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Science Technology

Steam Powered Underwater Jet Engine 323

Posted by chrisd from the seaquest-dsv-without-the-dolphin dept.
Bob Vila's Hammer writes "An Australian engineer, Alan Burns invented a very efficient underwater steam powered jet engine. "Steam that is produced from a petrol or gasoline fueled boiler emerges at high speed from a rearward-facing ring-shaped nozzle into a cone-shaped chamber. Shock waves created as the steam condenses are focused by the chamber to blast water out of the back. Besides powering watercraft pretty efficiently, it can also be used as an extremely robust pump. Pretty Cool."
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Steam Powered Underwater Jet Engine More

Steam Powered Underwater Jet Engine

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  • Direct link to a picture of it (Score:5, Informative)

    by Amsterdam Vallon ( 639622 ) <amsterdamvallon2003@yahoo.com> on Thursday January 30, 2003 @01:35AM (#5187428) Homepage
    The engine [newscientist.com]

    *nix.org [starnix.org] -- Latest article: "IBM Set to Replace AIX with Linux"

  • Neato (Score:5, Funny)

    by assaultriflesforfree ( 635986 ) on Thursday January 30, 2003 @01:38AM (#5187436)
    One thing I'm curious about is why they can only be scaled to 300 horsepower... Seems like if a 20 cm one can put out 30 HP, a big one could put out a lot more. It also might be fun to install a 20 cm one into a ketchup dispenser at McDonald's or something. And also, will it shoot potatos?

    • Guesses... (Score:5, Insightful)

      by Anonymous Coward on Thursday January 30, 2003 @01:57AM (#5187519)
      From more to less likely:

      (1) Efficiency could peak at 300HP designs - it may be that any larger becomes horribly inefficient. Since it relies on squeezing compressed air and steam into an open tube, there might be a point at which there simply is to much room for the reaction to take place in given an incoming water velocity.

      (2) The design may not be completed - possible design flaws may limit this versions' abilities to scale up.

      (3) They may simply not know how big it can scale if their simulator isn't powerful enough to run a detailed simulation of a larger engine.

      • Re:Guesses... (Score:5, Informative)

        by Anonymous Coward on Thursday January 30, 2003 @08:15AM (#5188355)
        The air bubbles are not mixed into the water flow, but instead more or less surround it. As the bubbles (with their water payload) enter the heating chamber, they are heated and expanded by steam. The expanding bubbles displace more water, and cause the water to speed up as it moves into the exhaust chamber. As the steam gives up its heat to bubbles (and water), the steam recondenses, hence the need to transfer the heat to air beforehand.

        The reason the motor has an upper scaling limit is probably because as the size of the central tube increases, the ratio of bubbles to water would decrease.

        It seems likely that as in turbojet engines, the motor's efficiency would increase along with an increase in the motor's forward speed.

        My understanding of the system may be lacking (I've only been able to see the diagram, just like everyone else), but I just don't see any "shock waves" occurring, being used, or needed for the engine to work.

        This has been your cowardly anonymous tech reviewer, AC.

    • Re:Neato (Score:5, Funny)

      by nounderscores ( 246517 ) on Thursday January 30, 2003 @01:59AM (#5187526)
      Maybe they only did safety factor calculations out to 10x? It might require a slightly different shaped engine for higher horespowers to avoid the KABOOM failure mode.

      Also, the article says that part of the engine was demonstration was to shove large amounts of lard and cardboard through it, so I would say Yes it is a machine potato gun... so long as your potatos start out underwater. (no water, no jet)

      hmmm. as an afterthought, have you ever heard about the Archerfish? [gamarine.com] It's a firefighting boat which uses a jet ski engine to get to the fire, and then reroutes the engine through the firehose to put out the fire. Secondary propulsion allows the boat to manouver in firefighting mode.

      If you fitted a grille over the intake of the super water jet engine, you could put out the fire with a more powerfull blast from a more reliable engine and not have any disadvantages like slugging the burning marina with underwater potatoes and sucked up fish.

      (one more thought)

      since the water is only 3 or 4 degrees warmer after it exhausts from the blast chamber, would trout that has been killed by being sucked up by the engine be in one piece and good to eat if you turned around and began to scoop up your trail of dead sucked up fish? It would be the simplest fishing trip since the invention of dynamite.

