Tony and I were discussing this issue on IRC and it seems we may have some wiggle room in the code.

 

Basically, we could probably create a rule in the code to deal with increased acoustic signatures when ships receive cumulative damage.

 

The easiest way to implement such a rule would be to effect an increase in BSL values for every increase in value of the DP damage.

 

For example, +2 BSL points for every 10 percent increase in damage.

 

There might also be a different rule for submarines than for ships.

 

This post is intended to provoke discussion on the topic, so please let us know what you think.

Basically, we could probably create a rule in the code to deal with increased acoustic signatures when ships receive cumulative damage.

 

The easiest way to implement such a rule would be to effect an increase in BSL values for every increase in value of the DP damage.

 

For example, +2 BSL points for every 10 percent increase in damage.

So in total there will be +20 BSL when the ship/sub sink. I have no idea how realistic the linear aproach is and I don't have HC right in front of my.

I would rather propose to create one relation (formula), which use the native BSL (smaller ships will have a smaller BSL delta), the percentage of damage, the current ship/sub speed and the current number of actions (sub with more actions will generate more noise?).

 

 

There might also be a different rule for submarines than for ships.

From my point of view there shall be one rule, which is modified with by factor.

 

 

Before to do this modifications, I rather propose to make active sonar detectable and the usage of sonar controllable in formation patrol.

So in total there will be +20 BSL when the ship/sub sink. I have no idea how realistic the linear aproach is and I don't have HC right in front of my. I would rather propose to create one relation (formula), which use the native BSL (smaller ships will have a smaller BSL delta), the percentage of damage, the current ship/sub speed and the current number of actions (sub with more actions will generate more noise?).

 

More noise is already generated with speed.

 

From my point of view there shall be one rule, which is modified with by factor.

 

I'm thinking two rules (one for ships, one for subs) might be better, because:

(1) Damage to submarines invariably affects their acoustic signature

(2) Topside (superstructure) damage (e.g. busted air search radar) might have zero affect on surface ship acoustic signature.

 

Before to do this modifications, I rather propose to make active sonar detectable and the usage of sonar controllable in formation patrol.

 

Tony and I broached the subject a bit last night, and it would take a lot more work to implement code that would, for example, make active sonobuoys detectable.

I'm somewhere between you two gentlemen. I don't see any harm in treating submarines differently than surface craft and find Brad's argument there very convincing (about above waterline damage not materially harming the passive sonar noise level).

 

I also think the equations to determine the increase in noise might be somewhat related to displacement (a field handily enough available to us). Or maybe noice increases by 2 points per 10% damage until 50% damage, and 1 point per 10% damage thereafter (on the premise that once it is damaged to 50%, it isn't going to get much noisier).

I didn't find any applicable rules in H3 paper but there is one in H4.1 paper.

 

Rule 7.2.5 Damage to Stealthy Ships

blah blah blah

If a ship or submarine sustains 10% damage or more from an underwater attach, treat them as a Noisy target for sonar detection (equivalent to a BSL of 48). Vessel also loses benefit of anechoic coating, if carried.

Okay, 24 more hours to make your case. Brad and I discussed on IRC again just now and are both satisfied that the approach below isn't outlandish.

 

The implementation of choice at present is...

 

Noise increases by 2 points per 10% damage until 50% damage, and 1 point per 10% damage thereafter (on the premise that once it is damaged to 50%, it isn't going to get much noisier).

Implemented in 2008.028

 

Notes:

0 DP damage means no noise added due to damage

1 DP damage in a 1000DP ship means 10% worth of damage for purposes of noise level

101 DP damage in a 1000DP ship means 20% worth of damage for purposes of noise level

 

So it is a pessimistic view, as soon as you cross one threshold you are into the next category, no rounding to the nearest 10% damage here, every rounding is up.

 

Shows up in the sonar log, for example...

Winharp32.exe -l sonar

 

You'll see lines like:

100000 search.c:3399 - RecalcSonarValues: Unit->kts=0, Cavitating=0, Interference=0, Name=Sayuri OrigBSL=46, SL=46

 

The comparison we're interested here is OrigBSL to SL (SL is the modified noise level after flags, damage, etc.)