GWX 3.0 - Ship Recognition Manual - Double entries?

[mark2398]

I noticed by skimming through the ship recognition manual several Merchants, which entries that are very similar (and identical from the picture):

Tug Boat:
Mast: 21,4m vs. 21,5m
Draft: 4,6m vs. 4,5m

Large Tanker:
Mast: 28,0m vs. 26,8m
Draft: 11,7m vs. 11,9m

Is that intentional? How would I differentiate them in bad weather through the UZO? :06:

Mark

[jlry]

I just noticed this problem as well. I didn't want to make a new post, so sorry for necro'ing this thread. I was unable to find any other threads that spoke of this problem. Someone told me for multiple entries one was the lit version and one was unlit. Any help/info is appreciated. Thanks for your time!

[scott_c2911]

I dont think its a problem. The ships have slightly different size parameters if you compare the two ships data. How to tell the difference I couldnt tell you though.

[Fourfifties]

You'll need to rely on your weapon officer to ID the right one on these cases.

[Sailor Steve]

Unfortunately people who play at 100% don't have that option. It's still a lot better than real life, where ID books had photographs of hundreds of individual ships, but often the information accompanying them was wrong. The captain's best asset was his experience. The truly great skippers could look at a ship and guesstimate everything at a glance, and like as not be close enough to get the job done.

[maillemaker]

The truly great skippers could look at a ship and guesstimate everything at a glance, and like as not be close enough to get the job done.

I must be closing in on "truly great". :D

I'm running 100% realism. There are so many entries in the ship manual that I almost never bother trying to thumb through and find them. I only really use them for escorts to determine their draft so that I can slide a mag torpedo under them when they are chasing me. But there are a lot less escorts in the warship book.

But for merchants, I just guess the speed, usually 5-7 knots, and get to within 500 meters and let them have it.

Steve

[Zosimus]

When you look at the ship through the periscope or UZI it will tell you generally what it is that you're looking at. So far I've only seen Warship, Merchant, or Coastal Vessel. I presume that the tugboat will show as a coastal vessel whereas the other will show as a merchant.

As for 100% realism, I play with the Realistic setting, which gives me 100% but still includes automatic map updates. If I didn't have that, I would simply shoot the weaponsmaster and dump him overboard. He must be good for something, right? Anyway if you really zoom in on the ship it will give you a kind of a size estimate based on the marker you see. Sometimes you zoom in and think, "That's hella small..." and when you get close enough to see it through the finder, it's invariably some kind of a coastal vessel like a sailboat or a trawler.

[jlry]

I must be closing in on "truly great". :D

I'm running 100% realism. There are so many entries in the ship manual that I almost never bother trying to thumb through and find them. I only really use them for escorts to determine their draft so that I can slide a mag torpedo under them when they are chasing me. But there are a lot less escorts in the warship book.

But for merchants, I just guess the speed, usually 5-7 knots, and get to within 500 meters and let them have it.

Steve

500 meters seems awful close. I would never get that close when engaging anything in a convoy. I guess a single merchant, this method would suffice.

When you look at the ship through the periscope or UZI it will tell you generally what it is that you're looking at. So far I've only seen Warship, Merchant, or Coastal Vessel. I presume that the tugboat will show as a coastal vessel whereas the other will show as a merchant.

As for 100% realism, I play with the Realistic setting, which gives me 100% but still includes automatic map updates. If I didn't have that, I would simply shoot the weaponsmaster and dump him overboard. He must be good for something, right? Anyway if you really zoom in on the ship it will give you a kind of a size estimate based on the marker you see. Sometimes you zoom in and think, "That's hella small..." and when you get close enough to see it through the finder, it's invariably some kind of a coastal vessel like a sailboat or a trawler.

Sorry I don't follow you? The issue is there is multiple copies of the same exact ship. They differ only in stats, sometimes mast height, or draft. The game doesn't render these ships differently. There aren't any physical difference. I don't want to rely on my Weapons Officer, but I guess I'll just have margin of error when engaging these ships. I doubt they had very accurate information in the real manuals anyway, at least not for every ship.

Anyway, thanks for the replies.

[Zosimus]

Maybe I don't get it. The first poster that started the thread was talking about the difference between a Tug Boat and a Tanker. I assume that if looked through the finder the Tug Boat will say "Coastal Vessel" whereas the Tanker will say "Tanker."

Second, why are you trying to ID the boats anyway? If they belong to a hostile nation, I just sink them straight up. Coastal Vessels I normally just take out with the deck gun. On merchants, I use a torpedo and then follow up with deck gun. The one tanker I saw I salvoed. Warships, I avoid like the plague. I assume destroyers can be killed with a single torpedo, but I never see them on a steady heading long enough to get their speed. Larger warships must need multiple torpedoes. I'm certanly not going to hit them with one and then try to surface to finish them off with the deck gun. :nope:

[jlry]

Maybe I don't get it. The first poster that started the thread was talking about the difference between a Tug Boat and a Tanker. I assume that if looked through the finder the Tug Boat will say "Coastal Vessel" whereas the Tanker will say "Tanker."

