How big is a boat?

Safewalrus, just give Gibraltar to Spain and shut up!
( than Spain it will have to give Ceuta and Melilla to Marrocos)

 

Well, I quite disagree. Eucaliptus plays its role in nature as any other tree. Think of Tasmania. What should be avoided is the inadecuate use of it, as it happens in our countries, where extensive and unduly controlled plantations have been done in a most messy manner, destroying other valuable woods and invading places where they should have never been planted.

By the way, 'Pinheiro bravo' isn't either a native tree from Galicia or Portugal. But ,together with eucaliptus served to 'make soil', prepairing the once deforested mountains (When Portugal and Spain ruled the seas, woods where dicimated to build the fleets, and at the beginning of the 20th century the landscapes of Galicia and North Portugal mountains were rather sad).

Eucaliptus is becoming little by little the wood of choice for houses and furniture building the world around. So we have in our countries a tremendous 'natural capital' for the future that has to be cleverly used. Not all the eucaliptus history in our countries is regrettable.

What has to be done is preserve and expand the original native woods where possible and limit eucaliptus plantations (think of it as wheat, i.e) to precise areas and using diverse silviculture techniques depending on the quality of wood required from them.

I think it's humans and their acts what have to be blamed, not the trees.

(Sorry Jonathan, I've come out of your topic but, on my side, it ends here)

 

Jonathan,
There is an european network named Maritime Visions looking for visionary concept ideas for vessels and floating structures. You may find more info at:
http://www.maritime-visions.net/
Within their pages I've found what seems to be a cruiser concept that somewhat resembles your idea. I attach a poor quality image taken from a video presentation there.

 

As usual Gilly the idea has merits but I believe the practicalities far outweigh these! primarily weather conditions!

Does thing have to survive in exteme weather conditions, of course it does othrwise it would appear pointless to have it. the requirement to shelter behind a "land mass" would cancel out the independance of the thing, which is I believe one of the main reasons for it's being! agree Jonathan?:?:

Vega, only one fly in that ointment (the same as the Falklands) the locals Just DON'T WANT TO BE SPANISH!! I can understand this, my sister was after all born in Gibraltar (poor girl)! Tell you what there was a time when the Portugese where allied to the Spanish (allied to such an extent that they were Spanish!) When You return to that state (a county of Spain) then we'll consider letting the rock return to Spain (It was actually more Moorish than Spanish) IF the locals want to!!

 

Look like Gilligan island to me........... too mind bashing beatiful...........

 

My original concepts were for a large floating city which would be located in the Pacific High (anti-cyclone) a permanent weather feature between Hawaii and California that moves slowly north in the summer and south in the the winter. This weather pattern, on average over 1000 miles in diameter, results in flat seas with clear weather. The closer you get to the center of this high pressure area the more glassy the seas become, the less wind and clouds. So that helps a lot with the weather problem. This area is also coincident with the North Pacific Gyre where millions of tons of polymers are floating waiting to be recycled into a floating structure. But to develop such a thing is very serious big money. So with the idea that you have to walk before you can run, I began developing the Oceanarium concept which is stationed about 5 miles off shore of Hawaii Island in the lee of the island where the weather is fair most of the time and the waves are only big when they break on shore. And supply and transport are not too big a problem. These kinds of technologies will have to be developed starting from what we already know. That's why the input from people with experience in every aspect of practical marine experience are invaluable. People like you Safewalrus. We have to start identifying the problems and then get experienced people to start figuring out the solutions.

The question of independence is really relative. There is no such thing as independence. Everything is interconnected. But there is relative autonomy where people have elements of control over the way they live, work and play. This can happen on a ship if the owners and the captain set up a set of procedures and systems to allow such a thing. Even on cruiseships as we speak, the owners pretty much determine what goes on board. So a large mobile, floating structure is capable of degrees of autonomy that allows innovative social and economic systems to be put into place.

 

On the weather front I believe that we have to both decide on the amount of independance required from whoever! The Possible area of operation, which can be partially linked to the former and also the weather expected in the expected area of operation! this will include such delightful extra's like the so called '100 year storm scenario'! We then need to concern ourselves with the prospects of the 'mother island' (for want of a better term) surviving this storm, and the possibilities of ensuring the island can!

Having decided all this important stuff! The 'mother island' ain't no use if she sinks at the sight of the first storm!

We can then move forward into methods of resupply of commodities that we cannot produce ourselves (depending on the size etc of the 'mother island' quite a lot of self production is possibly amazingly enough!)

I believe that despite all the proliferation we are still floundering around the inital estimates of our requirements! having said that every situation is of course individual and must be decided on on its merits! Quite a tall order Gentlemen!

 

You hit the nail on the head. The 100 year storm scenario. The thing will need to have sufficient displacement , strength and energy absorbing capability. Back in the 60's I was on the Hapag-Lloyd cruiseship called the Bremerhaven crossing the North Atlantic (New York to Bremen) in September. We passed within 90 miles of the path of a hurricane. The peak to trough height of the waves towered over the top of the ship. And she was rocking and rolling to an intense degree. Everybody on the ship was seasick, except me, because I went out onto the top deck, held onto the rails and watched the awesome power of nature. I was only 15 at the time. I probably should have been messing my pants. Too stupid I guess. Aint youth great?!

