Type VIIB U-45:Combined Surfaced/Submerged Attacks at Daylight

[Genghis Khan]

Hello all Kriegsmarine Captains :D

I am going new campaign with a new Type VIIB U-45 boat now,and,in order to get best tonnage during each patrol,I do practice somewhat I intend to call "combined surfaced/sumberged attacks".

You see,most favourable conditions for making an ideal attack on the convoy usually occur when the weather is fine and there is a rather long visibility at calm sea.But,it proves very difficult to approach a convoy in those conditions as you definately have to submerge and chase the convoy submerged.

Seems I have found an answer to the sophisticated destroyer behaviour in Silent Hunter III.Destroyers AI has been mainly programmed to protect a convoy,not to let U-Boats reach a favourable attack positions,rather then attacking an U-Boat itself.

So,if you approach a convoy surfaced at full speed (let's say 19-20 knots in Type VIIB with GW Kapselgeblasse engine upgrade),avantgarde or tail destroyer spots you and starts chasing.Turn away a several degrees from the original convoy course.

Convoy starts moving away at slow pace,destroyer chases you still.

Here is a break point.Destroyer considers himself being "too far" from convoy and leaving it unprotected,turns around and accelerates to approximately 35 knots back towards the convoy.

The distance between you and destroyer is growing faster than the distance between you and convoy!:D Destroyer himself goes into unfavourable convoy guarding position according your U-Boat position.

Now you can chase a convoy surfaced at full speed and start maneuvering in order to shorten attack distance as much as you can and to get favourable Gyro angles for the first torpedo salvo.

When you get to this suitable for attack position you must immediately submerge to periscope depth and launch a first 4 torpedoes salvo into most valuable targets (for myself they are C3 Cargo ships and T3 tankers generally).

After a first salvo start submerging to as deep as you can at "Secure from silent mode" reloading while submerging.At the depth of approximately 200 meters start maneuvering again towards a convoy on sonar contacts in order to get favourable attack positions for the second attack.At the same time destroyers will be dropping depth charges far above you.

When you approximately 1500 - 2000 metres to convoy start surfacing at "Silent" mode,I would also recommend to pump air into Air/Water Tanks (Chief Engineer Command) to surface faster to periscope depth.But not forget to give a "Periscope Depth" command 50 - 30 metres leaving to surface,unless you are willing to jump into surface straight into deadly destroyers fire.

Repeat an torpedo salvo at the remaining valuable convoy targets turn on "Full Forward" at your engines and submerge again down to 200 metres.Leave the attack area.

This tactics usually allow to sink 5 - 6 large cargo ships and get a patrol tonnage of approximately 35000 - 40000 in a short time.So you do really spare on patrol duration and have possibilities to intercept more convoys and get bigger total tonnage during campaign in general.

I am in June 1940 now with fully upgraded Type VIIB U-45 (KDB,GW Kapselgeblasse,AFA MAK 800 Batteries) and have a total tonnage of about 230 000 tonns.

Those tactics are still working,I don't know whether they will work in later war when even more advanced destoyers and aircraft escorts will be available.

Anyway,please post your comments regarding this tactics,whether you use it or not,and what are the perspectives to use it in later war.

I will be very glad to read your comments and advices.

Good Hunting to all Kriegsmarine Aces of the Deep :D :up: We will Win :D :up:

[TarJak]

Interesting theory. Are you playing with GWX or another mod or just stock SHIII?

Can't say I've tried this with GWX and I'd be surprised if it worked using that mod. The AI of the escorts has been modified quite a bit and they are usually faster than you with longer range guns so I think this approach method would be very risky.

I'll give it a go in GWX and see what happens and report back.:arrgh!:

[GoldenRivet]

TarJak this is Bdu...

Report position and status... we have been trying to contact you for several days now and we are growing quite concerned with the situation regarding your lack of communication with headquarters. Please respond as soon as possible. be aware that failure to communicate with BdU via enciphered enigma message before 1200 GMT tomorrow will result in you and your crew being placed into MIA status.

