Torpedo salvos

[fisherstoys1]

Hi there
Question today is getting your torpedoes to not hit the same spot.
I have tried the salvo but I really dont get much in response.
Is this because you cannot select the tubes to salvo or do you set the spread and then fire you fish.
I am running Opmonsun on its own right now,
it has been great to have one Atlantic fight and a secound Pacific side. The prime double agent.

There is something else I noticed that the US torps are much less effective than when I was runnnig just 1.4.

Grant

[Bubblehead1980]

Originally Posted by fisherstoys1

Hi there
Question today is getting your torpedoes to not hit the same spot.
I have tried the salvo but I really dont get much in response.
Is this because you cannot select the tubes to salvo or do you set the spread and then fire you fish.
I am running Opmonsun on its own right now,
it has been great to have one Atlantic fight and a secound Pacific side. The prime double agent.

There is something else I noticed that the US torps are much less effective than when I was runnnig just 1.4.

Grant

The US did not have a salvo option, they fired torpedos as individual shots.However, there are two methods.

One is what was the traditional.Say you want to fire three torpedos at a mid sized freighter.For max coverage you fire one at middle of target(MOT), one forward, say a forward mast, and one to the aft area.Find range and get a bearing on middle of target(MOT), send to TDC and FIRE1 Then using the spread knob on the TDC, adjust it the appropriate degrees forward(which would be starboard in this example situation if attacking from starboard side at a 90 degree angle, if attacking from port then would adjust the knob to port to send the fish forward of MOT, obviously) The number of degrees forward of course depends on length of the target.After adjusting the knob, fire two.Then adjust the knob a few degrees in opposition direction and FIRE 3 to send torpedo to target.May take some practice but this works and from my understanding was the more traditional method use by US subs, esp in earlier years of war.Of course make sure the PK(Position Keeper) is on as it keeps the bearing, range , and AOB updated.This was the major advantage US TDC's had over other nations.

The method I use is different and I find it more accurate.I got the idea to use this after reading Admiral Richard O Kane's books about his time on Wahoo and the Tang.Under Morton on Wahoo(and later on Tang under O Kane) shots were fired using new bearings.So find range and send bearing for middle of target, FIRE 1.Then move the scope crosshairs over the forward mast, send new bearing, FIRE 2.Then move crosshairs over desired point aft, FIRE 3.The torpedos really are aimed as individual warshots here.

Hope this helped.

[Armistead]

I do about the same as Bubble, cept I fire forward to aft.

The other method that works well is to fire by the wire as the ship crosses, basically a 90 degree OKane attack, but you can do the same with the stad, get the same info you normally would by stad, then set a bearing in front of the ship, unlock PK and shoot the spots you want as they cross the wire.

[WernherVonTrapp]

Originally Posted by Armistead

I do about the same as Bubble, cept I fire forward to aft.

Hmmmm, now I've had some of my best spreads firing aft to bow.

[razark]

Originally Posted by WernherVonTrapp

Hmmmm, now I've had some of my best spreads firing aft to bow.

That's usually what I do. Read somewhere it's harder for the target to evade all the torpedoes if they are traveling in a divergent spread.

Originally Posted by The Book

602. TYPES OF SPREAD:

(a) Divergent Spread
A divergent spread is a spread in which the torpedoes of a salvo intersect the target's track at different points along the target's length and at different torpedo track angles. This type of spread is difficult to avoid because of its fan-shaped pattern. (Diagram A, Plate XV).

(b) Longitudinal Spread
A longitudinal spread is the spread obtained by firing a salvo of torpedoes along identical torpedo tracks. Torpedo #1 hits the target at A, #2 at B, and #3 at C, due to movement of target across the identical track of the torpedoes. It is a simple type of spread, having the disadvantage that the target which can avoid one torpedo track undoubtedly can avoid the others which are following in the wake of the first. (Diagram B, Plate XV).

The first is a Middle of Target, Stern, Bow spread, as opposed to an Aft, MoT, Forward spread, but it illustrates the point.

[Daniel Prates]

Longitudinal spread may be difficult to acheive when the Position Keeper is on, right? Since the target's position will be constantly updated. I think that the skippers that rely heavily on the TDC and PK may find it easier to use the spread option, to hit diferent places in the target. It has the advantage of allowing you to calmly set diferent angles and fire, as the TDC/PK will be constantly keeping up with the target.

Now, those crafty methods come in handy when you have, say, a damaged computer or an u-boat on your hands - specially so with u-boats, as it's computing device is archaic and its accuracy decreases seconds after you made an gyroangle estimate.

