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View Full Version : Anti convoy tactics - 1942 onwards


Paul Riley
04-19-09, 12:23 PM
Not sure if this has been discussed in a previous post.

I am,as I speak,creating and compiling my own specific tactics for dealing with convoys,taken from historical references together with some of my own ideas,as the allies have certainly improved their ASW techniques since last I met a convoy.What I would like,is to hear some of your methods for dealing with convoys during 1942 and beyond.The biggest problem I had,before developing my techniques,was obviously radar,which is by now far more sensitive than earlier on in the year.I shall for the sake of the topic detail my own methods for observing,tracking,intercepting and finally engaging.Also,it needs to be said that I havent actually engaged the current convoy in my campaign,but i'm sure there is a good chance it may work.

The initial radio signal of the sighted convoy.

I recieved the radio signal about 12 hrs earlier in my current patrol,and calculated whether I could intercept it from my current position.The calculations were made and I estimated that it would take no more than 2 days,longer than I would normally attempt to chase a contact.The convoy was sighted in AK48,heading NE at 9 kts.I worked out my fuel allowance for the journey and set speed at full.As I got nearer to my future position another radio signal was recieved,and the convoy was coming within reach.Visual contact was finally made,and I dived to PD,and took a rough observation of the convoy,it was confimed at 53 degrees,and at 9kts.While I was doing this 2 warships (WSs) appeared on the horizon heading my way,I was obviously picked up on radar.My first real experience with a convoy's improved radar capability.I prepared for the inevitable,and Dcs were dropped,with no hits.I went to 200m and set speed at slow,silent.More DCs were heard,fading.I stopped my engines to check for the WS's engines,which could be heard,but fading.I had slipped through.After about 1 hour I did a standard sound check,and the WSs were not in my immediate area,and so I went to PD,and checked the horizon,at normal magnification,and at zoom,nothing.I surfaced at slow speed,with no air from the tanks,so as to mask my submerged noises as much as possible,you never really know do you.I then contemplated the current position I was in,and decided to make thorough plans on paper,which is where I am now.This was the first phase in my scenario,and now i'll move onto the second,the observation phase (OP).

The observation phase - observing convoy composition,strength,and future marked targets

This for me,is where I take all neccessary information needed for a successful attack on the convoy.I need to check exactly whats in the convoy,number of lanes,depth of the lanes,military strength of the convoy,and to mark targets deemed important and a priority.I have decided the best position to be in for doing this is from either of the front corners of the convoy,and facing 45 degrees into the convoy,so as to get better views of overlapping ships.Naturally daylight is needed,with extremely strict measures on using the Periscope (PS),as I have been detected using it before.Observations will be carried out all the time as the convoy approaches and finally passes me.I could attack from here if I wanted,but I don't like rushing into things,and a methodical approach is what is needed,for me that is.I then plot a tracking course (will be explained soon) perpendicular to the convoy,then move onto phase 3,the Tracking Phase (TP).

The tracking phase - Surveillance of the convoy,keeping it within sound range.

This phase I have called the tracking phase.What my idea was,was to keep the convoy under close surveillance using the hydrophones,all the while keeping myself out of their radar.I did a few tests earlier and worked out that a convoy's radar range in late 42 is approx 15km,as at this range I have no more incoming WSs to my position.I run on my current course,15km from the convoy,and do the first sound check,to confirm the convoy is not changing course etc.I then surface and repeat the sound checks at intervals of about 30mins.During other times I normally conduct sound checks on the hour,but in this case 30mins is needed,as I need precise bearings on the convoy.I keep doing this until the convoy's sound signature is at about 270 degrees or 90 to my position.This then tells me that I am now on a precise run for an interception.This takes me to the next phase,the Interception Phase (IP).

Interception Phase - Plotting a course for the interception of the convoy

The scenario is now in its last stages,and as the above states I now attempt to intercept the convoy at a point dictated by myself,allowing me to pick the battle on my terms by deciding whether it will be at day or night,or any other condition I might want.What I do here is give myself a run of about 2 hours,then turn 90 degrees into the convoy,at the distance of my choosing,and await the convoy.This then takes me to the final and critical phase,the attack!.