Second, why are you trying to ID the boats anyway? If they belong to a hostile nation, I just sink them straight up. Coastal Vessels I normally just take out with the deck gun. On merchants, I use a torpedo and then follow up with deck gun. The one tanker I saw I salvoed. Warships, I avoid like the plague. I assume destroyers can be killed with a single torpedo, but I never see them on a steady heading long enough to get their speed. Larger warships must need multiple torpedoes. I'm certanly not going to hit them with one and then try to surface to finish them off with the deck gun. :nope:

The first post is comparing two tug boats and two large tankers but not comparing against their types, i.e. tug vs tanker. He is comparing their mast and draft. See the vs in-between stats.


Tug Boat:
Mast: 21,4m vs. 21,5m
Draft: 4,6m vs. 4,5m


I'm going to assume you aren't playing on a high realism setting. Without ID ranging is difficult for myself.

I figured out the issue though, and will release a small patch to clear up duplicate ships in SRM.

[Zosimus]

All right, let's work this through and see where the communication is breaking down. Here's my procedure:

Normally my first step is to get a hydrophone contact. I generally hunt submerged, and I have found that I can get hydrophone contacts from much farther than I can see visually.

As soon as I get a hydrophone contact, I hit ESC twice to reduce my time compression to 1. I draw a small circle at the far edge of the hydrophone contact and then measure the bearing to the target using the protractor. I turn my heading to proceed directly for the sound contact and proceed submerged at flank speed. I up the time compression to 64 and wait for recontact. Depending on various factors that may take up to 15 minutes of game time.

When I get recontact I again hit ESC twice and then draw a line through the middle of my original circle to the end of the new hydrophone contact. This gives me the target's heading to within a few degrees. I surface and proceed towards the target based on its speed. If it's slow I assume it is traveling at 7 knots–the fastest slow speed. If it's medium, I assume it's traveling at 11 knots. I calculate my intercept course using the procedure at http://www.subsim.com/radioroom/showthread.php?t=88961

I proceed along the intercept course at standard if the ship is slow or at full speed if the ship is medium. The only time I encountered a fast target I couldn't catch it even at flank speed so now I give up on fast targets unless they're approaching. I usually arrive at the intercept point ahead of the ship because I err on the high side of the ship's speed. If the ship exactly on time then I know my guess of the ship's speed was on. If the ship arrives later, I know the ship is going more slowly than the guessed speed. Once I get the ship spotted notification, I ask the watchman for the range and write it down. If the ship is closing I call all stop, otherwise I reduce speed and try to parallel its course.

The ship normally shows as a small block on my screen. I center this block and zoom in until I get a fuzzy blob that kind of tells me something about the ship. Certain shapes make me think it's a coastal vessel. If I think so, I will try to get a visual on the target using the UZI. If it is a coastal vessel I close to deck gun range and engage the target, weather permitting. If the weather does not permit, I abandon the target and resume my previous course or search pattern.

Assuming it is some kind of a cargo or merchant ship, I get the mark tool and wait until it moves a bit. Then I slap an X down the ship's stern. I count "thousand-one-thousand-two-thousand-three" as I hit O and get the mouse near the stopwatch. I start it at the end of the thousand-three count. I believe this is pretty close to 3 seconds. I then time the target for 6 minutes 26 seconds. As you probably know, the target should cover 100m times its speed in knots in 3 minutes 14.4 seconds so I do double that: 6 minutes 28.8 seconds. I multiply the number I get by 5, so if I measure 1.4 on the compass, I calculate the target's speed as 7 knots. I write down the target's speed and then calculate its course from the first mark through the bow of the ship. I have never had this bearing be off by more than a degree.

If the target is closing, I try to take the shot immediately. I turn perpendicular, submerge, and enter the information into the TDC. I choose 2 meters depth, impact torpedoes, AOB 90, 0 bearing, and enter the target's speed. I try to get within 2000 meters of the target before firing. I am very aggressive with underwater speed to reach a good range. I won't hesitate to go flank speed underwater. I draw a 2.0 circle from the drawn intersection point between my course and that of the target. Once I pass the 2.0 circle I either call all stop and drift part of the rest of the way, or I call back slow if the target is close to the optimum firing point and call all stop once my speed drops to 0 knots.