[razark]

Originally Posted by Daniel Prates

Longitudinal spread may be difficult to acheive when the Position Keeper is on, right? Since the target's position will be constantly updated.

Yes, with the PK on, you will achieve a divergent spread, but (given perfect data input into the TDC) each torpedo will be aimed at the exact same spot on the target. Really defeats the purpose of the spread.

Originally Posted by Daniel Prates

I think that the skippers that rely heavily on the TDC and PK may find it easier to use the spread option, to hit diferent places in the target. It has the advantage of allowing you to calmly set diferent angles and fire, as the TDC/PK will be constantly keeping up with the target.

I use the offset dial, and it works just fine. It may take some practice to get good with it, or you can actually figure out the math as to where to put the torpedoes.

From the book:

(c) The following table should be used for the sine of the torpedo track angle.

Torpedo Track             Sine
       15-30              1/4
       30-45              1/2
       45-60              3/4
       60-90               1

(d) The following table should be used for torpedo run.

Torpedo Run Actual           Torpedo Run Used
      700 - 1250                   1000
      1250 - 1750                  1500
      1750 - 2250                  2000
      2250 - 2750                  2500
      2750 - 3250                  3000

[Daniel Prates]

Great info, razark! But surely, the hardest way to do it!

The offset dial for spread angles is easy to use with mere visual info gathering, once you understand it (and I only understood it here in the forum, recently by the way).

Basically, the targed "fills in" a certain ammount of space in your scope view. If your scope is centered and locked in the very midst of the target, that portion will be "0 degrees" in the scope, obviously. Well, the spread angle you want to set is the same ammount of degrees as the other portions of the ship appears in the scope. Then it's all about measuring the extremities of the target. So let's say the bow is at +3 degrees and the stern is at -3 degress, If you want to hit 6 torps in quasi-identical distances, you set angles for +3, +2, +1, 0, -1 and -2, and you will be hitting everything but the propellor (which would be at -3 degrees).

Obviously, the farthes away the target is, the less ammount of degrees it will fill in your scope. So if the ship is very far away it may only fill in "-1" and "+1" in the scope, maybe less, so for farther targets using the spread angle is probably unadvisable as you risc not hitting anything.

[Nisgeis]

Someone on the Torsk put together quite an impressive gadget (complete with carboard wheels that you could turn) to calculate it visually. I recreated what I could of it here (from the one VERY pixelated image I could find of it - hint hint AVG):

http://www.subsim.com/radioroom//sho...d.php?t=144202

Visual calculation of the value involved, all you need is an eye and a finger to use it (connected to the requisite brain of course). I find the less 'heavy lifting' I have to do, the less likely I am to introduce an error and the less busy the final moments of the attack.

This gadget was mounted above the TDC, so perhaps it would be good above the 3D TDC? Hmmm...

[Nisgeis]

Originally Posted by Daniel Prates

Basically, the targed "fills in" a certain ammount of space in your scope view. If your scope is centered and locked in the very midst of the target, that portion will be "0 degrees" in the scope, obviously. Well, the spread angle you want to set is the same ammount of degrees as the other portions of the ship appears in the scope. Then it's all about measuring the extremities of the target. So let's say the bow is at +3 degrees and the stern is at -3 degress, If you want to hit 6 torps in quasi-identical distances, you set angles for +3, +2, +1, 0, -1 and -2, and you will be hitting everything but the propellor (which would be at -3 degrees).

That's a good rule of thumb, but it's oversimplifying in a way that might make you miss, unless yourself and the target are stationary and the scope is at zero degrees. The angular length of the target in your scope is different to the angular length of the target at the calculated point of impact.

For example, if you were abeam a target at an AoB of 90 degree and the target was observed to have an angular length of 6 degrees, then we know that as the target is moving, the torpedoes have to be giving a gyro angle order that will put them on an intercept course. They will have to travel ahead of the target in order to get there, so will cover a distance greater than the range to target, known as the run length. When they arrive at the impact point, the target has drawn ahead, so now presents an AoB of less than the optimal 90 degrees, so the target appears shorter than 6 degrees. The slower the torpedoes, the more pronounced this affect is.

You also have to consider the effect of high gyro angle shots, where the reach of the torpedo comes into play and also shots where you are shooting from ahead will have a torpedo run length less than the range to target with an AoB more favourable, so will give a better target and your calculated 100% spread maybe much lower than you think.