The Attack Phase

This is the part that has took the most thought and effort by myself,using many possible methods of attacking,working out my chances with each method,ultimately giving me my preferred method for engaging convoys,and I think this may,and I say may be the best method.What I wanted was as I stated earlier to put myself at a very precise point relative to the convoy,allowing for surgical attacks on the convoy,while minimizing risk as much as possible,as it is less chaotic than other methods,like racing straight in on the surface,which may have been useful earlier on in the war,but allied radar is too deadly now I have observed.Earlier during the OP,I would have picked targets deemed 'juicy',have them marked,and concentrate all efforts on sinking JUST those ships.I have noticed in this convoy I am engaging consists of many merchants,but in the 2 centre lanes are tankers,and I have also noticed a troop carrier.These are my marked targets.The convoy is huge (biggest so far I have encountered,others added up to say no more of about 10-15 vessels),and I have observed between 60 and 70 vessels,in 6 lanes,about 10-12 deep,with a strong screen of 6 WSs including a destroyer escort up front.My plan is to put myself on the centre lanes,approx 500 metres from the first vessel I am targetting.In the OP I would have made lines representing the 2 centre lanes,with points where the marked targets should be,give or take a few metres.I have also worked out there are approx 1.2km between each lane,vital information I think.I have decided to penetrate the convoy from within,as this gives me a greater chance of hitting targets due to the short range involved,and also allows me to pass under and out the rear after the attack,using the noise from the convoy to try and mask my own.Standard evasion methods will be used at this point to evade the enemy.While this allows for very precise hit and run style attacks,it is possibly the most dangerous,due to the close proximity to WSs if I am detected,and I wouldnt have much time to make an emergency dive if things screw up.But in all honesty,I do prefer this methodical surgical style,and rushing in is just opposite to my character also.I will try to engage 2 ships if possible,but if doubts in my mind arise for whatever reason,I will then concentrate on just the one,maximizing my concentration and efforts,in effect slowly breaking down the convoy.I will also be on silent operations during the entire process,except of course just seconds before the actual torpedo launch.Even if I havent been detected I think its good practice to carry out all precautions,and use them all the time,ensuring safety as much as possible.Ideally attacks will be at night,masking the PS,but daylight attacks are also to be carried out if needed,allowing for round the clock attacks.If a daylight attack is to be carried out I will position myself outside the convoy perimeter,and attack from about 1-2km,and at a 45 degree angle,so I can see the overlapping targets,which would otherwise be obscured possibly.If I score a hit,no matter what happens to the stricken vessel I will immediately dive as deep as possible at 1/3,and attempt to exit the convoy's rear,using the hydros to check on the convoy.I will then run under for 1 hour,then come to PD,and repeat all the previous to set up for a second attack.Approx 4-5 hr intervals between attacks.This then will be continued until the convoy has been depleted of the marked targets,or I run out of torpedoes.And for good measure I have also made it a standard to carry one homing torpedo in the aft tube,just in case this fox is in trouble trying to get out of the chicken coup before the farmer arives with his DCs.

This then concludes my post,and I want to hear your comments on my method,and to also hear some of your methods.Also,I dont assume this is the best method,but it is the method preferred by me,and feels safer.

Cheers :salute:

unterseemann
04-19-09, 04:38 PM
Wow! Big and interesting thread. I think your method is good but how do you place your sub in order to sink ships in the center lanes??

when a convoy is detected near my position i try to get far ahead of it. I wait at PD until hydrophon contact is made. If i am roughly in their supposed path i switch to silent running, set speed to 1 or 2kn, depth at -20m and i sail towards the convoy. Hydrophon check every 5 or 10 min, normally convoy is between 355 and 005. When i think the convoy is close enough i go to PD and have a look outside. When visual contact is made ( with escorts mainly) i try to position the sub in front of the outer columns to avoid detection by the lead escort. When lead escort is passing me by i get slowly into position (+/- 90°) and present her the smallest profile of my sub. I don't aim for the biggest targets as they are often too far but i try to attack a good one with maximum chance to sink it (it means two or three torpedoes to ensure the kill). Before diving i launch every torpedo i have in my tubes even if ships are starting to zigzag.
Attacks in late war are time consuming because you have to be very careful about everything and TC is rarely above 8x. So when i reach the convoy without being detected, i try to wreak maximum havoc on it even if only one boat is sunk!

You said you need a 4-5h interval between two attacks, for me it's more around 10-12h...

Last thing: I don't even try to attack a convoy with wind inf. to 4m/s...Storms are my friends!

