whats your favorite way to calculate speed?

[nattydread]

Originally Posted by Banquet

It is difficult.. I'm struggling too for the same reasons.. but one way around it is to make pass a periscope depth.. take a look at the general layout of the convoy, ship types, escorts and most importantly heading and speed of the convoy. Then increase distance.. come back to the surface and steam ahead of where you calculate (based on their heading and speed) they will be. You can then settle into a nice submerged position as they roll by. You should already have their speed, a good idea of AOB (set it for 90 degrees and hold fire till they hit that position) All you need to do is ID them again and get range.. Unless they change course.. in which case you're buggered! (been there, bought the T-shirt!)

Its hard to do execute end-arounds in a S-boat.

[Dustyboats]

Providing you are dived, your passive sonar gives you a bearing. Use the "marker" to place an "X" at the extreme end of that bearing and note "time".. As the bearing rate alters, place another and so on until you have about 6 or 7 "X's". They may seem to be scattered but you can take a mean line through them, using the "ruler". This should give you a fairly accurate course of the target until you close to your "prior to aiming point". Having those "X's" timed you can now work out speed by taking the "compass" tool and get "distance travelled by target" measuring from your first "X" marker to your last......in so much time, (which you have noted), target has travelled so many nm or meters(or parts of)...you have your speed to within + or - 1Knt.

[skullman86]

Not really a favorite per se but it's currently the only way I know how to get speeds and it works.Yes...........I guess the speeds , only because I cant figure out the tdc (I got used to SH3, I could sink 'em while submerged then they go and change it ), I just use the periscope.....From my experience, merchant vessels go about 3-4 knts on average (when they are unaware of my presence) and cruisers/destroyers go about 8-10.5 knts on average (again.....only if unaware of my presence).I hit my targets quite often actually, not always kills *cough* duds *cough* but I do at least hit the target :rotfl:.

[LukeFF]

Originally Posted by nattydread

Its hard to do execute end-arounds in a S-boat.

It's essentially a WWI-era boat. Go figure...

[AVGWarhawk]

Originally Posted by duelen

im sorry for so many questions

when you say you look in your periscope to compare to the top picture in the pk, are you talking about the bearing numbers or the picture of the boat? ITs probly simple but my mind is not graspinng it

Ok, simpler terms. Say the target is at 90 degress to your bow. You set the AOB on the PK at 90 degrees. Now imagine if you will your sub travelling north and your target is travelling west. The PK outline of the target will have pointed bow pointing to the left. Your PK for your sub will have the bow pointing up and at a 90 degree to it. Set what you believe to be the target speed. Wait about a minute and check AOB again. If you see the targets AOB has increased visually from the scope as compared to your first 90 degree AOB input to say 100 degrees then you know you have dialed in a lesser speed then what is seen in your scope. The PK AOB dial will still show 90 degrees because this is the value you inputed to for he PK to keep. But hey, I look in my scope and now the target is at 100 degrees AOB and my AOB on the TDC said it should still be at 90 degrees. My target is moving faster than I predicted. Slow the speed down in the TDC of the target and get another look in about a minute. Look of the target shows 90 degrees to my eye and my PK outline of target is showing 90 degrees. My target speed is dead on. Keep making checks every minute or so. As long as the top dials AOB is not changing in relation to your observation in the scope then you know you speed calculation is good.

[Hitman]

The PK AOB dial will still show 90 degrees because this is the value you inputed to for he PK to keep

Are you sure? The PK does a simulation or prediction about the target movement, based on your first inputs. The AOB will only stay the same if you are approaching your target from 90º at the SAME speed the target travels (Both sides of that triangle turn shorter at the same proportion). But if you or he are going faster, the AOB will change even if the solution is still correct.

I think it is the target bearing in the own ship dial what will tell you if speed is good or bad, not the AOB. The AOb in 99% of the situations is dynamic, i.e. changes constantly as the ships approach. Only exception is the one described above.

I think

[Banquet]

Originally Posted by nattydread

Its hard to do execute end-arounds in a S-boat.

It goes faster than most merchants.. it will take longer but it's do-able

[AVGWarhawk]

Originally Posted by Hitman

Are you sure? The PK does a simulation or prediction about the target movement, based on your first inputs. The AOB will only stay the same if you are approaching your target from 90º at the SAME speed the target travels (Both sides of that triangle turn shorter at the same proportion). But if you or he are going faster, the AOB will change even if the solution is still correct.

