The four bearing method

[j4ckkn1fe]

So I have been trying to comprehend the four bearing method by Kuikueg. I don't get it at all...He loses me after taking the first 3 bearing readings. To be more exact the problem I'm having with is the red line. If someone can help me with this portion of the tutorial it would help me out immensely. I have tried my best with and looked up makman99's videos. However, he skips over the red line portion and the circles he is making make no sense to me. Also there are so many versions to this method I'm getting mixed up understanding all of them.

Thanks for any help!!

[sublynx]

A long and link filled rant following (the idea: there's many ways of skinning the cat), don't bother reading if short of time - and I'm not trying to answer the question about Kuikueg's method as I don't use it myself.

I use a 2x3 bearing method that was described in a 1941 US Navy Maneuvering board manual. It's the same thing but executed a little bit differently. It takes first three bearings, then one makes a change of direction, and then take 3 new bearings. Here's the method described in a modern manual:

http://msi.nga.mil/MSISiteContent/StaticFiles/NAV_PUBS/RNM/310ch6.pdf

(Example 25: Course, speed and position derived from bearings only)

Here's a good and easy video clip on how to use a maneuvering board (part 1, numbers 2 and 3 are very useful as well):
https://vimeo.com/103997969

If someone would like to try using a maneuvering board in the game, it's possible by printing a maneuvering board on paper or using computerized options:

Maneuvering board usable with free 3D design program Sketchup:
http://www.subsim.com/radioroom/downloads.php?do=file&id=3708

Maneuvering board modded into the map:
http://www.subsim.com/radioroom/downloads.php?do=file&id=4228

A draggable maneuvering board for MaGui F (1024x768)
http://www.subsim.com/radioroom/downloads.php?do=file&id=3675

A draggable maneuvering board for MaGui Widescreen SA (1360x768)
http://www.subsim.com/radioroom/downloads.php?do=file&id=4598

The more I play the less I feel determining course, speed, and position by bearings only is really helpful. Perhaps determine course with three bearings, then get approximately in front of the ship, then use the constant bearing method in closing the distance.

Hitman GUI has an excellent two-page document in it, where Hitman describes how the U-boats actually approached the target. The methods are very simple, and very effective:
http://www.subsim.com/radioroom/showthread.php?t=167126

What I am saying is that I feel that Kuikueg etc's methods are nice, fun (if one likes geometry), but not that efficient. They are time consuming and somewhat inaccurate even when you know what to do.

Understanding the basic submarine approach tactics simplifies the approach. Here's a link where Lieutenant Commander Bakos describes four different approach tactics, based on leading the target, lagging the target and pointing at the target:
http://calhoun.nps.edu/bitstream/handle/10945/31516/95Mar_Bakos.pdf?sequence=1

Here's a site that gives really detailed info on both approaching a target, and attacking it with a torpedo: http://www.tvre.org/en/acquiring-torpedo-firing-data

The plot in that page, made by the British submarine HMS Venturer of the course of U 864 is an example of one needed to do to sink a submerged target that you have only heard in the sonar, and never seen. A sinking by bearings only.

Target approach and torpedo attacking can be made really complicated and mathematical, but in the game there's really no need for it. Simple methods are really effective. The more I play SH3 the more I realise that every player needs to develop a set of methods that work with their personalities. My guess is that's historically accurate as well. Probably the more theoretically oriented U-boat commanders and officers used different methods than the more practically oriented.

(End rant)

[j4ckkn1fe]

Holy cow man thank you! I will be doing a lot of reading this night it looks like.

I will post back if it was successful.

[Laufen zum Ziel]

http://imageshack.com/a/img661/9851/H5VEbf.jpg

http://imageshack.com/a/img661/6492/6JRtKK.jpg

[banryu79]

A long and link filled rant following ...
[Lots of info & useful links to follow]

Ehy man, thank you thank you!!
Very useful and intresting info in this post of yours :up:

[banryu79]

Understanding the basic submarine approach tactics simplifies the approach. Here's a link where Lieutenant Commander Bakos describes four different approach tactics, based on leading the target, lagging the target and pointing at the target:
http://calhoun.nps.edu/bitstream/handle/10945/31516/95Mar_Bakos.pdf?sequence=1

I think this one in particular would be of much interest for DWs players...

