Simple, cheap, solution to Europe's problem with N. Africans coming in boats

Discussion in 'World Events' started by Billy T, May 18, 2015.

  1. billvon Valued Senior Member

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    I am claiming that any torpedo that contains enough explosive to damage a propeller blade will do far more damage to the hull than the propeller.
    Correct! The shock wave propagates and acts against the large surface. In fact, an explosive a short distance from a ship often does more damage than an explosive that is against the hull, since a destructive overpressure is generated over a larger area. You seem unaware of this, given that you are claiming that the short distance from the propeller to the hull will protect the ship from the destructive effects of that overpressure.
    Not even close. Look at the damage to any such ship. The damaged area is deformed inwards.

    From what you've posted, you don't really have any idea how explosives work. Suffice to say I am glad no one is taking your ideas seriously.
     
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  3. sideshowbob Sorry, wrong number. Valued Senior Member

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    Nobody is disputing that a torpedo could hypothetically hit a boat at a very precise point. What is being disputed is what happens to the boat when it is hit. Many of the vessels involved are just barely floating as it is (indeed, some of them do sink "spontaneously" on the way). It's just ridiculous to pretend that you can predict accurately the effect of an explosion on the boat.
     
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  5. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    No, not claiming that short distance from hull provides protection, although it does some. It is much more that the prop is at the end of a conical shape as I illustrated with post 14 refuting your false ideas about the prop being strong to withstand hitting rocks, etc. That photo is reproduced at end of this post, with its associated text. Thus there is no "broad-side" pressure, but an easily scattered (little momentum transfer / force) shock wave incident upon this basically conical stern end of the ship. Also as the article I quote from below stated: shock waves in water loss their energy much more quickly (shorter distance too) than if in air.

    Below is what I think happens, as I told already, to efficiently sink a big ship:

    Please Register or Log in to view the hidden image!

    Sorry the drawing, Fig 2, showing the boat cracking as it falls into the bubble with stern and bow still supported will not copy for me - go to link to see it.

    Please Register or Log in to view the hidden image!

    Stern of one ship shown is on left, Bow of another shown on right.
    Man has his hand on the trailing edge of the prop I.e. seen from behind rear of ship it turns clockwise. I think this is a big ship "assembly line."
    Note the lowest part of the prop is at least a foot above the ship's bottom.

    Compared to punching hole in convex steel surface it is easy to bend the outer section of a prop blade as it is relatively thin and far from any support, like internal ribs of a ship.

    It is not productive to attack me or my knowledge - I just quote the experts and show photos refuting your statements.
     
    Last edited by a moderator: Jun 11, 2015
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  7. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Yes some of the boats used are not in good shape; but they would be more likely to sink by harmonic wave forces repeatedly stressing them than by a small impulsive explosion on their prop. Note what I said about the shock wave scattering on the basically conical shape of the prop support and what my quote of post 43 said about the rapid attenuation of the shock in water compared to air.

    Again: I am trying to make it a financial losing bet for the criminal human traffickers by reducing their ships to beach scrap, after the desperate passengers are safe on land again. That is them cheapest and most effective way to end most of Europe's wave of illegal immigration with hundreds of people per boat. - Take the profit out of their operations.
     
    Last edited by a moderator: Jun 11, 2015
  8. Kristoffer Giant Hyrax Valued Senior Member

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    Take the profit out, not the fucking people on the boat.

    Your torpedo idea is insanely hard to implement.

    Minor miscalculation = a few hundred dead... Or are there enough choppers (which you suggested dropping these wonder torpedoes from) to pick up the 200+ you keep going on about?
     
  9. billvon Valued Senior Member

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    OK, I admit it. Completely safe mini-torpedoes capable of impacting a specific point on a blade spinning at hundreds of RPM's while not harming people a few feet away are a sure thing, and much safer than waves. But why stop there? They sound expensive. How about these much cheaper - and just as safe - solutions?

    -Sharpshooters that shoot the tiller (or wheel) out of the helmsman's hands and point it where they want it to go. A cascade of perfectly aimed bullets (a task which is, after all, a lot easier than hitting a specific point on a spinning prop) would keep the tiller pointed in whatever direction you wanted, with no risk to the people on board.

    -Rocket propelled grenades with soft pillowy fronts that nudge the boat's bow in the right direction. Again, much cheaper than torpedoes, and there's no way a soft-fronted grenade could damage a steel hulled boat.

    -Helicopters with grappling hooks that simply hook the boat and tow it back to the land they came from. You could easily make the hook completely safe, 100% accurate and non-releasable.

    -Trained killer whales that threaten the boat with their toothy jaws (to convince them to turn around) and then nudge it with their bodies to make sure it goes in the right direction.

    I am sure that with a combination of snipers, killer whales, rocket propelled grenades and helicopter grappling hooks this problem could be solved with no risk to humans on the boats.
    -
     
  10. sideshowbob Sorry, wrong number. Valued Senior Member

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    Where there is a demand there will always be somebody trying to profit from it. Even IF your plan worked, the traffickers would have another plan in place before you could catch your breath.

