A non compressible concrete hull can stabilize its flotaion at any depth with no use of depth control surfaces. This was first applied in the BEN FRANKLIN project.
Although Ben Franklin features 4 electric motors which can turn around 360 degree - they are not intended for 24/7 hovering in a dynamic way like a helicopter. They where not used during the voyage. The boat regulates the buoyancy so exactly that it stops sinking in colder and denser water and stays stable suspendend in the watercolumn in a certain depth that the crew can choose. Military boats can not do that because the "additional buoyancy effect of colder denser water" is overpowered by the compression of the hull plating which creates buoyancy loss at depth and maintains the (military boat) falling down without limit to the ocean bottom. A non compressible hull as Ben Franklin can come to the point where the additional buoyancy effect of colder denser water at depth holds the non compressible hull in static suspension - it is like floating - but submerged. The boat sinks trough the less dense warm surface layer and gets suspended when reaching the denser cold water of the depth that creates more buoyancy No 24/7 controls and no hovering under motor power is necessary. It is a bit like floating in a hot air baloon by fine controling the buoyancy you can choose the suspension depth. Once you hang there no dynamic process is needed to hold depth.
If you do that in snorkel depth it is even easier because you can use the buoyancy of the snorkel tube to stabilize the boat where you want it. If you stick the snorkel a meter more out of the ocean you loose a couple of liters of buoyancy (the tube volume) if you go deeper more of the tube comes into the water and adds buoyancy to the boat - so the boat automaticly finds a equilibrium with a certain length of tube in the water and a certain lenght in the air and stays stable there. Submariners call that "hanging on the snorkel tube" it is tremendously difficult for a military sub due to the compressibility of the hull that tnds to overrule the stabilizing effect of the snorkel.
In a non compressible concrete hull as the 20m prototype the required ballast for changing buoyancy was 1 liter - the volume of the snorkel tubes was about 20 liter so hanging on the snorkel is very easy safe and stable.
You can train the crew to achive it in 5 minutes. Once hanging on the snorkel depth control is automatic with no dynamic surfaces are required.
It is the same stabilization principle as a semisubmersible platform -the buoyancy of the colums stabilize the platform. The snorkel works in the same way as the colums do - and the surface platform with the drill derrick gets stripped.
Sea Orbiter is a snorkel boat concept with a "extremly thick snorkel" and a "not very streamlined hull". If you think how this concept stabilizes its depth without control surfaces you will understand that "thinning out the snorkel" and "making the underwater part blimp shape" you end up with a submarine yacht in snorkel mode - still stabilized by the bouyancy of the snorkel. Underwater tunnels use a similar "depth stabilizing by buoyancy" concept.
This Week in Diving History -- July 14, 1969 -- BEN FRANKLIN (PX-15) begins gulf stream drift diving mission.
This Week in Diving History -- July 14, 1969 -- BEN FRANKLIN (PX-15) begins gulf stream drift diving mission.
July 14, 1969 8:56 P.M. -- The Ben Franklin (PX-15) subsurface research vessel left surface off Palm Beach, Florida on a 30-day drift mission in the Gulf Stream with a crew of six. Its final destination would be 1500 miles north off of Yarmouth, Nova Scotia. The vessel was named in honor of Benjamin Franklin who recognized, publicized and named the current "The Gulf Stream" in 1770.
Its Mission: to investigate the secrets of the Gulf Stream as it drifted northward at depths of 600-2,000 feet; to learn the effects on man of a long-duration, closed-environment stressful voyage; to demonstrate the engineering-operational concepts of long term submersible operation; and to conduct other scientific oceanographic studies.