[j4ckkn1fe]

So am I suppose to be moving when I take these readings? I downloaded the magui addon and I just drag it over the sub. However, it doesn't follow it just rests on the map static. Trying to follow along with example 25.

Also for those videos they are using radar that calculates distance for you. I am using the hydrophone that gives practically no range you can count on.

[sublynx]

Learning to use a maneuvering board can be pretty hairy at first. Just try to do exactly as it says in example 25. When I was learning to do that myself I did not understand a thing about what I was doing at first. Now I'm very slowly starting to understand something about why and how it works.

Try to forget about the position of your U-boat or the position of the target. Print a maneuvering board and draw the picture on paper to make sure you are not confused by the sight of your U-boat on SH3's Navigation Map. Think about movement instead of positions. It's like two cars driving towards each other. Positions are old history, to avoid a collision you want know the speeds and directions of your car and the other car. It's the same with U-boats and target ships, just the other way around: you want to find a collision course in order to get close enough for the torpedoing.

[j4ckkn1fe]

Ohhhh ok so I continue moving when taking the readings just draw out the bearings from the center always. Well that makes the magui addon pretty much useless the lines are always drawn on the map and not on the board so they are just left behind.

[sublynx]

You are still thinking about positions and the sight of you U-boat on the Navigation Map is confusing you. Try rolling your map to Siberia for instance and do your maneuvering board work there.

Mobo work can be pretty difficult to comprehend at first. I think downloading an electronic maneuvering board might make the principles of mobo work clearer: http://www.subsim.com/radioroom/downloads.php?do=file&id=648

The Electronic MoBo also has many tutorials with pictures on how it works.

[ljqcn101]

The 4-bearing method can also be modified to use relative motion plotting on a maneuvering board. A basic idea is posted here: http://www.subsim.com/radioroom/showthread.php?t=240883

[John Pancoast]

A long and link filled rant following (the idea: there's many ways of skinning the cat), don't bother reading if short of time - and I'm not trying to answer the question about Kuikueg's method as I don't use it myself.

I use a 2x3 bearing method that was described in a 1941 US Navy Maneuvering board manual. It's the same thing but executed a little bit differently. It takes first three bearings, then one makes a change of direction, and then take 3 new bearings. Here's the method described in a modern manual:

http://msi.nga.mil/MSISiteContent/StaticFiles/NAV_PUBS/RNM/310ch6.pdf

(Example 25: Course, speed and position derived from bearings only)

Here's a good and easy video clip on how to use a maneuvering board (part 1, numbers 2 and 3 are very useful as well):
https://vimeo.com/103997969

If someone would like to try using a maneuvering board in the game, it's possible by printing a maneuvering board on paper or using computerized options:

Maneuvering board usable with free 3D design program Sketchup:
http://www.subsim.com/radioroom/downloads.php?do=file&id=3708

Maneuvering board modded into the map:
http://www.subsim.com/radioroom/downloads.php?do=file&id=4228

A draggable maneuvering board for MaGui F (1024x768)
http://www.subsim.com/radioroom/downloads.php?do=file&id=3675

A draggable maneuvering board for MaGui Widescreen SA (1360x768)
http://www.subsim.com/radioroom/downloads.php?do=file&id=4598

The more I play the less I feel determining course, speed, and position by bearings only is really helpful. Perhaps determine course with three bearings, then get approximately in front of the ship, then use the constant bearing method in closing the distance.

Hitman GUI has an excellent two-page document in it, where Hitman describes how the U-boats actually approached the target. The methods are very simple, and very effective:
http://www.subsim.com/radioroom/showthread.php?t=167126

What I am saying is that I feel that Kuikueg etc's methods are nice, fun (if one likes geometry), but not that efficient. They are time consuming and somewhat inaccurate even when you know what to do.