I write down the gyroangle and draw a line from my new position to the perfect firing point on the map. I measure the distance to target down the gyroangle line, not the torpedo line. I use either the ruler or the compass tool to do so. I flood the torpedo tube, and then I turn my scope until the gyroangle reads zero and then ask the sonar guy for a report on the nearest sound contact. I do that every minute until the target is at or near the bearing I am looking at. Once it is, I go scope up, lock the scope, and fire. I don't wait for the "perfect" gyroangle. I prefer night shots and only abort the shooting procedure if the ship is lit. I don't look for a flag. I follow the torpedo progress on the F6 screen. When I see it is near the ship I go scope up and try to note where on the ship it impacts. Sometimes the ship notes my scope and zigs, but it's usually too late or the zig improves my shot.

If the ship is not closing I take another tack. I zoom out to where I no longer see the graph paper lines and draw the longest course I can for the ship from one side of the screen to the other. Then I calculate and draw a perpendicular line to that course. Ideally this line goes right through the ship. Next I use the compass tool to draw a circle large enough that the target should not be able to see me. I use the original range to target I got from the watchman and wrote down at the beginning. If I made visual contact at 4400 meters then I draw a circle the size of 5000 meters. I then plot my course to take me to the edge of that 5000 meter circle. If the target is quite close, I go slowly or submerge. If it is moving away, I usually proceed at full speed on the surface. Once I am beyond that 5000 meter circle (or whatever range) then I turn to parallel the ship's course and go to flank. If I can still see the ship I will make periodic course corrections to try to keep the ship's bearing at 90 or 270 once I have passed it. That will send me in slightly towards the line. If I have lost sight of the ship, I will just proceed parallel until I think I've passed it and then change course so that I intercept the very end of the drawn line. Once I'm close to the end of the line I submerge and go to one knot. I set up the shot the same as above.

Under no circumstances do I identify the ship. I don't know what I've sunk until after I've sunk it. It magically shows up on the captain's log with the exact time, type, and tonnage.

What's your procedure?

[Pisces]

All right, let's work this through and see where the communication is breaking down. Here's my procedure:
...

I ask the watchman for the range and write it down.
...
I get the mark tool and wait until it moves a bit. Then I slap an X down the ship's stern. There is your difference. You ask your crewman to come up with a range, ... based on what? Or rely on the all knowing GPS-accurate map-updates.

The other way is to relate size features to angles and thus range. That involves alot more.

[EDIT] Not saying any one method is better. Just different.

[Pioneer]

Reinstalling on a new PC.

[maillemaker]

The only reason I check the ID manual is to confirm target drafts so that I can slip magnetic torpedoes under their hull, particularly escorts.

If you don't have map updates on, the 3:15 rule is harder to use to obtain ship speed.

In which case if you really need to know the ship speed you will need the target length to use the Fixed Wire method of speed calculation.

I'm running 100% realism with map contacts off also. I usually estimate the speed unless it is a convoy radio contact where speed was provided.

Steve

[Zosimus]

There is your difference. You ask your crewman to come up with a range, ... based on what? Or rely on the all knowing GPS-accurate map-updates.

The other way is to relate size features to angles and thus range. That involves alot more.

[EDIT] Not saying any one method is better. Just different.

Well, I use the 100% realism feature provided with GWX. This provides map updates. Now I assume that what happens is the watchman on the deck calls down his observations to one of the three sailors I have working on the bridge, who relays them to the weaponsmaster, and he and I roughly set it up on the map we're looking at.

Now you may ask: How does the watchman know the range? Well, I assume that he stands at one end of the observation tower while someone else stands at the other end and look at the same thing. The difference in their bearings serves to triangulate.

But let's say, for the sake of argument, that you decided to nix all of that, and you refused to use the ranges provided by your hydrophone officer, too. You were determined to do things the unrealistically hard way. Fine. Use the four bearings method that was mentioned at http://www.subsim.com/radioroom/showpost.php?p=2212109&postcount=37

I'm sure you must have heard of it considering that the manual is up on YOUR website.

[maillemaker]

Well, I use the 100% realism feature provided with GWX. This provides map updates.

Bear in mind that there is "100% realism", and then there is "100% realism". :)

I, too, played at 100% realism with map updates on for a couple of years. Just in the last 3 careers have I switched to "true" 100% realism with all difficulty levels maxed including no map updates.

It's a totally different game when you have no map updates. The only stuff that shows up on the map is what you can draw on there yourself based on information your WO gives you if you are surfaced.

He will give you range and bearing, which you can plot. Of course, you have to be surfaced to do this, and the time delay and imprecision of making the plots will probably negate its usefulness for doing the 3:15 speed computation as is easy when map contacts are on.

Is "no map contacts" unrealistic? Perhaps. I find the most difficult part trying to estimate range based on a 2D display.