      • Re:Neato (Score:2)

        by LS ( 57954 )
        You are quite clever, son. Have you ever thought of procuring and internship with Dean Kamen?

      • Re:Neato (Score:2, Insightful)

        by julesh ( 229690 )
        since the water is only 3 or 4 degrees warmer after it exhausts from the blast chamber, would trout that has been killed by being sucked up by the engine be in one piece and good to eat if you turned around and began to scoop up your trail of dead sucked up fish? It would be the simplest fishing trip since the invention of dynamite

        No. Its described as 'macerating' anything solid it takes in. Basically, you'd get trout soup out of the other end. But then what would you expect - the thing works by injecting a stream of steam into water at faster than sound speeds. That's gotta be worse than just knocking em on the head with a shockwave or two...

    • It'll make mountains of julienne french fries!

    • Ever seen what cavitation does to ship propellers? Go to a shipyard and have a look at a propeller that has been in service for 5-10 years.

      After that you will think again about coolness and neetness of cavitation...

    • It would make one HELL of a prank gift; especially to those you aren't really intending to keep on the good side of.
      But I think I could see (without actually breaking out the physics texts) why this wouldn't scale up well; I think the chamber would have a pretty fixed maximum scale.

      Calcium Carbide makes a great potato gun fuel; I can't think of anything I'd rather use. It's portable.

    • Re:Neato (Score:3, Funny)

      by tcr ( 39109 )
      I was thinking of McDonalds too, when they said this... :-)

      Todman shoved large quantities of lard and cardboard into the inlet without the pump suffering any ill effects. It could even mix materials used by the food industry.

    • And also, will it shoot potatos?


      Certainly. Pealed and boiled, ready for mashing (on impact)


  • from the article (Score:5, Funny)

    by Anonymous Coward on Thursday January 30, 2003 @01:40AM (#5187442)
    Todman shoved large quantities of lard and cardboard into the inlet without the pump suffering any ill effects.

    COWBOYNEAL NOOOOOOOO!!!!!!

    • Re:from the article (Score:3, Funny)

      by Anonymous Coward
      ...because i'm always hitting large quantities of lard and cardboard when i'm out on the water, and it's good to know this motor can take it.

  • usefull (Score:2, Informative)

    by phantomwolph ( 552305 )
    This is something that would really be great in areas where there are lots of scuba divers or manatees. I have seen the results of flesh being chewed up by prop blades. Not pretty.

  • Hmm... supercavtation stuff coming soon... (Score:5, Interesting)

    by lingqi ( 577227 ) on Thursday January 30, 2003 @01:44AM (#5187455) Journal
    I remember reading in a super-cavtation article about underwater engines like that - basically "underwater jet-engines" - I mean, of course it's not quite true, it operates on different principles, but the functionality is pretty similar.

    btw, super cavtation is where you make the nose of your _insert_vessel_here_ blunt but it goes so fast that the vapor pressure drops until the vessel (usually a torpedo / bullet / whatever) would be in an airbubble (technically steam bubble! - though there are dissolved air that boils into the bubble too) that it creates itself (and maintains) and hence has no liquid drag for the rest of the vessel (as in, besides the blunt nose).

    The engine I read about was actually reacting seawater directly with aluminum shavings and expelling hot steam (or something like that). I am pretty sure there were something else but I can't remember what it was (I don't think it was iron-rust, though, for all of you thinking of thermite). Anyway - neat stuff; should change underwater combat a whole lot.

    should get myself one of those to go war(ship) driving ;-)

  • is it really feasible? (Score:3, Funny)

    by trmj ( 579410 ) on Thursday January 30, 2003 @01:44AM (#5187456) Journal
    Sounds to me like it's full of hot air.

    • Re:is it really feasible? (Score:5, Funny)

      by Myco ( 473173 ) on Thursday January 30, 2003 @03:11AM (#5187722) Homepage
      Are you saying the theory doesn't hold water? That it's a tempest in a teapot? I could certainly see getting all steamed up about that. Might have to jet-tison the whole project. Then they'd really be in hot water. On the other hand, if it does work, it would be a real watershed event. Certainly more than just water under the bridge, anyway. Well, maybe they'll just have to set this whole steam thing on the back burner for now -- after all, a watched pot never boils.
  • From the article: With no moving internal parts, and no propeller, the engine should be cheap to manufacture.

