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Old 06-24-07, 08:01 AM   #1
U-161
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Default Less than 18knots?

I wonder at the fact in this game that when the engine speed was ordered flank, the nuclear sub can not run more than 18knots in shallow water.
Even the non-nuclear surface ship can run more than 18knots.
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Old 06-24-07, 04:16 PM   #2
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it all works on the basis of hydro dynamics but i dont know the rest have to re read it all.
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Old 06-24-07, 05:44 PM   #3
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Does it matter because you will sound like a train anyway at those sort of speeds in shallow water!
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Old 06-24-07, 08:25 PM   #4
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Hello, Kapitan and Linton

It all works on the basis of hydro dynamics
------------------------------------------------
But torpedoes can run more than 18knots in shallow water.

Does it matter...
--------------------
When the torpedoes chase around you, it does matter.
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Old 06-25-07, 03:49 AM   #5
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U-161 what is your definition of shallow water?To avoid cavitating your speed should be no more than the square root of your depth.
If you are being quiet=stealthy then torpedoes shouldn't be chasing you!
Compare the size of a torpedo and the flow of water around it to that of a submarine.An adcap is 21 inches wide-a submarine is 34 feet.In the submarine you are disturbing a much greater body of water and this is obviously interacting with the seabed causing a disturbed flow.This in turn produces drag around the form of the submarine.
http://www.dsto.defence.gov.au/publi...TO-TR-1622.pdf

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Old 06-25-07, 09:53 AM   #6
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You should be competant enough if you work it well that you can avoid and evade torpedos in shallow waters at slow speeds put against an ADCAP fired at 8nm you should be able to make it out of its cone easily simply by laying down a CM turning another CM turning.

the CM's throw the torpedo off the turn means its nose which for a MK48ADCAP has a seeker range of 3000m and angle of seek at 60* means you could in theory turn twice lay down two CM's and have that torpedo run right past you without it locking on.
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Old 06-25-07, 11:42 AM   #7
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Quote:
Originally Posted by Linton
U-161 what is your definition of shallow water?
Depth less than 200 feet.

Quote:
Originally Posted by Linton
To avoid cavitating your speed should be no more than the square root of your depth.
Thank you for let me know that.

Quote:
Originally Posted by Linton
Compare the size of a torpedo and the flow of water around it to that of a submarine.An adcap is 21 inches wide-a submarine is 34 feet.In the submarine you are disturbing a much greater body of water and this is obviously interacting with the seabed causing a disturbed flow.This in turn produces drag around the form of the submarine.
I believe the same situation will happen to the surface ship. But I have never heard that surface ship is draged by the disturbed flow caused by seabed. Besides, if the distance between seabed and surface is several thousand feet, it is impossible to cause any disturbed flow.
Maybe sub builder has decided to limit the speed because flank running in shallow water for torpedo evasion will cause more torpedo attack by enemy and easily damaged by mines.
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Old 06-25-07, 12:07 PM   #8
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Quote:
Originally Posted by Kapitan
You should be competant enough if you work it well that you can avoid and evade torpedos in shallow waters at slow speeds put against an ADCAP fired at 8nm you should be able to make it out of its cone easily simply by laying down a CM turning another CM turning.

the CM's throw the torpedo off the turn means its nose which for a MK48ADCAP has a seeker range of 3000m and angle of seek at 60* means you could in theory turn twice lay down two CM's and have that torpedo run right past you without it locking on.
Thank you for sharing your knowledge.
I always try to deceive torpedoes by changing the thermal layer, but it does not work at Hormuz straits.
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Old 06-25-07, 04:08 PM   #9
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The straights of hormouz are very shallow in places it doesnt have a thermal layer and in any case it doesnt really matter to a smart sub driver !

the straights of hormouz have i think its called bottom coveragence zone ie no layer sandy bottom affects sonar capbility, the way around it it to run mid range with towed array 2/3 extended that way its not long enough to drag on the floor.

A tip about evasion on torpedos and thermal layers:

A good submarine captain will sit his submarine under the layer by around 100 feet (50 meters for me say) i will fire a UUV and send it above the layer so ive got now a sensor above and below the layer so no matter where you try to hide in the two layers i can always find you.

So ive now found you and your 8 miles away steady bearing speed and course, i will set two 65cm's to hunt you one above and one below the layer that way you cant change depth without running into one or the other.

So what do you do?

Deploy a CM then hit 90* turn right or left go for a while then do the same and if your loaded again do the same twice more that way your well out of the torpedo seeker range and theres so much noise you could run at flank and me and my UUV will struggle to find you.

Just a lesson

note i drive akulas not 688i or seawolf.


If you want some practice online then im availible just arrange a time and date.
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Old 06-26-07, 04:50 AM   #10
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Quote:
Originally Posted by Kapitan
So what do you do?

If you want some practice online then im availible just arrange a time and date.
If I detect strong periodic signals from the torpedos, I will break my silent running and move toward the surface at flank for intentionally attracting torpedos. Then launch CMs in the periscope depth and dive toward the bottom of the sea with silent running.
It works. However, I think I have already exposed my position and you will launch more torpedos until you hunt down me.
Your tactics is more sophisticated than mine.
I had enjoyed Jane's 688i for long time. I have just finished the training mission of seawolf. I am looking forward to play these games with you.
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Old 06-26-07, 09:30 AM   #11
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The idea of attracting them too you well yeah you will surely loose every time, if you detect the torpedos ping and its every 3 or more seconds before the next ping then the torpedo does not have you.

Only if the ping becomes constant louder and less than 2 seconds does it have a lock and bear in mind a safe range of 5000 meters in front of the torpedo can break the lock.
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Old 07-02-07, 09:46 AM   #12
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Quote:
Originally Posted by U-161
I wonder at the fact in this game that when the engine speed was ordered flank, the nuclear sub can not run more than 18knots in shallow water.
Even the non-nuclear surface ship can run more than 18knots.
i think that no sub cdr would cavitate so wildly, as cavitation damages the blade(s) too... and with such a blade you will cavitate at lower speeds next time, when you will prefer (or need) to remain fast but silent...
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