RoaldLarsen
04-19-09, 06:10 PM
The described approach sounds close to ideal if one presumes that it is possible to make the sort of observations described. I wonder if it is possible to use this approach without some sort of unrealistic assistance with observing and plotting the enemy ships. How do you precisely measure the spacing between columns and rows, through a persisope in a boat that is bobbing up and down. What realism settings are you using, expecially regarding observation and plotting?

I play at 100% realism, so everything I plot I have to measure and mark myself. To get the information described, you have to make accurate range observations on at least three separate ships, plus observe and record several other ships. To measure thes distances with the accuracy that would seem to be required, one would have to make the observations from within the screen. This involves significant risk of exposure. I find I am often unable to obtain sufficient information of this type before being spotted. On my last attempted attack on a convoy, I was detected while attempting to make my first or second distance obsservation. I would not even have attempted this observation if I had had course and speed information, but since I had detected the convoy myself, by hydrophone, and it was moving fast, in restricted waters with a large number of enemy warships patrolling the area, I had limited opportinites to get the data necessary to plot an attack.

My primary objective is to survive, therefore I want to reduce risk, and maximize the reward for risk. That measn minimizing the number of observations that may lead to the enemy discovering my presence. I never have a separate observation phase from within the screen of a convoy. Once I get in undetected I am going to attack. My first objective after penetrating the screen is to locate two prime targets. If I have had the chance to observe the convoy from outside, I already have an idea of where they are. Next I want to make sure I have the data necessary to calculate a firing solution. Usually I will already have course and speed before I enter the convoy, but in the case above that was not possible. Then I adjust position to be able to attack, if necessary, then, and only if I have extra time, which is rare, do I make other observations. When I fire my second salvo, my periscope is already on the way down, and I alter course and dive immediately.

I have lost count of how many attacks I have attempted to make on convoys, but I estimate it to be well over 75. In all those attacks, I have only lost one boat to convoy escorts, and that was over 40 attacks ago (in 1942, coincidentally). The number of times I knew the total number of ships, the number of rows and columns, and the spacing between them is probably no more than 1/2 dozen, almost all before 1942. Most attempted attacks resulted in at least one ship sunk, the average is probably close to two. Most of the attempted attacks where I didn't sink anything were ones when I was detected before I could get to a firing position, either while attempting to penetrate the convoy screen, or more rarely, while making observations.

abclkhan
04-19-09, 10:22 PM
Cool!

Last time I played late war, I have made my atacks from a distance of 2-3km, usually during daylight, because it improves theirs but also MY visibility of distant targets.
Spend all renown with falkes. Then, use those fishes to sink the escorts near your pretended atack position.
Now you can approach the convoy again and choose the side with the smaller amount of warships... :arrgh!:
When approaching, dive when the convoy is at 20Km from your position.
Do not stay between the side escort and the convoy...
Do not use steam torpedoes.
FaT torpedoes are ineffective unless you know how to use it. Thersīs an excellent manual someone has written about FaTs I forgot where I found it:nope:
Target the ships on the opposite side of the convoy. If you are atacking from left, target ships on the right side. DDs will head to the other side of the convoy he he he

Thats it, sorry for my broken english:rock:

Synthfg
04-20-09, 06:50 AM
I tend to go more aggressive

1) Attract the attention of an escort by approaching on the surface until one steers towards me,

2) Drop to PD, up scope and head directly towards the escort at 1/3 ahead, If I'm lucky the escort is heading towards me at 12-15 KKts, at worst he's zig zagging at 35, either way not a problem

3) Ensure a Type I is in a fore tube, set to Fast 4m Magnetic Fuse (note a type II will work with the same depth and fuse setting)

4) Keep heading directly towards the approaching escort, scope up, using the boat as bait to draw him in,

5) At the opportune moment (approx 500m) shoot the eel down his throat, don't turn yet else he will and you reduce your chances of a kill
9 times out of 10 it will scoot beneath the escorts hull and explode usually sinking said escort within minutes,

6) as soon as the eel explodes turn like buggery to get out of the way

7) rinse and repeat for the remaining escorts, once the escorts are gone the convoy is at your mercy

unterseemann
04-20-09, 07:45 AM
I think most players here try to be closer to the reality, so sinking escorts like you do is not a good option ( but it's just my opinion). The main goal is keeping undetected by making a perfect approach and sink only merchants.
Without escorts there is no more challenge and it's a waste of torpedoes...

