The ugliest sail ever...

[LoBlo]

The ugliest sail ever...

http://www.dt.navy.mil/pao/hi%20res%20images/2001/June/Adv_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: :(

[goldorak]

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:

[ASWnut101]

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:

[goldorak]

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.

[LoBlo]

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 (http://www.amazon.com/Cold-War-Submarines-Construction-1945-2001/dp/1574885944/ref=cm_lmf_tit_1_rdssss1/103-4926157-5914246$40) bucks?..:shifty: :-? ... Is it worth the price? I might buy it if its good...

[goldorak]

Hmm.... why is that book so expensive? $40 (http://www.amazon.com/Cold-War-Submarines-Construction-1945-2001/dp/1574885944/ref=cm_lmf_tit_1_rdssss1/103-4926157-5914246$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.

[LoBlo]

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:

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 (http://www.fas.org/man/dod-101/sys/ship/docs/sotf.htm). 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:

[LoBlo]

[quote=LoBlo]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.

Ok, you've convinced me. :)
*goes to buy the book*

[Frying Tiger]

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

[Captain Sub]

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/ship/ssn-virginia-56.jpg

[LoBlo]

yeah what is that sub in the very upper picture?

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

[Captain Sub]

looks a bit like Jule Vernes Nautilus :)

[timmyg00]

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

[LoBlo]

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.

[LoBlo]

looks a bit like Jule Vernes Nautilus :)

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%20pages/2001/advSail6_01.html

[Hartmann]

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:

[Dr.Sid]

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.

[FERdeBOER]

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!!

[Captain Sub]

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

It is more like subs without a sail were disadvanced.

[Bubblehead Nuke]

The sail is needed. Not only for placing sensors, but because without it, the sub would rotate on its longitudinal axis without control.


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.

[LoBlo]

So so far the advantages/disadvantages of the sail-less-ness are:

Sail-less
Good
-Less prone to wave action per say (mostly caused by the sail)
-Less drag = quieter and higher top speed
-Less draft = more manueverable in littoral waters
Bad
-Extremely long mast = slower and noiser 'mast up'
-If short mast used then shallower PD
-port transits complicated by no bridge (PD dependent)

Sail
Good
-Deeper PD
-shorter/stronger mastup's
-visible in surface transits
Bad
-worst in higher sea state (wave action on the sail)
-more drag = more self noise and slow speeds
-shallow water limitations

Modified sails (in picture)
Good
-more internal volume
Bad
-more drag
-Ugly as sin (induces intractable vomiting):doh:

[LoBlo]

I've got a solution! Retractable sails!:|\\

Just suck the whole sail into a chamber when in shallow waters are high speed transits :yep: :)

[timmyg00]

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.
What about sensors on floating platform connected by cable ?.... Or something like UUVs equipped with cameras, RWR or Radar masts. See, i knew somebody would say that...

Sure .. snorkel is a problem, but you don't need it that much. Right, and when you need it and don't have it, how would you feel about it then? Pretty chagrinned that you let the bonehead engineers back on land sell you a sub with no snorkel, after you suffer a major power plant casualty, battery runs low, and you with no diesel generator...

Or even better, UAV (unmaned airborne vehicle) inside UUV, with both radar and cameras. and how do you propose to control it without radio masts? ;)

Or just long mast supported with wires .. like snorkel on german subs - folded backward on the hull (or inside hull cavity). More drag and self-noise. Not an option. This is why submarine designers (including the Germans, with the Type XXI sub) removed external projections, such as guns and railings, and moved antennas and sensors into a protected, streamlined sail.

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. Much better technical explanation than mine.... typical nuke... :roll: :up:

TG

[FERdeBOER]

The sail is needed. Not only for placing sensors, but because without it, the sub would rotate on its longitudinal axis without control.


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.

That's ok when the sub is stabilized, but when turning at a speed the submarine would be much harder to control without a sail.

[Kapitan]

Not true as it goes reading some time ago a thesis on submarine hydro dynamics it turns out the higher the sail the more prone to snap roll the submarine is, as ive been told the "skipjacks were the worst".

Without a sail the submarine is just as stable, if you have noticed the russian submarine sails are small (you cant even break a leg if you jumped), the akulas sail is about a foot taller than the bullet at the back end its also longer and more sleek looking.

The quote "Skipjacks were the worst" came from xabbarus a while back he got that from an acctual skipjack submariner.

[FERdeBOER]

I'm not saying the sail must be big, I'm saying that is good for stability when navigating. Of course can have cons, everything is good for something and bad for another things.

And, please, what does "Skipjacks were the worst" means? My English is not as good :hmm:

[Wim Libaers]

So perhaps the best thing to do would be to have two classes of submarine, one with a sail for those that are expected to stay near the surface often, and one without a sail for those that will almost always be deep (countering other subs, tapping underwater cables, that kind of stuff).