    You might as well suggest a chemical that turns heroin into lemonade. The addicts will still want the real stuff and the traffickers will find a way to supply it.
     
  11. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    No, really quite simple, with modern ultra sound imaging, and processing there of it as blade's image slowly changes position. (Computer has billion or more computational clock cycles compared to one cycle of the prop's very much slower rotational changes.) Computational power in an iPod is more than able to compute the trajectory the torpedo needs to intercept a particular prop blade on its mid-line 2/3 from the only support that thin metal has (the hub).

    Helicopters don't take any one off - the people climb down a ladder onto the beach after the tug has pushed the disabled boat up on it at high tide. As I told in post 1.
     
    Last edited: Jun 12, 2015
  12. sideshowbob Sorry, wrong number. Valued Senior Member

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    Again, nobody is disputing that you can hit the propeller. What's ridiculous about your proposal is the idea that you can selectively damage only one part of a boat that you know nothing about.
     
  13. Kristoffer Giant Hyrax Valued Senior Member

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    This.
     
  14. billvon Valued Senior Member

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    Yep.
     
  15. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    ed
    But I do know some things about the boat that are not true of the propeller. For example:
    (1) The hull is made of steel and that of the prop of a more corrosion resistant (and weaker) alloy in the bronze family.
    (2) The steel hull is convex out ward but the prop blades are nearly planes, inclined to their spin axis.
    (3) The hull has many ribs behind its outer surface and is thus stronger and much harder to bend inward which increases the point (1) effect /strength.
    (4) The prop blades are thinner as the outer perimeter is approach, almost knife like at their outer edge, and easy to bend.
    (5) The prop blades are supported on only one tiny fraction of their perimeter, the central hub.
    (6) The prop hub is at the apex of a basically cone shaped steel structure so that the flow thru the prop can be stream lined, not turbulent, for max thrust.
    (7) Any small explosion on the rear surface of mid-line of a prop will make shock waves that are to large extent traveling way from the hull, as the deforming motion induced in the prop blade will have sub sonic speed due to the inertial of the metal blade.
    (8) The pressure spike that does travel to the prob's support cone will be refracted by it away from the main hull and as this moving water in the pressure pulse is only scattered (or refracted not 180 degree reflected) thru modest angle there is not much momentum transfer (from the conical support) needed to change the water motion flow direction. When the momentum transfer is small, the forces associated with it are small too.

    As an example of point (8) consider how fast a ball must be thrown at a stack of bricks in single layer wall. If the ball hits the wall "straight on" or at zero degree incident angle, and reflects back towards the thrower,* it can knock over some bricks of the wall with much less energy than if it hits the wall at 60 degree incidence. (from the normal).

    * that is nearly a factor of two change in momentum; but if bouncing off the wall at 60 degree, only a slight change in momentum or the force impulse on the wall is less than 25% of what the bounce back straight reflection force is.

    PS this is probably my last reply. I am growing tired of defending what I said with facts and quotes of experts, when only ASSERTIONS have been made to claim it is not feasible, or dangerous to the passenger, but thanks for now admitting modern technology can hit the mid-line of a chosen prop blade about 2/3 from the hub where it is easier to bend. - Converting prop to a "turbulence generator" without the needed stream line flow's thrust.
     
    Last edited: Jun 13, 2015
  16. sideshowbob Sorry, wrong number. Valued Senior Member

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    No, you do not know that those examples apply to every boat.
     
  17. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Nor did I imply they did. They do apply to steel hulled boats that can carry 200+ passengers. That is the main portion of Europe's current illegal trans-Med immigration problem. Which of my eight facts does not apply to this limited class of boats?

    Even if for a few, say 5% of the boats in this limited class one or more of the eight "facts" are not valid claims, I think trying to beach the 95 % and let the passengers safely return to N. Africa, is a good idea. I suspect more than 5% will slip thru detection efforts, perhaps by luck or perhaps by "hugging close" to a cargo ship, like a much larger oil tanker on its routine and known run to European port.
     
    Last edited: Jun 14, 2015
  18. sideshowbob Sorry, wrong number. Valued Senior Member

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    I did a quick google for images of those boats and none of them seems to fit your criteria. Where are you getting your information?
     
  19. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    From internet - the links I gave. Do you have link? Also please, as asked before, be more specific - which of the eight points I listed is not true? Vague claims and assertions are not possible to reply to.

    For example are you saying wooden, not steel boats, are being used to transport more than 200 people?
     
  20. billvon Valued Senior Member

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    I think I see the problem here.
     
  21. sideshowbob Sorry, wrong number. Valued Senior Member

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    What links? Give us a link that says 95% of the refugee boats have steel hulls. If you've already given it, repeat it.

    It's YOUR vague claims and assertions that are being questioned - for example, that an explosion would/could/should selectively damage the propeller but not the hull. Has the experiment ever been done?

    I'm asking how you know they're steel.
     
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  22. cosmictraveler Be kind to yourself always. Valued Senior Member

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    I wonder who is supplying the weapons that are being used to kill and put fear into people in the country that has the most refugees coming from it.
     
  23. billvon Valued Senior Member

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    Odds are that it's the US.
     

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