This mission would be the longest privately-sponsored undersea experiment of its kind. It ended more than 30-days (and 1,444 nautical miles) later, when the Franklin and its crew of six surfaced some 300 miles south of Halifax, Nova Scotia on August 14, 1969 at 7:58 A.M. This was and remains an unparalleled feat -- no other mesoscaph has gone for a more extended or deep drift type mission. All that being said; here is why many have likely never heard of it. The Ben Franklin was greatly overshadowed by the Apollo 11 man on the moon mission that was launched only two days into the Franklins historic mission. Ben Franklin made a few more dives after 1969, including the first deep-sea dive for Dr. Robert Ballard, the discoverer of the wreck of the Titanic. Dr. Ballard said he has fond memories of the Franklin, as its large size and comfortable bunks gave him his best "sleep in the deep." Usually, submersibles are small, cramped and you spend hours in contortions with cold water from condensation dripping on you. Recently, the Ben Franklin was overhauled and preserved to be displayed at its final resting place where it proudly sits at the Vancouver Maritime Museum. The following is an excerpt from the documentary "From Sea to Shining Sea" narrated by Walter Conkrite; regarding the Ben Franklin and its place in history:
"Timing is everything. In the summer of 1969, within one day of each other, two courageous crews set out to explore new frontiers. Both were missions of pure discovery. One would go to the Sea of Tranquility, the other to the massive eastern boundary current known as the Gulf Stream. One would completely obliterate the other in the world's awareness. For eight days in July, the world looked skyward, transfixed, as Apollo 11, with three astronauts aboard, rocketed to the Moon. No one noticed the launch of PX-15. Manned by six brave aquanauts, the mission of PX-15, in the mesoscaph Ben Franklin, endured a perilous 30 day, 1400 mile drift-dive deep in the Gulf Stream. Though regarded as an analogue to prolonged missions in space, it was little remarked and all but forgotten at the time. The achievements of Apollo 11 have since become a celebrated event in human history; the astronauts are American heroes. The achievements of PX-15 and her crew were never noticed, and remain in oblivion. While the world looked up toward the Moon as the Eagle tracked over the rugged terrain of the Moon and landed, the 50' Ben Franklin was drifting at 1200 feet, 40 feet off the bottom of the Continental Shelf, taking stereoscopic pictures of equally rugged terrain. While the astronauts walked and worked on the Moon nearly 240,000 miles away, the aquanauts carried out their mission under crushing pressures between 800 and 2000 feet deep in the ocean. The danger to both missions and both crews was extreme, with little margin for error and very little hope of recovery in the event of an accident or emergency. Yet, one returned to the accolades of an adoring world, while the other returned to the notice of almost no one. The coincidence of the Apollo 11 moon mission and the Ben Franklin Gulf Stream Mission in 1969 is a strange and rare historical event, one that involves two of my favorite subjects - space and ocean exploration." - Walter Conkrite
Within a few years, the frontiers explored by Apollo 11 and PX-15 were abandoned and a golden age of human exploration came to an end. Sending something into the unknown has now largely replaced sending someone. As you hear about the 40th anniversary of the Apollo 11 moon landing, keep in mind the contributions of the Ben Franklin.
... running a diesel 24/7 is not cheap, even if it is the smallest diesel you can find. The beauty of a snorkel boat concept is in the fact that your diesel can be very small - much much smaller than anything that a surface ship of similar size could have.
In a surface ship the diesel needs to be strong enough to bring the bow into the wind during a storm. In a snorkel boat the diesel just has to overcome the windforce created by the sail area of the snorkel.
The diesel in a submarine yacht is ten times smaller, needs ten times less fuel. The high tank capcity is a option that you can take advantage of when you visit a country where diesel is incredible cheap - so you can get a year supply of fuel. You are in no obligation to fill this enourmous tank to start your journey.
If you are low budget you might use your diesel only the first day to engage the golf stream in Florida then shut it down and opt for a pure drift dive ocean crossing as Ben Franklin (see log Benjamin Franklin drift dive) did - and start your diesel again at the end of the voyage when England comes in sight some 45 days later. The total diesel use for crossing the Atlantic would be a few liters.
Other than the Ben Franklin which was assisted by a surface ship to catch the golfsteam - a whale shaped boat with a small diesel can take the trip into the stream with no assitance.
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The crew of the Ben Franklin was the first to stay in open ocean in a small boat without beeing afected by waves and seea sickness - this leads to the submerged living bubble concept as first choice for colonizing the open oceans with small scale structures.
The fact that oceanic waves move structures makes comfortable stay in open ocean only feasible for structures and platforms in excess of 100m loa and 40m beam - there is only one way to stabilize a small living space in open ocean to "permanent housing comfort grade" - submerge it like Ben Franklin.
Once you achive housing comfort in the open sea - the need to stay in the marina that ties all small yachts- is gone.
A real worldwide nomadic lifestyle can be created.
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