Understanding the basic submarine approach tactics simplifies the approach. Here's a link where Lieutenant Commander Bakos describes four different approach tactics, based on leading the target, lagging the target and pointing at the target:
http://calhoun.nps.edu/bitstream/handle/10945/31516/95Mar_Bakos.pdf?sequence=1

Here's a site that gives really detailed info on both approaching a target, and attacking it with a torpedo: http://www.tvre.org/en/acquiring-torpedo-firing-data

The plot in that page, made by the British submarine HMS Venturer of the course of U 864 is an example of one needed to do to sink a submerged target that you have only heard in the sonar, and never seen. A sinking by bearings only.

Target approach and torpedo attacking can be made really complicated and mathematical, but in the game there's really no need for it. Simple methods are really effective. The more I play SH3 the more I realise that every player needs to develop a set of methods that work with their personalities. My guess is that's historically accurate as well. Probably the more theoretically oriented U-boat commanders and officers used different methods than the more practically oriented.

(End rant)

(old thread) I couldn't agree more with this last paragraph. There's a lot of overly complicated methods out there to do something that is very simple and very common sense.
Keep it simple. You'll sink plenty of ships and I bet have more fun too.

[Wolfcat]

I use the 4-bearing method. Had fairly good results. I recommend watching the youtube videos rather than purely reading his pdf file. His pdf file is not very well written and contains some confusing points (probably due to language issue). The whole point about this method is to use the first 3 bearings to calculate a 4th hypothetical bearing line. Then change course to triangulate the exact position, which should theoretically lie on the intersection between the hypothetical and the real 4th bearing line. The caveat of this method is that you need VERY accurate measurements on your bearing lines and time. When you do your map exercise you have to very exact. Tiny bit of measurement or drawing errors would put your final calculation miles away from the truth. I am not sure if you use full realism in your game settings. If you do then you won't be able to see the red sonar line on your map. Without that, your manual sonar readings would probably be off by a lot making your 4-bearing method virtually useless. I mostly use this method for surface runs. I only do visual measurements thru either binocular or periscope since sonar is not reliable.

[ljqcn101]

In my opinion the particular method for ownship constantly moving is too heavy on the workload of plotting. It is easier to use the idea from US Navy Maneuvering board manual.

When ownship is steady on course and speed, just plot the bearings from the same point, as if ownship is stationary. By using the stationary 3-bearing method, you'll get a relative course or relative motion of the target.

http://www.subsim.com/radioroom/picture.php?albumid=1215&pictureid=10318

Then you can just use the stationary 3-bearing plus one method to triangulate the target position and get the relative speed of the target.

The only additional thing to do is to convert the target relative motion and speed to true course and speed, by drawing a simple triangle:

http://www.subsim.com/radioroom/picture.php?albumid=1215&pictureid=10319

Much simpler. I also recommend trying out the historical 2x3 bearing method used by USN from 1941 to get a grasp on relative motion plotting.

[John Pancoast]

Or one could just easily figure out course/speed, etc. via various methods of eyeball observations.
Setup an easy fast 90 attack, boom, scrap metal made.
But no big deal; different strokes/folks.

[Pisces]

I agree that Kuikueg's explanations are a bit tough to digest. It is explained like a mathematics course. Eh, who can blame him.

Another forum member Neuro has published his own explanation of the methods shown by Kuikueg. I think it is a lot easier to understand why and how the steps are done.

http://ricojansen.nl/downloads/Four_bearings_method_revised_v2%2C%20Neuro.pdf

And if the work load seems to much for the navigator, simply allow more time between the bearings. It doesn't have to happen in within minutes.

I'm sure it depends on the kind of person which tactics or methods are chosen. But at extreme range you don't really have visual means to set course perpendicular too the target track. At best you can guestimate. And that works. So aside from it being a person thing, it is clearly also a situation thing.

[ljqcn101]

Both the explanation from Kuikueg and Neuro worked great for me. But still, it is the particular method for ownship constantly moving that I was concerned about.

Not just because of the workload, but also this method relies heavily on the little triangle formed by 3 bearing lines to determine the extrapolated 4th line. In practice, this triangle could be pretty far away or relatively small that would contribute to plotting errors. And the two anchor points that the extrapolated 4th line passes through are always close to each other, making any plotting error to be exaggerated.

By changing your mind to plot relative motion, you can use the stationary method which is less prone to plotting error.

You can also use the formula and a calculator, or a disk. But I guess people using this method really love plotting.