BdU radioman turns and looks at Admiral Doenitz... "sir, what was this boats last known intentions?"

Admiral "I ordered him to patrol BF12... he agreed but he kept going on and on about this new 'awesome theoretical strategy' he wanted to try... it sounded insane to me but he wouldnt listen."

BdU radioman: "Whay theoretical strategy might that be?"

Admiral: "Here it is... have a read" (hands radioman Genghis Khan's subsim posting)

BdU radioman: reads the posting :huh:"Riiight... do you think that perhaps we should skip further attempts to call Capt. TarJak, pass completely by the whole MIA paperwork issues and just call him killed in action then?"

admiral: (sigh) "Yeah... yeah i guess your right." :cry:

[TarJak]

I'm back! GR is pretty much right. My test Kaleun is now KIA with no hpe of me trying that one again. GWX DD's are NOT, I repeat NOT interested in defending the convoy that much at all and they will attack and kill you if you attempt to appraoch them on the surface.

Please take the above advice with the grain of salt it deserves unless you are playing vanilla SHIII or another game entirely.:yep:

[Genghis Khan]

Hello TarJack,

I am running stock SH III version 1.4 with U-Boat:Battle in the Mediterranean Add-on.

Destroyers are extremely fast,but this is not the main point.Their AI seems to have "distance from convoy" values,they cannot exceed.If they start chasing you and get away themselves from the convoy initially after some time (usually 5 - 7 minutes) of pursuit they turn back towards the convoy at twice higher speed.

Example:they chase you (as I observed at 14 -17 knots for Type "M" Destroyer) and when they are too far away from convoy initially they turn back and return to convoy at huge 35 knots speed.As a result of this speed difference they may overtake the whole convoy (if you are approaching from the tail of convoy) and open something like a surface "corridor" for your attack positions.I mean you can arrive to attack position faster with lower speed surfaced,then destoyer with his really awesome speed.

[Genghis Khan]

A little bit history.Type II,VII,IX boats are not suitable for chasing or attacking convoys submerged only.During real naval war of WWII they used to sprint to attack positions surfaced and attack/evade submerged.

This was the original reason of Type XXI creation.Quote from Wikipedia:

"The streamlined hull design allowed the XXI to travel faster submerged than surfaced. The ability to outrun many surface ships while submerged, combined with improved dive times, made them much harder to chase and destroy. It also gave the boat a 'sprint ability' when positioning the boat for an attack. Older boats had to surface in order to sprint into position. This often gave the boat away, especially after aircraft became available for convoy escort."

Source: http://en.wikipedia.org/wiki/Type_XXI

Moreover,have you ever heard why was PQ-17 convoy massacred?The reason of that was an order from British Royal Navy Admiralty to WITHDRAW DESTROYERS AND ESCORTS FROM CONVOY.Trial proceedings were made 15 years after the tragedy happened.

"First Sea Lord (http://en.wikipedia.org/wiki/First_Sea_Lord) Sir Dudley Pound (http://en.wikipedia.org/wiki/Dudley_Pound), after agonising for several hours, eventually made the fateful decision to scatter the convoy, reasoning that Tirpitz, with its high speed and 15 inch (380mm) guns, would be capable of inflicting massive losses on the closely bunched merchant ships."

Source:http://en.wikipedia.org/wiki/PQ-17

Naval wars theory states,that merchant convoy ships are never left without escorts.So guys,there is really something wrong in GWX's destroyers AI behaviour ;)

[Brag]

In GWX and in the SHIII stock game I've played, surface attacks are suicidal. I wonder at what realistic settings for damage GK is playing,:hmm:

[TarJak]

I doubt that it is a fault in the GWX AI for DD's because they come at you at 20+ kts if you approach them on the surface rather than plodding along at 14-17kts which I think would be less reaslistic tahn having them race towards you as fast as they can and shooting you up.

