target speed: the eighty-ten method

[tater]

Quick and dirty example. This is in effect the same diagram nisgeis posted.

Sub moves some distance in the period from observation 1 to 2. Let's say she's moving 5 knots.

The top target observed at bearing 280 in both cases has an AOB of 65. In the time interval of obs1 to obs2 she moves ~108% of the path length of the sub. That's 1.08*5 = 5.40 knots. This might well be ruled out by the sonarman's speed range.

The next target has an AOB of 35. Still at 280 on both bearings. So she must move ~174% of the sub's movement in the time period from obs1 to obs2. That means she has to go 8.7 knots. If the sonarman said 8-12 knots, this path is entirely possible.

The next has an AOB of 28. She'd have to move at 10.6 knots to keep the relationship. Still within the 8-12 as a valid solution.

Note that there are INFINITE solutions like this. Note also that all the above examples cross the sub's path at angles not equal to 90.

Greyrider's givens are 080/280 bearing. Closing target with sonarman speed range estimate. Submarine speed. All else is unknown. He seems to say that if it is possible to keep the target on 080 at >0 to max submerged speed, then the AOB must be 010, which, obviously, is nonsense.

[Armistead]

This thread ain't all bad. I've learned a lot here from tater and RR I didn't know...so don't count it all for loss. I actually even learned a tip from grey about attacking convoys sonar attacks only, but only workable with other provable tips provided.

not a total loss.

[Rockin Robbins]

It's been fun. I was gratified that others came to lend their insight and also that nobody descended into a total food fight. We continued to talk about the issues and ideas in spite of extreme provocation at times. Actually these issues have driven the real submariners crazy for 100 years.

Just recently we have developed methods of passive sonar motion analysis that are consistently good enough to shoot by, but that is well beyond the ability of SH4. It is possible with a real World War II submarine to do some bearing rate analysis and get a relative course and speed for a target that is good enough to shoot with if you are willing to waste enough torpedoes. They weren't in real life. I've never read a report of a World War II patrol where they shot by passive sonar.

They were dealing with handicaps that we are not in the game, because the game gives us impossible information:

• Whether the target is approaching or going away
• Whether the target is slow, medium or high speed, with these speeds in precise ranges of knots.
• A sonar that is perfectly accurate to one degree with exactly 10 degrees each side of the bearing where you can hear the target.

All this makes it possible for us to game the system enough to develop cheats to narrow down the possible solutions. But they will not allow us to shoot, only to get close to the target. Shooting is by other methods, not related to passive sonar tracking techniques. These methods are well known and do not include point and shoot whatever that may be. No definition of that has been forthcoming either!

But be that as it may we have all learned that we can go home and quit posting as greyrider invented all possible ways of shooting torpedoes from submarines. Everyone else, presumably including the brave sub sailors of World War II, are merely copying him (badly by the way. Nobody is as good as greyrider even when we are just stealing from him) and trying to steal the credit. All credit belongs to greyrider for all techniques. We all hail! I'll cut greyrider in for half the profits from Dick O'Kane, John P Cromwell, vector analysis. and my analysis of the criticality of entering information into the TDC in a certain order if you use the PK. He doubtless figured that out many years ago and just forgot to teach it.

It's all good!

[Rockin Robbins]

Now if you are really interested in a non-WWII TMA analysis showing target course (a graphical application of the bearing rate method) and also triangulating the actual position, hence giving you a decently accurate firing solution, check this out by gutted.

Gutted is one of the primary sources for all my attack methods, along with many others, pointedly not including greyrider. Note that the Hydrophone Tracker has clear, unambiguous instructions and meets nine of the ten tests of a valid targeting technique, lacking only enthusiastic adoption by successful captains. That will change as it becomes used on a wider basis.

Unlike 8010, it meets the rigorous test of a real targeting technique. This is a passive sonar targeting technique that sinks your target without ever raising the periscope! It's a true shooting method. Check it out and enjoy the difference!

[greyrider]

this is not an 8010 shot, but what it is is the only known encounter in ww2 of one submerged submarine killing another submerged submarine,
by hydrophones alone.
this was not a spread shot, as the torpedoes were fired 17.5 seconds apart, at different depths, this was hms venturer taking down u-864, off the coast of norway.
unseen, purely underwater, kinda blows the oppositions pov, of needing to see the target, and that hydrophones alone cannot be used to destroy
another ship.
ah, i love it!

its a documentary, in 5 parts, on u-tube. the links are at the bottom of the post.
pay attention rockin, your going to learn something!


