I agree with most of what you say, but you seem to imply that I am wrong about the bail out h.p. air.
In subs you always need more than one way of doing things, and if you are a safe subman, you will have bail out air on your boat.
Read The American Bureau of Shipping's: Rules for building and classiing underwater vehicles, systems and hyperbaric facilities. OR Busby's Manned Submersibles for more information.
To pressurize a sub to match water pressure with air would be extremely dangerous if done in a hurry and the air would become poisonous; to breathe under pressure at depth (Deephabs) you have to be slowly pressurised with exotic gases. Note that regular submarines only increase pressure a little when submerged.
There is no way you are going to beable to open the hatch if the outside pressure is greater than the internal pressure. Flooding the sub is diffinately an option, but depending on the sub, this can take time (most people put large enough bailout valves to do this in a reasonable amount of time), also if you sub is damaged or disabled you might not beable to flood it. Even with the sub flooded, you still want a small bubble of air to work in while you release the hatch (although you can use scuba gear, but the bends might be more of an issue).
Some psubs allow you to flood them so you can go for a swim and then return.
Immediately you let go of the sub you find yourself ascending at an incredible rate, gas rushing from your mouth, nose ears and eye sockets and your lungs searing. Finally you arrive at the surface travelling at such a rate that you are thrown several feet in the air. Somehow your lungs/arteries didn't rupture during the ascent but you now die in 20-30seconds from the massive nitrogen boil-off in your veins as you suffer from an incredible case of 'bends'
Yell all the way up. The bends won't normally be a problem since you are not spending enough time under pressure to become saturated (of course, if you had to spend a lot of time trapped in you sub while under pressure this would be an issue).
No two ways about it, submarines are still extremely dangerous.
Hehe, agreed, but everything is dangerous if you are stupid enough.
Re:No, you just have to worry about nastier things
on
Build Your Own Submarine
·
· Score: 2, Insightful
Please note that 100 meters is roughly 300 ft or so. These depths were "challenge" even for WWII submersibles, and those beast were after all advanced.
Two points here: 1) the diameter of the cylinder dramatically effects the crush depth. 2) They have been vast improvements in steel working, producing steel that is many many many times strong that steel in 1945.
I would think twice before going below 10 meters (30 ft), for escape could get very tricky, if not impossible.
Small subs carry bail out gas, if the people in the sub have to leave the vessel they will pressurize the sub so it the same pressure as the outside water, then they can easily open the hatch and return to the surface. Some submarines allow you to do this and go scuba diving (up to a certain depth) then return to the submarine (of course it's flooded so you've gotta have some way of emptying it, either high pressure air or a pump).
Re:No, you just have to worry about nastier things
on
Build Your Own Submarine
·
· Score: 2, Informative
Structural failure leading to implosion!
Even at just 100 meters depth, you don't get much warning of a hull failure. One buckled plate becomes a total breach in about 1 second.
That is why all submarines are designed with large safety factors. A submarine with an operational limit of 100 meters will be tested to 300 meter and have calculated crush depth of ~600meters or more.
Viewports are normally the weakest part of a submarines pressure barrier. But they just burst open, they will turn a milky color, the start to star crack, then after about six hour they will burst. OF course you notice the viewport (window) turning a milky color and return to the surface ASAP.
Buoyancy is the problem. You need to carry enough weight onboard to submerge. But this means you're not going to just float back up without a means to float again (usually compressed air). If anything happens to that system, then you go down like a rock.
Submarines will normally have atleast 3 or 4 ways of surfacing. Primary and secondary main balast tanks, either of which could surface the submarine alone, variable balast tank (sometimes using a pump rather than compressed air) and a lead drop weight which can be drop via a lever from inside the sub. They are normally two seperate high pressure air systems as well.
From where would you supply the air for the necessary bubbles? If you're in a submarine that's been submerged for say 2 weeks, is there a stable source of air to inject?
Well, you could use the exhaust from what every engine you are using to produce the steam (probably a closed cycle diesel if you're not a super power).
They are other problems with using this on a sub, such as, when you dive the extern pressure goes up reducing the effectiveness (pressure difference) of the steam produced.
