View Full Version : Noob Situational Question
05-11-2009, 11:45 PM
I now recently aquired SH3 and downloaded GWX3 and Commander 2.7. I am on my first patrol, 100% realism.
My ship is traveling directly West. The time is 20:35, and I am traelling at 7 knots 10 meters submerged.
My Sonar Officer has just informed me of a sound contact, "Merchant Moing Slow! Closing! Bearing 47! Long Range!
I go to my navigation map, but I do not see the ship marked on the map. I do see a black line pointing toward the general direction of the ship's bearing. I do not know what to do next? My periscope is up, and either it is too dark to see the ship, or it is jut too far away from my ship.
How do I find out how far it is and where it is located? Does closing mean it is moving toward me?
How do I know what angle to take to intersect the ship? (Thanks Wazoo)
Is this really 100% realism if a line is pointing to the ship on my Naigation screen?
If I saw the marker for the ship on my map, I would know what to do next, but I am at a lost now. I am brand new to the simulation genre, but I think I am becoming overwhelmed by it. Thank you for your time.
05-12-2009, 12:10 AM
maybe its best to start as a beginner,
easy mode,like all games,like say? riding a bicycle,
Learning the basics before jumping to 100% realism,
is Subsimulation at its best,
Learn the basics,
Happy Hunting :salute:
Pepe le Moko
05-12-2009, 12:16 AM
Having both no external views and no map updates together makes the game really challenging. Maybe you should lower the realism settings a bit at first and go from there.
The black line you see is the direction of the hydrophone contact. The reason you can't see the is because it is too far away. Sound travels more easily underwater, so the hydrophone can pick up contacts outside of visual range. It's also worth mentioning that if you turn all the realism options, you won't have those lines, so you must have missed one.
Closing means it is moving toward you.
To intercept it, I'm not sure what you do. I use GWX, and I think it is impossible to plot a contact's course using only the hydrophone with this mod. At least, not as accurately as you can in the base game, where you can figure out the ship's speed by listening to it's propeller RPM. "Moving slow" generally means about 6kts, so just plot a line from your submarine in the direction of the contact, wait five minutes, and plot another line. Then wait another five minutes, and plot another line Assuming the ship moved at a rate of 6kts for a knopwn amount of time, you can calculate the distance it travelled. Then you can "draw triangles" to determine its approximate heading based on the bearing lines you drew and the fact that you know how far it went in a given amount of time (you have all three lengths, you just have to figure out how they connect up.)
I'm tired right now, and I know my explanation sucks. If someone else doesn't chime in, I will try to draw a picture tomorow to explain.
I hope I helped.
05-12-2009, 12:35 AM
Welcome aboard! :yeah:
05-12-2009, 05:31 AM
You have a contact but you can't see it through the periscop, it's not a big problem.
The range for hydrophon is around 25-30km ( 50km for a convoy) , for the periscop it's less than 10km. Go to the hydrophon post and listen to it: if the sound is weak it means your contact is quite far so you can estimate the distance around 22-25km, it's not very accurate but you can now report its supposed position on the map ( you have a bearing and a distance).
Now you have to make a visual contact. What i do is running at the surface at full speed to the contact ( in your example you have a contact to your 047 so i turn 47° to the right) FOR 10min then periscop depth and listen to the hydrophon. Normally it should not be in your 0 anymore but in your 10 or 350 (and the sound is stronger) so you now have the target's global direction. What you have to do now is surface the boat and anticipate: It's important to have a visual contact but if you can be ahead of your target the attack will be easier. So if the contact is in your 350 set your uboat to 330, surface and run at full speed. If visual contact is not made just go to periscop depth and listen to the hydrophon again ( if you do this correctly you can't lose the hydrophon contact) Soon you will have a visual contact. Determinate the ship's course now is easy but i need some screenshots to explain it.
Keep on practice and if you need something you will find everything you want here as you may have noticed!
This is a basic approach for a single merchant with no escort, good weather, don't try this in 44' with a hunter-killer group in bad weather :arrgh!:
05-12-2009, 09:58 AM
I feel too tired right now to expand on it, but here is a tool that can help determine the AOB (and from that course) of a contact by bearings only:
You can use it in conjunction with the methods described in here, to get speed and distance:
There is also a thread in the SH4 section someone recently stated that figured out the same procedure:
This a more systematic approach, and takes some time to work out. It involves no guess work. The solutions provided here by the others also work (probably with quicker visual contact) but with more trial-and-error.
As a very simple solution you could do, just to get close, is to just move perpendicular to the direction of the target (put the sound on your 90 or 270 hydrophone), in the direction the bearing drifts (left or right). Since this is reported as a slow contact (less than 8 knots) you can likely manage to do this submerged. If it was faster (medium or fast merchant) you would probably have to surface and move fast. If you keep adjusting your course a bit towards him until this drift stops (sound stays on the same bearing for a long time) you are infact intercepting him (or aka collision course, so be carefull in the end). So you close the distance as fast as possible and maintain you position forward of him. If he was moving away this would have worked quite different. Meaning you can still adjust your course (almost in the direction of the target) until the bearing stops drifting, but you need to be alot quicker then him. Most likely needing to surface and flank, while regularly diving again to know how the bearing drifts. Also keep in mind then that the drift depends on the compass direction towards him, but the hydrophone direction changes as you turn the boat. The sum of your course and hydrophone bearing must stay constant.
If you just set your course to get the sound on the 90/270 direction only initially (so no course adjustments afterwards) then you actually move more forward of him,while he only does the work in closing the distance. It buys more time and distance ahead of him. The tough part is figuring out when you are on his course line and must stop to prepare for shooting. This would have to rely on making visual contact before then.
05-12-2009, 10:00 AM
This was extremely helpful everyone. I can't wait to get back and try it out for real. Thank You.
05-12-2009, 11:24 AM
Welcome aboard cueball7000 http://www.psionguild.org/forums/images/smilies/wolfsmilies/pirate.gif
05-12-2009, 11:28 AM
Welcome aboard CB7000,going in at the deep end eh!:hmmm: Best of luck to you:03:Happy hunting :yeah:
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