Torpedo Manual Targeting discussion

[Bosk]

Hi there,

I've been using manual targeting for the past couple of weeks in SH3, having been a 'full auto' kind of guy for many years. I've found it really adds another level of satisfaction to the game making going back to weapon office assistance very difficult indeed.

I know it's possible to use mathematics to calculate AOB when you aren't able to use the "easy method" of simply approaching perpendicular to your target each time.
What I'd like to know is does calculating AOB become something that experienced captains (who've been manually targetting for years) can do off the top of their heads, simply by looking at the angle of an approaching ship and estimating it's speed?
I ask because I've tried using such a method and have had a small amount of success, but are concerned that I might be getting myself into 'bad habits' and limiting the accuracy of my torpedos unecessarily.

Another thing that interests me is setting the torpedo bearing in manual TDC.
I'm aware that to ensure maximum accuracy the bearing should ideally be as close to 0 as possible to ensure 000 gyro angle, making the torpedo head do as little work as possible.

The thing is though, when coming to periscope depth near (or in the middle of) a convoy it is often very, very difficult to perfectly line the sub up with the approaching target to guarantee a 'perfect shot' in time before the escorts spot you. It would often be very useful to "slingshot" torpedos using a gyro angle much greater/less than 000 to attack targets to the far left or right of the submarine without having to come around.
My question is, does taking this sort of approach compromise the accuracy of one's torpedoes unecessarily?
And does it lead to an anacceptable percentage of dud's due to the shallower angles at which they strike their targets?

I would like to get the views of experienced high-realism captains on these matters.

I'd also be very interested to hear if there were any protocals/guidelines in place during the War which dictated the way real German captains were encouraged or forced to used their torpedoes- or were these matters that weapons officers tended to handle instead?

[von Zelda]

I've found it really adds another level of satisfaction to the game making going back to weapon office assistance very difficult indeed.

I know it's possible to use mathematics to calculate AOB when you aren't able to use the "easy method" of simply approaching perpendicular to your target each time.
What I'd like to know is does calculating AOB become something that experienced captains (who've been manually targetting for years) can do off the top of their heads, simply by looking at the angle of an approaching ship and estimating it's speed?
I ask because I've tried using such a method and have had a small amount of success, but are concerned that I might be getting myself into 'bad habits' and limiting the accuracy of my torpedos unecessarily.

Another thing that interests me is setting the torpedo bearing in manual TDC.
I'm aware that to ensure maximum accuracy the bearing should ideally be as close to 0 as possible to ensure 000 gyro angle, making the torpedo head do as little work as possible.

The thing is though, when coming to periscope depth near (or in the middle of) a convoy it is often very, very difficult to perfectly line the sub up with the approaching target to guarantee a 'perfect shot' in time before the escorts spot you. It would often be very useful to "slingshot" torpedos using a gyro angle much greater/less than 000 to attack targets to the far left or right of the submarine without having to come around.
My question is, does taking this sort of approach compromise the accuracy of one's torpedoes unecessarily?
And does it lead to an anacceptable percentage of dud's due to the shallower angles at which they strike their targets?

I'd also be very interested to hear if there were any protocals/guidelines in place during the War which dictated the way real German captains were encouraged or forced to used their torpedoes- or were these matters that weapons officers tended to handle instead?

You've asked many thoughtful and complex questions.

Regarding weopon officer assistance, it was the First Watch Officer duty to man the UZO, call out information and conduct the attack while surfaced. The Captain maintained control of the boat. On submerged attacks, the Captain manned the periscope. This is my opinion, in real life there were many men to share the attack responsiblities and procedures. In SH3, there is only one person trying to do it all, that's quite a bit to handle.

The most important factor in manual targeting is target speed. The second most important factor is AOB. The mathematics of AOB is this: Assuming you are on an intercept course, AOB of the course intercept point is the difference between the target's true course and your reciprocal course. Example: target heading is 350-degrees, your heading is 90-degrees; your reciprocal is 270-degrees, thus 350 - 270 = 80-degrees angle at target intercept. If you now set your UZO/periscope to zero degrees and input 80-degrees RED (port) into the note pad, all rotation of the scopes will accurately produce the correct AOB at scope cross-hair. This is the easiest way to set accurate AOB.

Gyro angle really has nothing to do with the angle in which the torp hits the target. At zero gyro angle the torp is firing straight out of the tube with no turns. Thus, the greater the gyro angle the more turn the torp needs to make and less accuracy. I usually set up an attack position, figure out target speed, AOB and am in a good distance to torp intercept. Then I'll rotate the scope to zero gyro angle and wait for the target to cross they cross-hairs and fire. I hit many targets with much less than a 90-degree torp to target angle of impact. The less the angle, the more chance of a dud of course. A more important facture to me is depth. I like shallow depth settings, no more than 1/2 of draft.

