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

As someone who used to spend a lot of time on a boat - that just means a delay, not stopping them.

Perhaps - but that would still leave Italy killing a fair number of helpless refugees.

 

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I, personally, have no good solutions to offer, but explosives and doubling the chances of dying at sea are surely not the way to go.

 

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Why? It was first done 75 years ago by the GNAT/T5 (German Navy Acoustic Torpedo, version 5). As you can imagine, there has been enormous improvements since then. (Much of it secrete.) The GNAT was fired at surface ships, usually disabling if not sinking, an escort ship of a trans-Atlantic WWII convoy. A sub armed with GNATs was sunk in shallow black sea waters and two USSR divers recovered at least one GNAT. The USSR said they would give it to the American for evaluation, but never did. They figured out how it worked and told that (in their own self interest as US was supplying them).

American quickly developed the defensive FOX, a powerful underwater toss-over-board noise maker that masked the prop noise (loudest sound source of a ship) when an approaching torpedo was detected but many cargo ships without escorts were still sink. The first two convoy ships hit by a GNAT were not sunk, only damaged. Their props hit, I suppose. I think active sonar was soon added for the final stage as to sink the ship the Germans did not want to hit the prop, but impact the ship's hull. The first two (or more ?) ships sunk were the German subs that launched the GNATs! For securitiy of the sub the GNATs were fired at least a mile from the intended target and ran out about 250 meters before beginning noise homing, but that was not always enough. (Sound propagations in water is complex and unpredictable - even lensing occurs.) In at least two cases, the GNAT turned 180 degrees and sank the sub that lunched them as its prop noise was greater than that of the distant target ship.

Soon the German Navy issued order to kill sub motor before GNAT launch and dive immediately after launch. GNATs ran at a fixed depth - typical of propeller depth and only had two horizontal acoustic sensors they tried to get equal sound intensity into by turning to the stronger one until the intensities balanced.

America which mainly needed to sink German Subs very quickly developed the Mk 24 "Fido" which had four acoustic sensors and was air dropped. (Less HE and weight than the GNAT but more accurate, I think.) It could and did follow the diving sub down. The fighter/bomber carrying the Fido and a fighter worked as a team that quickly eliminated the German Sub threat. The fighter would dive from high altitude at the sub found on the surface and had high speed armour piecing shell, so the sub was forced to dive. Then the MK24 Fido was dropped and essential no German Subs could survive this team approach.

The prop noise homing torpedo suggested of the OP would be air dropped by helicopter within a 100 meters of the prop and thus hit only the intended ship's prop. To be light weight and make sure it can not sink the ship, the HE charge would also be smaller - just enough to significantly bend the prop blade it hit. They have support only at the shaft hub - are quite vulnerable to HE bending. With modern guidance, US can fly a cruise missile thru a chosen target window 600 miles from the ship that launched the missile. There is no reason why a final optical guidance system could not pick and hit a particular prop blade's midline about 2/3 of the blade's radius from the hub to make bending torque maximum; however, better than optical would be ultra-sound active imagining could be used for final guidance to an optimal impact point on a particular prop blade. - The Doppler shift of the turning prop would help "lead the chosen blade" like duck hunter lead a flying duck with aim of his shot gun.

Your doubts are completely unfounded. Doing this now days (after 75 years of development) is hardly even a challenge.

 

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Why not just use the Coast Guard as it's meant to be used, and avoid all the controversy? Italy and France are more than capable of protecting their borders and sending back anyone they don't want. If Europe wants to change its refugee policies, they don't need fancy semi-lethal torpedoes- just a pen, paper and some ink would suffice.

 

Um... the German Navy was trying to sink ships with their torpedoes. A couple of failures do NOT count as evidence that a torpedo could reliably disable but not sink a ship.

 

Then put your money where your mouth is. Detonate an explosive that will destroy an outboard motor propeller while you are sitting next to it. Otherwise, do not demand that others take risks that you yourself are unwilling to take.

 

Of course not. The GNATs sank many ships - what it was designed for. The first two times it was fired at ship of a convoy it only damaged the ship it hit. Where it hit I don't know but the propeller it was homing on while chasing the ship from the stern, is certainly a very strong possibility.

