concretesubmarine.com/ FORUM

The Treasure of the San José

Why global sustainability requires rocket fast technological progress:

http://concretesubmarine.activeboard.com/t58921987/sustainability-population-growth-consumption-growth-ocean-co/

 

Marine business will lead to Seasteading:

http://www.seasteading.org/forum-list/topic/marine-business-will-lead-to-seasteading/page/8/#post-24163

 

-- Edited by admin on Tuesday 4th of November 2014 04:54:23 PM

The handling of a submarine yacht requires no "classic seamanship" it is as simple as pointing the bow in the direction you want to go - no special consideration of climate, wave conditions, the submarine ambient is a constant ambient with very little changes. It is like going in a business jet but without the pumps and airtraffic considerations.

its not really hard-- you would do much the same as a surface yacht...there are a few other things you would learn--but-not much. I plan on using standard cameras and fish finders or mayube cheap off the shelf depth finders.. need a strobe at night on the mast...military sunmariners have always looked at surface vessels as inferior...and they truly are compared to the low power requirements of a below surface vessel. they dont cost any more than a surface yacht..

 

they handle well due the streamlined control surfaces and the shape.. and the almost weightlessness of the vessel...

 

-- Edited by u-boatdreams on Friday 16th of September 2011 10:55:48 PM

 

No long distance surface swimming animal exists because this is not energy efficient. Even whales which need the surface for breathing (because they started as a surface animal similar to a nutria -ambulocetus-) swim now below surface - why ? because they cruise up to 12,000 miles each year and nature shapes all animals to be energy efficient. Here we are - if you are looking for a model for a energy efficient ocean crossing submarine yacht take this. A 200 ton whale with a length of 30m (cut some of the tail section for hydrodynamic efficient length - take some 25m) can come up to a speed of 30 knots and has been measured at those speeds. Biologists and Physiologists estimate its maximum power output at 400 horsepower. Whales are mammals so their energy physiology is similar to other mammals. Which means there is a big gap between the energy output you can get from the organism in a emergency situation for a few minutes of fast swim and the energy output you can get 24 hours a day. The most educated guess on that is a factor 10 you can run very fast for 1 minute but if you wander 24 hours a day you have to do it at a slower rithm. This means what you have on a whale tail 24 hours a day during wandering is maybe 40 horsepower possibly less. If you take into account that whales do not feed which means do not re-fuel 6-8 months during wandering - how is this possible ? - only if they use VERY VERY little energy for swimming over VERY VERY long distances. What is the efficient speed range ? Smaller whales cruise at some 3 knots bigger whales at up to 6 knots. Taking a stream speed of 3 knots in your favor as ben franklin did in its 30 day Golf Stream drift dive - you could have a whale economic ocean crossing at 9knots over ground in a submarine yacht - not bad ! Having this in mind i took my prototype concrete submarine to water back in 1996 it was whale shaped had 20 tons like a small whale and my most important question was not top speed with a big engine - this is quite clear anyhow - my question was the limbo - how low can you go... so what i did first was installing a ridiculously small electric engine of 200W into the sub and pushed the switch. - What happened? First nothing then after a couple of seconds the hull took up speed and kept taking up speed until it reached a speed of what would be in the range of a whale efficient cruising speed - some 3 knots. So i never came to the point to install the big combustion engine i had in mind in first place - it was not necessary. I later put a small generator in to reload the small battery pack and extend the range - that was all. In all my submarine yachting years i never saw a situation i would have had a need for a bigger engine. This ridiculously small engine pushed me trough storms had no problem to get nose into the wind... So i am well aware what engine size is recommended for surface yachts - BUT - based on my own experience i would be concerned that such a engine would have a short life in a yacht submarine yacht because it has to run all the time in under load during cruising . I also have no problem if somebody wants a 400hp engine in a 200 ton submarine yacht to run all the time at whale emergency speed of 30 knots - you could water ski behind it...
My personal preference is doing it like those gentle giants - cruise oceans energy efficient at moderate speed.

