Basic ASW Tactics

[Mr.Grinch]

Basic ASW Tactics


I'm embarrassed to say this but I've owned “Janes 688”, SubCommand and now Dangerous Waters and still havn't learned the basic tactics. I've been through all the tutorials and red the manual many, many times over. I've read the various “guides” floating around the net about thermal layers, propagation, convergence zones, etc but I still have no idea what to do with my submarine.


Could someone please explain to me, without going into the minutea of the sensor equipment the very basic steps they take when conducting an ASW search. Let's say for example you've just loaded up a Dangerous Water “Quick Mission”, you're in an improved Los Angeles class and there's empty ocean all around you...what do you do?


Assuming auto-crew for everything, (I turn it on and off as needed) Do you sit at the computer and wait for a sound contacts, do you spin and check your baffles?...how do you start your search?


Now you've got a sound contact, let's say you're picking up the lower frequencies from you TA, now what?...do you turn towards it and try to get closer so your hull/sphere array can pick him up?


I'm lost on the very basic tactics of these games, could anyone please shed some light? :damn:



Thanks,
Matt

[Bellman]

Well minutia is really what its all about. But focusing on several particular clues and eliminating the dross in an orderley process gets results.

I have 20 minutes so dont propose attempting a summary. Please get my SVAK from SubGuru which is a basic guide to manual sonar and covers the issues you raise. Work through the scenario and accompanying notes.(Visual aids not imperative) Then read TimmyG00s excellent guide, use the monitor settings pdf attached to the package and pay particular attention to his very good TMA notes.

Points to watch with 'Quick Missions'. 1. The aggressiveness of AI subs is greater and more realistic under LwAmi. 2. The number of AI subs increases with difficulty setting (obviously) but this can mean at the highest difficulty setting that you can be faced with up to two subs close-in with high rates of bearing change.

It is not always obvious but if you were tasked with finding a couple of Gibbons in a jungle I think you would prepare yourself by knowing what they sound like and if you had listening equpment showing the frequency distribution of the sounds of their calls you would quickly eliminate sounds not conforming to those patterns. Similarly you would attempt to get a cross bearing from two pieces of equipment.

Then you have to turn your sound recording equipment for best reception and to avoid baffles remembering to cover the previously baffled zones.

Just a quick potted simplistic answer I know, with the time I have, but I hope the reading references may help you further.

[Molon Labe]

I'm assuming you're driving a sub since you're talking about baffles. The basic principle at work here is that you want to cover as much area as quickly as possible without being counterdetected. Covering the area will require you to (1) shut off your damn autocrew and scan the NB sonar yourself, as you can detect a contact at a much greater range than the AC can, (2) make zigzags of at least 60 degrees repeatedly to move the baffled area around so you don't stay blind in any one direction, and (3) maintain speed just under washout (usually around 15 knots for US boats, depending on array and game version). Preventing counter detection, however, may require you to slow down significantly, depending on your opposition and game version. There is no hard and fast rule here, but factors to consider include: the amount of area you need to cover and the amount of time you have to do it in, the likely speed of your enemy (transiting, patrolling), game version (LW/AMI has a steeper NL/speed curve), class of sub (Victors will not be able to counterdetect you first even if they're at 0 knots and you're at 15; an Akula II is another story altogether), and the terrain and acoustic conditions (which affect how much area you'll actually be covering).

Hope that helps a bit.

[SeaQueen]

Could someone please explain to me, without going into the minutea of the sensor equipment the very basic steps they take when conducting an ASW search. Let's say for example you've just loaded up a Dangerous Water “Quick Mission”, you're in an improved Los Angeles class and there's empty ocean all around you...what do you do?

Assuming auto-crew for everything, (I turn it on and off as needed) Do you sit at the computer and wait for a sound contacts, do you spin and check your baffles?...how do you start your search?


Hehe, search tactics... you asked for it.

It depends on which type of quick mission you're performing. Is it the "area search" or is the "barrier search." If it's the "area search" then you want to plot a course through the area such that the area covered by your primary search sensor (usually your towed array) is equal to the size of the area. Usually you can do this by driving a ladder pattern. The spacing of the various waypoints depends on how far you think you can see. You can guestimate it from experience or you can do what I do, and use the mission editor. If you look in missions I design, I actually try to include that information as part of the briefing.

It doesn't really matter much what you do when you're in the box, statistically, though, because complicating factors such as target motion, maneuvering for TMA, flight ops, and unmasking weapons, means that you the area covered will almost always overlap itself a little bit no matter how carefully you plan the search. That has the effect of making almost every search equivilent to random searching. The formula for the cumulative probability of detection as a function of time is given by the Koopman random search equation.