To avoid wasting the explosion against the prop, the Germans added active sonar guidance for the terminal stage - I. e. After getting close* to the ship via acoustic homing, it guided on the main sonar reflector - the hull, not the propeller and then they sank ships, not just damaged their propellers. With a much smaller, better guided to the mid line of one particular prop blade about 2/3 out from the prop hub, a much smaller HE charge (and smaller torpedo, suitable for air drop from a helicopter less than 100 meters behind the prop,) there is no risk of sinking the ship and high probability of great impeding it forward motion. I.e. make the prop into a turbulence generator, with very little, if any trust.

* it is trivial data processing to know when a torpedo is getting close - the sound intensity increases at least as the inverse square of the distance yet to go. The Brits caught many a battery power German sub on the surface recharging it batteries by similar clever trick:

The power of their radar return signal, which first spotted the sub on the surface was very weak as the two way path reduced the reflected signal strength by 1/(d^4) but at the sub it was down only by 1/(d^2) I.e. the sub always knew there was a plane searching for it before the plane knew there was a sub on the surface. The Germans monitored the intensity of the planes radar transmission and had plenty of time to calmly dive still remaining when that signal became four times stronger (Plane had probably discovered them and cut the distance between them selves and the plane in half).

What the Brits did (a very top secrete) was to continue straight toward the then known position and distance, d, from the sub, BUT decrease the radiated power as 1/(d^3). I.e. the sub, which was getting stronger by d^2 fraction of the radiated power received net of 1/d decreasing signal as if the plane were flying ever more distant from its location. The plane in contrast with its return reflection 1/(d^4) fraction of the power it was radiating got a return signal that was INCREASING by 1/d. I.e. the plane was getting stronger radar returns all the time.

The German realized the plane was approaching only when they heard the noise of the plane's motor but by then at least its emergency dive bubbles and wake told plane where to drop its depth charges.

 

... And after the first deadly mishap are you willing to take responsibility?

 

I would have no concern about being on a large ship (one holding more than 200 desperate people) that had its propeller carefully hit by small HE on a particular selected propeller's blades very near the optimum spot (mid line and about 2/3 out from the hub, I assume is near that and easily achieved by imagine sonar the can see a baby's penis, if it is a boy). The propeller is supported only on one small section at the shaft hub, much easier to bend than blow hole in the ships hull.

In addition to solving Europe's problem, I am trying to save many immigrants lives - stop their attempt to cross the Med in which many are now dying before they have covered even 10 % of the journey and tow their disabled boat back to near by beach where it is shoved aground at high tide.

 

Yes, I think it is impossible for small HE charge that can bend a prop blade to sink a steel hulled ship*; but for taking responsibility I want credit for the thousands of lives saved from their current fate of drowning by beaching their boat at high tide on a near by beach. (All as suggested in post 1, in more detail.)

* As the hull is convex outward, I doubt it would even be dented but if it is, so what?

 

A 'large' ship holds way more than 200. Especially if they're desperate refugees.

Leaving a vessel with civilians on board drift on the tides after you disabled it is fucked up.

 

Here's an Ethiopian refugee boat:

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Again, I challenge you to sit next to an outboard engine and disable it via a small explosive charge placed nearby. If you like you will be allowed to use six inches of water and two millimeters of rubberized canvas to protect yourself.

Your comments are akin to the people who post regularly about how they can make their magnet motor work if they can just tweak it to solve a few small problems. They are sure it can be made to work; it makes sense to them.

I presume, therefore, you would have no compunctions about being circumcised by a small, carefully placed explosive charge aimed very accurately by sonar, and dropped from an airplane? After all, look how accurate sonar can be . . . .

 

Yes. I was stating that only a steel hulled boat capable of holding at least 200 would be suitable for selective propeller damage. . I suggested it should not be long before a tug can take the disabled boat in tow, then switch to pushing it up on a beach at high tide.