When you plan an engine for a submarine yacht you should forget anything that is recommended for surface yachts and come back to the basics. Fortunately there exists a fine model made by mother nature that has about the size of a submarine yacht and travels long distance as a submarine yacht is supposed to do - Whales! A streamlined body such as a whale can travel over long distances with incredibly low energy use. Studies suggest that a whale uses 5 times less energy for swimming under surface than swimming on surface where additional drag from wave resistance comes up. A graywhale of 18 tons displacement has 3000 kg (14 kg of fuel/day) to travel 20.000km (95km/day) in this journey he has about 589g/hour of fuel available for life support and locomotion. To simulate the locomotion model of gray whale a submarine yacht of the size of my prototype (20tons) is well equipped with a diesel of 1-3 horsepower. This fits well with my own field data that suggest that a small electric engine of just 200W can move a submarine yacht hull of 20 tons under all weather conditions. Such a submarine yacht is able to go 95km per day with 14kg fuel use per day - the problem is you might not find a diesel small enough for this.

....right whales are slow swimmers, rarely exceeding 5 knots, with an average speed of only 2 knots. Gray whales are also not too fast, clocking a maximum speed of only 6.5 knots. Humpback whales do about 5 knots on average, but can put on bursts of 9-10 knots. Sperm whales are much faster, doing about 10 knots on average, and able to accelerate up to 20 knots or so if pushed, though only able to maintain this speed for a short period. Speeds of 14 -18 knots have been reported for the minke whale. The sei whale appears to be the fastest of the lot, able to achieve a sprint of about 32 knots, although again for only a short stretch. Some dolphin species can also go this fast, and are generally a lot faster than whales on average.

Energy efficency

hydrodynamic cost of swimming for a graywhale
muscle and digestive efficiencies of 25% (Gosline 1993) and 80% (Thomson and Martin 1986)

Models developed by (Bose and Lien 1989) for a fin whale

model for a typical gray whale (Sumich 1983) estimates the daily requirements for gray whale locomotion come close to 60 Mcal/day.

Gray whale if swimming near to surface encounter wave drag which can increase total drag by a factor of five (Hertel 1966)

It makes sense for whales to travel at depth greater than 3 times their body depth (Sumich 1983)

Metabolic rate from oxygen consumption Studies:
(sumich 1983, Wuersig et a. 1986, Wahrenbrock et.al.1974, Highsmith and Coyle 1992)

hydrodynamic models:
Bose and Lien 1989, Hui 1987,

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Bose N, Lien J (1989) Propulsion of a fin whale (Balaenoperta physalus): Why de fin whale is a fast swimmer. Proc R Soc Lond B 237:175-200
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Hertel H (1966) Structure, form and movement. Reinhold Publishing Corporation, New York.
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Hui CA (1987) Power and speed of swimming dolphins. J Mamm 68: 126-132
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Kleiber M (1975) The fire of life: An introduction to animal energetics. Robert E Krieger Publ Co., Huntington, New York.
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Pike GC (1962) Migration and feeding of the gray whale (Eschrichtius robustus). J Fish Res Bd Canada 19: 815-838
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Sumich Jl (1983) Swimming velocities, breathing patterns, and estimated costs of locomotion in migrating gray whales, Eschrichtius robustus. Can J Zool 61:647-652
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Wahrenbrock EA, Marushak GF, Elsner R, Kenney DW(1974) Respiration and metabolism in two baleen whale calves. Mar Fish Rev 36:3-9
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Blix, A.S. and Folkow, L.P.(1995) Daily energy expenditure in free living minke whales. Acta physiol. scand. 153, 61-66
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Hui (1987) estimated that dolphins energy bursts represent a 166-fold increase of the metabolism over resting rates.