But to make a long story short, something the size of several cruiseships displacement and with wave absorbing technology, should be able to handle the occasional big one. Of course, just like on land, you don't try to make deliveries in a hurricane.

 

You got it Jonathan, however at the same time due to the way we live these days you MUST produce something that can live with a decent guarantee of sucess, through this 'storm' if you don't You'll never recover etc.

OK, I know, if you don't you'll be dead but unfortunately it's about being "seen to be keen" as much as anything else! If you can't prove there will be no problem you'll probably get no inhabitants for 'mother island' in the first place!

Plus of course if it does go to ratsh** your 'delivery vessels' become 'rescue vessels', you need to be able to prove they can get in to rescue and also of course are capable of rescue!

The other point, can you evacuate a casuality TO 'mother island' in heavy weather to see Your Doctor!! You may be OK but as your a floating structure you have a duty under maritime law to assist in times of danger, if reasonably practicable! You intend to have full medical facilities on the 'mother island' I presume, be bloody silly if you don't!

 

Just stay landlocked and start supply to crazy people int he Nirvana project....... safe and sound....... Imagine a torpedo of 600Mph hit a platform........... dangerous as they can dodge the blow.....

 

Jonatahn:
Have you considered rogue waves?
http://www.esa.int/esaCP/SEMOKQL26WD_index_0.html

 

As I said earlier in this thread, I have experienced them first hand on the Bremerhaven in '63. Interestingly the ship I returned on 9 months later was the Bremen which according to this article was later nearly lost due to being damaged by such waves. But the waves that night on the Bremerhaven were not single freak waves, they were huge towering waves that went on for hours. The skill of the crew kept that bow perpendicular to the waves. Otherwise we surely would have been capsized by any one of those walls of water. I am not sure exactly how high they were, but the Bremerhaven stood at least 6 or 7 decks above the water line, say 50 or 60 feet (15-20 meters) and when the ship was in the trough, the peak of the waves seemed maybe 25 to 30 feet higher than the top of the ship.

So yes I have given a lot of consideration to these monster waves. So here's my reasoning. If I put a normal sized skiff in a wave tank that is meant for 1/50th scale models, then the biggest wave created by the wave making mechanism will barely cause the skiff to move even though it might be a "rogue wave" to the scale models usually tested in the tank. In this case, size matters.

The people working on the concept ship called the Freedom Ship (http://www.freedomship.com/freedomship/overview/overview.shtml) have stated that with a design length of 4,500 feet, a width of 750 feet, and a height of 350 feet, Freedom Ship would be more than 4 times longer than the Queen Mary and that a 100 foot wave would cause a vertical displacement of 1 foot. I don't know if that is correct, but something that large would surely dwarf the biggest waves. That is the first defense. Then how suitable the structure is to absorb the wave's energy without cracking, splitting or capsizing is the next issue.

I believe the shape of my oceanarium concept, which is a toroidal shape, is capsize-proof if it is sufficiently large because it is the same dimension in all directions. I think the toroid is about the strongest possible configuration other than a sphere. Regardless of the direction of the waves it won't capsize unless it breaks into pieces. So that means that the hull has to stay intact. That is why I developed a hydraulic system for absorbing and storing wave energy which can be used to power the ship. It is described in an earlier post. I would be interested to hear comments on my reasoning.

 

That's my major concern, not stability.
Toroid is nice, but I imagine you won't have a resisting structure in the top of it, only at the bottom and probably some intermediate others up to a 'main' deck. And depending on total size and relative dimensions between outer and inner circunferences, as well as the section's radius, the impact of a 25 m rogue wave or a series of no so high ones in resonance with one of the vibration modes of the toroid, may impose huge loads on the structure.
On the other hand we have the problem of the 'rear' aperture to allow boats come into the inner circle. If the toroid is not closed twisting and bending efforts can become very important.
But I'm just speculating because I don't have the picture and dimensions of the whole thing. Could you post more picture and/or drawings, not just the underbody, as well as its main dimensions?

 

From experience during 'heavy weather' in Ocean areas it is a known fact amongst 'super tanker' crews that you can stand on the poop of the ship and watch the fx'cle flex one way then another in completely different time to the roll of the vessel in general! Quite a frightening experience! It's such a well know phenomina that most 'tanker' crews are not even aware that it's happening (you dare not think about it anyway! you can't do much if the damn thing does snap!)

Thinking about Guillermo's observation on the 'rear' appature this would be fairly easy to close up in bad weather - a simple door/caisson could be employed to close the entrance above a certain wind/sea force, thus also keeping the vessels inside safer anyway (pumping out the water and allowing the vessels in the dock to come to rest in purpose made cradles is a option here for complete stability [Naval amphibious vessels some time known as LPD's use this system - Landing Platform Dock - it has some reccomendations, apart from the fact that all vessels in dock would have to conform to a norm or depart before pumpout]) the only problem thus being the size of the dock and thus the water contained would affect stability, at a time when more rather than less ballast would be advisable!

This door incidentally would need to be 'dogged' in place to ensure lack of movement during the adverse weather conditions!