Q. 110 track?

[commandosolo2009]

Hey skippers,

I wonder how to get a 110 deg track for torpedoes, since I'm playing 100% realism and having read O'kanes' Clear the Bridge! I notice that everytime he shoots, Fraz tells him 15 degrees to go capt, or 10 degrees to go capt, or 5 degrees to go capt. And he consistently mentions a 110 degree track.


Another thing, is that he aimed from aft forward and the explosions were in that order, how is it possible? I mean the only logical thinking was that the target was dead in the waters for shooting in any way aft/fore or fore/aft. Or am I missing something?

[magic452]

The way I understand it Fraz would be winding the TDC backwards, which we can't do, to match the peri view and he would be reading the track angle from the TDC.

O'Kane would point the peri at the stern and shoot, MOT next and last the bow, Fraz would adjust the TDC accordingly. The first torp will hit first. Same going the other way by shooting off the wire but no TDC adjustment was needed.

You can do this somewhat in the game, unlock the target and aim at the stern, send bearing to TDC and shoot, aim at the MOT and send bearing and shoot etc. You gotta be quick to make this work.

Magic

[commandosolo2009]

I think I'm not fast enough for this. My regular attack is 2 bearing and range readings from stadimeter, picking a firing bearing and adjusting range dial to half expected range (say he's assuming course 339 true, and I'm on course 74 true, so I take two bearings say 45 and 35, read out and plot them on map, drag a line, check course consistency and adjust my wheel to it, then pick bearing 20 or 15 for firing at his expected range, the AOB being read from the wheel too.. Now I also get the speed from the tracking bearings [45 and 35], use a stopwatch, then divide distance over time)..

It works everytime. But today, I'll go ahead and try o'kanes' method.:yep:

[magic452]

We can't do it the same way O'Kane did as we can't turn the TDC dials backwards. The O'Kane method in the "bag of tricks" thread is as close as we can come, and it's easy to use and very accurate as long as you get good speed and course for the target. Range really doesn't come into play with this or vector analysis type shots.

Magic

[TorpX]

Hey skippers,

I wonder how to get a 110 deg track for torpedoes, since I'm playing 100% realism and having read O'kanes' Clear the Bridge! I notice that everytime he shoots, Fraz tells him 15 degrees to go capt, or 10 degrees to go capt, or 5 degrees to go capt. And he consistently mentions a 110 degree track.


Another thing, is that he aimed from aft forward and the explosions were in that order, how is it possible? I mean the only logical thinking was that the target was dead in the waters for shooting in any way aft/fore or fore/aft. Or am I missing something?

Magic's explained it pretty well, but I will elaborate slightly:

The targets ship would have been determined well in advance by the plot, and the sub conned so that, the boat's track angle is 110 deg. The TDC would show the gyro angle ticking down towards zero. At this point they would make the attack (a few degrees gyro doesn't matter here). The periscope would be turned just in front of the stern and the bearing transmitted to the TDC (you have the PK off at this point), so the torp is launched at the moment the stern passes the wire. Then the periscope is turned so it is ahead of the MOT and the process is repeated. Finally the periscope is turned ahead of the bow and the last torp is launched. In this way the torps are aimed at stern, MOT, bow. The key here is that the periscope is turned ahead a few degrees for each shot. The order going stern to bow was preferred as this would make for a divergent spread and make it somewhat harder for a target to evade the torpedos.

I consider the system O'Kane and Morton used to be very effective. It allowed O'Kane to focus on making accurate observations and, Morton to focus on conning the boat into the best position. Many skippers would have been too egotistical to even consider this arrangement. It showed that Morton and O'Kane made a great team and also that Morton had great confidence in O'Kane. :salute:

[commandosolo2009]

Magic's explained it pretty well, but I will elaborate slightly:

The targets ship would have been determined well in advance by the plot, and the sub conned so that, the boat's track angle is 110 deg. The TDC would show the gyro angle ticking down towards zero. At this point they would make the attack (a few degrees gyro doesn't matter here). The periscope would be turned just in front of the stern and the bearing transmitted to the TDC (you have the PK off at this point), so the torp is launched at the moment the stern passes the wire. Then the periscope is turned so it is ahead of the MOT and the process is repeated. Finally the periscope is turned ahead of the bow and the last torp is launched. In this way the torps are aimed at stern, MOT, bow. The key here is that the periscope is turned ahead a few degrees for each shot. The order going stern to bow was preferred as this would make for a divergent spread and make it somewhat harder for a target to evade the torpedos.

I consider the system O'Kane and Morton used to be very effective. It allowed O'Kane to focus on making accurate observations and, Morton to focus on conning the boat into the best position. Many skippers would have been too egotistical to even consider this arrangement. It showed that Morton and O'Kane made a great team and also that Morton had great confidence in O'Kane. :salute:


Thanks for the elaboration Torpx. I'm now indulging in Wahoo and soon (like 2 weeks) should get 5 extra books about WW2 American Fleet Boats.

I'm running hot, straight and normal when it comes to this...

[TorpX]

Thanks for the elaboration Torpx. I'm now indulging in Wahoo and soon (like 2 weeks) should get 5 extra books about WW2 American Fleet Boats.

I'm running hot, straight and normal when it comes to this...

Yeah, this forum is a great resourse for good books. O'Kane's are my personal favorites. :DL

[Rockin Robbins]

Nisgeis and I went through this awhile ago when he trotted out the graph that shows the ideal torpedo track angle to make the shot most tolerant of course and speed changes was about 110º, varying depending on the speed.
http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/screenshot77.jpg

Here's the chart for 46 knot torpedo, a Mark 14 on high speed. The angle changes slightly with target speed. The ideal angle increases for a slower torpedo. Now you can drive yourself crazy with the chart, setting up your boat 110º (or a different angle if you REALLY want to be ugh.........fussy).

But if you digest all the numbers for all the charts for all the target and torpedo speeds, they all reduce to one simple procedure. First of all, just set up your boat 90º to the target course. Gyro angles less than 30º were considered straight shots and having no impact on accuracy. Don't sweat the small stuff!

Secondly there is a simple procedure for getting the correct torpedo track angle. Toss out all the charts and complicated setup instructions, we're going to automatically get the correct TTA every time and never change procedure.

Just set up for a Dick O'Kane type shot 90º from the target track, set your AOB for 90º (for the correct side!) and shoot when the target bears zero. Automatically, your TTA will be about 110º, increasing and decreasing automatically with target speed, increasing and decreasing automatically with torpedo speed.

No worries mate! He's going down.

[commandosolo2009]

hey thanks Robbins. Curve is very informative and I'll try your shot. Just one thing though. O'kanes attack needs a ranging (at least with me) since if I follow the procedure as described, maxing range to 3700 meters will need to move in closer and our cumulative range (me and his) would quickly get me in visible range, unless I stop and back up while he's coming to, just to keep it@3700 (max range without identification or mast height) or even with mast height. I also think that if the target is identified, sonar ranging becomes more accurate, at least while maintaining his speed. I shoot when the range difference between sonar\stadimeter is 100 meters or less. More would require a recalculation. I'm guessing the O'kane method somehow lacks clarification.