Migrating gray whales have a minimum CT (cost of transportation) that occurs at the mean velocity of 2.0m/s (Sumich, 1983). The stored engery resevers allow a migration of 15.000-20.000km during which the whales fast.

Cost of locomotion estimated, based on Lockyer(1981) and an average swimming speed of 6.3km/h for gray whales (Perryman et al. 1999)

Total blubbermass used in migration in a 18000kg whale is 3000 kg available for six to seven months without feeding - while migrating 20.000 km

energy by respiration...
The estimated O2 consumption of about 150 l.min(-1) is in line with the general allometric regression for mammals and corresponds to an energetic expenditure of 85-95 kJ.kg(-1).day(-1).

( BLIX AS, FOLKOW LP. Acta Physiol Scand 1995;153(1):61-6.) Mink Whales
...We found that cost of swimming is remarkably low in these large animals and that their estimated daily energy expenditure on average only amounts to 80 kJ kg-1 day-1.

http://concretesubmarine.com

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Oceanic concepts shaped by mother nature.... no surface ocean traveling animal exists...

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To have a realistic perception of the propulsion for a oceanic sistem that operates submerged look at the propulsion of ocean fish farming cages the thruster setup size operation envelope. All this is VERY different to a surface ship or a military submarine.

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When talking about protection from wave damage we should have clear that one thing is being protected from wave hazard and sea sickening movements what happens inmediatly when you are submerged - and the other thing is how deep in the ocean you might notice the pass of big waves.

Wave hazards come from 2 factors:

1) breaking crests that can hit a structure with hundreds of tons of force

2) Hog and Sag, bending and torsion, forces which appear when a ship is supported by water (and bouyancy) at one end and in the air at the other end. Those forces can break a ship or lead to fatigue. They make a ship stamp and roll.

If you leave the math and wave amplitude thing apart, you can easyly understand that neither wave crests nor hog and sag can exist anymore as soon as you have a thin water layer closing above you, even when this layer is just a foot deep. The structure will be supported uniformly by water at its whole length and this uniform support leads inmediatly to a much calmer behavior.

This is what a diver experiences when he jumps from a rocking surface boat  - there is inmediatly this incredible calm uniformly supported floating status when you go below the surface it dos not  start gradually dozends of meters down - it is just below the surface. No wave is HITTING you anymore no wave is pushing you and your equpment around as it is the case when you swim on the surface. The only thing you experience below is a kind of current that changes direction with every wave. So you can "percieve the wave movement" when you have a visual reference to the sea bottom. If you don`t have this visual reference you will not notice the movement.

I know a lot of divers that are suceptible to seasickness in a rolling diveboat and they are always the first to jump overboard - once you are below seasickness is gone.

I experienced this in extreme form at Malpelo Island which is a island in the pacific 500 km off the coast of Colombia between Cocos and Galapagos - you have those real big pacific waves comming in directly towards a volcanic rock face. There is no doubt that any ship no matter the thickness of its steel plating would be hacked to small pieces within minutes. The divers jump overboard far from the rocks and swimm below the surface directly towards this rockfaces - this is where all those beautiful fishes are. You hang there 1-2m below the "hackzone" relaxed enjoy the smooth waiven of the waves comming in, you can feel the real big suckers in your ears, as the waterdepth changes while the crest goes trough. It is a wonderful place to mediate about the fact why nature never developed a surface swimming animal for the open sea - maybe living below is just so much better.

The other experience i can contribute is the experience i had with the submarine yacht prototype - while i had the sub on its anchorplace and was tooling around inside i closed the hatch to avoid questions from courious visitors - i was there for an hour or so and when i opened the hatch i noticed that a storm had come up, several trees felt down, sailing yachts in the 30 foot range where calling SOS, and the local rescue crew was busy to assist. - I did not even notice the storm. And the hull was still on the surface exposing the sail (tower) and the central rounded part of the hull a bit above the surface. Obviously this did not present enough wave and weather attack surface to make the hull rock and roll.