[LoBlo]

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. Much better technical explanation than mine.... typical nuke... :roll: :up:

TG

Well, the mast can easily be telescoped into the depth of the pressure hull. 30ft base telescope half extended with a 30ft interior telescope half extended would give a 30 ft reach. If strength and resonance is an issue one could choose high strength composite materials (modern day composites have 2-3 times the strength of titanium) which would provide more strength and decrease resonance. With 30 ft mast, periscope depths would be 30 ft mast + 33 ft to keel = 63 feet PD, roughly the same as some PD depths now if I understand correctly... and if BH is right the sail-less hull would be less prone to wave action. The captain would just have to except the fact that the design doesn't allow him to drive as fast with 'mastup'. Its the trade-off for better littoral maneuverability, shallower draft, less drag...

... And it sounds like the US Defense Science board recommendations believes its worth the tradeoff


We believe that this "bomb bay" innovation should be part of a redesign of the entire front end that should include considering:

eliminating the sail (and thus gaining speed and agility at shallow depth at high sea state and reducing radiated- and self-noise)
replacing the sonar sensors with an integrated system having much improved performance.

[LoBlo]

I'm not saying the sail must be big, I'm saying that is good for stability when navigating. Of course can have cons, everything is good for something and bad for another things.

And, please, what does "Skipjacks were the worst" means? My English is not as good

He's saying that its the sails that's causing the snap roll effect when turning (the sub turns, and the water pushing on the sail makes the sub roll). From what I read, at higher speeds, the sail also tries to pitch the nose of the sub up and also causes flow irregularities at the aft control surfaces.

[Oberon]

I'm not saying the sail must be big, I'm saying that is good for stability when navigating. Of course can have cons, everything is good for something and bad for another things.

And, please, what does "Skipjacks were the worst" means? My English is not as good :hmm:

http://navysite.de/ssn/images/ssn592_2.jpg

This is a Skipjack class SSN (The USS Snook to be precise), take a look at the height of the sail....almost the size of my house! This would make the sub aquadynamics a nightmare, and prone to snap-rolls. Hence the "Skipjacks were the worst".

I think the Russians come onto a good thing with their sail designs, short and streamlined is the way ahead in my opinion. Even the US has realised that now, the short slope at the base of the Virginia and Seawolf's sails are surely to improve the flow and stability of the sail. It probably won't be long before they slope it up like the sub at the start...I once designed a sub with a sail like that....long time ago....I also made the front sharp and pointed...which, now I realise, severely reduced the maximum depth for the design. Subsequent redesigns removed the pointed bow in favour of a more conventional shape, but kept the sloped sail. Looks like I wasn't alone in thinking that kinda sail might be something worth looking into...

So...if you're looking for other ideas US Navy? Drop us a line.... ;)

[Sub Sailor]

If you completely do a way with the sail, yes it houses mast and sensors, but what about entering and leaving port?
Where is the conning officer going to stand when maneuvering along side the pier. Also look at pictures of subs on the surface going through various canals or entering or leaving port with other ships around, they are really hard to sea, even in good light and conditions.
No doubt it is a great idea to rid subs of the drag of the sail, and nukes are not on the surface much, but I cannot figure out how to accommodate the needs when they have to be surfaced.

Ron Banks MMCM(SS), USN(Ret)

[timmyg00]

Well, the mast can easily be telescoped into the depth of the pressure hull. 30ft base telescope half extended with a 30ft interior telescope half extended would give a 30 ft reach. If strength and resonance is an issue one could choose high strength composite materials (modern day composites have 2-3 times the strength of titanium) which would provide more strength and decrease resonance. With 30 ft mast, periscope depths would be 30 ft mast + 33 ft to keel = 63 feet PD, roughly the same as some PD depths now if I understand correctly... and if BH is right the sail-less hull would be less prone to wave action. The captain would just have to except the fact that the design doesn't allow him to drive as fast with 'mastup'. Its the trade-off for better littoral maneuverability, shallower draft, less drag... This might be OK if the masts in question were not hull-penetrating, i.e. if the "bomb-bay" is not part of the pressure hull. I wonder how they justify the part about the gain in speed and agility at shallow depth and high sea state.

TG

[Kapitan]

Reasons for a sail:

They house the mast's and antennas
They can be enclosed to protect those who are on watch from the bad weather
Without them the submarine would look wrong
Navigational lights are on the sail without them theres going to be plenty of collisisons

Just some of why sails are needed.

