatch at the top.
Here is a Pisces class boat:
That large device protruding from lower forward is a torpedo claw, it rotates and clamps to secure a 21 inch submarne torpedo. Barely visible under the left (in drawing) viewport is a manipulator used to recover small and lighter objects.
From WAPO right now:
…There are few workable options to lift the submersible from the ocean floor if it has come to rest on the bottom. Many uncrewed vessels cannot descend at the depths needed for such a recovery. The Navy utilizes the Curv-21, a remotely operated vehicle that can work down to 20,000 feet underwater, which took part in the recovery of an F-35 fighter jet that was lost in the South China Sea last year.
But the Curv-21 needs specialized ships to lift it into the water and then pull it back, along with whatever material it hauls up. The Navy has only a handful of those fleet ocean tugs, and it deactivated one such ship that operated in the Atlantic, the USNS Apache, in August…
…There is no clear answer as to why the Titan lost contact with the Polar Prince, but experts have ideas. Ofer Ketter, a submersible pilot, told The Washington Post that the vessels have two communication systems, one for verbal contact and one for location tracking. He said not being able to talk to a vessel is not immediately an emergency, but “the actual ‘where is the submersible,’ that is a different system.”
Ketter said the systems could disconnect because of underwater conditions, density or salinity of the water or the current, but added that the length of time without contact is worrying.
“It’s definitely odd to have lost all types of both location and communication,” he said. “That is an odd scenario.”…Ketter said that if he were piloting a submersible stuck at the bottom of the ocean, he would lower the flow of oxygen to a point that it’s safe but less than standard, assess battery power, and monitor carbon dioxide exhalation as well as temperature and humidity. But before all that, he would ensure that his passengers are remaining calm.
“You have to manage the mental system,” he said. “No one is trained to be in that condition.”…
Do these little subs have positive, negative, or neutral buoyancy?
Didn’t the early navy owned submersibles use sheet lead for weight that could be jettisoned to allow the sub to rise up naturally in the event of a power loss?
The sub has a few different things it can jettison to surface, as heard on NPR about 20 minutes ago. It is not like a Navy sub that needs compressed air to blow ballast tanks.
The boat is normally ballasted for a degree of bouyancy on the surface that provides some desired freeboard. Soft ballast tanks are sized to provide that bouyancy when dry. When the soft ballast is vented and floods the boat becomes slightly negative and submerges. There are “hard” ballast tanks that can be partially filled to adjust bouyancy and trim to meet dive requirements and variable equipment or crew loading. Hard ballast tanks can be flooded or pumped at full depth. Soft ballast is blown by compressed air and must be carefully handled to avoid uncontrolled ascent as depth decreases and to avoid wasting compressed air. All the boats I piloted used a heavy lead drop weight that could be manually dropped from within the personnel sphere in the event of an emergency. This was a weight adequate to ascend under most normal loading and trim conditions. When working on the bottom we would trim aft and slightly heavy in order to ski along with the skids slightly nose up. When working mid water we trimmed neutral and used thrusters to maintain depth and heading.
It appears that the support vessel on this occasion was the M/V Polar Prince:
Source: Coast Guard searches for missing vessel visiting Titanic wreck with 5 people on board
The Polar Prince also belong to Horizon Maritime, but a far cry from the Horizon Arctic.
She is a 67 year old former Canadian Coast Guard vessel and Buoy tender:
Looks like ABS publishes rules for manned submersibles. Some interesting reading. Sadly no section on carbon fiber hull however…
USCG reports sounds like banging may be from sub but yet to be confirmed.
Picked up by Canadian P-3 and P-8 aicraft, sounds at 30 minute intervals near search area. Sounds heard 4 hours after original contact. ROV’s investigating.
Per the report on NPR:
This sub has ballast that is held on by an attachment system that will dissolve in water, so after X hours it will surface even without any human intervention.
If I had to take a random guess, it is caught in a net or other entanglement.
What if they don’t want to be found? Multi millionaires could have the resourses to disapear, maybe they were not even in the sub, or had another vessle retreave them.
All of the people onboard?