Patrol techniques and conventions

[mrbannon]

(Forgive me if there's already a thread on this.)

OK, here's the deal. It's Aug. 1, 1939. 7/13 flotilla out of Konigsberg. I've been ordered to patrol AO98 (which is only a few hours away). Here are my questions.

- How far would a u-boat be from shore when navigating towards its patrol sector?

- Once in the patrol sector, what speed would the u-boat keep?

- What makes a good patrolling pattern? (AO98 is special because less than half the sector is water.)

- I'm assuming one should switch between sonar (periscope depth) and visual (surface) during the the patrol. At what frequency should these legs change?

- Are there depths that are NOT safe to submerge in? (For example, a depth of 12 meters could quickly become less than that. How would a captain know?)

- If a contact is made, does one immediately surface to report it, or wait? (I assume one waits, unless it's a special circumstance.)

- SH3-specific question: do the crew automatically rotate shifts, or is that the player's responsibility?

- Anything else I should know?

Tx,

Ryan

[the dark knight]

I am not sure about the type VII or the type II, but I do know that Type IX captains would cruise around 7-8 knots to and from the patrol area to conserve fuel during the war. I do this in my type IX's in game, and once in my grid square, I will search in a ladder pattern. There are also defined shipping lanes that I like to cruise in on my way to and from a grid square. (these are shown in the GWX folder. I found them through trial and error in stock SHIII)

You will need to rotate your crew manually, unless there is a mod out there that will allow it automatically.

I do most of my searching on the surface, and will search with the hydrophones at night or in bad weather. That is early war, later on you will only be safe at night on the surface, so you will need to stay submerged during the day instead.

I would say do not dive in anything shallower than 20M with anything other than a type II. If a merchant sneaks up on you, it will ram you and you have no where to escape to. As for how to know the depth, your navigator can tell you the depth under keel.

[Marcello]

Insofar routes go you can get a feel by reviewing patrol maps at uboat.net (http://www.uboat.net/boats/patrols/patrol_336.html) ; I usually employ search patterns crossing the probable shipping route at 90°, what was usually used in reality I never looked at admittedly. There is the u-boat commander handbook which can be found here (http://www.hnsa.org/doc/uboat/) , it apparently gives a wide latitude to running searches as commanders see fit..

[mrbannon]

Thanks for the replies.

dark knight, regarding the navigator giving you the depth, does this depend on a ping towards the bottom, or is it taken from the map? If the former, this could give position our position away, yes?

[the dark knight]

It uses a sonar ping to determine depth under your keel. In real life, yes, this ping would give you away to the enemy. In SHIII, the enemy ignores the depth ping. What I do, (for realism for myself) I will not ping when I am near a convoy, or an enemy warship. Merchants did not have hydrophones, so you can be as noisy with them as you want, as long as a warship is not near.

[mrbannon]

It uses a sonar ping to determine depth under your keel. In real life, yes, this ping would give you away to the enemy. In SHIII, the enemy ignores the depth ping. What I do, (for realism for myself) I will not ping when I am near a convoy, or an enemy warship. Merchants did not have hydrophones, so you can be as noisy with them as you want, as long as a warship is not near.

I wonder if a MOD could be made for that. I wonder if I could do it. I wonder how one MODs SH3 in general. :)

Edit: Now looking at Silent 3ditor.
Edit edit: Scratch that. I won't be able to figure this out.

[Gustav Schiebert]

- How far would a u-boat be from shore when navigating towards its patrol sector?
That depends entirely on where the patrol is. It's usually advisable to stay at least 100km from an enemy shore to avoid mines - although by aiming to stay in deep water (which you should do as standard), that will normally keep you far from the enemy shore. At this stage in the war it is less of an issue but air cover needs to be avoided. The stock SHIII map shows how air cover changes throughout the war. Short answer - as far as you can, while still heading efficiently towards your target.