Pd = 1-exp(-2R v t / A)

where R is the sensor range, v is your speed, t is time, and A is the size of the area you are searching. It's just the exponential distribution. You can find detailed derivations of it in Wagner's Naval Operations Analysis, or Koopman's Search and Screening. You might also be able to find it in SAR manuals. Search tactics for ASW and search tactics for search and rescue are basically the same ideas. You want to find something where you have only a rough idea of it's location as efficiently as possible. From that you should be able to make a pretty good estimate of how long it'll take you to find him, on average.

For the case of the barrier quick mission, you just need to drive back and fourth between the two waypoints. The probability of you succeeding in detecting a target depends on your speed, your sensor range, the length of the barrier and the target's speed. In the literature I just mentioned, they give formulas for the Pd of barriers as well. By making assumptions about the target's speed and your sensor range, you can often optimize your speed to maximize your probablity of detection, given the constraint of wanting to minimize your noise level.

Checking your baffles isn't necessarily the first thing you do, but it can't hurt. I actually have a random number generator in an Excel spreadsheet, to generate things like random times and bearings, so that I don't get too predictable. Some people do it regularly. One of the good things about your towed array, though, is that it gives you pretty good coverage of every place but the endfire forward. The baffles clearing thing is mostly an issue with submarines that lack a towed array.


Now you've got a sound contact, let's say you're picking up the lower frequencies from you TA, now what?...do you turn towards it and try to get closer so your hull/sphere array can pick him up?


That's one possible answer. The first thing you need to do if it's a TAPNB contact is figure out it's bearing. You do that by turning and waiting for the towed array to stabilize again. Notice how the target's relative bearing changes as it stabilizes. That should allow you to deduce the direction of the target.

Next, I'd start trying to figure out how far away he is in a vague sense. Not so much his exact range, but whether he's "near" or "far." If it's a low bearing rate target, then there's two possiblities, he's either on a collision course with me or he's a long way away. If I turn AWAY from him (don't turn towards him because if he's close you might bang into him), and the bearing rate rapidly increases after the towed array stabilizes, then he was on a collision course and may have even avoided hitting him. I had that happen once, and promised myself to never do it again. It was a sad. If the bearing rate stays relatively unchanged, then he's far away.

Next I'd figure out his direction of relative motion (DRM). This is just highschool geometry.

NOW I'm ready to plan my approach...

Somewhere in the process of approaching my target, I end up widdling down the area of uncertainty surrounding the contact to something I think is acceptable, then shooting at him.

Hopefully he doesn't get a sniff of me or my torpedoes, and counterfire at me so I can sneak away without having to evade anything.

Edit:

Found a paper on search tactics discussing computer modeling and historical results using U-boats in the Bay of Biscay. It's air searchers using the naked eye, instead of a sensor, but much of the essentials remain the same and there's a sample of search patterns in it.

http://www.informs-cs.org/wsc03papers/121.pdf#search=%22Koopman%20random%20search%22

[Kapitan]

Some tactics i use:

Crazy ivan, this tactic is dangerous dont attempt it unless you do have a fair idea of where the enamy submarine is as chances are you might bump him!

Stay on steady course and speed, then at random speed up full rudder either way do a 180 degree turn (by this time you want 24 knots or more) then slow down, if anything is in the way your going to sink it. (not a recmmended tactic but one for fun)

Get a faint contact on towed array mark both it and its ghost, turn 45 degrees wait for the array to straighten out again and thats your true contact, the ghost contact will move.

Check layer (i call it chekker):

Move to where your submarine is above the layer by about 25 to 40 meters then slow to 2 or 3 knots let the towed array hang down and you might pick up a contact.

Other than that im not prepared to revel any other tactics i use sorry!

[Bellman]

The topic is 'Basic ASW Tactics'

There is some reticence about revealing 'own techniques' both for competitive reasons and lets face it the understandable desire
of any current or future contributor to avoid the prospect of long possible nit-picking debates about some techniques.
Avoiding engagement is a legitimate technique. ;)

Elsewhere Linton posed the question - ''What did Sonalysts leave out of the manual? Is it time for a basic/advanced technique manual
to be produced? '' This is a fundamental question vital to those who do not wish to enlist in Fleets. If potential contributors sit on their hands
the state of gameplay for this sector will enter a 'persistent vegitative state' !
Can we concentrate on the 'Basic' element raised by both posters ? Focusing on ASW, I would just like to throw into the pot some further considerations.