When you get near or inside a convoy, just set up an attack position, shoot all your torpedos as best and as quickly as possible then get out of there. Leave the accuracy to the unescorted targets, you have time to plan those attacks.

There is a paperback book that you should be able to find, it's called the U-boat Commanders Handbook. It's the English reprint of the original commander's handbook. There are also many other great books available about u-boat warfare, Battle of the Atlantic and the Kriegsmarine. You can search for these on Amazon and eBay.

I hope this answers some of your questions.

[Brag]

anti poll bump

[joegrundman]

you can also get the U-boat commander's handbook for free on the internet here,

http://www.hnsa.org/doc/uboat/index.htm

but i don't know if its exactly the same as the one von Zelda indicated

[von Zelda]

you can also get the U-boat commander's handbook for free on the internet here,

http://www.hnsa.org/doc/uboat/index.htm

but i don't know if its exactly the same as the one von Zelda indicated

It is exactly the same as far as I can tell. It lacks the book's introduction, but otherwise the reprint of the original in English is all there.

[joegrundman]

Another thing that interests me is setting the torpedo bearing in manual TDC.
I'm aware that to ensure maximum accuracy the bearing should ideally be as close to 0 as possible to ensure 000 gyro angle, making the torpedo head do as little work as possible.

The thing is though, when coming to periscope depth near (or in the middle of) a convoy it is often very, very difficult to perfectly line the sub up with the approaching target to guarantee a 'perfect shot' in time before the escorts spot you. It would often be very useful to "slingshot" torpedos using a gyro angle much greater/less than 000 to attack targets to the far left or right of the submarine without having to come around.
My question is, does taking this sort of approach compromise the accuracy of one's torpedoes unecessarily?
And does it lead to an anacceptable percentage of dud's due to the shallower angles at which they strike their targets?


You don't want to fire on a bearing of 000, you want to fire on a gyro angle of 000. It maybe that you mean the same thing here, but generally speaking the gyro angle is the angle the torpedo will adopt relative to the heading of the submarine, whereas the bearing is the bearing to target. They are not the same thing at all.

Assuming you have a track angle of 90 (that is your submarine is perpendicular to the track of the target), then the bearing to the target at which there will be a gyro angle of 000 is a function of the torpedo speed settings and the target speed. Typically for a fast running torpedo against a target moving at 7 kts, the bearing to target is +/- 9 degrees from dead ahead. For a target moving at 18kts, it's around +/-22 degrees.

The mathematics of it mean that when you are positioned perpendicualr to the target track, and fire on the 000 gyro angle, range becomes irrelevant. The further you are from that ideal situation, the more critical range becomes.

In the extreme case, you are travelling parallel to the target track and intending to fire more or less at a gyro angle of 90 degrees. it is fine to do this, but you must have a very good range estimate. The reason range suddenly becomes so critical is because of torpedo tube parallax, which is to say the difference between the position of the scope view and the torpedo once it has completed its turning circle. With a 90 degree shot this is significant. The TDC will have programmed a converging course for the torpedo to meet at the range you have given. Unless that range is accruate, it could easily follow a very different angle and miss the target altogether.

[von Zelda]

In the extreme case, you are travelling parallel to the target track and intending to fire more or less at a gyro angle of 90 degrees. it is fine to do this, but you must have a very good range estimate. The reason range suddenly becomes so critical is because of torpedo tube parallax, which is to say the difference between the position of the scope view and the torpedo once it has completed its turning circle. With a 90 degree shot this is significant. The TDC will have programmed a converging course for the torpedo to meet at the range you have given. Unless that range is accruate, it could easily follow a very different angle and miss the target altogether.

Well said.

[U49]

I'm aware that to ensure maximum accuracy the bearing should ideally be as close to 0 as possible to ensure 000 gyro angle, making the torpedo head do as little work as possible.
[...]
I'd also be very interested to hear if there were any protocals/guidelines in place during the War which dictated the way real German captains were encouraged or forced to used their torpedoes- or were these matters that weapons officers tended to handle instead?

As you already wrote, accuracy is degraded as the gyro angle is not a perfect 0 deg.

Kriegsmarine advised their weapons officers to prefer 0 deg if the situation allowed for it. Not so much about accuracy but it remedied the fact that a broken torpedo guidance unit could ruin the shot.
On such an occasion the torp' would still have good chances to hit the target if fired a 0 deg.