    I especially like the part about no moving parts... Moving parts are good to avoid in all cases, when possible... They wear and need replacement. Nice one!
  • It is estimated that a gazillion fish die every day from cold. This new jet engine provides a wonderful means of transportation and enriches the lives of nearby sea food.

  • Junkyard Wars / Scrapheap Challenge (Score:3, Funny)

    by spike666 ( 170947 ) on Thursday January 30, 2003 @01:55AM (#5187510) Journal
    and in only 15 years we'll be seeing one power some sort of vehicle on Junkyard Wars / Scrapheap Challenge...
  • That could be scary. Imagine that thing in your hot tub.

    Tim: Ahhhhh... This is great, all we need now is a bit more power. [Grunt] I'll just set it to 500 knots.

    *click*

    *foom*

    Jill: Gargle gargle gargle

    Tim: Jill? What are you doing? You know, going underwater in the hot tub isn't good for your ears. Are you listening?

    I guess that's a bit off topic... Meh...
  • Come on, that has to be a joke.

  • Hmm (Score:5, Insightful)

    by ShooterNeo ( 555040 ) on Thursday January 30, 2003 @02:10AM (#5187566)
    Well, I'm sure somone else has noted this : a nuclear energy source like on a warship would be perfect for supplying the steam. By venting the secondary steam from the boilers directly into the water like this you could easily get ten times the power with the same size engine (though you'd need more higher output reactors) I am sure an engine like this would be EXTREMELY noisy, so the warship would have a set of these steam jets it could fire up when it needs to move somewhere fast, and some quieter source when submarines are a worry. Imagine an aircraft carrier and a few destroyer escorts with flank speeds in excess of 70 knots (it would have to have hydrofoils as well, because otherwise the hull speed would be to limiting. Yes I'm aware it might be decades before a carrier this sexy is built, if ever). Sure it would be vulnerable to torpedoes, but the idea is it could be a MUCH more threatening weapon with this kind of speed. It could patrol a larger area, escape from danger, and have a certain intimidation factor when its located somewhere since it could arrive suddenly, launch a strike force, and depart before the enemy was aware.

    As long as were speculating, imagine an even more effective weapon, a ship loaded full of missiles and rocket launched drone strike aircraft (so no human pilots risked. Yes I'm aware that such aircraft might be say, half as effective as human piloted planes but if they cost 1/4 as much to build its a MUCH more effective weapon. It could very well be cheaper to turn out somewhat dumb long range missiles and semi-reusable drones by the thousands, with no additional pilot training needed. The "pilots" would be a group of technicians behind consoles far from the battle, with embedded computing in the planes doing most of the flying, the human being just to pull the trigger. Without all the risks of training pilots and maintaining aircraft (the planes would be stored in sealed containers until needed, with a small set used for training) and the fact that these planes don't need nearly the quality control in manufacturing (if you lose 10% of them in a mission due to shoddy construction but they cost half as much or less to build its definitely worth the trade off) you'd have a better solution than at the present.

    Why isn't this done already? Well, in the 1970s and earlier where most of the present airplanes were designed, communications technology and computers were not good enough or reliable enough. Today, most of the money is spent on operations and on a couple of new aircraft. Also, the current leadership is made up of pilots, who don't want to be replaced by scrawny pasty faced techs sitting at control stations. Finally, there's a current bandwidth problem : military communication satalleits don't have the capacity for the hundreds or thousands of video links needed.
    • It's a pity that the stall speed of most modern fighter aircraft is around 150 knots. Imagine how easy carrier landings would be if you and the carrier could head into the wind and the carrier would match speed with the fighter!
      • Well, matching speeds with the fighter may be a little beyond conceivable tech After all, instead of doing that why not just give the aircraft enough range to reach anywhere in the world from a few bases on land, or VTOL capability? It would definitely be easier. Yes I suppose its conceivable to build a nuclear powered hydrofoil carrier thats basically a scaled up racer, but almost unbelievably expensive. But it would certainly help if the carrier were closer to the speed of the fighter, perhaps.

    • Re:Hmm (Score:5, Interesting)

      by Anonymous Coward on Thursday January 30, 2003 @03:03AM (#5187704)
      I'll refer to your paragraphed by numbers.