As for "shock waves of steam condensing" it would seem more like it was the bubbles coming in contact with the hot steam and expanding to force the water out the back. On a Jetski, the exhaust is injected in to jet (I think after the impeller) and the expanding bubbles force the water out faster.
The pressure would pose a problem, but, contrary to what you might expect, the viscosity of water actually decreases with pressure, until around 150 MPa of pressure. After that, viscosity starts increasing with pressure.
How about a reference? Or should I just take your word for it.
I'll try and dispell some myths for you rather than just calling you dumb.
Since it is designed to cut through the water rather than force its way through (conventional sub) it should work.
There is no difference between how this submarine moves through the water and how a "conventional sub"
would move through the water.
Making sure your seals can stand the pressure
Any rubber seals are just for the first few feet. After 30 feet the water pressure will be creating a metal to metal bond (or metal to acrylic or what ever) so the seals will not do anything. If you're refering to the metal to metal bond as a seal, then you kind of right, but any problems would have notice at around 30 feet. As you go deeper the bond will just get stronger.
Not only that, but at the proposed dive/accent speeds they might have to worry about the bends.
The bends only apply if you are exposed to outside pressure. This is a 1 ATM sub, you are always at the same pressure as you where on the surface.
Eg: To make it go ~12knots it would take roughly twice the battery power, reducing its effective time from 8h to 4h (I know there are more things..but that is the major factor).
Another technique is to increase the size of the props. But that takes more energy to get them spinning (for more thrust though).
This isn't really true either, it would probably
be more like a quarter of the endurance for twice the speed. But they might be other things limiting the speed such as drag, the sub isn't a very hydrodynamic shape and might have a low terminal velocity.
Yes, and I suppose only the people with children should have to pay for PUBLIC school, and only the people who visit parks should have to pay for them.
It is in everybodies best interest that the children of this country have access to education without regard to finical standing.
(Although I'm sure some extreme right wing people could claim otherwise.)
The last time I visited a California state park I paid $5 to park my car. So it would seem things are to be heading that way. If it works and we keep our parks, great, the money must come from somewhere and we can't always count on the government to provide the necessary funds (from the taxes I've already paid).
But, you are saying that it should be right that somebody driving less than 1,000 miles a year pay the same amount for the up keep of the roads as somebody driving 35,000 miles a year....
A milage based tax will reward people who drive less. I think given the world situation any incentive for people to drive less is a good idea.
What about privacy? Well, even though you basically give up some of your rights when you get in a car, having a box in your car that track you movement does sound a little scary and open to possible abuse. But, I dout that the box could transmit your live location to anybody. It might record your location in some form that can be extract and used as evidence against you at a later date. Although, it shouldn't be impossible to have a box that just records total distance travel and not the locations visited.
It's a Tcl/Tk widget, it's pretty friendly
and cross platform. There are a couple of
3D modellers using Togl. One of them is called
Ayam3d (it's kind of like Maya
but not, it's also open source). AC3D is the other modeller I know using Togl, and it's shareware.
No, that is greed, not human nature. Although, if you are surrounded by people who are greedy then I could see how you would stay that. Maybe you could say that "it is American nature to always want more."?
OK, enough of that, who should we invade next to boost the economy so we can have more open source jobs..... Come on, let's just go for Poland.
You probably mean "...countries that have not done anything, except aggressively invade their neighboring countries, refuse to disarm, and use poison gas on their own inhabitants that warrent[sic] an attack."
Isn't this exactly what we armed them for in the first place? We (and some others) supplied the poison gas to use on it own people, we told Iraq to invade it's neighbor
(Iran) and we would give it lots of war toys to use, we told Iraq it was ok to use gas against people in Iraq who supported Iran.
Of course, as soon as they start thinking on there own we don't like it any more. We've already attacked Iraq for invade Kuwait and your saying that we should attack them again just to make sure?
If we start killing Iraqi's on Iraqi soil without provocation, then the world will have no sympathy if Iraq's where to start killing Americains on Americain soil.
You've just woken up. Most other countries have been living with terrorists on there home soil for decateds. Britain, France, Spain, Russia, China, Japan, etc.....