[LoBlo]

I think the Russians come onto a good thing with their sail designs, short and streamlined is the way ahead in my opinion. Even the US has realised that now, the short slope at the base of the Virginia and Seawolf's sails are surely to improve the flow and stability of the sail. It probably won't be long before they slope it up like the sub at the start...I once designed a sub with a sail like that....long time ago....I also made the front sharp and pointed...which, now I realise, severely reduced the maximum depth for the design. Subsequent redesigns removed the pointed bow in favour of a more conventional shape, but kept the sloped sail. Looks like I wasn't alone in thinking that kinda sail might be something worth looking into...

So...if you're looking for other ideas US Navy? Drop us a line.... ;)

There most awesome sail design ever... heh heh... http://img381.imageshack.us/img381/1345/08002327ctx0.jpg :cool: :|\\

[Bubblehead Nuke]

Well, the mast can easily be telescoped into the depth of the pressure hull. 30ft base telescope half extended with a 30ft interior telescope half extended would give a 30 ft reach. If strength and resonance is an issue one could choose high strength composite materials (modern day composites have 2-3 times the strength of titanium) which would provide more strength and decrease resonance. With 30 ft mast, periscope depths would be 30 ft mast + 33 ft to keel = 63 feet PD, roughly the same as some PD depths now if I understand correctly... and if BH is right the sail-less hull would be less prone to wave action. The captain would just have to except the fact that the design doesn't allow him to drive as fast with 'mastup'. Its the trade-off for better littoral maneuverability, shallower draft, less drag...


You can telescope a mast but only to a point. The BRA-34 radio masts we had did that. You have a hydrodynamic shpe on the lower half with a more cylindrical shape above. Regardless of the strength of the material (and I have no doubt that it COULD be constructed) you will have the harmonic resonace problems. Having it supported at one end, with water flowing around it, it going to make it 'twang' at a harmonic directly proportional to its length.

Speeds at PD are slow already. Having speed restricted even more would make most captains shudder. Subs are hard enough to control with as little way on the ship they have now. Imagine having to hover the whole time you are clearing a broadcast or using the ESM gear. A real heart stopper? Be at PD at night clearing a broadcast and have a ASW plane pop out of the cloud cover and hit you with its spotlight (yep, had that happen once). You WANT to have some speed on cause you have to go down FAST. Flooding negative on the hover system while you are waiting for these LONG multi-telescoping masts to retract BEFORE you can start really moving.. THAT would be a huge pucker factor.

[Bubblehead Nuke]

Much better technical explanation than mine.... typical nuke... :roll: :up:

TG

You know us nukes... too dang technical for our own good.

[LoBlo]

You can telescope a mast but only to a point. The BRA-34 radio masts we had did that. You have a hydrodynamic shpe on the lower half with a more cylindrical shape above. Regardless of the strength of the material (and I have no doubt that it COULD be constructed) you will have the harmonic resonace problems. Having it supported at one end, with water flowing around it, it going to make it 'twang' at a harmonic directly proportional to its length.

Speeds at PD are slow already. Having speed restricted even more would make most captains shudder. Subs are hard enough to control with as little way on the ship they have now. Imagine having to hover the whole time you are clearing a broadcast or using the ESM gear. A real heart stopper? Be at PD at night clearing a broadcast and have a ASW plane pop out of the cloud cover and hit you with its spotlight (yep, had that happen once). You WANT to have some speed on cause you have to go down FAST. Flooding negative on the hover system while you are waiting for these LONG multi-telescoping masts to retract BEFORE you can start really moving.. THAT would be a huge pucker factor.

I guess the only way to compare whether or not the benifits outweight the risk is to quantify the wave motion effects vs ship depth for a sailless design to see if its worth it or not... as well as quantifying the maneuverability gains...

... but know ones' going to be able to do that completely unless a full scale model is built. Even the navies LSV might not be effort to tell the real effects (as far and rough sea stability gained, versus rough sea shallowness *instability* penalties)...

... surely a full scale model is somewhere in the future

[timmyg00]

I guess the only way to compare whether or not the benifits outweight the risk is to quantify the wave motion effects vs ship depth for a sailless design to see if its worth it or not... as well as quantifying the maneuverability gains...

... but know ones' going to be able to do that completely unless a full scale model is built. Even the navies LSV might not be effort to tell the real effects (as far and rough sea stability gained, versus rough sea shallowness *instability* penalties)...

... surely a full scale model is somewhere in the future What the Navy needs is another USS Albacore to test designs like this!!

TG

[Kapitan]

Heres a question:

If they built a submarine without a sail how would it surface and allow the men to get out of the submarine at the north pole?

No sail means no break in the ice right? cause sometimes its only the sail that can get through right?

[ASWnut101]

they use a long retractable chainsaw to cut a hole in the ice, and then fire a dud VLS TLAM into the ice to shatter it!:|\\