Fast 90 Attack tutorial for Wolfpack

[Jonny-Dog]

Here is a tutorial I've made for setting up a "Fast 90 Attack" in Wolfpack.


https://cdn.discordapp.com/attachments/576595241679716377/1085144072638959616/Fast_90_Attack.png


Enjoy,
Jonny-Dog :Kaleun_Periskop:

[Pisces]

Here is a tutorial I've made for setting up a "Fast 90 Attack" in Wolfpack.
I could not figure out how to insert an image to this post, so you have to download it at 4shared (https://www.4shared.com/s/fEXNMQaYEgm).




Enjoy,
Jonny-Dog :Kaleun_Periskop:You can attach an image (or whatever small file) like shown in the image I just attached.

[edit: hmm quality is pretty bad though. I guess I didn't pay attention to image filesize and resolution]

[Justaguyinnc]

hope this helps...:salute: just bracket the image file with internet file location
https://i.imgur.com/l6tWG81.png

[Jonny-Dog]

Perfect :Kaleun_Thumbs_Up:

[Pisces]

I don't have that button. Down in the left corner it says "You may not post attachments".
Never mind, just download the file from 4shared. :yep:Ok, maybe this has to do with the level of our post-counts. Or that I made a donation for the annual Subsim Fundraiser. Never the less, the upload to an external site that you and Justaguyinnc did is a better solution. But it will eventually vanish I suspect. Free services don't have a long lifetime.

[Onkel Neal]

How to add images at Subsim
http://www.subsim.com/radioroom/images/photo_howto/

[Jonas Grumby]

Seems like the O'Kane method.
Took me months to get that down on SH4. I've had it mastered for years and now I have to study and practice all over again.
I love it!

[gutted]

Seems like the O'Kane method.
Took me months to get that down on SH4. I've had it mastered for years and now I have to study and practice all over again.
I love it!

Approach from 90 degrees. Set scope to 0, set 90 AOB (port or starboard), input speed, ignore range. Swivel scope until the gyro reads 0 and thats your shoot point. It's not hard.

The only difference with this game is that you can't actually see the gyro while in the scope. So you have to disable the TDC from the scope then move the heading dial on the TDC (which should really be labeled bearing) until you find the bearing that zero gyro is on, then re-slave it to the scope and put the scope on that bearing. Or just have the man on the TDC tell you when the you are on the zero gyro.

[pfs]

:up: excellent

[Aktungbby]

pfs!:Kaleun_Salute:

[JuanLiquid]

Maybe I didn't understand it right.

But once you know speed and course (aob), it should be as easy as aim with the attack periscope to the ship, place speed&aob in the TDC, and a estimated range (very rought one, by eye) and fire.

I don't see any advantage using this method. In fact it is very uncomfortable if you are targetting multiple ships which are sharing speed&heading :hmmm:

Could someone explain it further? Why is it better than classic method?

[Pisces]

It is almost the same as you do, except that by turning the heading/bearing dial until the torpedo gyro angle shows 0, you take range out of the equation. As it is only needed to correct for the straight and then curved path the torpedo takes after leaving the tube. Range is also needed to calculate the spread for a salvo on a target of certain length. But if you want to fire single shots then range is no longer a factor if torpedoes move out straight ahead.

When positioned perpendicular across the target track you get the best benefit of their broadside showing the largest angle to hit into. Less chance of a miss compared to bow-on or stern-on shots. You can orient the uboat to be off from perpendicular if you wish, but then it is best to set the AOB off as much from 90 degrees as you are from perpendicular. AOB is less than 90 if you are oriented towards the oncoming targets, and AOB should be more then 90 if you are slightly oriented towards the target course.

Once you know the target course it becomes 'easy' to position yourself ahead perpendicular of the approaching convoy. Waiting to become in-line with the first (or any) row of the convoy. With the speed, AOB and the periscope set to the lead angle (set according to those Fast 90 steps) then the TDC will be prepared to fire the torpedoes. Only differences maybe the particular torpedo depth required for a particular tube intended for a target.