Only Brillvon seem to be speaking of out board motors and rubber rafts. Here a paragraph from my second post:
"Also one does not pack even a couple of dozen people, much less a few hundred, in any boat powered by an out board. There is a shaft from the larger / more powerful than car engine INSIDE the steel hull, that separates engine from propeller by more than a dozen meters. A small torpedo, which can immobilize the ship via propeller damage, probably with not even bend the shaft. "

I am not claiming to solve 100% of Europe's illegal immigration problem just greatly reduce it and save a few thousand lives each summer the current crisis continues.

 

I thought purposefully altering other members names were against the rules.

Still not hooked on your torpedo idea. Way too big a chance that shit'll go wrong.

 

An "r" got into Billvon's name by accident. I'm a little dyslexic and did not notice. Can you suggest how it might "go wrong"? As charge is too small to blow hole in steel hull, even if it missed the prop and hit there, only way I can think of is it could be a dud - fail to explode at all - then a second would be dropped. To save lives, these boats full of hundreds of immigrants need to be stopped while not too far from Africa's N. coast, and pushed up on the beach at high tide.

Then to make sure no one breaks a lag getting down 20 or more feet to the sand, a rope ladder could be dropped if none appears as I suggested in post 1. I'll also add that even with the warning leaflets in many languages dropped warning and a few small bombs dropped in the water also at least one man lowered by the helicopter should search the boat t make sure all are off. It is important when that is confirmed to reduce the ship to scrap metal - losing a few hundred thousand dollars will be a good deterrent to the criminals human traffickers - they will stop buying or renting boats for this purpose.

 

Accidentally sinking the ship. Those ships aren't new, they're probably held together by rust and chewing gum.

 

Explosives don't work like knives. They work by creating a compression wave that acts against a surface. If the surface is small (a propeller) then it takes a large amount of explosive to deform the metal. If the surface is large (say a boat hull) then it takes very little explosive to deform the metal. You could easily blast a hole in a metal hull with an explosive that wouldn't even dent a propeller.

Here's something to consider. Did depth charges have to actually hit a submarine to cause their destruction?

For every complex problem, there is a solution that is clear, simple - and wrong. This seems like a perfect example of that maxim.

 

Then why did you use it as an example that a torpedo could be used with surgical precision to disable a ship?

 

Because I wanted you (and others) to know, I was suggesting homing on prop noise technology used in WWII, but with 75 years of improvement. Ultra sound imagining is not quite that old, but is fantastic (images a baby boy's penis!) Modern computers can easily note the speed and direction of a prop's rotation, and know precisely how far from contact with the particular prop blade being targeted the torpedo currently is and it speed, so the point in space and time when the torpedo can explode on the mid line of that blade about 2/3 out from the hub is very accurately known. Doing this now, not 75 year ago, is not even much of a challenge. Everything is happening very slowly compared to computer processing speeds.

Also I should note the torpedo's war head it not of the "shaped charge" type - just HE. You use a shaped charge to punch holes in a tank or a ship's steel hull. We don't want intense localized pressure on a square centimeter or less with the target metal being liquified. We want a very large pressure times area it acts on product to bend the targeted prop blade. - Convert the entire prop into mainly a turbulence generator. If this large, relatively low pressure explosion were to occur on the ship's steel hull, it would blow a big air bubble in the shallow water and at worst dent the convex outward hull inwards slightly.

 

So you assert, with zero logic or evidence. You are claiming a simple HE charge would "blast a hole" in a convex steel surface. I am claiming one that could bend a basically flat bronze surface which is only supported at one short arc edge is much easier to bend inward to wards the hull.

Perhaps you don't know that even much larger HE charges when attacking a big ship does NOT explode against the hull as that will NOT sink the ship. Instead it explodes many meters benigth the ship's bottom center, making a large bubble of gas which cracks the ship as the ship bends into the bubble (both ends still being supported by water).

Occasionally, just some lazy idiot loading oil into a tanker cracks the ship. I.e. if he starts loading the stern tank compartments first, the bow is lifted perhaps only a meter or two above it natural flotation level and that is a lot of bending torque applied donward at the bow - This happen in Brazil a couple of years ago, and the legal arguments are still not settled - who pays the repair. (Even just the time value of money lost in the oil paid for but not delivered is a few hundred thousand dollars!)

Read up a little on how and where to explode HE to sink a big ship. Also read the last paragraph of post 39.