Wolfpack: Lateral Speed Method

Wolfpack: Lateral Speed Method

In February, I discovered a new method to acquire data needed to shoot torpedoes. I only tested it on Wolfpack -that’s why I post in this section- but it should work on any sub game, and even in real subs.

I searched a bit and so far, I haven’t found this technique anywhere else. Maybe some of you could show me sources of what I think I merely rediscovered.

I will try to explain it in a few words:

Usually, one need at least AOB and target speed to shoot. Range is also needed if gyro angle is high.

Once the ship has been identified, range is quite easy to estimate. Speed can be trickier if you’re measuring it from an AOB that is far away from 90°. And AOB must be the hardest one since you have to either plot target course, measure width/height ratio, or maneuver to a position where target features are visually aligned (kingpost at AOB 90°, some masts at AOB 45°, target track at AOB 0°…)

With my method, I only use range and lateral speed (perpendicular to the bearing). The point is that you can acquire these data from any AOB. Here is a step-by-step procedure:
– Measure range from target with your preferred method.
– Choose a vertical feature on the target (usually a mast) and measure the time it takes for this feature to cross a certain amount of horizontal graduations (centiradians) on the periscope at 6x magnification, I often use 8.
– Use the following formula to compute lateral speed : lateral_speed (kts) = 0.486 * range (hm) * nb_centirad / time (s)
– Enter 90° for AOB input in TDC (starboard or portside, depending on the direction of traveling of the target).
– Enter lateral speed as speed input in TDC.