A 100% spread (e.g. a spread set so that the torpedos hit equally along the whole length) if almost perfectly calculated will mean one torpedo will miss. A higher spread, e.g. 125% is better if you aren't 100% on your data, or even higher sometimes, depending on your goal and the quality of your data. The key is to know what the angular length of the target is at the impact point accurately.

[razark]

Originally Posted by Daniel Prates

Great info, razark! But surely, the hardest way to do it!

The point of the formula and the simplified values is that it could rather quickly be done by someone who was used to using it, or had a sliderule at hand. It's not meant to be 100% accurate, but give enough of a good answer to hit the target.

Originally Posted by Nisgeis

Someone on the Torsk put together quite an impressive gadget (complete with carboard wheels that you could turn) to calculate it visually. I recreated what I could of it here (from the one VERY pixelated image I could find of it - hint hint AVG):

http://www.subsim.com/radioroom//showthread.php?t=144202

I've got a couple on my desk, and one tacked up on the wall behind the clipboard with the tracking sheet. Useful thing. (But your link is broken. It has an extra "/" in it.)

My usual solution is to drop everything into a spreadsheet I made. Enter target length, AoB at time of impact, range, coverage percent, and number of torpedoes. Read off the results for where each torpedo goes. I then ignore that and eyeball it when the target zigs right before firing. Not sure why I even use the spreadsheet anymore.

[Bubblehead1980]

Originally Posted by Daniel Prates

Longitudinal spread may be difficult to acheive when the Position Keeper is on, right? Since the target's position will be constantly updated. I think that the skippers that rely heavily on the TDC and PK may find it easier to use the spread option, to hit diferent places in the target. It has the advantage of allowing you to calmly set diferent angles and fire, as the TDC/PK will be constantly keeping up with the target.

Now, those crafty methods come in handy when you have, say, a damaged computer or an u-boat on your hands - specially so with u-boats, as it's computing device is archaic and its accuracy decreases seconds after you made an gyroangle estimate.

The PK does not affect the spread, it keeps the bearing updated so you dont have to send a new bearing, place crosshairs over MOT, send bearing and range and fire, can wait few seconds and fire again, the PK updates the bearing so torpedos would not fire at the last bearing but the updated bearing based off your last bearing, the spread dial of course adjusts this.

[Daniel Prates]

Originally Posted by Bubblehead1980

The PK does not affect the spread, it keeps the bearing updated so you dont have to send a new bearing, place crosshairs over MOT, send bearing and range and fire, can wait few seconds and fire again, the PK updates the bearing so torpedos would not fire at the last bearing but the updated bearing based off your last bearing, the spread dial of course adjusts this.

[Rockin Robbins]

I love longitudinal spreads, shot with the PK off. But if you're in smooth water in the daytime they can sometimes be avoided if you aren't close enough, especially if you're shooting from ahead of the beam of the target. The further ahead of the target's beam the easier it is for the target to merely turn into the torpedoes and let them pass on the outside of his turn.

With divergent spreads, the most divergent is stern, MOT, bow, then MOT, stern, bow. Since the torpedoes take different paths to the target they are more difficult to avoid. Avoiding one will most often put you more perfectly in the path of another.

[fisherstoys1]

Hi all

Great advice.
The problem for me is I hate unlocking once I have the target.
It seems that the USN needs to get the same targeting equipment as the Germans.
But yes when you are not under pressure from escorts then I can a spread working.
When I dropped in 1.5 I noticed that the salvo angle indicator does not show the secound line to the target any longer.

BUT, in reality the game is just that much better also. Sh3 seems to be to simple now compared to Sh4.
In an attack on a convoy yesterday I had three Agano light cruisers in the convoy so I started my attack at the first Agano figuring the way the convoys scatter in Sh4 I would be able to make run in on the convoy once the first hits happened. Basically what I do is go to high speed towards the confusion while reloading and damn the destroyers that try me. They ane not to hard to get around, but I cannot waste time. Once the run in is stared I only have a short time before the outter escorts start to come in. So get what you can.

My first move was three fish at the lead Agono but a dd must of seen the torpedo tracks because he sounded the alarm and Mr. Agano number 1 only got caught by two of the three my increasing speed and turning from me.

Even the U-boat's the AI plays well usually, I do find evasion after attack easier though. But as stated earlier I am only using the latest OpMonsoon.

So to pick a lesson here I guess from your posts I can do better and maybe I should start packing some electric fish also.

What other mods should I run now, I was thinking a dropping in RSRD?

Grant