Leaving port?

[Sam Buchanan]

Hello, i have a few questions about standard measures during leaving port, with a sub:
Which water deep is aquired to use the towed array? When leaving port, i am using only the bow sonar array. Releasing the towed array in shallow waters (30 feet) seems not to be a good idea.

Which is the minimum depth to go on periscope depth?

Which is the minimum depth to go to standard travelling depth (150 feet)?

Before opening a whole new thread, i am writing some more questions into this one:

Is it actually possible to hear the opening of torpedo tubes of an enemy sub in Dangerous Waters via Sonar?

[Molon Labe]

Hello, i have a few questions about standard measures during leaving port, with a sub:
Which water deep is aquired to use the towed array? When leaving port, i am using only the bow sonar array. Releasing the towed array in shallow waters (30 feet) seems not to be a good idea.
There isn't really a minimum depth for it, because it depends on your speed too. If you get up to 8 knots or so, it's pretty much straight (although maybe it dips if you real it out really far, I'm not sure).


Which is the minimum depth to go on periscope depth?Depends on the sub. Check the appendix in the manual for each subs PD


Which is the minimum depth to go to standard travelling depth (150 feet)?150 feet. Although its not a bad idea to have a self-imposed safety margin.


Before opening a whole new thread, i am writing some more questions into this one:

Is it actually possible to hear the opening of torpedo tubes of an enemy sub in Dangerous Waters via Sonar?As a practical matter, no. Although it is technically possible if you get ridiculously close.

[Transients]

As a practical matter, no. Although it is technically possible if you get ridiculously close.

I often get a brief transient on the broadband log when I open my own tubes on the 688. (I've not noticed this on the other boats.) If my own sonarman can hear it then I assume another's can too.

[sonar732]

This is a fine dance that is played. So many factors are key in seeing the transient of a torpedo launch that it could take a whole thread.

Main thing is the current SSP. From the SSP and layer depth, your next question is where you are related to the layer. Obviously, the next one is where the contact is in relationship to the layer. I was just playing a mission from Bellman where you monitor an Iranian/Russian Exercise. The layer depth was at 680 feet. I kept playing above and below the layer. While sprinting at 22 knots under the layer, I received a 'torpedo in the water' bearing 234 with my current course of 045 towards the AOP. So, I kept an eye out on both TA and SP BB for a transient somewhere between 000 and 180 after slowing to 15 knots. Nothing. So, during my drift of 4 knots, I peeked above the layer. Low and behold...'torpedo in the water' bearing 065. There's the transient in SP BB. Immediately change course to 090 for my TA BB to show the 065 bearing as a line drawn from 065 to the 234 contacts behind me show that quite a few 15's were launched.

Secondly is how far away from the contact are you?

I hope this helps you a little bit. The first thing that I do is check the SSP.

EDIT: Also, regarding your towed array deployment question...I always deploy my array to the 's' marker thru the main control screen/F1.

[Molon Labe]

I often get a brief transient on the broadband log when I open my own tubes on the 688. (I've not noticed this on the other boats.) If my own sonarman can hear it then I assume another's can too.

You cannot monitor your own SL with your sonar, so you cannot detect any self-transients. What you can see is ambient noise in the form of "static" on the broadband, which self noise is a contributor to. Self-noise is not ownship's SL, but rather a factor in calculating ownship's sonar performance. It is confirmed that having a torpedo tube door open or having a mast up increases the amount of static displayed. However, the SL outputed by your platform that can be heard by other platforms is completely unrelated in the sim to the noise that degrades your own sonar performance. While I do strongly suspect that having a mast up or a door open increases SL by a point or so, I am not aware of anyone having confirmed this (which would have to be done with LAN/MP testing). If SL does increase, however, this is NOT a transient. It is simply an increase that remains in effect while the mast/door is in the raised/open state.

This is a fine dance that is played. So many factors are key in seeing the transient of a torpedo launch that it could take a whole thread. Main thing is the current SSP. From the SSP and layer depth, your next question is where you are related to the layer. Obviously, the next one is where the contact is in relationship to the layer. I was just playing a mission from Bellman where you monitor an Iranian/Russian Exercise. The layer depth was at 680 feet. I kept playing above and below the layer. While sprinting at 22 knots under the layer, I received a 'torpedo in the water' bearing 234 with my current course of 045 towards the AOP. So, I kept an eye out on both TA and SP BB for a transient somewhere between 000 and 180 after slowing to 15 knots. Nothing. So, during my drift of 4 knots, I peeked above the layer. Low and behold...'torpedo in the water' bearing 065. There's the transient in SP BB. Immediately change course to 090 for my TA BB to show the 065 bearing as a line drawn from 065 to the 234 contacts behind me show that quite a few 15's were launched.

I hope this helps you a little bit. The first thing that I do is check the SSP.
I'm a bit confused here, if your sonar was on the wrong side of the layer at the time of the launch, it could not have recorded the transient. It's not like when you switch sides of the layer the history gets re-written as if you had been listening on the right side.

More importantly though, it is important to distinguish between a transient caused by a door opening and that of an actual weapon launch. I can't count how many times I've seen a transient at the narrowband screen when the sub I was watching fired a weapon. But just opened a door? Probably never.

A long time ago, back in the SC days, Ramius (IIRC) addressed this question and posted some screenshots. His broadband history had recorded a transient caused by a door opening, perhaps even the tube being flooded. But, the screenshots were also taken from extremely close range, close enough that the target sub had been leaving a nice bright streak on the broadband. And even at that incredibly close range, the transient was still barely visible. Ramius's screenshots demonstrated that the torpedo tube door transient is real, but also implied that the conditions under which it could be observed are so unlikely that the transient is of no practical value. To date, there has not been any information that has come out to contradict that implication that I'm aware of.

[sonar732]

I'm a bit confused here, if your sonar was on the wrong side of the layer at the time of the launch, it could not have recorded the transient. It's not like when you switch sides of the layer the history gets re-written as if you had been listening on the right side.

More importantly though, it is important to distinguish between a transient caused by a door opening and that of an actual weapon launch. I can't count how many times I've seen a transient at the narrowband screen when the sub I was watching fired a weapon. But just opened a door? Probably never.

A long time ago, back in the SC days, Ramius (IIRC) addressed this question and posted some screenshots. His broadband history had recorded a transient caused by a door opening, perhaps even the tube being flooded. But, the screenshots were also taken from extremely close range, close enough that the target sub had been leaving a nice bright streak on the broadband. And even at that incredibly close range, the transient was still barely visible. Ramius's screenshots demonstrated that the torpedo tube door transient is real, but also implied that the conditions under which it could be observed are so unlikely that the transient is of no practical value. To date, there has not been any information that has come out to contradict that implication that I'm aware of.

When I first received the TIW, I was merely looking as I didn't know what to expect and got scarred that I had someone under the layer like I was. That's why I went above the layer because I went thru a few TIW's behind me before I went above. All I was thinking was "how the heck did they find me while the SSP showed that there was a steep gradient?

As for the actual transient...I appologize for not clarifying that it was the launch of the SS-N-15's and NOT the actual tubes opening.