But it really does make an entirely different game experience. With map contacts on, I spent most of my attack game time at the map screen. Often I would raise the periscope but not even peek through it - just watch the ships magically appear on the map! :)

Shoot I got to where I could even pick off circling escorts from the F6 map screen by using the TDC dials to dial in lead and shoot entirely from the map.

With map contacts off, I find myself playing the game in a much more "real time observational mode", that is, watching targets from the bridge and from the periscope. The game also becomes much more cerebral in that you have to keep the spacial understanding of the battlefield in your head much more strongly than if you can constantly refer to a real-time God's-eye map.

In that sense, I think it's probably quite realistic in that it forces you to develop situational awareness in your mind just like a real uboat captain probably did.

In the end, you have to play it in the way that gives you the most enjoyment. I gave up on SH5 in the end because in spite of the graphics, the game play wasn't as fun as SH3 for me.

But, if you want to see the ultimate in difficulty, turn off those map updates. :)

Steve

[P_Funk]

I'll just leave this here.

Die Handelsflotten der Welt 1941 (http://www.uboatarchive.net/KTBNotesGroener.htm)

Suffice to say, ship identification was a much more laborious process than it is for the SH3 player. One thing to note is that the one man show that is SH3 is not realistic on its own. Even the guys who do things in the "proper" 100% realism way are not really being realistic because a real U-boat would have many individuals working towards the "problem" of attacking the enemy ship. So, someone might be looking through the identification book while someone else is plotting, while someone else is estimating range or AOB while the captain is conferring with the navigator about location and heading and whats nearby, if the ship is going to change course soon, while the watch will tell the captain if the ship starts to make any shifts, if its zigzagging, if its changing course, etc etc etc. At the attack the captain might not even do anything other than say "Number 1, hit that ship first, then that one, time attack for as near simultaneous explosions as possible".

The multi-tasking mania of SH3 realism is a fun challenge, but not necessarily realistic in any form, no matter your mods.

Realism won't be complete until we get a sim that'll give us coop crew multiplayer, like that Star Trek bridge simulator.

[Zosimus]

Well, I agree with most of the recent posters here. It is, after all, a game, and it will never be even close to 100 percent realism. If I were really a German U-boat commander during WW2 then picking up the correct ID manual would be a breeze because German would be my native tongue. Additionally, I probably wouldn't look through the book at all. After calling "Periscope depth" I would just hand the book to the Watch Officer as he hurried down the stairs and say, "You got a good look at it, didn't you? Pick it out of the book for me. Oh, by the way, what was the weather like?" He will definitely not say, "I'm sorry captain, you called periscope depth 10 seconds ago, so I have completely forgotten what the weather was like. If you need to know, we'll have to go up again and take another look."

In the game if you get a hydrophone contact at 0241, that's no problem because you're at the keys. In real life you are being awakened at that time in the middle of the night. You haven't been sleeping well since your quarters are, after all, right off the bridge. Additionally, you have spent the last week in the same clothes and been trying to wash yourself in salt water with that crummy soap that leaves a sticky film on you. On the other hand, you probably spent at least 6 weeks in training on how to be a good captain so if calculating intercept courses is part of your job, they've drilled it into your head so many times you can do it in your sleep.

There is simply no way to simulate even half of that, so I see no point in turning off map updates because, as far as I can tell, you have a navigator, weapons officer, and three sailors helping you with the map while the helmsman steers, the sonar guy listens, and the radio guy receives messages.

In conclusion, I have no problem with people playing the game however they choose. If you get more enjoyment out of trying to do the job of 6 people on your own, more power to you. Nevertheless, I stand by my original claim:

It's not necessary to ID the ships through the scope. Just use the four bearing method and you'll have the ships exact course, position, and speed. Then go set up your shot and remember, if the time compression freezes at an orange 32, then it's not a neutral ship so blow him out of the water.

[Zosimus]

No, this is another tick box above 100% realism. This is not GWX, but standard SH3



That is where the game lacks, you are on your own, where in real life, you would have help



I would read the GWX manual, it happens, as you identify the target and depending on the distance between water and mast height gives you range.



You are the captain, on your boat. Do as you want too. However the hydrophone guy could not say, bearing 325 at 14km.

I do agree that at times, you would have more help. But as captain you would be checking this information as well.

This is no way knocking your style of play. I had a couple of times with WE help on. But for immersion, I went the full hog. I always wondered if I got it right, 90 percent of the time I am.
Can I assume that you're referring to page D-6 in which it says: "The GWX team suggests [that] you pause the game when the horizon line is at the horizon, and then [adjust] the mast line at your leisure."

