The ''broken'' TDC Attack Method

[makman94]

The ''broken'' TDC Attack Method
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at this tutorial you will see a method that you can use for attacking after you have found target's speed and course (drawn on map) .

with this method you can attack with any angle (angle between target's and own courses) you want,you don't care about aob or distances to target at the moment of firing or where exactly on its course is the target and by this method you can always achieve the perfect shots.perfect shots are the ones that torpedo's run course intercepts vertically with target's course.
another 'hot' point of this method is that you can change course during attack .(you will have to adjust ,after changing your course, only ONE value)

the example :
at the following example i have allready draw target's course and have found also its speed that is 5 knots

after you have draw target's course on map get the angle lb .at my example lb=105 degrees


as we want to make a perfect shot that means that gyroangle is G= lb-90=105-90=15 degrees

note: if lb>90 then G=lb-90
if lb<90 then G=90-lb

set TDC to MANUAL and NEVER switch it to auto from now on.
adjust the gyro angle to the desire value (15 degrees) via bearing's dial


now the only thing that we want to know in order to make the shot is the shooting bearing . in order to find the shooting bearing we need to know first the angle ''x'' .at the following pic i have drawn the situation and there is showing the angle x


the angle x can be found via the 90° column of the shooting bearing tables.be carefull to choose the table with the torpedo speed that you will use (in this case,we will use the ''44Kts'') and the angle x can be found like this:


so ,at our example the angle x=6,5 degrees so the shooting bearing is 15+6,5=21,5 degrees .thats it ! everything is ready...
we will shoot the target when reach the 21,5 and we know that the impact point will be when target is showing on 15 degrees


you can use freelly your scope (tdc is always on manual) and from now on either you will point your scope to 21,5 and wait the target to cross from there or you lock your scope on target 'following' him till the 21,5 degrees


at 21,5 .....you guessed correct ....FIRE !



and impact will be at bearing 15 degrees




SITUATIONS :

A) PORT ATTACKS





B) STARBOARD ATTACKS






important note 1: the angle lb will determine the gyro angle so you will turn your sub (when starting the attack) that way in order to have a small gyroangle (the method works great also with big gyroangles but less accuratelly,i have made shots with G=50 ) .good gyroangles are + - 20 degrees which means that you will turn your sub in order to adjust the lb to be between 70 to 110 degrees

important note 2: if you change your course during attack the angle that is changing is the lb . so, once you changed your course ,get the new lb from map and the only value that must be readjusted is the Gyro angle . (the angle x remains the same)
so readjust the gyro angle and recalculate the new shooting bearing (a two seconds job with your mind)


important note 3 : at the unusual situation that target have pass the shooting bearing, simply let your scope pointing at the shooting bearing(and don't touch it again from now on) ,then set maximum speed ahead (or backward depending on the situation) and now sit at your scope (don't touch it) and wait till the vertical line ''meets'' the target and ...shoot !

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the idea of this method was ''born'' in my mind after some discussions i had with Geosub (he does not like to use tdc) so credits for this method must also be given to him.



Makman94