Authentic method of getting firing solution?

[Tom]

Ok, this is the first thread I start... so sorry if I'm asking something that's already been discussed here.

I've recently started doing my targetting manually with no map updates, using watch officer estimates for target range when overhauling and periscope range finding when closing in, and plotting the solutions on the navigation map. What I would like to know is the authentic method used by the germans to turn target range/bearing/time information into target AOB/speed. (The Submarine Commander's Handbook calls for "estimation of range and position at regular intervals of time", but doesn't (or I just somehow missed it) explain the preferred method of calculating AOB/speed from these.)

They obviously didn't have a navigation map displaying the exact location of the submarine at all times, but they could have plotted the submarine's movement based on course and speed, together with the target bearings/ranges/times, and use this information to plot the course and speed of the target much like I do it on the navigation map now. But is this how it was done?

Furthermore, how did they estimate the firing solution in cases where observations over a longer time weren't available? (Bad weather, target changed course moments before attack, etc.)

Using search I found several threads explaining working methods for manual targeting, but couldn't find out which was the actual method used. If I just missed the information, could someone please point me to the thread?

[Puster Bill]

They used one of these:





Which you can download, print out, assemble, and find the directions for it's use in this thread:
http://www.subsim.com/radioroom/showthread.php?t=114351

Alternatively, you could use a regular linear or circular slide rule if you have one handy, as long as it has an 'S' scale on it. The thread that explains that one is here:
http://www.subsim.com/radioroom/showthread.php?t=112765

This is also a helpful document, even though it applies to the American Submarine Attack Course Finder/IS-WAS:
http://www.hnsa.org/doc/attackfinder/index.htm

[Tom]

Thank you very much. I recall seeing some of those threads, but somehow missed them when trying to search for them yesterday.

Those of you who use a wheel like that: what are your experiences regarding accuracy and ease of use? My intuition would be that a wheel is easier to use than plotting solutions on map, atleast once you get the hang of it. As for accuracy, when plotting on map it easy to refine the solution when you get more observations. How do you do this with the wheel (which, if I understand it correctly, gives the solution based on two observations only)?

Ah, well, I guess I'll just have to build one and try it out myself.

Originally Posted by Tom

Those of you who use a wheel like that: what are your experiences regarding accuracy and ease of use? My intuition would be that a wheel is easier to use than plotting solutions on map, atleast once you get the hang of it. As for accuracy, when plotting on map it easy to refine the solution when you get more observations. How do you do this with the wheel (which, if I understand it correctly, gives the solution based on two observations only)?

I was thinking about building the wheel but gave it up for now. I was doing some serious plotting but now nearly I don't draw more than a single line - a general course if I need to follow. It all started when I removed my position from the map (as to use celestial navigation). Suddenly I have found myself calculating in my head bearing, speed, course etc. I started to see things differently, started to fell relative courses etc. Another thing is that to be realistic you need to make some observations like timed hydro readings, manual range through your scope etc. The more you spend on the see the more it's obvious and very quickly you just know what to do, how to react. This gives a very nice feeling of being a true, trained and experienced captain who has everything in his head!!

[Tom]

Originally Posted by Hadrys

I was thinking about building the wheel but gave it up for now. I was doing some serious plotting but now nearly I don't draw more than a single line - a general course if I need to follow. It all started when I removed my position from the map (as to use celestial navigation). Suddenly I have found myself calculating in my head bearing, speed, course etc. I started to see things differently, started to fell relative courses etc. Another thing is that to be realistic you need to make some observations like timed hydro readings, manual range through your scope etc. The more you spend on the see the more it's obvious and very quickly you just know what to do, how to react. This gives a very nice feeling of being a true, trained and experienced captain who has everything in his head!!

My problem is finding enjoyable balance in the game. First I used map contact updates and weapon officer assistance. Soon practically every torpedo I fired hit. Then I turned off weapon officer assistance and used the updating map contacts to plot tracks and generate solutions. Nothing changed, practically every torpedo hit. Recently I turned off map contacts and started plotting manually based on observations. Now I miss about 10% of the time, with something like 50% of my torpedoes hitting within 5-10 meters of point of aim.

The only thing that has changed as I've turned on more realism, is that I now only fire from good positions. No more instant weapon officer solutions against zigzagging targets in poor positions. Also, gameplay has become a lot slower - plotting takes time.

I'm not ready to go through the trouble of navigating myself. That would slow gameplay even more. With my current settings I already find the game a bit too tedious to my liking. A real captain would have had crew to do some of these tasks. Unfortunately the game crew is too good at its jobs, making hitting targets too easy for the game to be enjoyable.

So I'm looking for a method of playing the game without making tedious observations and plotting, being able to hit about realistically, and not using the way too accurate crew observations, if at all possible. Good suggestions are welcome.

One solution I'm currently considering, and will test out next, is this:
- Overhauling the target on surface, keeping a long range and a general bearing of 90 or 270 to target. This should give me an idea of target heading as I visually observe aob changing during the maneuver, as well as some idea of target speed.
- Submerged approach on a (as close as I can visually determine) perpendicular course, setting speed, when possible, so that the bearing to target keeps constant. This gives me a good idea of target speed and puts me in a good firing position. I can also stop and measure target speed quite accurately using the stopwatch and target length, if I am in doubt.
- Visually verifying aob and measuring range through the scope, and adjusting the TDC accordingly, just before firing.

I'll have to see how this works out. I just fear that I'll end up with worse solutions than a real captain would have in a similar situation, and won't be able to hit much anything. Hopefully I'm wrong about this.

[joegrundman]

The wheels are great! Transforms your game. You never need to waste time on plotting to get course again. Unless visibility is extremely poor, I find I often don't draw anything on the map at all, although this does depend on what it is I'm hunting.

The fact is that in RL neither the GErmans or Americans wasted their time using bearing plots -just too inaccurate. There are far more effetcive ways of doing it (although I still will do the 3 min 15 sec thing occasionally, if the situation calls for it, for example if I'm already sure of course and I'm just lying in wait, it's an easy way to confirm your earlier estimates)

As for finding manual plotting a bit too slow...well, that changes soon. The challenges never really stop too. With plotting etc you can get into position and make an easy kill some of the time. There are lots of contacts you will be unable to catch that way. A big part of the joy of this game is the discovery of new ways to get those targets you used to just give up on.

[Hitman]

****breaths deep*****

OK....long story short:

I have been already for some time doing an article exactly about that: How the germans collected data for their firing solutions in real life. The information is far from complete and easy to get in the web, I have been researching the matter for several months and now I start to have a clear picture. I can't sum up what I am putting together in an already 12+ pages long article (with pictures included), but I can tell you that it is 100% sure that germans did NOT make any plot on the map for the target solutions (Though they certainly plotted the contact info from BDU about convoys until they made visual contact for the first time), unlike their american Silent Service counterparts. Aboard a german sub only two persons did the full job of getting data and feeding the TDC: The commander at the scope (submerged) or the IWO at the UZO (Surfaced), while a petty officer auxiliated with some calculations and recognition manuals, and fed the data into the TDC. And they did it "on the fly", without any plotting. That was achieved through the combined use of certain manouvering tactics (Constant helming and bearing) during the approach at long distance, and the use of the specific instruments in the U-Boot optics when already close (submerged of surfacer), like the Rangefinder, Course finder, etc.

And no, they did NOT make always simple estimations of the AOB like the americans, they used instead a device (Mechanical wiz-wheel linked toa split prism optic) in the scope for measuring that.

The article should be available first in spanish and later in english in some time, I have written it already and I'm now busy drawing some schemes and re-organizing and revising the text.

P.S. I'm also working on that real life periscope wiz-wheel for printing and building up your own one. Hopefully also someone who knows how to add moveable dials to the game (Like the 6-dials simfeeling mod) will be able to help me adding it to SH3

Originally Posted by Hitman

The article should be available first in spanish and later in english in some time, I have written it already and I'm now busy drawing some schemes and re-organizing and revising the text.

Wow very impressive, can't wait to put my hands on it but I don't know a word in spanish... so till now it's good to know that my approach is quite good! With celestial navigation it gives a very nice feel as a commander.

Gut gemacht!

[Hitman]

I started to see things differently, started to fell relative courses

Yes Hadrys, that's the key....