Gotta love that 100% realism. :yeah:

As for your claim that the hydrophone guy could not say "bearing 325 at 14km" yes, he very well could!!!!!!!! As you can read at http://www.cdvandt.org/GHG1996.pdf if using the Gruppenhorchgeräte, which is the very equipment my fine boat is equipped with, the signal input was accompanied by a potentiometer calibrated in ohms and a 270 degree scale. Upon detecting the ship my fine sonar guy can simply adjust the parallel potentiometer until the signal disappears and then announce an approximate range to target based on the ohm measurement at which the signal disappeared. :rock:

[P_Funk]

Coming back to discussing what real Kaleuns actually did, its clear from reading their KTBs that very often they didn't bother with exact identification* and instead relied on having a general estimate of what the ship was based on common dimensions.

I imagine, particularly as the war went on, that it would become easier far more often to guess at a ship's type based on the outline and the corresponding mast height and length. Mass production of common ship types would make pages like this more common as the years wore on I think:

http://www.uboatarchive.net/Groner408.jpg

I also imagine that as the war turned against Germany's favour that their intelligence gathering became less effective and so the identification books would be less comprehensive.

The perfect ident figures we have in SH3 creates an environment that I think would better represent a pre-war training environment where you're taught perfect methodologies based on unrealistically accurate variables without any respect for the practical realities of the war, similar to what informed pre-war American doctrine. I imagine per-war German doctrine would probably have been a bit more clever owing to how many experienced U-boat captains from WW1 were in charge.


* Often identification came only when recording an intercepted SSS/SOS where the ship self identified. Often I've read an estimated GRT being corrected no doubt based on the "accurate" figures that they must have looked up once they'd read the ship name off of the radio intercept. Estimates were often wildly inaccurate and so it both tells us that tonnage figures are always to be mistrusted (no surprise) but more imoprtantly that wildly incorrect estimations of the ship's dimensions didn't appear to hinder many kaleuns' success.

[/meandering babble]


Can I assume that you're referring to page D-6 in which it says: "The GWX team suggests [that] you pause the game when the horizon line is at the horizon, and then [adjust] the mast line at your leisure."

Gotta love that 100% realism. :yeah:

Early periscope optics in U-boats furnished the commander with a split prism stadimeter, similar if not identical to the one in SH4, which does not require the periscope's reticle to be on the target ship's waterline to be accurate since the ghost image could be correctly lined up regardless of the image's bobbing. Basically the ghost image would bob in sync and so it was much much easier to get the correct angle for range estimation. SH3's stadimeter is as a result much harder to use than it was in real life, ironically.

[Zosimus]

Early periscope optics in U-boats furnished the commander with a split prism stadimeter, similar if not identical to the one in SH4, which does not require the periscope's reticle to be on the target ship's waterline to be accurate since the ghost image could be correctly lined up regardless of the image's bobbing. Basically the ghost image would bob in sync and so it was much much easier to get the correct angle for range estimation. SH3's stadimeter is as a result much harder to use than it was in real life, ironically.
Although this may be true, my objection to the pause function is not that it makes identifying the ship's mast height too easy but that it virtually eliminates the possibility that the periscope will be seen by the target vessel, which would immediately begin zigzagging motions to avoid torpedoes.

[P_Funk]

Although this may be true, my objection to the pause function is not that it makes identifying the ship's mast height too easy but that it virtually eliminates the possibility that the periscope will be seen by the target vessel, which would immediately begin zigzagging motions to avoid torpedoes.

It cuts both ways though. If you have to keep your scope up much longer trying to get the SH3 stadimeter to work than if you had a split prism image you're in more danger of being detected.

[P_Funk]

Proof of concept for a more realistic SH3 recog manual.

http://i58.tinypic.com/11qhi0n.png

Took many more hours than it should have owing to my perfectionism.

[scott_c2911]

I read a book called Operation Drumbeat not long ago to find out more about the boat I have on my game at the moment and it turns out Reinhard Hardegan frequently misidentified his targets but he didn't miss very often. He would overestimate tonnage which is understandable but he would sometimes call merchants or freighters a tanker too. This could be exaggeration to impress his peers and/or senior officers but the point is he didnt miss. Id and range I firmly believe do not matter but I cannot comment fully as I do not play the game with manual targeting switched on. I can only quote historic facts.

[Zosimus]

Well, let's not put words into my mouth. The hydrophone is a fantastic piece of equipment. My sonar guy can absolutely tell me that there is a ship at bearing 325 at 14km. Maybe he can't tell me that the ship is really at 13,541.3 m, but I don't hold that against him. In my experience the ship is always closer than the hydrophone guy says.