- Once in the patrol sector, what speed would the u-boat keep?
Cruising speed depends on a lot of factors. LF (2/5) speed is (in game and IRL) the most economical and will give you a speed of about 10kts.

- What makes a good patrolling pattern? (AO98 is special because less than half the sector is water.)
No convention here - as has been mentioned, a random zigzag will do just as well unless there is a definite route, ie you are close to a port and can guess where the enemy will be. West coast of Africa is a good example.

- I'm assuming one should switch between sonar (periscope depth) and visual (surface) during the the patrol. At what frequency should these legs change?
Visual - particularly at this stage of the war - was standard, even at night. Only in poor weather would a hydrophone check be carried out.

- Are there depths that are NOT safe to submerge in? (For example, a depth of 12 meters could quickly become less than that. How would a captain know?)
Periscope depth is safe in almost all situations. If you are worried about hitting the bottom at 12m you are too close to the shore. A good check - if the TC will not go any higher than 4x that means you are too close to land to submerge. Real captains would have years of experience at sea to judge that, as well as more accurate charts.

- If a contact is made, does one immediately surface to report it, or wait? (I assume one waits, unless it's a special circumstance.)
Single contact - surface, report, attack.
Convoy - surface, report, wait for orders (game will always tell you to attack, although IRL commanders were often ordered to shadow), attack.
At this stage in the war almost everything was done on the surface.

- SH3-specific question: do the crew automatically rotate shifts, or is that the player's responsibility?
Depends on your mod. In the stock version the crew do not rotate and will get tired; GWX and SH3 commander allows you to manually select fatigue levels, ranging from disabling the whole aspect to several 'halfway' solutions.

- Anything else I should know?
Attack! Always attack! 1939 is the safest time to be a U-Boat. Make the most of it! :salute:

[Herr-Berbunch]

- Anything else I should know?
Attack! Always attack! 1939 is the safest time to be a U-Boat. Make the most of it! :salute:

But not in August, wait for 3rd September!

For this shake down cruise I'd stay surfaced, a practice dive in any deep water. Not at war so I'd ping for depth, I keep to the patrol grid but away from the shore, just a nice slow speed with a course parallel with the coast.

@mrbannon - I'm with you on figuring out how to mod, luckily for us there are many who have the tenacity to figure it out. :yeah:

[Gustav Schiebert]

But not in August, wait for 3rd September!

Ah yes - very important. That might be why father insisted I leave the diplomatic service and join the Navy.

[BigWalleye]

For a search pattern, I prefer what is called a “retiring zigzag” - moving along the expected line of advance with legs about equal to the visible range and legs about 60 degrees to the line of advance. This gives a search corridor about 2x the visible range and uses the sub’s motion to extend the searched area.

Hydrophone searches are useful at any time of the war, and I suspect a sharp Kaleun would use them regardless of doctrine. According to available data (http://www.uboataces.com/hydrophones.shtml (http://www.uboataces.com/hydrophones.shtml)), German early-war hydrophones had a range of about 20 km – for a single ship contact. That’s as good as the best modded horizon of 20 km, and almost 3x the range of the stock SH3 horizon, and the horizon is only the visibility range under optimum weather conditions.. A hydro dive every several hours should be good to catch most merchants. Once contact is made and the enemy line of advance determined, close to engage on the surface.

[nionios]

- It's usually advisable to stay at least 100km from an enemy shore to avoid mines - :salute:

Are mines real in SH3? At what depth approx.?

[the dark knight]

Are mines real in SH3? At what depth approx.?

They are very real, especially later in the war. They are around 7 meters in depth (roughly), so if you are in shallow water you will hit them while surfaced, and possibly while submerged too. In one of my early GWX games, I tried to sneak into Greenock, Scotland. The Royal Navy used this as their main naval base after U-47 sank HMS Royal Oak at her moorings. I was almost inside, sneaking through the channel, and.... booom, severe flooding, bow torpedo destroyed, sub sinking fast..... then death. I am extra cautious in shallow water now, and wont try to sneak into Greenock again.