Historically, if a u-boat was spotted on the surface the escorts would engage at speed and try to catch them before they could submerge which was the best defence for them, unless they could outrun a slow escort such as a corvette. Most DD's, DE's and Frigates were capable of more than 20kts with some later war models able to make 35-38kts.

Their job was to force the attacking boats away from the convoy and to get them to submerge where their speed and manouverability was significantly impaired.

Let's just say your tactic won't work in GWX and leave it at that eh?

[rb4door]

Interesting theory, but at least in GWX - total suicide I believe.

I've "experimented" with escorts abilities since upgrading to GWX, simply to see if all the claims I had read were in deed true. They are :hmm:

At any time an decently armed escort sights you on the surface, their artillary literally opens up like a stream of fire. Tracer rounds and cannon fire come raining in like a hail storm! The time it takes to crash dive is still painfully long and you just have to pray you only sustain light damage, even with the smallest profile of your U-boat showing. If you are at an oblique angle to one and presenting a length wise target - you are indeed probably going to keep sinking all the way to the bottom.

Sorry if I bore anyone, however I will continue with an interesting story - feel free to stop reading if you have better things to do... :p

For example, on patrol last night I hit a Fiji class twice with eels - and she got left behind by the convoy. Unfortunately I was totally expended of all fish - so at dawn, while she sat in the ocean motionless and half sunk. My intention was to try and put some HE shells into her to finish the job. After all I still hadnt been credited with the kill. I had waited about 3 hours and it was quite definate she was not going to sink on her own accord.

Now, get this, I surfaced 4.8km's away from her - still in darkness.

At first I thought i'd see if she'd spot me - a waited a good 2 or 3 minutes on the top without any peep from the Fiji - so I started lobbing some HE's her way.
Got off about 5 shots - then she opened up like the gates of hell!

I was shocked at the response, and as I was sitting without any speed, the crash dive took some time. I sustained massive hits / damage & severe flooding.

After barely escaping with my life & the U-boat - I decided continuing my career was a better option than going anywhere near that Fiji again on the surface :lol:

Morale of the story - armed navy vessels on the surface = i'm staying the hell under water!

[GoldenRivet]

In stock SH3 one could nearly approach a task force while surfaced, take out half the escorts with the deck gun torpedo the other half and simply sink the HMS rodney by shouting harsh language at it from the conning tower. I still love SH3 vanilla as it is a vast improvement over subsims of the past, but it suffered from many historical inaccuracies which GWX has fixed.

sure you could sprint on the surface toward a convoy, and you could probably launch a successfull attack against it using that practice AS LONG AS ITS 1939-1941... after that the allied escorts will pick you up on radar, divert the entire convoy around you, and the escorts will charge at you from well beyond visual range.

there are some distance from convoy issues in SH3 vanilla, but i believe thats all gone in GWX because in GWX's case art immitates life in the form of escort vessels obsessivly hunting down submarines. I have been charged by several black swans for 3 and a half hours while the convoy steamed along about 20 miles away.

Genghis Khan... your strategy will work, and it is good for SH3 vanilla the game... but for SH3/GWX the SIM, you will end up riding an iron elevator to the depths of the atlantic. I only say this because GWX has corrected many historical innacuracies regarding the AI threat level of escorts. they have more effective ASDIC, more effective passive sonar and are more likely to call for assistance when they detect you.

If one catches you in fairly shallow water you might get lucky and get away... but you only have about 30 minutes to an hour in the game to make your escape, because i can assure you that escort has made some phone calls and has at least 4 planes and 2 or 3 other escorts moving toward your position at full blast.

i dont mean to imply that GWX is too hard or too challenging... its realistic to the point where you have to play smart and you have to ask yourself before every attack "IS WHAT IM ABOUT TO DO REALLY A GOOD IDEA?"