I reiterate my stance that if you want to know everything there is to know about the ship, you should use the four bearings method. If anyone out there has misunderstood me, let me restate that I think that the best method for locating a target with absolute precision is the four bearings method. Range is completely irrelevant–all you need is four bearings. Stop the sub submerged and take your first bearing, then start the stopwatch. Draw the bearing on the map and wait for 2 minutes 10 seconds. Take your second bearing and draw it on the map. Pick any point along the second bearing and mark it with your marking tool. Wait until 4 minutes 20 seconds and take your third bearing. Go to flank speed perpendicular to the ship. Draw the third bearing from where you were stopped and then use your arbitrary point along the second bearing to draw two lines: One perpindicular to the first bearing and one perpindicular to the third. The first bearing will intersect with the perpindicular to third bearing and the third bearing will intersect with the perpindicular to first bearing. The line connecting those two points shows the exact course of your target hereinafter the ("course line"). The course line crosses bearing 1 at point "A" bearing 2 at point "B" and bearing 3 at point "C". Extend this line to create a point "D" such that the distance between A and B is the same as the distance between C and D. Draw a line from your original stopped location through point D and extending outwards. At 6 minutes reverse engines so that you are all stop by 6:30. Take a 4th bearing and where this bearing intersects the 4th line (through your original stopped ship and point D) is the target's exact triangulated location. Draw a line through the target's triangulated location parallel to the course line and you can extend that line forever and know that the target will be somewhere on that line unless it changes course.

Now, since you carefully planned to take your first and fourth bearings at exactly 6:30 apart, you can simply measure the distance from where his real course intersects bearing 1 and bearing 4 and multiply it by 5. You now know the target's real course, location, range, and speed to such a high degree of precision that you can use these details to find him in the pouring rain, set up your perfect 90 AOB shot, 500 meters off his starboard bow, and send him to his watery grave.

No amount of time on a real sub is going to convince me that the four bearings method is anything other than in-fricking-fallible with the added benefit that the target will not see you performing any of these procedures. There is no scope to spot and you can perform all of these well out of visual range of the target.

As for setting up my shot, I triple check everything. If the target is substantially off from the course line then I will not fire the torpedo. I triple check the estimated range, the speed, the torpedo speed (slow), not magnetic but impact, 2 meters depth, and triple check that when the bearing reads 0 AOB reads 90.

I go scope up when I can see the target approaching along the track. If he is running perpindicular to the track (not uncommon) then I redraw the entire map solution scenario on his course, showing the 000 gyroangle line, the 000 bearing line where the target should be when the torpedo track intersects his course. I use the measuring tool to measure how far he is from the gyroangle line. I use his speed to indicate how long it should take him to get there, and I use the stopwatch to measure his approach to the ideal firing point. If anything is off, I will not risk a torpedo on him.

In short, I will not fire unless alles en ordnung. I flood the tube and go scope up before the shot. The target will already be in my scope. I lock and fire. I immediately go scope down and start proceeding towards my new course line on the opposite side of the target so that when I come up three hours later I will be on the opposite side with deck guns blazing to finish the job in case the torpedo fails.

And in all this time I have never visually identified a target, nor measured his mast height by pausing the game at the appropriate moment. In all honesty, I don't get it. What's the point? Just use the four bearings method and you will know everything you need to know about finishing off the ship. Obviously the easiest way is just to have the sensible option of having map updates on. Should you choose not do so, or should the weather make visual contact impossible, just use the four bearings method.

[maillemaker]

Stop the sub submerged and take your first bearing, then start the stopwatch. Draw the bearing on the map and wait for 2 minutes 10 seconds. Take your second bearing and draw it on the map. Pick any point along the second bearing and mark it with your marking tool. Wait until 4 minutes 20 seconds and take your third bearing. Go to flank speed perpendicular to the ship. Draw the third bearing from where you were stopped and then use your arbitrary point along the second bearing to draw two lines: One perpindicular to the first bearing and one perpindicular to the third. The first bearing will intersect with the perpindicular to third bearing and the third bearing will intersect with the perpindicular to first bearing. The line connecting those two points shows the exact course of your target hereinafter the ("course line"). The course line crosses bearing 1 at point "A" bearing 2 at point "B" and bearing 3 at point "C". Extend this line to create a point "D" such that the distance between A and B is the same as the distance between C and D. Draw a line from your original stopped location through point D and extending outwards. At 6 minutes reverse engines so that you are all stop by 6:30. Take a 4th bearing and where this bearing intersects the 4th line (through your original stopped ship and point D) is the target's exact triangulated location. Draw a line through the target's triangulated location parallel to the course line and you can extend that line forever and know that the target will be somewhere on that line unless it changes course.

I've tried to make sense of this but it makes my head hurt.

When you say "Go to flank speed perpendicular to the ship" what does that mean?

Are you saying to to flank speed perpendicular to the current bearing to the target? Or are you saying go perpendicular to the target's track? If the latter, how do you know the target's track at that point?

When you say, " Draw the third bearing from where you were stopped", to you mean draw the third bearing line from where you started (stopped), or are you supposed to stop at 4:20?

