Lil Help please
 

thanks much

First off, I'm glad to see interest in the Is-Was I made; I hope it helps people enjoy SH 4 even more.

Regarding transparency, the original had both the C and Periscope dials clear, but after your comments, I don't see why the C dial couldn't be printed on paper. But the Periscope dial must be clear so that you can see the values underneath.

The way I believe the wheel works is like this. Prior to a ship sighting, the A and B dials can be pre-set together to your heading, with the "0" degrees mark of the A dial representing the front of the ship, and the B dial showing true heading of the ship, by placing the heading value at the A dial "0" degrees mark. So if you're heading due east (90 degrees), then the A dial "0" degrees mark = the B dial "90" degrees mark.

So let's say you're traveling due east, 90 degrees. Then suddenly, you get a ship contact (Via sonar, periscope, etc. It doesn't matter). "Sir, new contact, 300 degrees relative!" What I do is I move the Periscope dial so that the triangle is over the A dial "300" degree mark. This is also equal to a B dial value of "30" degrees. The B dial can now tell you what true heading to take if you want to head straight for the contact. "Helm, make new course 30 degrees".

But let's pretend you don't change course. Ok, now the last bit of the puzzle is Angle on the Bow. You have two ways to use this. First, if you can determine the true course of the contact via plotting, you can input the contact's heading to determine AoB. "Sir, contact heading is plotted out to be 330 degrees!" You do not move the A, B, and Periscope dials; you move the C dial until the "0" degrees mark of the C dial is pointing to the "300" degrees mark of the B dial. When you do this, you look at the Periscope dial marker 180 degrees opposite the Periscope triangle. This marker points at "120", on the left side of the C dial ship, so this tells you that the contact AoB is 120 degrees port.

On the other hand, let's say you visually estimate the AoB, and decide it to be 100 degrees port. You move the C dial "100" port value so that it matches up with the Periscope dial marker that is 180 degrees opposite the triangle. When this is done, you can then determine via the B dial that the contact's heading is 310 degrees true.

Once this is done, you decide to make a direction change, and head straight for him. You do not move the B, C, or Periscope dial; instead, you just move the A dial so that the "0" value matches up with the Periscope marker that you had already preset above.

That's probably a way-too-verbose answer, but I hope it helps. I suggest playing around with it for a while, and eventually you'll get the hang of it. Good luck!

im not sure if i get it right...

You can find the course of your target with that? Why anyway? the more interestning thing to find out would be the AOB.

btw ive seen pictures of a wiz wheel as it was used in german submarines. They have used the known or guessed length of the target to find its AOB. Basicly its the same method as you find the range by mast high.

Hmmm - now this sounded like a very cool (and relatively easy) idea at first - if you have a decent range estimate, and you can measure the observed/apparent length (presumably by reference to the markings along the horizontal/x-axis of the scope/TBT), it would seem to be a relatively simple matter of math/formulas to compute the AOB based on the relationship of the apparent length to the actual length (available from the recognition manual). However, I wonder if a wiz-wheel to do this would really be any easier to deal with than the Is-Was thing described in this thread, and this one seems to let you calculate either AOB or target course, depending on which data you already know, which is probably more useful than the above sort of special-purpose AOB calculator would be. Will have to see if I can put one of these Is-Was things together - sounds very cool.

Submarine Attack Course Finder (a.k.a. Is-Was / Banjo)
 

Thanks CC!

That did the trick!

Cheers :up:

I'm finishing a tutorial with screenshots on a method to get the AOB based exactly on that. I call it the "Aspect Ratio" method, because it relays basically in how much the relationship between height and length of the ship you see changes towards the standard aspect ratio when at 90º AOB.

This is the part that dials with the AOB:

Excellence awards to :

Capt K for iswas & Hitman for aspect ratio. Nicely done gentlemen. :up:

well actualy the real AOB finder that ive seen pics of only needed the known length and "angle of projection" data. Seemed to be very easy and quickly to set up.

angle of projection is the ralative angle of the ship to your boat from bow to stern. You can find it by counting the horizontal marks in your persiscope. The manual says each mark is 1° or 4° depending on zoomscale.

Well, I assume that you would still need to know something else besides the known length and apparent length ("angle of projection") - i.e., the range, because the apparent length will obviously be different at different ranges. I was thinking about a method that used the range directly, along with actual and apparent length, but that of course requires you to first determine the range and then input it into some formula/chart/wheel mechanism for solving AOB. The aspect ratio approach outlined above takes the range into account indirectly - since the apparent mast height also changes with range like the apparent length, by using the ratios of the two you don't need to actually determine or know the range to solve for AOB - you only need the apparent height and apparent length (to compare against the known values from the recognition manual or pre-determined aspect ratios from a chart), and both of those can be obtained from the 'scope - a clever way to avoid the stadimeter CTD bug for those who still have that :)

I'm not sure if I'll take the time to use these methods during combat, but they sound like a pretty good way to confirm my AOB estimates and "train" my eye during sub school practice to make better guesses using the Mark 1 Eyeball.

Perhaps this and any other device link could be made into a sticky??

Exactly that :D

As I had previously stated , so the range is irrelevant.

In the german method indicated by WernerSobe you must have at least one range readout, otherwise you have nothing because the same ship can f.e. extend 24 scope marks in horizontal at 90º AOB at 2000 yards or at 45º AOB at 1200 yards (Numbers not calculated precisely ). With my method that's not needed at all.:know:

Making the Is/Was
 

I bought three different sized, circular plastic, school boys protractors. Cost UK £2.

The back side is the run time calculator.

Sorry sqk7744 but I think you got it wrong :-? Though I might be wrong, of course, but see if this example seems more correct:

http://img224.imageshack.us/img224/6...njo1bs8.th.jpg

1.- Our own ship true course is 90, as highlighted in the red circle or our own ship BOW. The target's true course is 300º.

2.- We need to turn the scope left 60º, to our relative 300º, to see the target. The A ring scale is inverted exactly for that. When we turn the upper part of the scope left (Yellow arrow) we can correctly read in the opposite part of the scope ring that we have gone to the "300" mark of the A ring (yellow triangle marker in the handle), i.e. of our relative bearing. We also can see now in the middle ring (B ring of true course) that the relative course to our target would be 210º for us.

3.- Finally the AOB of the target can be read in the other scope ring marker (Highlighted with a green triangle). In this case it is 90º, not 120º as you had indicated. You got the wrong result because you reversed the own ship. This can be seen clearly in this edited picture of your setup:

http://img300.imageshack.us/img300/7...ring300qf6.jpg


Hope that helps:up:

EDITED to add:

The tool is in fact, as the name says, a "course finder" so in real life the inputs of the tool would be: 1) Own true course, 2) Target bearing and 3) Target AOB. With that input the tool would give you as output the true course of the enemy.
But in SH4 as in SH3 people tend to do the opposite, i.e. determine first true course of target and use the tool to get the AOB. Probably as someone highlighted in another thread, this is due to the AOB being more difficult to determine in a flat screen as opposed to real (3Dimensional) world, but anyway the real use of this wiz-wheel comes to be very clear when you play at 100% realism, i.e. with no map contact update and view limited to your bridge/scope/TBT.

Also, another problem with this wheel is that in SH4 we are used to see in the upper part of the scope the graded reticle for the target bearing, so we tend intuitively to look for the bearing in the upper part of the scope. But when doing so in this wheel, the AOB would be reversed! This is the main reason why the scale is reversed in the A ring: That you can have in the same marker (Scope ring handle) both target bearing and AOB. If you put one of them in the opposite side, you get a wrong reading, and if you put both in the other extreme, you have a reversed result.

My take on this neat addition to whiz-wheels is:

You have 3 templates:

A (the big outer wheel) = True compass

B (middle wheel) = Submarine (all bearings relative)

C (inner wheel) = Target

Scope (transparency) = cursor

Here is a copy of my old orig SH1 whiz-wheel,

http://img256.imageshack.us/img256/6941/wizha6.th.jpg

as you can see, (forgive the blurriness), I've set it to the params of the problem. You need to do the same with the new wheel.

Cheers,

youre right there was also the range involved.

Don, in my opinion you can't apply this to the wheel we are using because the outer ring has the ship silhouette -thus purpose made for own ship- and also inverted bearing scale. As I said before, the only way to make sense of that inversion is when turning scope left or right.:up:

I like give my 2 cents worth on how to use the Is-was/banjo using cpt krunch example.

The Is-was/banjo has 4 dial

A dial is the submarine
B dial is the true compass
C dial is the periscope ruler
D dial is the enemy ship

The banjo can used to find the AOB of the enemy ship or the course of the enemy ship. However in each case three piece of information is required.

1) TO FIND AOB OF ENEMY SHIP

Three piece of information is require - your sub course, the relative bearing, the enemy course

a) Our sub course is 90 degree east.

According to cpt Krunch, he align B dial 90 degree to A dial at 0 degree.
I disagree that is the right procedure.

I think you should align B dial 90 degree to A dial at 180 degree. The triangle protruding out of the A dial is always the submarine bow and the opposite semicircle in dial A is the submarine stern.

b) From the periscope we spotted a ship and the relative bearing is 300 degree.

This is the same as capt Krunch. Move the periscope tab or c dial so that the outer marker in the periscope tab is over the A dial at 300 degree mark. Note in the periscope tab, there are two markers. One is pointing to A dial and the other is pointing to D Dial.

c) We have a contact heading 330 degree.

Move the D dial 0 degree (which represents the bow of the enemy ship) to B dial at 330 degree. (B dial is the true compass)

When you have done this, you can find AOB easily by reading from the periscope tab, the inner marker which points to the D dial at 120 degree port.

2) TO FIND THE COURSE OF ENEMY SHIP

Three piece of information required: The sub course, the relative bearing and the estimated AOB

a) Our sub course is 55 degree.

B dial 55 degree to A dial at 180 degree. The triangle protruding out of the A dial is always the submarine bow and the opposite semicircle in dial A is the submarine stern.

b) From the periscope we spotted a ship and the relative bearing is 260 degree.

Move the periscope tab or c dial so that the outer marker in the periscope tab is over the A dial at 260 degree.

c) Estimated AOB is 45 degree starboard.

Move the D dial starboard 45 degree to the inner marker of the periscope tab. At this point the outer marker is pointing to 260 degree of A dial and inner marker is pointing to D dial at 45 degree starboard.

To find the course of ship, read the 0 degree of D dial (which is the bow of the enemy ship) to B dial. You will find the enemy course to be 90 degree.

I hope I have not confuse the picture further. My only difference is that I believe the 180 degree in A dial is the bow of the sub where as the 0 degree is the stern of the sub.

Igorry

Rgr that, Hitman.

I'm in the process of building one of the new w-w's. I'll follow your instruction tomorrow when it's completed. (kinko's)

tnx,