In late 1944, U-864 was dispatched from Germany under the command of Korvettenkapitän Ralf-Reimar Wolfram to take part in Operation Caesar.
This mission called for the submarine to transport advanced technology, such as Me-262 jet fighter parts and V-2 missile guidance systems, to
Japan for use against American forces. Also on board was 65 tons of mercury which was needed for the production of detonators. While passing through
the Kiel Canal, U-864 grounded damaging its hull. To address this issue, Wolfram sailed north to the U-boat pens at Bergen, Norway.
On January 12, 1945, while U-864 was undergoing repairs, the pens were attacked by British bombers further delaying the submarine's departure. With repairs
complete, Wolfram finally sailed in early February. In Britain, code breakers at Bletchley Park were alerted to U-864's mission and location through Enigma radio intercepts.
To prevent the German boat from completing its mission, the Admiralty diverted the fast attack submarine, HMS Venturer to search for U-864 in the area of Fedje, Norway.
Commanded by rising star Lieutenant James Launders, HMS Venturer had recently departed its base at Lerwick.
On February 6, Wolfram passed Fedje the area however issues soon began to arise with one of U-864's engines. Despite the repairs at Bergen, one of the
engines began to misfire, greatly increasing the noise the submarine produced. Radioing Bergen that they would be returning to port, Wolfram was told that
an escort would be waiting for them at Hellisoy on the 10th. Arriving in the Fedje area, Launders made a calculated decision to turn off Venturer's ASDIC
(an advanced sonar) system. While use of the ASDIC would make locating U-864 easier, it risked giving away Venturer's position.
Relying solely on Venturer's hydrophone, Launders began searching the waters around Fedje. On February 9, Venturer's hydrophone operator detected an
unidentified noise that sounded like a diesel engine. After tracking the sound, Venturer approached and raised its periscope. Surveying the horizon,
Launders spotted another periscope. Lowering Venturer's, Launders correctly guessed that the other periscope belonged to his quarry. Slowly following U-864,
Launders planned to attack the German u-boat when it surfaced.
As Venturer stalked U-864 it became clear that it had been detected as the German began following an evasive zigzag course. After pursuing Wolfram for
three hours, and with Bergen approaching, Launders decided that he needed to act. Anticipating U-864's course, Launders and his men computed a firing
solution in three dimensions. While this type of calculation had been practiced in theory, it had never been attempted at sea in combat conditions.
With this work done, Launders fired all four of Venturer's torpedoes, at varying depths, with 17.5 seconds between each.
After firing the last torpedo, Venturer dove quickly to prevent any counterattack. Hearing the torpedoes approach, Wolfram ordered U-864 to dive deeper
and turn to avoid them. While U-864 successfully evaded the first three, the fourth torpedo struck the submarine, sinking it with all hands.
The loss of U-864 cost the Kriegsmarine the U-boat's entire 73-man crew as well as the vessel. For his actions off Fedje, Launders was awarded a
bar for his Distinguished Service Order. HMS Venturer's fight with U-864 is the only known, publicly acknowledged battle where one submerged submarine
sank another.

part 1
part 2
part 3
part 4
part 5

[tater]

And that is relevant how?

[tater]

He instinctively ignores posts with any real meat to them.

[Armistead]

Has no bearing on the thread or your method, but it states..

"Launders spotted another periscope. Lowering Venturer's, Launders correctly guessed that the other periscope belonged to his quarry. Slowly following U-864, Launders planned to attack the German u-boat when it surfaced."

Seems he made visual contact and followed it by scope enough to get into position to attack by sonar. That statement in fact is the problem with your method, he had to put himself on course to attack to start with and did so with a visual.

His attack why well planned, was more luck and theory....I've sunk many ships by sonar alone with no visuals at all, but it was estimate info at best.
Here he had visuals to start with...


I use to have some respect for you, but this constant silliness trying to just jest at people is silly.

Thread needs to be lock and deleted, it has no merit at all.

[greyrider]

Originally Posted by Armistead

Has no bearing on the thread or your method, but it states..

"Launders spotted another periscope. Lowering Venturer's, Launders correctly guessed that the other periscope belonged to his quarry. Slowly following U-864, Launders planned to attack the German u-boat when it surfaced."

Seems he made visual contact and followed it by scope enough to get into position to attack by sonar. That statement in fact is the problem with your method, he had to put himself on course to attack to start with and did so with a visual.

His attack why well planned, was more luck and theory....I've sunk many ships by sonar alone with no visuals at all, but it was estimate info at best.
Here he had visuals to start with...


I use to have some respect for you, but this constant silliness trying to just jest at people is silly.

Thread needs to be lock and deleted, it has no merit at all.

what did i say at the begining, this was not an 8010, what bearing it has is that tater and a few other try again as usual, saying you cant track by hydrophones, it has an arc, or whatever else he imagines, so that documentary has bearing, it also has bearing in showing what a submarine can do, with a capable skipper, with audacious tactics, and a very capable hydrophone operator, thats what bearing it has.

it has bearing also, in that a submarine could track, and kill another unseen target, why ami not surprised you would deny the truth of that?

[greyrider]

Originally Posted by Rockin Robbins

Now if you are really interested in a non-WWII TMA analysis showing target course (a graphical application of the bearing rate method) and also triangulating the actual position, hence giving you a decently accurate firing solution, check this out by gutted.

Gutted is one of the primary sources for all my attack methods, along with many others, pointedly not including greyrider. Note that the Hydrophone Tracker has clear, unambiguous instructions and meets nine of the ten tests of a valid targeting technique, lacking only enthusiastic adoption by successful captains. That will change as it becomes used on a wider basis.

Unlike 8010, it meets the rigorous test of a real targeting technique. This is a passive sonar targeting technique that sinks your target without ever raising the periscope! It's a true shooting method. Check it out and enjoy the difference!

impressive! i will show you a pic tonight, of something similar i posted, in 2005, you will note the date, december 2005

it was the begining picture of the hydrophone tutorial, by greyrider

[greyrider]

Originally Posted by greyrider

impressive! i will show you a pic tonight, of something similar i posted, in 2005, you will note the date, december 2005

it was the begining picture of the hydrophone tutorial, by greyrider

i dont think mister gutted was a member either, in 2005

[razark]

Originally Posted by greyrider

impressive! i will show you a pic tonight, of something similar i posted, in 2005, you will note the date, december 2005

it was the begining picture of the hydrophone tutorial, by greyrider

Can you post a link to the location you posted it?

By the way, what were the results of testing the mission posted in Post #221 that you asked someone to post for you?

[greyrider]

awww heck, why wait, ill post it now, and continue on with more pics of the tutorial tonight, does this look familiar rockin?

note the date it was uploaded



By null at 2010-09-15

[greyrider]

Originally Posted by razark

Can you post a link to the location you posted it?

By the way, what were the results of testing the mission posted in Post #221 that you asked someone to post for you?

havent seen it until now, i will let you know