Now, you want to bomb Iraq because the Japanese bombed perl habour, and also because a rich Saudi was upset enough at the America for installing an anti-democratic government in his country that he blew up a couple of big buildings.
I'm more scared by the fact the country with the biggest military buget in the world wants to start invading countries that have not done anything that warrent an attack.
Policing is only easy in a police state. And the USA wants to turn the world into a police state.
Do you play with war toys? I did, I learnt two things, if you are attacked you attack back, the first person to attack is the bad guy....
Yep. When people have confidence in their leader and the direction of the country the economy does well. Bush does
nothing but scare the shit out of everyone who hears him (and has any money). Investors flee the market. Personally,
I also think that Bush is killing the tech market. His focus on oil, timber and natural resources and lack of interest in
anything tech isn't helping any of us. The bubble burst but Bush isn't helping pick up any of the positive pieces.
Well put. The inverstor in Germany in 30's did the same thing. In both cases the biggest drive was corperate socialism, when the goverment is handing out cash to the corperations, what should the invistors do? Investing X money in a corperation give you X say in that corperation because the corp. needs the investment money, but if the goverment in handing out $$$ then why should the corperations act in the interest of there investors. Remember, the money Bush gave to the airlines was OUR money, and I sure didn't get any shares in any airline...
Corperate welfare brings us really close to becoming a National Socialist country. Does anybody know another word that means National Socialist? How did this happen? Do we want to change this, or is it what we really really want?
We already know that the climate of the earth has never changed since the beginning of time. That is until the last 50
years or so, when man has started to burn fossil fuels and using hair spray.
This is totally unbelievable. The climate change is totally man caused, and we are the only people that can change it.
Well, it would seem that if we can get enough space junk in orbit around the earth we can effectively block out part of the suns rays and counter act global warming, which is currently only recognized by non-Americans...
I wonder how much is just spam advertizing and would this be a good time to introduce fedral anti-spam laws, er, so congress wouldn't have so much email to deal with. How about a 10 year mandatory minium?
We'd probably have to make sure we have the right to shoot^H^H^H^H^H arrest overseas spammers. Maybe we should ship all spammers to that little bit of Cuba that we stole... so we don't have to obey all those silly human rights laws...
If I remember correctly, the only remaining wonder of the world.
I was in certain museum in London a number of years ago, while being somewhere that I shouldn't
I found the beard of the sphinx. It was in a storage area used random stuff (include mops and brooms and other cleaning maintains things), the beard was hidden behind the door.
Nobody was about, so I tookout my pocket knife and chipped off an nice little chunk to keep for myself. I still have one somewhere...
I think we should take the whole pointy stone build down a put it up in a different country, this will complete confuse an space aliens that didn't build it.
People are really gonna buy a new Walkman every time they buy a CD. Great idea guys !
You know, if they can affort to ship a CD player with every CD, then don't you get the feeling that they are making CDs very very cheap, infact I don't see how they can justify charge $15-$30 for a CD the doesn't come with a CD player.
I have bought a CD since Napster got stopped the first time....
Slashdot Mirror
Read The American Bureau of Shipping's: Rules for building and classiing underwater vehicles, systems and hyperbaric facilities. OR Busby's Manned Submersibles for more information.
To pressurize a sub to match water pressure with air would be extremely dangerous if done in a hurry and the air would become poisonous; to breathe under pressure at depth (Deephabs) you have to be slowly pressurised with exotic gases. Note that regular submarines only increase pressure a little when submerged.
There is no way you are going to beable to open the hatch if the outside pressure is greater than the internal pressure. Flooding the sub is diffinately an option, but depending on the sub, this can take time (most people put large enough bailout valves to do this in a reasonable amount of time), also if you sub is damaged or disabled you might not beable to flood it. Even with the sub flooded, you still want a small bubble of air to work in while you release the hatch (although you can use scuba gear, but the bends might be more of an issue).
Some psubs allow you to flood them so you can go for a swim and then return.
