The ugliest sail ever...
 

The ugliest sail ever...

http://www.dt.navy.mil/pao/hi%20res%...v_Sail4LSV.jpg

Please don't tell me this is the future of sail design. I know, I know, form meets functions, but this thing is but ugly...:shifty: :nope: :(

The future of sail design is that there won't be any sail. :yep:
Imagine a sub sleek as a cigar, without any protuberances, now thats revolutionary. :cool:

Well, that would look like a....well...nevermind. You will probably figure out what I would say next.:dead: :dead: :dead:

Ok, just look at history :

At the end of the 1960's the US Navy looked for new concepts for submarine design for its SSN.
One of them was to have a sub without sail, the sub would only have a small bridge and all the masts and periscopes and the small bridge structure would fold within the hull when submerged.
You can see some images in the book "cold war submarines" from polmar & moore.
I tried googling for some images but nothing turned out.

Hmm.... why is that book so expensive? $40 bucks?..:shifty: :-? ... Is it worth the price? I might buy it if its good...

The book is a gold mine on sub design from the end of the second world war up to the end of the cold war.
It examines both soviet and american design filosophies as well the actual subs that were construted, and those that were imagined but never went beyond the design stage (The CONFORM project in particular was way too advanced for the technology of the time, a sleek sailless sub).
It is definiteley worth the price, if you're not sure about the book you can always ask someone else about it.
I think XabbaRus or Kapitan have it.

You know... Their was a USN task force a few years back that examined the "next SSN," meaning after Virginia, that recommends the same thing... US Defense Science Task Force on Submarine of the Future. Along with sail'less subs they also recommended bombay's and external weps...:hmm: Sounds like its geared to be a giant monstrousity to me.:shifty:

[quote=goldorak]Ok, you've convinced me. :)
*goes to buy the book*

Some of the original Virginia 3D models during the design stage (when it was the "Centurion") had a sail much like that picture.

yeah what is that sub in the very upper picture?

virginia concept
http://www.fas.org/man/dod-101/sys/s...irginia-56.jpg

Its the USS Ugly Fish... the ugliest sub ever created. It's meant to stun the enemy with instanteous and uncontrollable grimacing....:dead: :yep:

looks a bit like Jule Vernes Nautilus :)

The sail-less sub is not going to happen until somebody figures out a way to get sensors and other necessary devices into the hull.

Along with providing streamlining and protection for sensor, antenna, snorkel, and other masts, the sail also provides a margin of safety and stealth when coming to periscope depth for any reason. Imaging having no sail, and then coming to PD in rough seas to copy the submarine broadcast. You'd have to come so shallow that the rough seas would toss you around enough to broach the surface - then your whole topside is exposed. Bye-bye stealth!

Even with the current moderately-sized sail, subs broach in rough seas, but mostly it's just the sail (a much smaller visual/sensor target than the whole sub!) that breaks the surface. It happens. The better the driving team, the less it will happen, but it's going to happen anyway.

The reasons for reducing or eliminating the sail were reduction of drag, and reducing the possibility of the sail acting as a big giant stern plane (control surface) at high speeds. However, the other reasons mentioned above trumped these, and small(relatively speaking) sails were retained. You should see the difference in size between the Permit-and-later-class sails, and the Skipjack and earlier SSN sails.

I can hear it now: "Why not put the sensors in a UUV or pod on a tow-cable that you let float to the surface?" For one thing, a cable can break or be fouled, rendering the UUV/Pod useless. For another, a UUV/Pod will be less stable at PD or the surface than the sub itself, more at the mercy of rough seas than the larger platform. Additionally, the UUV/pod still doesn't answer the question of what to do about the snorkel mast, which is one of the most important pieces of emergency equipment on the sub. It serves to ventilate in case of fire or toxic gas, and also provides air to the emergency diesel engine.

TG

Well, every sub until this point has had some of its mast penetrating the pressure hull (ie periscope) and the mast was made to extend from the pressure hull into upwards. All you would have to do is create a compartment in the pressure hull to hold the mast and extend them from there... kindof like DiMercurio's concepts...

http://www.ussdevilfish.com/diag04c.htm

So there would be one solution.

Hmm... it kindof does. Its actually the LSV (Large Scale Vehicle) that the USN uses to test boat/prop designs. http://www.dt.navy.mil/pao/excerpts%...vSail6_01.html

why not a sail like a shark fin ?? streamlined and able to have sensors ?

sharks are very well adapter for slide through water during millions of years...:hmm:

What about sensors on floating platform connected by cable ? Some of such sensors are already researched .. like that floating up-looking fish-eye scope with computer corrected image. Radio wires and buoys are used even today. Sure .. snorkel is a
problem, but you don't need it that much.

Or something like UUVs equipped with cameras, RWR or Radar masts. Or even better, UAV (unmaned airborne vehicle) inside UUV, with both radar and cameras.

Or just long mast supported with wires .. like snorkel on german subs - folded backward on the hull (or inside hull cavity). With non-penetrating masts this is no problem.


I think the most important reason for sail is that there must be some place for watchmen in harbors. And sub-hull is not suited for that at all.

The sail is needed. Not only for placing sensors, but because without it, the sub would rotate on its longitudinal axis without control.
That's why all long-traveller fishes have the upper fin (don't know the name in English :damn: ).

You could say:" Whales haven't got one". Well, whales are not fishes but mammals, some whales have it and the whales without it have to compensate this with the movements and bodyshape.

Thus, the sail is the best design at this time... removing it implicates changing the design of the whole sub... maybe even the propulsion system.

Despite this, the submarine on the photo is horrible!!

why is it important for you to remove the sail in the future?

It is more like subs without a sail were disadvanced.

Um.. no. The metacentric height would prevent that. The center of gravity is below the center of bouyancy then ensuring a righting movement that would keep the top side UP.

When a sub is at PD it tends rock due to the forces acting on the vertical sail surface. Actually, I believe that a sub without a sail would be more stable at PD as the rounded surface would not be as effected by wave action.

But....

One reason for the sail is that the boat can be deeper and still pierce the surface interface. Thus the boat is less affected by wave action and surface tension/ducting.. If you place these masts and sensors in the hull, you have to have a MUCH longer mast, which will vibrate as it travels thru the water. Since you are talking a long, fairly stiff shaft, this means that you will have low frequency harmonics which travel better in the water. Also, you will be REALLY speed limited with this extra long mast supported from just one end. If you make the masts short so that these are not issues, then think of how close to the surface you will have to be. It would mean that anything over a state 2 or so sea would be impossible due to wave action.