The member on the furthest column in that row will pass the periscope line ( set to the leading angle) first. Don't turn the scope or it will cause the torpedos to turn to the non-zero gyro angle. Fire when it is centered on the line by it's own movement. And wait after switching to the second tube (with perhaps a different depth). Now the second-from-furthest column member will approach the line first. Again, wait for the 2nd target to be centered on the line by means of it's own movement, then fire. And so on for up to 4 column targets with your 4 tubes. The nearest one as last.

And eventually this will happen (if every thing is set up correctly).

edit: Guzz01's guide on steam explains virtually the same setup.
http://ricojansen.nl/image/OKanemethodanimation.gif

[gutted]

I made that .gif like 10 years ago.

[Pisces]

Ok, sorry. I didn't know who made it. Probably grabbed it through one of Rockin Robbins message.

[JuanLiquid]

Thank you for the in-depth explanation!!! :Kaleun_Applaud:

[gumbeauregard]

A few years ago when Hurricane Harvey was dumping millions of gallons of water on my roof I spent the inside time doing a couple of videos explaining how the basic firing angle is a simple trigonometry problem revolving around the ratio of the target speed to the torpedo speed.

The TDC in SH4 was not the easiest thing to get to work correctly so I rarely used it and developed this method (actually stole it directly from the guys who did all this for real). A "discussion" with another member who disagreed with this method prompted the videos

I have only fired three torpedoes in Wolfpack but I can see the theory behind this and learning the rules of thumb and having the prepared tables or calculator ready will make an excellent backup method for a quick shot or to confirm TDC setup.

Of course, one has to know torpedo speed as well as target speed or none of this works.

http://www.subsim.com/radioroom/showthread.php?t=233175

The original thread where I got my motivation to develop the two videos.

http://www.subsim.com/radioroom/showthread.php?t=232987

I am very excited about Wolfpack because I love the math behind plotting and executing an attack.

[kaptnkrunch]

"Turn your scope to bearing and that is your lead angle"

Well.. I am not sure I am reading the bearing correctly after setting up for fast 90.

There are 2 bearing dials - top one goes from 0-9 , bottom is 0-359

so.. which one am I adjusting the scope to?

Or maybe it's both.. both don't know how to read it properly?

Cheers!

[Aktungbby]

kaptnkrunch!:Kaleun_Salute:

[PeterS]

There are 2 bearing dials - top one goes from 0-9 , bottom is 0-359

so.. which one am I adjusting the scope to?

Both dials display the same bearing, you combine them to read the exact bearings.
Lower dial e.g. show "20 plus a little bit", top dial shows "2.4", then the bearing is 22.4

Basically the top dial is just for the last digit plus the first position after decimal point, which would be impossible to read from the lower dial alone.

Just look at the scope bearing, which allows you to see the last digit (but not the exact first position after decimal point) and compare to what you see on the TDC, so you should get a grasp of it quickly.

The first position after decimal point is somewhat irrelevant for setting the AOB (just round it), but can be useful for calculations for e.g. "Auswanderungsverfahren" (whatever that's called in English, don't know).

[kaptnkrunch]

Danke PeterS!

[derstosstrupp]

Auswanderungsverfahren = bearing change method! :Kaleun_Cheers:

[gumbeauregard]

No need to guess the firing bearing. If you know the target speed, the firing angle does not change. All you need to decide is periscope left or right of 0. Look it up on the chart and set the periscope accordingly to generate Zero Gyro Angle,

Example: The target is doing 12 knots with 90 Starboard Angle on the Bow.

Firing Angle is 22 degrees. Note that firing angle and firing bearing are the same for Port AOB shots.

For Starboard AOB, subtract firing angle (22 in this case) from 360 to get the firing bearing of 338.

https://i.postimg.cc/J7yhxk1S/Firing-Angles-and-Bearings-Page-1.jpg

[Jonas Grumby]

Approach from 90 degrees. Set scope to 0, set 90 AOB (port or starboard), input speed, ignore range. Swivel scope until the gyro reads 0 and thats your shoot point. It's not hard.

The only difference with this game is that you can't actually see the gyro while in the scope. So you have to disable the TDC from the scope then move the heading dial on the TDC (which should really be labeled bearing) until you find the bearing that zero gyro is on, then re-slave it to the scope and put the scope on that bearing. Or just have the man on the TDC tell you when the you are on the zero gyro.