Immediately you let go of the sub you find yourself ascending at an incredible rate, gas rushing from your mouth, nose ears and eye sockets and your lungs searing. Finally you arrive at the surface travelling at such a rate that you are thrown several feet in the air. Somehow your lungs/arteries didn't rupture during the ascent but you now die in 20-30seconds from the massive nitrogen boil-off in your veins as you suffer from an incredible case of 'bends'
Yell all the way up. The bends won't normally be a problem since you are not spending enough time under pressure to become saturated (of course, if you had to spend a lot of time trapped in you sub while under pressure this would be an issue).
No two ways about it, submarines are still extremely dangerous.
Hehe, agreed, but everything is dangerous if you are stupid enough.
Two points here: 1) the diameter of the cylinder dramatically effects the crush depth. 2) They have been vast improvements in steel working, producing steel that is many many many times strong that steel in 1945.
I would think twice before going below 10 meters (30 ft), for escape could get very tricky, if not impossible.
Small subs carry bail out gas, if the people in the sub have to leave the vessel they will pressurize the sub so it the same pressure as the outside water, then they can easily open the hatch and return to the surface. Some submarines allow you to do this and go scuba diving (up to a certain depth) then return to the submarine (of course it's flooded so you've gotta have some way of emptying it, either high pressure air or a pump).
That is why all submarines are designed with large safety factors. A submarine with an operational limit of 100 meters will be tested to 300 meter and have calculated crush depth of ~600meters or more.
Viewports are normally the weakest part of a submarines pressure barrier. But they just burst open, they will turn a milky color, the start to star crack, then after about six hour they will burst. OF course you notice the viewport (window) turning a milky color and return to the surface ASAP.
Submarines will normally have atleast 3 or 4 ways of surfacing. Primary and secondary main balast tanks, either of which could surface the submarine alone, variable balast tank (sometimes using a pump rather than compressed air) and a lead drop weight which can be drop via a lever from inside the sub. They are normally two seperate high pressure air systems as well.
Well, you could use the exhaust from what every engine you are using to produce the steam (probably a closed cycle diesel if you're not a super power).
They are other problems with using this on a sub, such as, when you dive the extern pressure goes up reducing the effectiveness (pressure difference) of the steam produced.
As for "shock waves of steam condensing" it would seem more like it was the bubbles coming in contact with the hot steam and expanding to force the water out the back. On a Jetski, the exhaust is injected in to jet (I think after the impeller) and the expanding bubbles force the water out faster.
Sorry.
How about a reference? Or should I just take your word for it.
Since it is designed to cut through the water rather than force its way through (conventional sub) it should work.
There is no difference between how this submarine moves through the water and how a "conventional sub" would move through the water.
Making sure your seals can stand the pressure
Any rubber seals are just for the first few feet. After 30 feet the water pressure will be creating a metal to metal bond (or metal to acrylic or what ever) so the seals will not do anything. If you're refering to the metal to metal bond as a seal, then you kind of right, but any problems would have notice at around 30 feet. As you go deeper the bond will just get stronger.
Not only that, but at the proposed dive/accent speeds they might have to worry about the bends.
The bends only apply if you are exposed to outside pressure. This is a 1 ATM sub, you are always at the same pressure as you where on the surface.
Eg: To make it go ~12knots it would take roughly twice the battery power, reducing its effective time from 8h to 4h (I know there are more things..but that is the major factor). Another technique is to increase the size of the props. But that takes more energy to get them spinning (for more thrust though).
This isn't really true either, it would probably be more like a quarter of the endurance for twice the speed. But they might be other things limiting the speed such as drag, the sub isn't a very hydrodynamic shape and might have a low terminal velocity.
It is in everybodies best interest that the children of this country have access to education without regard to finical standing. (Although I'm sure some extreme right wing people could claim otherwise.)
The last time I visited a California state park I paid $5 to park my car. So it would seem things are to be heading that way. If it works and we keep our parks, great, the money must come from somewhere and we can't always count on the government to provide the necessary funds (from the taxes I've already paid).
But, you are saying that it should be right that somebody driving less than 1,000 miles a year pay the same amount for the up keep of the roads as somebody driving 35,000 miles a year....
A milage based tax will reward people who drive less. I think given the world situation any incentive for people to drive less is a good idea.
