[Pisces]

Originally Posted by greyrider

with the constant bearing method explained and posted, the arcade nature of this game is over, but there were two others methods in the TFCM that were taught to u.s. submarines crews, the check bearing and continuous bearing methods. these methods, like the constant bearing method, have very little to go on, and so its alittle like reverse engineering, accept in most cases, there had to be some kind of product in hand to reverse engineer. there is nothing online or in the manual to explain these methods, accept a procedure when firing these methods, the angular set up of the track isnt mentioned, there is nothing, but I think I'm beginning to make headway on these methods and maybe, just maybe.

The differences between the 3 firing methods ''Check Bearing", "Continuous Bearing" and "Constant Bearing" are pretty clearly explained at about 65% of the Submarine Torpedo Firing Control manual. Chapter 7. And to emphasize, it's a firing procedure. Who does what to get the fish swimming. Not a method to close in on a target. Or a doctrine that defines the best angles to approach a target. That's a totally different phase of the whole thing. And nowhere in the whole document is there any suggestion of the approach triangle (AOB, lead angle, trackangle or in terms of sides: range, torpedo track, target track) having to be fixed with certain value angles. You are wasting your time thinking of ways which is the 'one and only true way': a 3-4-5 triangle, sharp or blunt isosceles triangle, 45-45-90, 30-60-90 or for heaven's sake that old 80-10 relationship. Just take the angles as the situation calls for. Maybe a 60 degree track angle to halve your active sonar reflections to approaching escorts. Impact pistol torpedoes don't always like perpendicular hits. Atleast that was one of the design flaws iirc. However, there is a graph for best torpedo track angle vs deflection angle and targer speed. That suggests trackangle should be greater than 90, not less. And periscope direction perpendicular to the target track. Magnetic detonators don't always trigger when crossing the hull perpendicularly underneath either. (Hmm, maybe that was a trick for SH1 I remembered. May not apply to all SH editions.) An angled torpedo trackangle gives it more time to detect the magnetic distortion. Obviously a torpedo track angle of near 0/180 ('down the throat' or 'up the butt') is never going to amount to success. Too easy to miss. Either way, you are free to choose. Each triangle shape has it's merits and drawbacks.

The firing point procedure basically deals with how long or where the Approach Officer (You, the guy looking through the scope calling the shots) keeps the periscope vertical line pointed to measuring range and bearing and aim at the thing to be hit. The TDC operator then adjusting the generated bearing and range (from position keeper I guess) to the actually observed bearing and range whenever the Approach officer calls it valid.

The following is a simplified reduction of the fully explained firing procedures. Go read them yourself for the details.

"Check Bearing" uses an single instant observation of bearing and range to correct the solution for a single torpedo. The torpedo is fired after the TDC dials show a valid solution and spread and the gyro angle in the tube matches to what is commanded by the TDC. The single instant observation is repeated if tracking of the torpedoes to the target is deemed insufficient after launch. Multiple torpedoes are fired after the TDC operator has made his corrections and the torpedo tracking seems good.

"Continuous Bearing" is a prolonged version of "Check Bearing". The Approach Officer keeps the vertical line on the desired spot for a longer period while the TDC operator twists the magic knobs to correct the solution. If the approach officer cannot keep the scope pointed he calls out that his measurements are invalid. Again firing is done under the same conditions as above.

"Constant Bearing" is basically a delayed pre-set version of the Check bearing method. The Approach officer sets the periscope angle ahead of the target bow. The TDC operator does his magic knobs thing again. Assistant TDC operator checks the validity of the solution, spread and gyro matching. The Approach officer then calls "Fire" when the intended impact point passes through the vertical periscope line. For subsequent torpedoes the same procedure is repeated for different target locations. Or with longitudinal spreads (firing of other tubes are delayed as aft-target-hull parts pass the periscope line later) the same relative bearing is used to drive the TDC.

Which one you choose depends on how you can replicate them in the game. Constant bearing is basically the Okane method. No need for explanation there.

Check bearing is basically using the position keeper running, and point the periscope once (no locking). Then send measured bearing and range by feeding data to the TDC. AOB and speed won't be corrected so as time passes the solution might still diverge from the real target track. But I think this applies to all three procedures.

Continuous bearing procedure in game can be simulated as Check bearing with locked scope on target. It won't update the bearing and range to the TDC until you send it though. It's not really a continuous update of the TDC. Just looks like it. Maybe fits best with the automatic TDC realism option turned on.