I think it is the target bearing in the own ship dial what will tell you if speed is good or bad, not the AOB. The AOb in 99% of the situations is dynamic, i.e. changes constantly as the ships approach. Only exception is the one described above.

I think

Good point and it might possibly be but I use the AOB indicator on the TDC. If she start changing to what I see in the scope, I know my speed is off. From what I see, your positions should not change at all on the PK once the values are inputed. My sub is the constant. I have my rudder amidships. I have not made an navigational changes. Therefore, the lower dial that is my sub should not change at all. Now, the target is unpredictable but in most cases just sails at a steady speed at a steady bearing. Therefore, the top AOB dial should stay the same as well. Once the PK is in motion the values inputed should remain a constant unless one of the values is screwed. More often than not the speed is screwed. Distance is pretty easy to get, setting the AOB is pretty easy...now guessing the speed is the hard part. At any rate, once your dials stay constant you have a good solution. What I have found is my AOB dial starts to move and looks nothing like I see in the scope, my speed is off. Make the adjustment until both dials (you and the target) stay constant. Get to under 1500 yards, dials look like what you see in the scope and you bag your merchant. Remember though, all three values are important because as you get closer the target is passing or getting ready to pass the bow of your submarine your dials should start to move as the PK is predicting mechanically were the target is. At a great distance your dials will move very little or not at all. As you get closer the dials will start moving. I mean 1500 yards and closing the dials will really be moving quite a bit. They should at this point be doing that. They are keeping the position based on your three inputs. No need to adjust again because the gyros are updated as to what angle and speed. Quite a simple machine the TDC, but a wonderful device once you play with it and learn how it works.

In fact, if you are dead on with you PK. Lower the scope. Watch your distance to target slowly diminish. Once you are under 1500 yards, fire! No need to look in the scope when you do this because the PK has keep the constant provided your last calculations were very accurate and the target did not change speed or course. Watch the clock until you hear "TREFFER" oops "Torpedo hit".

[Onkel Neal]

Originally Posted by nattydread

Its hard to do execute end-arounds in a S-boat.

And it should be! Guess that makes the pressure and suspense even greater.

[Schlageter-JG26]

Personally, I lick my finger and point it in the air to guesstimate.

In this game, unless you are firing A) beyond range of 3000, B) at a target as it zig-zags or C) at a ship which is bearing straight in on you.... the solutions aren't terribly difficult. Generally, 2 clicks left or right will hit. For me, it only gets tough when the ranges are under 800... say when a DD is hunting you at full speed. Then its a tough call, no matter if they are doing 5kn, 9kn, 21kn or 34kn. Getting the solution right at that range is a pain. Less so if you open the tube first.

Caveat: I try to take all my shots with a 90* angle on the target, thus my generality of 1-2 clicks works well... its rare that I slip one past the target.

[sea enemy]

From the book Wahoo by R.H. O'Kane:
"Two more fish were on their way to hit amidships and under her bow, all in an elapsed of 15 seconds.
Buckley reported, "All hot, straight and normal," but I could see the faint, blue smoke of our last torpedo
heading towards, not leading the enemy. They would all miss astern. We fired another torpedo with the destroyer's
speed on the TDC increased to 18 knots, but now alerted, she turned away just in time..."

They had the same problems in the real thing, too....Missing a DD at point blank range because of a 5 knot speed TDC entry error.

[Simets]

This is my favourite way

http://www.subsim.com/radioroom/showthread.php?t=110583

[AVGWarhawk]

Originally Posted by Schlageter-JG26

Personally, I lick my finger and point it in the air to guesstimate.

In this game, unless you are firing A) beyond range of 3000, B) at a target as it zig-zags or C) at a ship which is bearing straight in on you.... the solutions aren't terribly difficult. Generally, 2 clicks left or right will hit. For me, it only gets tough when the ranges are under 800... say when a DD is hunting you at full speed. Then its a tough call, no matter if they are doing 5kn, 9kn, 21kn or 34kn. Getting the solution right at that range is a pain. Less so if you open the tube first.

Caveat: I try to take all my shots with a 90* angle on the target, thus my generality of 1-2 clicks works well... its rare that I slip one past the target.

I do not tangle with DD unless I will win for sure or I'm cornered. I would rather fight another day.