Hitman
04-20-09, 03:14 PM
@Paul Riley: At what realism settings are you playing? Are you using a supermod (NYGM, WAC, GWX...) or is that stock game? :hmmm:

Paul Riley
04-22-09, 08:42 AM
Sorry for the delay in my replies,I have been away for a few days.
I was just this minute finishing quite a lengthy reply when I bloody hit the backspace or enter key by accident,and wiping all the typing away as it moved me onto another screen.
I will get back to you in a day or two. :up:

Paul Riley
04-24-09, 09:10 AM
Again,sorry for the delay in my answers,and so here I am.I will try to answer your questions as accurately as possible.As a few questions were about what realism settings I use I will answer that first.I play with stock 1.4 and Commander installed,and use all realism settings other than the map update option,which I have on,which probably explains the observation question,as if it was off I would not be able to make good observations very well.I know its not as hardcore as marking your own map markings,and I think i'm going to play my next patrol at 100 %,ive been using map updates for ages now,and I know I am skilled enough now to finally make my own map bearings etc.

Unterseemann.
The only way I can effectively get into my optimal position for my chosen attack is by using a 3 hr run at full speed during the interception phase,then give myself 1 more hour for the final leg,90 degrees to the convoy's expected position.During the observation phase (OP) I would have marked one or two ships for the first attack,and note their track on the map,and extend the line 4 hrs away,which at 9kts is about 60 odd km I think,you get the idea.If the convoy has remained on its original track and speed,I should therefore be able to position myself exactly where I want to be in order to attack my chosen ships.On my final leg towards the attack position I will dive to PD as I will be coming close to their radar detection zone (RDZ).I will then run at high speed to the attack position and wait for the convoy.Using the hydros I wait until the lead escort/s pass then raise the PS a tiny fraction,just enough to see my target/s,then fire.I will ideally be at about 500m from the stricken vessel,giving it no time to react.If I want to try and attack 2 vessels then a 45 degree angle into the convoy will be a better position to be in,giving unobstructed views of the overlapping ships.This however,is NOT my ideal angle,as I like to use a dead straight 90 degree shot.As soon as I shoot I will begin diving and out the rear of the convoy,then head 90 degrees away from the convoy's course,and repeat all my previously explained tactics for attack 2.Let me just say that I performed attack 1 last night,and it worked a treat,I hit a T3 with a spread of 2 and it broke into 2 halves practically straight away,giving me almost 11.000 tonnes to my 3.000 previously gained.
Hope you can follow this description ok,let me know if anything else needs clarifying.

Roald
I think your answer may be explained at the top of this post.
Cheers mate. :up:

abclkhan
Nice approach,simple and effective no doubt.

Synthfg
I really like your tactic,aggressive and taking the initiative all the time.Luring the WSs for an attack is a great way to remove the military presence of the convoy.However,in my current engagement there are about 6 WSs attached to the convoy,and trying to eliminate them wouldnt leave me with enough torps to attack any cargo vessels,tankers etc.There are loads of tankers in this convoy,and I love sinking those :D
I will more than likely use your aggressive approach if ever I get into a IX as the larger armament will be ideal for this,or against convoys with next to no protection,or for any other WS that may be sailing alone for instance.I wonder,would you use this approach to engage a battleship?,or would you stick to the standard attack methods normally used?.

Unterseemann
I also agree with what you said about conserving torps for cargo,oil etc.

Hitman
Just go to the top of the post mate.

Well I hope this is good enough.Just let me say this,after my campaign ends,which I have been playing for months and months now,I will probably begin a new one with all the neccessary mods to make the game more difficult and realistic.I just dont think its appropriate to end my campaign just to enable a few tweaks here and there,thats for another time as I just said.

Finally,lets try and keep this post alive,as we could all probably learn something here,about adopting new ways to engage convoys,even against those that would otherwise be deemed as too risky to attack.There is always a way,and I firmly believe that.

:salute:

Hitman
04-24-09, 12:38 PM
play with stock 1.4 ... and use all realism settings other than the map update option

Yes that pretty much was what I thought when I readed your first post. Playing with map updates off makes things different, it wouldn't be possibel to use some of the tactics you have indicated, and others are also impossibel to be used with GWX and NYGM, but nevertheless you made an excellent write-up and a good description of tactics; it's just that when playing games such as SH3 it is how huge important to know relaism settings and mods that are being used because the game changes o much that certain tactics that work in one situation won't work in others :up: