Bearing Rate Computer slide rule

[Puster Bill]

If you are interested in one, I put the graphics for it in these two threads:

http://www.subsim.com/radioroom/showthread.php?t=140397

http://www.subsim.com/radioroom/showthread.php?t=140421

You print them out, then cut them out and pin them together, and you'll probably want something to use as a cursor.

If you aren't familiar with the techniques of making "wheels", see these threads:

http://www.subsim.com/radioroom/showthread.php?t=106923

http://www.subsim.com/radioroom/showthread.php?t=114351

[jmr]

Saweeeeeeet! When I was reading up on plotting and TMA in chapter 10 of the NRTC Operational Specialists manual I kept thinking how nice it would be to have that bearing rate computer added to my homemade whiz wheel collection :}

Thanks for this, Bill!

[SandyCaesar]

I have a feeling it'll take a while to figure out. Once I do, however, I'll try it out. Wonder what this will do for my TMA solutions.

[Puster Bill]

Saweeeeeeet! When I was reading up on plotting and TMA in chapter 10 of the NRTC Operational Specialists manual I kept thinking how nice it would be to have that bearing rate computer added to my homemade whiz wheel collection :}

Thanks for this, Bill!
My pleasure.

I probably should have posted it earlier, but I don't play DW (just SHIII) so for me it was just a "Hey, I'll make one and see what it can do" kind of thing. So I went through a couple of TMA exercises with it, then shoved it in a drawer with the other wheels I don't use. I only use Hitman's Kriegsmarine whiz-wheel at this point, because it's the only one relevent to my needs. I think I made it about a year or so ago.

All I did to make it was to grab the graphic from the manual and instructions on how to do a TMA, make two copies of it, and erased the parts that weren't relevent to that particular part of the wheel. I'm no graphics wizard, but it is usable. Someone else with more talent should make a nicer one.

[Bill Nichols]

I actually have a real one, but I admit I don't use it.

[Puster Bill]

It's been brought to my attention that there should be *4* wheels, not just two.

You can still use them, you just have to print each sheet twice and trim one of each appropriately.

[TLAM Strike]

IIRC in DW you can get the Bearing Rate on the Nav Map. I'm not sure if its based on your TMA Plot's solution or on actual sonar data.




One of these days I got to print out that Is-Was so i can use it on the Kilo for determining target course. :hmm:

[Kapitan]

I wonder if you can buy this top seacret tech hmmm.

[Pisces]

IIRC in DW you can get the Bearing Rate on the Nav Map. I'm not sure if its based on your TMA Plot's solution or on actual sonar data.




One of these days I got to print out that Is-Was so i can use it on the Kilo for determining target course. :hmm:I think it's completely based on yuour TMA solution. I never saw the rate value until I entered a solution. (But I haven't used it much either.) So if that solution doesn't resemble the (short-term) bearing fan in the least of ways it's meaningless.

[Puster Bill]

I wonder if you can buy this top seacret tech hmmm.

Possibly. You might be able to find one on Ebay or something, but to be quite frank you will most likely end spending more than you would spend on the materials to make them.

Here is how I build my wheels:

First, I obviously print out the appropriate graphics. I generally use inkjet cardstock. I almost always have some because I use it to print out my QSL cards (I'm a ham radio operator).

I'll do a rough cut-out of the individual wheels, leaving plenty of excess at the edges.

Then, if I want it to be a very durable and stiff wheel, I take an Elmers glue stick (don't use wet Elmers!) and completely cover the back of each wheel, then stick another piece of cardstock to it. Then I put the result between two heavy books. If you aren't making a "permanent" wheel, you can skip this step. I will say though that I still use wheels I made before I started doing that step, and they are in perfect shape after a couple of years, so this may be "overkill". At any rate, feel free to skip this step.

Then, I use self-stick lamination to laminate BOTH SIDES of each wheel. Some people thermally laminate them. Whatever trips your trigger.

After that, really all you have to do is cut them out carefully along the edges, and pin them together. I used to use two push-pins. I'd use pliers to take the pin out of one of the heads, then I'd use the other pin to make the holes in the wheels. After putting it all together, I would use wire cutters to trim the pin, and I'd use the head of the other pin, along with a dab of super glue, to hold it all together. These days, I still use a pin to make the whole, but I use small hardware (nuts and bolts) to hold them together.

The only critical part of making them is putting the hold in the center of each wheel. Even then, if you are off by a *LITTLE* it won't effect the accuracy enough that you would notice in practice.

Go ahead and make one. You'll get hooked. :yep:

[Ramius]

Theres only 2 wheels on a "widger" and a cursor. :know:

I used to have a list of 101 things you could use it for, but its long since misplaced :oops:

And like Bill probably knows, by the time you get to know how to use these things properly, 95% of the time you can do it quicker in your head :up: :up:

[Puster Bill]

And like Bill probably knows, by the time you get to know how to use these things properly, 95% of the time you can do it quicker in your head :up: :up:
Well, yes, and no.

Certainly it's true that practicing and using wheels on a regular basis, or indeed any manual procedure gives you a good fundamental understanding of the problem, and can also help you develop a sixth sense about where you are in relation to your target, and vice versa.

On the other hand, I still use the wheels on a regular basis. There are some things I find them indispensible for, like calculating target speed. Funny side story: I was watching the sculling qualifications for the Olympics a while back, and it struck me: They travel 2000 meters in a certain amount of time, I wonder how fast that is in knots? Whipped out my trusty Kriegsmarine whiz-wheel (because unlike the BRC or the SACF/IS-WAS, it's measurement is meters, not yards), and figured it out. It was something on the order of 9+ knots, by the way.

I imagine that if you wanted to do a manual TMA, this would be a must-have. I'm going to build another one myself in the near future and try it out in SHIII.

Now, I could write the software to do all this crap for me: I'm a programmer by trade. But I have to admit, there is just something retro-cool :cool: about whipping out a slide rule to calculate something. It's cool enough that I don't bother reaching for my TI-82 programmable anymore, or any other. If I have something that needs figuring, I whip out my trusty Pickett N-200ES Pocket trig.

[jmarkantonakis]

My friend, the urls you posted are no longer visible (if my PC has not gone crazy). But if you own a Bearing Rate Computer, I would really appreciate if you scan it with fair quality an post it again, or recommend a url that I can visit and dload a printable version to make one at home.....Thanks in advance....

[Pisces]

Check this recent thread (ekelund range calculator):

http://www.subsim.com/radioroom/showthread.php?t=154396

[Puster Bill]

My friend, the urls you posted are no longer visible (if my PC has not gone crazy). But if you own a Bearing Rate Computer, I would really appreciate if you scan it with fair quality an post it again, or recommend a url that I can visit and dload a printable version to make one at home.....Thanks in advance....

Well, *PART* of them work, for the inner two wheels.

Here they are again:

Outer two wheels:

http://img441.imageshack.us/img441/2403/brcouter.jpg

Inner two wheels:

http://img441.imageshack.us/img441/1897/brcinner.jpg

You print each page out twice, and cut away the outer rings on one of each print out, so you have 4 'wheels' all of different sizes that should nest upon each other.

[sharky02]

Dear all,
I have a bearing rate computer slide rule, but I do not know how to use it. Please anyone tell me how can I use this rule and what is the goal of using it?

[Pisces]

Multiplication and division of numbers, with nautical meaning in this particular case. There isn't one way to use it. It depends on the formula you need to use. And what you know, and which variable you are after. It's very flexible.

Look at PusterBill's top image. On the top you see 15 knots aligned with 7.2 degrees (ish) of bearing rate. If you want to know how many knots would be needed (or are sufficient)for a 1 degree bearing rate then you keep the disks aligned as they are, and follow the numbers back to 1 on the bearing rate scale. Opposite of it you will find the number 2.08 (ish). Now you did a division by 7.2 (15/7.2=2.08333...)

Basically going around the scales you multiply or divide. For example, on the knots scale a halve lap clockwise is a multiplication of 10, or counterclockwise a division by 10. A full lap is multiplication/ division by 100. A quarter lap is a little more than 3 times bigger or a third smaller (depends on the direction) Though the actuall number might show less or more zeros at the end. You need to keep an eye yourself on where the decimal mark ends up in the resulting number. That is an easy mistake to make.

Another example, if you want to know how wide an angle of 10 degrees is at 4050 yards (bottom image of PusterBill) then you need to multiply 4050 yards by the sine of 10 degrees. (the angle scale is a sine scale) See that 90 degrees is opposite 4050 yards. The sine of 90 degrees is equal to 1 on the left side of the 90 mark. (But about 0.57 degrees at the right side of the mark. Why? sin(0.57)=0.01) Now go over looking at 10 degrees and you'll find about 700 yards on the adjacent scale. Or 4050 x sin(10 degrees) is 4050 x 0.1736. Grab your scientific calculator and compare with other numbers.

If you want to learn more I suggest you learn more about sliderulers that are based on a logarithmic scale.

BTW here is a better quality image of how it should look like.

http://people.msoe.edu/~schlehln/subsim/photos/02_17_02/IMG_0002.jpg

For those that want to make a DIY version of it. The Range in yards should be visible through the top disk, that contains only the bearing rate and angle scale. The bottom disk contains only the Speed/knots scale and the range/yards scake. Using the Pusterbill's images on the other page (with the 2 most outer scales seperated from the 2 most inner scales) might be difficult to recreate this.

[kgsuarez]

That looks really nice. I am going to have to give this a try. This would make a great addition to my slide rule collection.

I wonder if I could take care of most of the project by going to a Kinko's. I'm sure they have most of what I would need.

[micky wannop]

i can send it to anyone who want with instructions on use i used it for real for 23 years yes they still use them in the royal navy submarine service although its a dying art:D

[naseem6611]

am serving on conventional submarine, i want to know the complete procedure on use of bearing rate computer brother above me can help