'Quick Missions' would not be my first choice with which to practise ASW given unrealistic unit mixes and separations.
The pressure is analagous to coming on watch in ATC Approach after a power failure ! Such missions are fine for stress testing your manual sonar techniques.

There are many excellent missions out there, both the above have some fine examples. In addition you may find some MP scenarios
designed around a two hour exposition provide just the right ballance for SP practice.
Mr G has tasked us with avoiding minutia but in so doing he misses the point. The allure, or hook if you prefer, of ASW is precisely that we
are searching for small clues from which to build a hypothesis about the reality of the world around us. The ultimate Detection challenge ?

Some 'Basic' ASW headings:-
1) Know the mission designer - Do they leave footprints in the form of red herrings and teasers. Fishing boats, Trafalgars around red AI etc..
2) Know your opponent (MP) Is he prone to take a sneak radar scan before WF ?
How does he prefer to 'setup' with his team-mate ? Modus operandi etc...
3) Study and have to hand the sonar profiles of your target/s and those units both military and civilian
with similar profiles.(lower freq. profs.generaly)
4) Prepare Check Lists egs 'Setup Procedure' TimmyG00 has an example.
5) Study the Topography - utilise delays in physical operations to familiarise yourself in Navs modes with any features which will assist you
or your opponent. Mark relevant depth changes, note seamounts, observe choke points and potential 'trap'locations etc....
6) Clear your baffles and dont be afraid to use a visual aid for stress moments when you need to be 100% sure you have cleared them.
I use a a CD cutout as shown in SVAK - it has saved my bacon many a time. (still does !)
7) Follow a manual sonar procedure making turns appropriate to the LwAmi or vanila SA baffle.

Now, as requested, we have to hold our horses as we are about to enter the realm of minutia !. Sadly that is where the real fun starts ! :yep:

[Bellman]

Just an afterthought which more properly belongs to the topic Linton raised.

The avowed purpose of all who contributed to OneShots original CADC was to help and assist
newcommers to DW in acquiring basic skills and enjoying the full potential of the game. Progress seems
to have stalled.

I am sure the reticence, mentioned above, is a prime inhibiter. Not everyone likes a public Wicky
for many reasons. The preferred approach may be to run any paper in front of respected senior
players prior to publishing. I approached Molon Labe, who kindly cast an eye over
SVAK before it went public and I have acknowledged this in the documentation.

Another process would be to establish a 'Steering Committee' of 'seniors' to approve papers on
techniques prior to publication. The sole objective would be to agree and approve standards.
Lets face it currently a newcommer is either faced with a complete void or a choice of good,
bad or indifferent advice. Catch 22 ? You need to be expert to distinguish but you wont
become expert until you can ?

[SeaQueen]

'Quick Missions' would not be my first choice with which to practise ASW given unrealistic unit mixes and separations.


There's definitely something to be said for that. Actually, I think the biggest problem with the ASW quick missions is that there's usually too many targets. I think Jamie said something about the possibility of editing it though. It might be interesting to look into that...

[Kapitan]

Create your own ASW scenarios 1v1 then 2v1 then so on and make it more complex as you go along so you might have 3 own side sub 12 other side subs 18 own side surface with 12 air and 36 other side with 24 air plus 19 nutrels including 3 bio's.

But learn sonar first!

[Madman_GNSF]

Point your sub in the area where you might think the enemy subs are - go to your active sonar and send one loud active ping. Presto your search is over! lol

hehehe jk :-)

[Kapitan]

wanna play i can assure you that if you ping there will be 14 torpedo's on thier way before you can say davy jones. :D

[sonar732]

Point your sub in the area where you might think the enemy subs are - go to your active sonar and send one loud active ping. Presto your search is over! lol

hehehe jk :-)

:rotfl::rotfl::rotfl::rotfl:


That was plain mean!

[Captain Sub]

You should always turn towards your target, otherwise your asw/stallion will have to adjust their cust themselves, that means that they get distracted from the curse slightly but heavily on distance.

[Sonoboy]

I remember the first MP games I played in DW. It went something like this:

Send out active ping and mark all contacts.

Emergency blow.

Raise the radio mast.

Promote contacts.

All friendly units prosecute contacts and sink them very quickly. Game over.:rotfl:

This worked very well with games that had no neutrals and no bios.
But it did kill the game pretty much.

[Dr.Sid]

Mine was:

Uh .. so lets check what we have here .. hmm .. nothing .. what ! TIW ? I don't see anything ! It must be somewhere distant .. not my problem .. Kaboom ! Captain ! We're loosing depth control ! :rotfl:

[Madman_GNSF]

For the record - I use active sonar ALL THE TIME against human controlled subs - and my world never comes crashing down.