The plotting we are used to in SH3/4 asumes the perfect knowledge about our sub's position, but in reallife that was very difficult if not impossible in the middle of a sneaking approach. Thus the methods developed by germans involved heavily relative comparisons between what the target and the own U-Boot were doing, not to were they were located in GPS style coordenates . For example, constant bearing of the enemy plus an AOB estimate gives you speed with simple Law of Sine maths, and constant bearing of the enemy at 90º/270º allows you to easily get a very exact AOB with rather simple maths or even some pre-configured tables. Non constant bearing can also provide rough speed estimates, applying corrections and so on.

All that was done during the long range approach, then the U-Boot submerged for the close approach and did ocasional periscope checks. By the time she was on firing range, most data were well confirmed....

Wow very impressive, can't wait to put my hands on it but I don't know a word in spanish... so till now it's good to know that my approach is quite good! With celestial navigation it gives a very nice feel as a commander.

There will be a english version also

[irish1958]

Hitman,
I am awaiting your info and work. I am sure it will be a hit.

Originally Posted by Hitman

Yes Hadrys, that's the key....

To be even more specific I try to hit from 90° and really I can't explain right here right now how I do it. Simple relative position which I can draw even on a piece of paper or in my mind. Check how changes contact sound, get visual (now when I play at 1680 resolution this is even better because far targets look great and very precisely getting out of the fog so I can later observe masts, lines, details etc. Just gives a good fell of using great Zeiss optics). The most important part of it is that now when I hear target on bearing 291 I instantly know where it is! Looking through the scope I can tell quite good what's the range, than use "double peri view" to give a more accurate range. This is all very simple, intuitive and fun but hard to explain at first. Just practice! Also when using T1 torps the attacks are very lethal up to 2 km.

Try celestial navigation as we probably finally figured out how to calculate longitudes!

[Maraz]

Originally Posted by Hadrys

than use "double peri view" to give a more accurate range.

So are you using the two periscopes as a telemeter? Measuring parallax?

Maraz

Originally Posted by Maraz

So are you using the two periscopes as a telemeter? Measuring parallax?

Maraz

Nah, just wrote it that way - periscopes were equipped in special system that allowed to put two views onto each other and in that way let measure the mast height. Just like in SH3 except there is a simple line. Don't want to mess here because I've read about it somewhere, can't remember where and you should make some research for accuracy.

[Puster Bill]

Someone put Hitman on the payroll. He's done a *LOT* of good work.

[Hitman]

Now you got me started LOL

Here is a preview of what I'm actually working on....

This is an adaptation of the real item the U-Boots had attached to their periscope around the eyepiece (Rough eyepiece drawn in the center of the wheel below). In real U-Boots, the wheel had less scales, but since I inted to use it in SH3 I needed an extra one to show what was automatically moved in the scope when the captain adjusted the split images.

Basically, the procedure was as follows:

1.- Get range, like it is done in SH3 (Mast heigth known or estimated)
2.- Turn the eyepiece 90º (Yes it was rotational!) and set the distance you got from the first step in the middle wheel (Entfernung) to align with the known or estimated length of the enemy vessel in the outer wheel (Basis). In this case we have a 200 metres long ship at 950 metres distance
3.- Now using the split images horizontally instead of vertically (Like he did when the mast was measured), the captain aligned bow of one image with stern of the other, and the handle he moved to do that is mechanically connected to the inner dial (Kurswinkel) of the wiz-wheel, which rotated proportionally as much as the split image was moved. So it indicated the AOB of the target in a certain mark (Opposite the 100 mark of the outer wheel), in our case below, the AOB is 90º.

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Now for SH3 I had to add a new scale between distance and AOB because we don't have a system of horizontal split images. So I had to work with a fixed inner ring and the new scale displays the scope horizontal marks. In this case, the AOB of 90º is almost 13 scope marks at the low power zoom (The one used at U-Boots for measuring this all), so if you see for example that the target extends only 8 marks, you see opposite that value in the scope marks scale an AOB of 40º in the Kurswinkel wheel.

I have this already finsihed for external print & build a wiz-wheel, but I would really really love to be able to implement it inside SH3, in the scope screen (The UZO used another method). Would be amazing stuff to use in-game!