Steve

[Zosimus]

I've tried to make sense of this but it makes my head hurt.

When you say "Go to flank speed perpendicular to the ship" what does that mean?

Are you saying to to flank speed perpendicular to the current bearing to the target? Or are you saying go perpendicular to the target's track? If the latter, how do you know the target's track at that point?

When you say, " Draw the third bearing from where you were stopped", to you mean draw the third bearing line from where you started (stopped), or are you supposed to stop at 4:20?

Steve

Since a picture is worth a thousand words, you should start by going to http://ricojansen.nl/downloads/the_four_bearings_method_v2,%20Kuikueg.pdf

As you can see the sub is stopped at point S. The first step is to note three bearings at equal time points from each other. It doesn't matter the exact time apart, but 2:10 is a pretty good number to use as is 3:14 . Really, however, you could use any number although if you're going to use the stopwatch provided with SH3 you should definitely pick a number lower than 4 minutes.

By picking an arbitrary point (point P) along bearing 2, you can draw a line through point P parallel to bearing 1. It crosses bearing 3 at point G in the diagram. Similarly you can draw a line through point P parallel to bearing 3. It crosses at point C in the diagram. By connecting point E to point G you have the target's course. Step 1 is complete.

Now you will need to determine the target's location. You cannot do that by remaining at the stopped point S. On page 3 diagram 3 the sub has moved to a new point at I. As you can see this point creates a roughly 90º triangle from bearing 2. Really the actual position doesn't matter, although ideally it is as far from point S as possible. By moving perpindicular and at flank speed you get far away and that adds to the accuracy.

Since you know the target's course, you can project that at the next time interval the ship will be along the line that connects S to H. To create this line you must first determine point H. As you can see points E, F, G, and H are equidistant along the line. Once you have point H you can draw a line through point S. Since you are now at the new point I you will have a bearing that crosses the line S-H at point J. Point J the target ship's exact position.

By this time you know the ship's course and precise location. The next step will be to determine the speed. If you picked a convenient time interval (such as 3:14, 2:10, or even 6:29) you will already have the data you need. Just measure the distance the ship has traveled and apply the 3:14 rule to determine the ship's speed in knots. If you chose a different number, it's still no problem. You can just reset your timer, take a new bearing, and wait another 3:14 or 6:29 and then determine the ship's speed by measuring the distance and multiplying either by 10 for 3.14 or by 5 for 6:29.

If you read further in the document there is another procedure for when the ship is moving. So far it's too complicated for me, but you're welcome to look at it and see if you can figure it out.

[Zosimus]

Zosimus,

The four bearing method is easy, you also don't have to take bearing at 3:15 or multiples thereof, you also don't have to go flank speed at a perpendicular course either. As long as the first three are equal, you could go along at any angle, dead slow if you wish, for any length of time.
No, you cannot go at any length of time. You must go for EXACTLY the period of time you were using before. Nor can you go along any angle you please. If you choose, for example, to proceed along an angle the same or similar to the 4th bearing angle from your sub's position, then you will not know where the ship is. The ideal is to create as different an angle as possible so that your measurement is improved. That's why I recommended that the ship proceed at a 90º angle.

Think your statement about being 0.4587km out, is a tad harsh.

I fail to see what any of that has to do with the four bearing method.

Let's summarize the points I've made from the beginning.

Point 1. It doesn't matter if some ships in the manual are identical because you don't need to identify the ships at all.
Point 2. It's a simple matter to determine ship course and speed using the stopwatch with map updates on. You don't need to look at the ships and determine mast height. Just look at them on the map, put a mark, wait 3:14.4 or 6:28.8 and measure.
Point 3. People who say that GHGs could not tell users approximate ranges don't know WTF they're talking about. GHGs came with a potentiometer in parallel that permitted the operator to determine the singal strength. That could be translated into a rough measurement of the ship's distance.
Point 4. If you want to play with map updates off or you're hunting in the rain, just use the four bearing method.

You get an exact same ship, they will be different, louder or softer, depending on condition of the boat, cargo its carrying.
Use the four bearing method.

Even the way crews operate, will even make a difference, so no you cannot accurately predict distance on one contact.
Use the four bearing method.

In real life at least, in SH3, all the same type have the same sound, regardless of above.
Use the four bearing method.

So in reality, short, medium, long bands are more accurate than anything else on a first contact and probably counteract the same sound signatures, to a degree.
Use the four bearing method.


(Insert any other irrelevant comments here).

Use the four bearing method.