      1. The article says it is quiet, but doesn't specify if this is because noise is ultrasonic, or the process is just plan quiet. Regardless a ship doesn't avoid submarines by being quiet. It avoids submarines by using bloody huge active sonar, propulsion noise hardly matters, a ship still makes a lot of noise carving through the water, unlike a sub it is not completely covered in the same medium, but two (air, water).

      Also torpedoes do not home on noise (aka passive sonar), they home on returned "pings" from active sonar, who cares if they know where the torp is, if they have no hope of out running it.

      The article doesn't speculate that this will necessarily make ships faster. It will certainly mean less drydock mantainence, and better reliability from the drive.

      2. Until they develop completely unjammable communication links between machine and pilot, with zero possibility of being hijacked by the enemy, there will always be a need for manned aircraft.

      Even if we get sentient un-manned aircraft, would you trust it carrying a bomb? Would you want to take responsibility when it decides to bomb a school?

      3. On the contrary I think many of them would love to do something to stop their men from being killed, so long as they don't lose control of air defence. eg: SAM sites were proposed to be run by the army, so the airforce fought tooth and nail when it was suggested that interceptors, etc were unnecessary.

      • Re:Hmm (Score:3, Interesting)

        by ShooterNeo ( 555040 )
        "zero possibility of being hijacked by the enemy". THAT possibility already exists. Its quite simple. You have say 2 flash memory cards (or other solid storage device where the contents are sealed), stored in a sealed metal housing with a circuit board and a small controller. A tiny wire antennae feeds atmospheric radio noise...essentially a completely random source...to the chip. It fills the 2 cards up with this string of numbers. When it comes time to deploy the aircraft, one card is plugged into the remote console, one card into the aircraft. COMPLETELY impossible to hack, as all communications would be encryted using this one time pad. No, not even quantum computers can break this kind of code.

        As for jamming : a high frequency beam is directed from an antennae dish on the plane to a satellite. As long as the satellite is intact, and knows approximately where the aircraft is it can effectively ignore all other sources of EMF. There is absolutely no way to jam this kind of link(short of detonating nukes in the atmosphere, or as of yet nonexistant conventional emp weapons.). Physical destruction of the satellite is a possibility...a very powerful missile or laser on the ground could do it. Still, a more sophisticated system would use other remote aircraft circling in the sky as communications relays, again not jammable. And anyways, if the comunications are jammed of course it won't fire any weapons, instead going to some preprogrammed contingency (perhaps circle or fly low to the ground til it needs to return to base?)

        As for sentient unmanned aircraft...well, at that point I think I'd be more worried about losing control of the world entirely rather than a few random bombings. Once sentient computers are possible it is pretty reasonable to assume humanity's trek is effectively over. (whether or not humans go on living, they won't be relevant)
        • If you count on line-of-sight just fly a drone higher and send down a counter signal
      • Oh, two more things. Why would this tech be faster? Well, a couple reasons but a big one is the heat generated by this engine as it converts steam to work is dissipated right into the water. No cooling radiator needed or condenser. Just crank that nuclear pile up to 11 and all the heat gets carried away by the engine itself. Remember, the main limit to how fast an engine can run is how quickly it can dissipate the heat it is producing. Instead of props, driveshafts, transmissions, multibladed delicate steam turbines that have to run with pure distilled water, you have a nuclear pile and a giant heat exchanger steam generator, with the steam coming off that thing going right outside to the engines which are basically more efficient steam rockets. Why would it be noisy? Well, cavitation is caused by air bubbles forming around rapidly moving propellors, and is a big source of noise. I can't imagine how noisy an enormous quantity of steam bubbles would be, but I'm guessing it would be pretty loud.
      • Uhhh your paragraph one is way off. Almost all torpedoes have a passive homing or "wake-following" mode. They also can be steered by the passive sonar on the firing platform if the torp is wire guided. A torp can't usually carry enough power for active guidance throughout the run, particularly if fired at extreme range. Quieter surface ships do work against subs, since the the sub is unlikely to be using active sonar itself to acquire a surface target. It's a great way to advertise your position to ASW forces.
      • torpedoes do not home on noise