What about privacy? Well, even though you basically give up some of your rights when you get in a car, having a box in your car that track you movement does sound a little scary and open to possible abuse. But, I dout that the box could transmit your live location to anybody. It might record your location in some form that can be extract and used as evidence against you at a later date. Although, it shouldn't be impossible to have a box that just records total distance travel and not the locations visited.
You might want to take a look at Togl
It's a Tcl/Tk widget, it's pretty friendly and cross platform. There are a couple of 3D modellers using Togl. One of them is called Ayam3d (it's kind of like Maya but not, it's also open source). AC3D is the other modeller I know using Togl, and it's shareware.
Hey, slashdot admins! Why don't you take your own advice and follow it, that way we will only read *new* stories and none of this repeat crap....
in soviet russia....the crap tolerates you.
No, that is greed, not human nature. Although, if you are surrounded by people who are greedy then I could see how you would stay that. Maybe you could say that "it is American nature to always want more."?
OK, enough of that, who should we invade next to boost the economy so we can have more open source jobs..... Come on, let's just go for Poland.
how about a duplicate story category?
Then I could just select not have stories from the duplicate story section on my front page...
OR maybe slashdot doesn't work like that.....
Isn't this exactly what we armed them for in the first place? We (and some others) supplied the poison gas to use on it own people, we told Iraq to invade it's neighbor (Iran) and we would give it lots of war toys to use, we told Iraq it was ok to use gas against people in Iraq who supported Iran.
Of course, as soon as they start thinking on there own we don't like it any more. We've already attacked Iraq for invade Kuwait and your saying that we should attack them again just to make sure?
If we start killing Iraqi's on Iraqi soil without provocation, then the world will have no sympathy if Iraq's where to start killing Americains on Americain soil.
Now, you want to bomb Iraq because the Japanese bombed perl habour, and also because a rich Saudi was upset enough at the America for installing an anti-democratic government in his country that he blew up a couple of big buildings.
I'm more scared by the fact the country with the biggest military buget in the world wants to start invading countries that have not done anything that warrent an attack.
Policing is only easy in a police state. And the USA wants to turn the world into a police state.
Do you play with war toys? I did, I learnt two things, if you are attacked you attack back, the first person to attack is the bad guy....
Cool, you mean just like OS/2?
Hmmmm, I think you need another prediction there.....
Dude, it's a PDA, it has batteries.
Yeah, imagine the sound of all the hard drive chirps as 100,000 geeks longing for quieter hard drives click on the link...
Maybe tomorrow then....
PS: does anybody know if they cover laptop harddrives as well?
Well put. The inverstor in Germany in 30's did the same thing. In both cases the biggest drive was corperate socialism, when the goverment is handing out cash to the corperations, what should the invistors do? Investing X money in a corperation give you X say in that corperation because the corp. needs the investment money, but if the goverment in handing out $$$ then why should the corperations act in the interest of there investors. Remember, the money Bush gave to the airlines was OUR money, and I sure didn't get any shares in any airline...
Corperate welfare brings us really close to becoming a National Socialist country. Does anybody know another word that means National Socialist? How did this happen? Do we want to change this, or is it what we really really want?
Well, it would seem that if we can get enough space junk in orbit around the earth we can effectively block out part of the suns rays and counter act global warming, which is currently only recognized by non-Americans...
Hmmmm, taco bell will have to rush if they are to put out a target this time.
We'd probably have to make sure we have the right to shoot^H^H^H^H^H arrest overseas spammers. Maybe we should ship all spammers to that little bit of Cuba that we stole... so we don't have to obey all those silly human rights laws...
I was in certain museum in London a number of years ago, while being somewhere that I shouldn't I found the beard of the sphinx. It was in a storage area used random stuff (include mops and brooms and other cleaning maintains things), the beard was hidden behind the door. Nobody was about, so I tookout my pocket knife and chipped off an nice little chunk to keep for myself. I still have one somewhere...
I think we should take the whole pointy stone build down a put it up in a different country, this will complete confuse an space aliens that didn't build it.
You know, if they can affort to ship a CD player with every CD, then don't you get the feeling that they are making CDs very very cheap, infact I don't see how they can justify charge $15-$30 for a CD the doesn't come with a CD player.
I have bought a CD since Napster got stopped the first time....