People are to scared to use it...All it gives away is your bearing - the same info you get from sonar (just doesn't continue after pinging has stopped). Best of all - if you get a return - you get the enemies exact location - in exchange for only your bearing.

Although I only use it against submarines that are human controlled :-)

[SeaQueen]

Using active sonar makes sense especially if your sonar range is in all likelyhood less than your opponent's. The reason is that the excess range gives him the time to develop a solution while you haven't detected him. If he closes, you won't have the time to develop an equivilent solution so it's best to just ping.

For the record - I use active sonar ALL THE TIME against human controlled subs - and my world never comes crashing down.

People are to scared to use it...All it gives away is your bearing - the same info you get from sonar (just doesn't continue after pinging has stopped). Best of all - if you get a return - you get the enemies exact location - in exchange for only your bearing.

Although I only use it against submarines that are human controlled :-)

[Molon Labe]

I'll use a sub's active sonar in two situations. First, if I'm hunting a Kilo--active detection range is greater than passive against a Kilo, and it is often greater than the maximum range of the Klub-ASW's. Yeah, I know, not very sporting, but it's something I started doing to counter the Kilo BB cheat.) The other situation is when I know my opponent has already detected me and probably has a solution. In that situation, a ping from me only evens the score.

In my experience, though, many people who use active sonar tend to use it too often. There have been many cases where I didn't have a good solution on my opponent but it firmed up real quick when they started pinging away.

[kage]

Search tactics for ASW and search tactics for search and rescue are basically the same ideas.

Except that if the target should detect you first, he may maneuver...

This makes some search tactics less useful than others. A ladder or barrier search, for example, means that he can wait, and then run past on one side as you're pretty much on the other side of the ladder.

[SeaQueen]

Except that if the target should detect you first, he may maneuver...

This makes some search tactics less useful than others. A ladder or barrier search, for example, means that he can wait, and then run past on one side as you're pretty much on the other side of the ladder.

That's true. One of the shortcommings of the mathematical formulation of search theory is that it assumes that you're using passive sensors and the target won't do strange things to evade detection. Those assumptions are pretty good so long as your sensor range is longer than your target's, but if it's shorter than your target's or even just comparable to your target's, the possiblity of the target adopting specific evasive tactics becomes possible.

That's why it's good to have a sensor advantage.

[LoBlo]

It depends on which type of quick mission you're performing. Is it the "area search" or is the "barrier search." If it's the "area search" then you want to plot a course through the area such that the area covered by your primary search sensor (usually your towed array) is equal to the size of the area. Usually you can do this by driving a ladder pattern. The spacing of the various waypoints depends on how far you think you can see. You can guestimate it from experience or you can do what I do, and use the mission editor. If you look in missions I design, I actually try to include that information as part of the briefing.

It doesn't really matter much what you do when you're in the box, statistically, though, because complicating factors such as target motion, maneuvering for TMA, flight ops, and unmasking weapons, means that you the area covered will almost always overlap itself a little bit no matter how carefully you plan the search. That has the effect of making almost every search equivilent to random searching. The formula for the cumulative probability of detection as a function of time is given by the Koopman random search equation.

Pd = 1-exp(-2R v t / A)

where R is the sensor range, v is your speed, t is time, and A is the size of the area you are searching. It's just the exponential distribution. You can find detailed derivations of it in Wagner's Naval Operations Analysis, or Koopman's Search and Screening. You might also be able to find it in SAR manuals. Search tactics for ASW and search tactics for search and rescue are basically the same ideas. You want to find something where you have only a rough idea of it's location as efficiently as possible. From that you should be able to make a pretty good estimate of how long it'll take you to find him, on average.

For the case of the barrier quick mission, you just need to drive back and fourth between the two waypoints. The probability of you succeeding in detecting a target depends on your speed, your sensor range, the length of the barrier and the target's speed. In the literature I just mentioned, they give formulas for the Pd of barriers as well. By making assumptions about the target's speed and your sensor range, you can often optimize your speed to maximize your probablity of detection, given the constraint of wanting to minimize your noise level.

Checking your baffles isn't necessarily the first thing you do, but it can't hurt. I actually have a random number generator in an Excel spreadsheet, to generate things like random times and bearings, so that I don't get too predictable. Some people do it regularly. One of the good things about your towed array, though, is that it gives you pretty good coverage of every place but the endfire forward. The baffles clearing thing is mostly an issue with submarines that lack a towed array.

Nice! Thanks:up: