von Zelda

As it applies to SH3, this is an attempt to write a tutorial for the Whizz Wheel to determine and set AOB with a known target course. The basis for this is that there is a constant angle or AOB at the intercept point of your course and that of the target's course. You can easily determine this mathematically: the difference between the target's know course and the reciprocal of your course = intercept angle. As an example: your course is 39-degrees (reciprocal = 219) and target's course is 315-degrees. Therefore, 315 - 219 = 96-degrees at intercept point. But, the following is how I think you can determine this by the Whizz Wheel without doing the math:

1) Determine the true course of your boat and that of the target.
2) Set the red triangle on the Angr/Krus rotor tool to the zero bearing on the outer non-movable ring (this is becaue your bow is zero bearing and your aft is 180-degree bearing).
3) On the movable middle ring, align the outer degree scale to the red triangle (zero bearing on the outer ring) for your true course. (This is your true course or direction in degrees that your bow is heading.)
4) Using the rotor with the black triangle and yellow boat, locate the target's true course on the outer degree scale of the movable middle ring then rotate and place the black triangle to the target's true course on this ring.
5) Rotate and align the zero bearing of the movable inner AOB ring with the target's true course (black triangle on the yellow boat).
6) Depending on which side the target is passing across your bow (port = red and starboard = green) locate the degrees for AOB on the inner ring that lines up with your course on the Angr/Krus rotor. This represents the AOB degrees at the intercept point of your course and that of your target. It's worth noting the two little boats on the Angr/Kurs rotor. One has a black bow and the other a black stern. If you are traveling toward the target's course you would look for the boat with the black bow at lower end of rotor which is actually pointing to the reciprocal of your course because as mentioned in the first paragraph, the angle is the difference between the target's course and your reciprocal course. Now, if you are traveling away from the target's course (firing stern tubes) you will look for the boat with the black bow on the upper part of the rotor. The solution in degrees now results from the difference between target's course and your true heading.
7) (to set AOB in the game) If you are firing from the bow, set the UZO/periscope to zero bearing and input degrees determined in step six into the note pad for angle on the bow. If you are firing from the stern, set the UZO/periscope to 180-degrees and input degrees determined in step six into the note pad for angle on the bow. Pay close attention to inputting red for port and green for starboard. You now can rotate the UZO/periscope to the target and you will automatically have the correct AOB as it travels along its course.

8) (optional method to set AOB) After step six, locate target in the UZO or periscope and "mark" the bearing (tap lock on, then tap lock off and then don't touch this bearing until after step ten). Observe and note the target's bearing in the UZO or periscope.
9) Using the odd looking Vorhalt rotor, set its pointer to the target bearing you noted in step eight. Read the degrees where it crosses the line on Angr/Krus rotor. Whether or not green or red, this is the number of degrees (+ or -) to adjust from the degrees at course intercept point. Most likely your target has not passed the intercept point, in which case you subtract this amount from the degrees at intercept AOB. In the remote chance that the target has passed the intercept point, you would add the degrees to the degrees at intercept point. The result becomes the AOB at your "mark" (bearing) in step eight.
10) With the UZO or periscope still set to the bearing in step eight, enter this calculated AOB using the note pad. You now can rotate the UZO/periscope to the target and you will automatically have the correct AOB.


An example from a merchant that I sank last night. It is interesting because I set up an attack from the stern tubes.
1) My true course was 219-degrees which was the reciprocal of the heading towards intercept point of 39-degrees. The target was heading 315-degrees. (If you'll note from the first paragraph, this a 96-degree (red) angle at the point of intercept.)
2) Set the red triangle on Angr/Krus rotor to zero bearing of outer ring.
3) Turn and align 219-degrees on outer middle ring with the line on the Angr/Krus rotor and red triangle.
4) Turn and place black triangle in yellow boat rotor on 315-degrees on outer scale of middle ring.
5) Turn and align zero bearing of the inner AOB ring with the 315-degree mark on the outer scale of middle ring (black triangle in yellow boat).
6) Read the resulting degrees on red AOB scale which aligns with line on Angr/Krus rotor. Note that this reads 96-degrees. This is the angle to intercept point for torpedo run of both courses.
7) With UZO/periscope set to 180-degree bearing (remember I'm firing from the stern) input the 96-degrees red (port) into the note pad. Remember to click all the check marks to input to the TDC!

8) Option for Step Seven: Using the UZO, I marked the current bearing of target at approximately 209-degrees.
9) Using the Vorhalt rotor, I set its pointer to approximately 209-degrees on the outer ring. This resulted in an approximate 31-degree red on the Vorhalt rotor. Now, subtract 31-degrees from 96-degrees in step six since the target had not passed the course intercept point. You have a 65-degree AOB at your UZO "mark."
10) At the UZO screen without changing the UZO bearing from step eight, input 65-degrees red (port) into the note pad. Click all checkmarks. This should result in the correct AOB as you rotate the UZO onto the target.

Well, try this out and see what you think. Hope this might be helpful.