In case anything I have said above might cause you to think that I swear up and down that GHGs are spot-on precise, that ships all had the same volume level, that hydrophones are perfectly accurate, or that super skilled hydrophone users could overcome all the problems, or any other strange ideas that you pull out of your head that I NEVER EVER EVER EVER said, I just want to say:

USE THE FOUR BEARING METHOD. Any problems real or imagined with GHGs either in the game or in real life can be easily overcome by using the four bearing method.

[maillemaker]

Since a picture is worth a thousand words, you should start by going to http://ricojansen.nl/downloads/the_f...%20Kuikueg.pdf (http://ricojansen.nl/downloads/the_four_bearings_method_v2,%20Kuikueg.pdf)

That is very helpful, thanks a lot!

I think this kind of geometric problem solving is something real sub commanders would have drilled in at uboat school.

Steve

[Zosimus]

What you ranting on about, I use the four or even more bearing method.

The first thing you quoted, yes the 1st 3 must be the same, however the last can be anytime, As long as you do the maths, to where the ship intercepts, the bearing at the time you choose.

You stated that you could predict where the ship was using original one sonar contact, I was responding, yes to a degree, but not with accuracy using hydrophone only.

I'm going to leave this conversation now, as I really don't think you understand or really want to understand what is being said. Maybe I am not saying it best, but the last quote any other ramblings or something like that, pisses me off.

You have been on for a month (this forum), I have watched you shouting about inabilities of the game (yes we all agree, has its limitations).

You asked So don't jump down others throats when they express their opinions.

So my friend, get on with it by yourself and happy hunting.
First of all, kiltsman, I'm not shouting. I think you're daft, but I'm not shouting.

Second, I remind you that I said, "...if using the Gruppenhorchgeräte, which is the very equipment my fine boat is equipped with, the signal input was accompanied by a potentiometer calibrated in ohms and a 270 degree scale. Upon detecting the ship my fine sonar guy can simply adjust the parallel potentiometer until the signal disappears and then announce an approximate range to target based on the ohm measurement..." I'd like to follow that up with a simple question: Do you know the meaning of the word approximate?

Third, I remind you that I said that as soon as I got the hydrophone contact I merely turned towards the signal and proceeded at flank speed until I got another contact. Using those two contacts I calculate "the target's heading to within a few degrees." I never said it was spot-on accurate, nor did I say that it gave me perfect range.

Next I said, "Once I get the ship spotted notification, I ask the watchman for the range and write it down." Assuming that you think that I think that the range of the GHG is God's gift to the universe, why would I ask the watchman for the range?!

Later I said, "I measure the distance to target down the gyroangle line, not the torpedo line. I use either the ruler or the compass tool to do so." As you can see, I do not rely on the GHG for range. I calculate it on the map.

Finally, when Pisces challenged me on how my crew determined the range I replied, "...let's say, for the sake of argument, that you decided to nix all of that, and you refused to use the ranges provided by your hydrophone officer, too. You were determined to do things the unrealistically hard way. Fine. Use the four bearings method."

In conclusion: I recommended using map updates and a ruler to determine range to target. When I was informed that some people don't use map updates, I suggested using the four bearings method. At no time, in no post, and in no way did I ever suggest that GHG ranges were perfect, good, or even equal to other in-game options. What I recommended was the four bearings method.

Now if you think the four bearings method is bad, for some reason, I'll be glad to debate the virtues of said method with you. If, however, you merely continue to insist that the GHG is not as reliable as I never said it was, then we're just wasting each other's time and that of the other readers. Let's just agree to dejar la fiesta en paz and get on with our lives.

[Pisces]

The 4 bearing method is a very valuable method, as it is totally passive and can give you all the necessary navigational parameters. But it should not be considered as the perfect solution for every situation. It has a significant drawback in that it relies on accurate bearings taken from the hydrophone and them being transferred as accurate as possible to the geometry plot. Also it doesn't work well in convoy situations. Most importantly, it takes quite a while of time to get a meaningful set of bearings if the bearing resolution is substandard. Or else the range of possible courses can get very wide. How you play makes a big difference here though. The way the game plots the sound bearings makes it a lot more precise to plot bearings (sub degree accuracy). As compared to plotting them by hand (considering realistic vocal transfer from hydro operator to plotting party: multiple degree in-accuracy)

This makes the method not very practical for close contact situations where visual contact is possible and things can change quickly. Taking a stadimeter range and AOB look is done quicker than the full extent of the 3/4 bearing method. It can be done also, as there is no difference between a periscope bearing and a hydrophone bearing in this regard. But I guess having a look at what you are up against is more preferable. Also, in the very end you need to know if the target is friend or foe or neutral. So some class ID and flag ID is eventually necessary. But maybe not the actual class when it comes to civilian ships.

I don't want to continue this topic into off-topic territory with my take on why an bearing-interval of say 10 minutes is improper. As it still is about the recognition manual itself. It's not about which method should be used regardless.