        Although it has been a long time since I was in the Navy dropping torpedoes from a P-3 Orion, at that time the torpedoes were quite capable of passive accoustic guidance. This is still true, as a quick google search will show. Active sonar is used only when a target has been acquired.
    • Has a carrier ever been sunk? I have never heard of one being sunk. I would seriously doubt a couple torpedoes could sink a carrier. Besides which carriers move around in groups with submarines, tankers and all kinds of support vehicles. You'd have to make all of them go fast.
      • The idea is the carrier plus some destroyers for defense would race ahead of the fleet when needed (so the carrier effectively could cover more territory, sending its airplanes farther) or to surprise the enemy. Well, perhaps "surprise" is the wrong word...but its about intimidation. Other world leaders will have to draw much bigger circles around this kind of carrier to represent its strike radius. Obviously when it runs low on jet fuel or ammo the ship would need to return to its tenders. As for carriers being sunk, this happened all the time in WW2. Those aircraft carriers were pretty big, and they still went down (admittedly not the size of a Nimitz class but at least half that). As for sinkage, well, to effectively destroy a carrier you merely have to disable its propulsion system (screws or rudder). Once that happens its just a floating piece of metal of little miliary importance as most heavy aircraft cannot be launched without enough airflow over the flight deck.

    • buckminster fuller, who coined many terms, among them synergy, came up with two words to describe application of technology - killingry and livingry

      ok, they're not as hip sounding as synergy, but i'm sure you get what they mean - and buck fuller devoted his life to creating livingy such as the geodesic dome and his many other inventions

      so why, i wonder, when the article in new scientist has nothing to say about 'defense' applications are there so many posts like yours inthis thread about using this invention in military applications? to quote george w bush out of context, you're either with us or against us - on the side of livingry or on the side of killingry
    • I was thinking more of the possibility for torpedo engines - if it's small, cheap, powerful, and fast (and sufficiently fuel-efficient, which the article didn't mention was good or bad about this) it may be more effective for making anti-ship weapons than faster ships.
      • Ahem. Where you getting the steam from, buddy? If you are burning something, you need an oxidizer as well(a torpedo runs underwater...). And I strongly suspect this engine isn't as fuel efficient as standard piston or turbines anyway. Its SIMPLER, but probably not more efficient.
        • Its less efficient because the hot water after condensation goes out the rear of the engine. Ship steam turbine engines reuse that heat. Go look up the specific heat of water, and calculate how much it takes to go from 20 degree C (ambient water temp, actually it might be lower) to 100 degrees C (right on the cusp of boiling). That energy adds up FAST. I said in an earlier post though it would be appropriate for nuclear propulsion because the extra fuel used isn't really a problem (you run out in 5 years instead of 13) but the engine could run much faster.
    • "Imagine an aircraft carrier and a few destroyer escorts with flank speeds in excess of 70 knots (it would have to have hydrofoils as well,..."

      An aircraft carrier with hydorfoils? I've gotta say, just the mental image of that is pretty amazing.

      Can you imagine surfing on the wake from a nuclear-powered hydrofoil aircraft carrier?

  • logical progression (Score:5, Funny)

    by silverhalide ( 584408 ) on Thursday January 30, 2003 @02:28AM (#5187628)
    I love the way technological evolution works:

    Diesel Powered -> Nuclear Powered -> Wood-fired subs!

  • ... jet engines vs. propellors did for 'planes, we got a winner. But if i remember rightly (no expert here, don't hurt me), the advantages to aircraft are higher power to weight ratio and lower maintanance costs. Only one of these (the latter) seems to be really relevant in the water :( Any thoughts? BTW when checking this with google, look at the first link i got: http://www.dkgroup.dk/hydro2.html - the "Hydro Air Drive", yet another related idea.
  • I wonder how small an effective boiler can be made. Gives new meaning to the idea of letting the engine warm up. People have been working with steam power for a very long time, but new materials for the steam generation part could perhaps give this invention an incredible array of applications.wow.

  • What's the catch? (Score:5, Insightful)

    by pediddle ( 592795 ) <pediddle+slashdo ... ATSet minus poet> on Thursday January 30, 2003 @03:12AM (#5187725) Homepage
    This sounds amazing:

    * Cheap to produce
    * Incredibly robust (no moving parts)
    * Efficient (although they don't give any numbers)
    * Safe(r) for the environment
    * Multiple uses (pumps)
    * Scales well in a small package

    Without seeing any numbers, it sounds like it beats the pants off of outboard engines. My 70HP Evinrude has been rebuilt twice because of sand-suckage, and standard jet impellers are too inneficient.

