SCXIIC-blind zones of sonar detection

[Stanny]

Hello everybody,

I am the driver of SSN-21 Seawolf in Sub Command 1.08 SCXIIC.I am trying really hard in practicing manual sonar operations on this great submarine.

I can't find any sensible explanation for such phenomena,that sometimes occurs during my missions.After tracking surface groups for some time,I suddenly loose contacts on all sensors.That looks like this:STA broadband waterfall dispay is showing a huge amount of background noises,narrowband display is showing just a row of equally high peaks.Switching to towed array gives sounds of loud noises in all bearing ranges,no contacts are shown on sphere array.

That situation can be corrected by changing course and depth of the sub.After doing so,you gain back normal pictures on both broadband and narrowband displays,and can establish a contact again.

Does anybody know,how to explain those sudden huge noises?I must stress that speed of own sub is very favourable,I mean from 2 to 5 knots.

Thanks everybody for your help and have good hunting guys.

Regards,
Stan.

[sonar732]

Originally Posted by Stanny

Hello everybody,

I am the driver of SSN-21 Seawolf in Sub Command 1.08 SCXIIC.I am trying really hard in practicing manual sonar operations on this great submarine.

I can't find any sensible explanation for such phenomena,that sometimes occurs during my missions.After tracking surface groups for some time,I suddenly loose contacts on all sensors.That looks like this:STA broadband waterfall dispay is showing a huge amount of background noises,narrowband display is showing just a row of equally high peaks.Switching to towed array gives sounds of loud noises in all bearing ranges,no contacts are shown on sphere array.

That situation can be corrected by changing course and depth of the sub.After doing so,you gain back normal pictures on both broadband and narrowband displays,and can establish a contact again.

Does anybody know,how to explain those sudden huge noises?I must stress that speed of own sub is very favourable,I mean from 2 to 5 knots.

Thanks everybody for your help and have good hunting guys.

Regards,
Stan.

Sounds like your towed array is dragging.

[Pisces]

Yup, must be your towed array dragging over the bottom, especially if you are close to the bottom. Solution is to speed up a bit (above 6 or so it won't happen, I think), rise, or even better is to reel it in as neccessary. It doesn't need to be extended all the way anyway. A 3rd of the length is usually enough for good sensitivity. But that depends on your environment/tactical situation (and it also makes straightening after a turn go quicker)

[Stanny]

Yes,it seems,you are right,guys.This thing usually happens while operating in shallow waters.

Anyway,thanks for your help.

[sonar732]

Originally Posted by Stanny

Yes,it seems,you are right,guys.This thing usually happens while operating in shallow waters.

Anyway,thanks for your help.

Sorry for my short and to the point post above...was being paged. Anyhow, what I do with my towed array is stream it to the 'S' marker and have a general speed of 7 knots.

In litoral waters, you need all of the help you can get with sonar due to the bad dynamics, so the speed combined with the shortened towed array will keep it from scrapping the bottom. Make sure that you scan NB almost exclusively in these waters as the BB will suck with all the surface noise.

[Stanny]

I just started playing SCXIIC with professional Aiwa Hi-Fi headfones.Rather old ones,but listening to broadband sonar station with them is just amazing.There are far more different noises in the water,than narrowband station is actually able to classify.

[sonar732]

Originally Posted by Stanny

I just started playing SCXIIC with professional Aiwa Hi-Fi headfones.Rather old ones,but listening to broadband sonar station with them is just amazing.There are far more different noises in the water,than narrowband station is actually able to classify.

I'll leave it at this...you aren't hearing even half of what's out there.

Remembering my oath...

[Stanny]

Originally Posted by sonar732

I'll leave it at this...you aren't hearing even half of what's out there.

Remembering my oath...

Headphones add great atmosphere to sonar operations.I like to hear actual differences between sounds of cargo ships and,let's say fishing boats,the way blades are rotating.I think that sonar specialists also use headphones alongside waterfall displays in real subs.

[sonar732]

Originally Posted by Stanny

Headphones add great atmosphere to sonar operations.I like to hear actual differences between sounds of cargo ships and,let's say fishing boats,the way blades are rotating.I think that sonar specialists also use headphones alongside waterfall displays in real subs.

My time on the boat has instilled in me the need to have one ear piece off and one on no matter the application. I'll be working at my cubical listening to music and have people laughing at the sight of a ear piece behind my ear.

Kids get in trouble all of the time as I'm able to hear little things they say.

[Stanny]

Originally Posted by sonar732

My time on the boat has instilled in me the need to have one ear piece off and one on no matter the application. I'll be working at my cubical listening to music and have people laughing at the sight of a ear piece behind my ear.

Kids get in trouble all of the time as I'm able to hear little things they say.

Anyway,listening gives additional abilities than just viewing.Signals maybe too weak to distinguish them even on waterfall displays.At least,if you scroll through bearings,you may find out the bearing of "something unusual" in field of background noises.You can plan further actions in appropriate way,take favourable positions according to that possibly dangerous signal and so on.

Do you remember "Hunt for the Red October" movie?Of course,it's just a movie,but I really like the way conn sonar guy is working there on USS Dallas.