Thank you. Did not realize someone replied to my comment.
I have the Fast 90/O'kane method well in hand now for Wolfpack.
Very easy. It also has the added benefit of making it easier to gauge the convoy speed by using only one of the escorts. In my opinion, it is MUCH easier to identify an escort for my speed determination than it is to identify a merchant. Sometimes the merchants can be tricky when they are massed together and the masts and kingposts get jumbled together.
I've been sinking ships at will while surfaced by myself quite successfully with this method.

[Beckham]

This is just really cool. Having allot of fun with this. This procedure makes targeting very predicable.

:Kaleun_Thumbs_Up:

[Jonny-Dog]

Aktungbby, I fail to see what your post has to do with Fast90/O'Kane method, other than confuse new captains.


Please elaborate...


Jonny-Dog

[Aktungbby]

Aktungbby, I fail to see what your post has to do with Fast90/O'Kane method, other than confuse new captains.


Please elaborate...


Jonny-DogSorry about any potential confusion. The diagram is from wiki's tdc site and has been used extensively by me and other old kaleuns. fixed.

[ElJammos]

I made a video about this a while ago, also going into a little bit of detail (a very small bit) why this works (mathematically).
I can't say I agree that this works for different angles of approach as well (such as 75, 110, whatever) as those are not right triangles anymore. The further from 90 you are, the less accurate it will be in that case by quite some margin. It's still very much possible to figure out the lead angle then, but you need a bit different math (law of cosines, for example) for that.
I also feel that just setting the gyro to 0 on the Tvre and manually calculating the lead angle (or reading it off a a chart) is a bit easier and less prone to accidents than manipulating the Tvre to get there. That's just a matter of taste though, both are perfectly fine of course.

At any rate, here's the video.

https://youtu.be/lPdZKAUaVy0

[derstosstrupp]

That’s a great video Jammo. Range ceases to matter at any impact angle, not just 90, so yes it will work at others as well and was the preferred method to use. Remember, all we care is the “lateral speed across the line of sight”, then we still have a right triangle. That’s by factoring in the sine of the AOB.

arcsin ( target speed / torpedo speed x sin (AOB))

And since it was ballistically advantageous to have an impact angle of slightly less than 90, often times they will wait until the 90° AOB to even shoot. Then that’s simple as well, simply take the arcsine of target speed over torpedo speed, and then lead the course by that lead angle, such that when you pull the trigger the target it will be AOB 90 when gyro is 0. That way they also then had the added benefit of being able to recognize easily an AOB of 90 right at the shot as confirmation.

So for example, target course is 0, I put myself on course 270. I want to compute the lead angle at 90° AOB, target speed 8.5 and torp speed 30. I do the division, take the arcsine, 16.5°. I then turn to course (270 + 17) 287, and wait for the target to cross the wire.

[II WO]

nice vid Jammo! Now can you do one with map tools and as little actual math as possible? (non 90°)

(like this: https://www.subsim.com/radioroom/showthread.php?t=233175)

[ElJammos]

Thanks. :)


I'm not quite sure what you mean by that though... You mean, just shooting torps using map tools without calculating anything? Could be doable indeed... I was actually working on a tutorial on how to shoot based on matching speed and course (an idea I completely stole of Stosstrup, but he knows.).

At any rate, if there's something you'd like me to do a video on, let me know. :)

[II WO]

yeah stuff like getting lead angle off the map and subsequently doing that for more obscure aob than 90. i think i figured it out now but another perspective is always interesting. (slime)

[derstosstrupp]

Definitely, it can easily be done on the map:

1. Draw a line toward the “target”.
2. From that line draw a line at the angle of the AOB you intend to shoot at (50 in this case). Make the length of that line equal to the target speed, in this case 15 kn.
3. Draw a line of a length equal to the torpedo speed from the starting point, 30 knots in this case.
4. Move the target speed line down and adjust the torpedo line til their ends meet. Do not change the lengths of the target and torpedo lines though!
5. The lead angle will be the angle at the starting point (22.5 here).

https://www.subsim.com/radioroom/picture.php?albumid=1301&pictureid=11121