    So what's the catch? I want to see some real numbers. If there's no catch, then I hope and think this thing will revolutionize the small-craft market.
  • I read it as 'steak-powered' :D
  • From the article:

    "The steam drive can also function as an extremely robust pump. It can shift water, sewage or oil, and in a demonstration for New Scientist, Todman shoved large quantities of lard and cardboard into the inlet without the pump suffering any ill effects."

    So the real question is when will someone make one big enough to become the first under water roller coaster?

    Furthermore:

    "It doesn't simply mix -- it macerates," says Todman".

    Hmmm... macerates... "to soften and cause to disintegrate as a result"... oh well... just don't turn it up all the way :-)
  • While there seems to be some very good features of this design (simple, light, cheap to build, and if the blurb is true efficient) I'd like to know how well it works at part throttle. IIRC this is a major problem with current jet designs - they're fine (not as efficient as a prop, but comparable) at high speeds, but chew juice like crazy at lower speeds.

    You also couldn't reverse the thing the same way you reverse a normal vessel, but, hey, just run a small set of pipes to the front and a miniature one of these jet gadgets and you've got instant bow thrusters :)

    • You also couldn't reverse the thing the same way you reverse a normal vessel

      But with an engine that small and no mechanical or electrical linkage needed to the actual engine - just turn the whole thing around.

      You could use it like an outboard/sterndrive affair

      On tug craft you could use several to replace the current bucket prob designs.

      On large ships you could use banks of these along the hull. If they can orient them then you can spin the vessel in its own length, move it sideways, offset the forward and stern banks to assist the turning. Stopping would be easier as a big stern prop is horribly ineffecient in reverse, but turning the engine pods around would not effect them (Probably - not sure if reverseing the water flow over them may make them less effecient). Want to avoid a collision, just turn them sideways under way and shove yourself out of the way sideways.

      The beaty IMHO is this thing is so simple all you need is a pipe and valve to regulate the steam from a central boiler, and a control system to turn it.

      This could potential make for very agile vessels.
  • . . . Todman shoved large quantities of lard and cardboard into the inlet without the pump suffering any ill effects. It could even mix materials used by the food industry. "It doesn't simply mix -- it macerates," says Todman.

    Interesting, this sounds very much like the Windhexe story [slashdot.org] which was posted a couple months ago.

  • How does it get started? (Score:3, Insightful)

    by black_widow ( 41044 ) on Thursday January 30, 2003 @07:35AM (#5188231) Homepage
    I can't conceive how it will function as a primary power source because of the mechanics that would be necessary to start the process.

    In the same manner, you won't have a "neutral" since it probably can't be turned off and on rapidly for docking maneuvers, et al. Perhaps it could use buckets like a jetski (or any jet aircraft using clamshell reversers), but I wonder how well it reacts to a high backpressure created by such a device....

    Maybe we'll get to see some of that great KABOOM action when these things explode or when two boats collide!

  • Helooo??? (Score:4, Informative)

    by Pig Hogger ( 10379 ) <pig.hogger@gmail ... m minus caffeine> on Thursday January 30, 2003 @09:11AM (#5188608) Journal
    Anybody home there? This uses **EXACTLY** the same principle as the GIFFARD INJECTOR [railroadextra.com] which was invented almost 150 years ago, and since then used to stuff water into high-pressure steam boilers.

    Engineers should be forced to study railroads, they were the high-tech of 150 years ago, and they actually invented many things, most especially modern telecommunication networking!!!!

    • Re:Helooo??? (Score:2, Insightful)

      by Gekke Eekhoorn ( 27027 )
      Well, not exactly. As you can see in the drawings, they add air bubbles to the mix where the Giffard Injector doesn't.

      My theory is that the steam mixes with the bubbles, and given the low caloric density of air, these will expand rapidly, leading to a volume increase and therefore providing extra boost. Further down, they mix with cold water and become cool again, but then it's already out of the jet. Should make for interesting current patterns...

  • I read that as steam powered underware, I was really disapointed when it turned out to be more boreing...

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