Silent Running?

[Ghostpro71]

Hi guys - How do you perform silent running for the sub? Just do "Forward 1"? Is there a rig for silent running command?

[Robbo (AR)]

Use the light switch to turn the interior lights blue. (So I'm told)

[branimir.maksimovic]

Switch of gyrocompass and set steering to manual. Hover over eye icon to see what is causing sound

[[82AD] ♤Stonewall♤]

Set light to blue and turn off anything that makes a noise. Blue light decreases crew usage of oxygen amongst other things. Go deep. Check the eye and make sure the headlines of both seactions are NOT red.
To get the hull "invisible" for enemy sonar you have to go to around 160-170m...sometimes 180.

[Greggbert]

There is no silent running you have to do it all manually

[urseus]

Ahead 1 isn't silent running. Even with everything turned off I have to not move until depth charging. As soon as I turn on ahead slow they make a beeline directly for me

[Tanker D18]

Originally posted by urseus:

Ahead 1 isn't silent running. Even with everything turned off I have to not move until depth charging. As soon as I turn on ahead slow they make a beeline directly for me

If they're directly on top of you there's a chance they'll hear you at forward 1, once they're a few hundred meters off of you though you should be able to move that slow. They also can't hear you if you're behind them, but if they're on top of you they still might. At least this is what I've noticed when monitoring the detection hint.

[diecastano]

Hi Ghostpro71... As all above but trying to add the steps

1 - Change light to red or blue (both of them makes crew stop generating noise)
2 - Turn Off Gyrocompass
3 - Turn off electric dive controls
4 - Stop Uboat
5 - Dive below surface level

If all above is complete in any order, when you hover the mouse over the eye symbol on the right side, you should not see anything generating noise.

Step 1 to 3 can be performed holding tab key to open quick menu. This is also nice to increase hydrophone range area when hunting for prey!

[kimdownunder]

One for the Devs? Everyone seems to say “stop the boat”, but is that realistic? WW2 subs did not have the depth keeping aids of modern subs so were unable to hover ( unless at periscope depth when they could hang on the periscope).
Stopping the motors, they would either rise or sink. Usually, sink.
They needed SOME forward movement to maintain a steady depth. This ought to be modelled to force us to keep moving. At least, on the harder settings.

[wolf310ii]

Originally posted by kimdownunder:

One for the Devs? Everyone seems to say “stop the boat”, but is that realistic?

Nothing of that is realistic.
The gyrocompass is nothing you can turn on and off like a light, it need hours for self adjusting. The gyrocompass was only tuned off if it was absolute necessary, like damage, malfunction or laying on the ground playing dead, with a destroer on the surface doing the same, not on silent running were the e-motors are much louder than the gyrocompass anyway.

Also manual steering is much louder than electric steering.
Instead of silent e-motors close to the dive planes/rudders you have rods and gears running through the whole boat to move the dive planes/rudders.
Manual steering was only used if the electric steering failed.

[Jim (VG)]

Originally posted by wolf310ii:

Originally posted by kimdownunder:

One for the Devs? Everyone seems to say “stop the boat”, but is that realistic?

Nothing of that is realistic.
The gyrocompass is nothing you can turn on and off like a light, it need hours for self adjusting. The gyrocompass was only tuned off if it was absolute necessary, like damage, malfunction or laying on the ground playing dead, with a destroer on the surface doing the same, not on silent running were the e-motors are much louder than the gyrocompass anyway.

Also manual steering is much louder than electric steering.
Instead of silent e-motors close to the dive planes/rudders you have rods and gears running through the whole boat to move the dive planes/rudders.
Manual steering was only used if the electric steering failed.

Having just read the Silent Running section of "Diving Regulations for U-boats" (pages 50-51), I think you're right.

E. Silent Running

196. At the order "Silent running" the E motors are set for silent running revolutions. This is established for each boat by sound trials. The engine telegraph is set on the propulsion setting nearest to this revolutions.

197. All auxiliary motors in the boat are secured except for the gyro-compass installation, diving plane motors, rudder motor and 0.3-kW sound converter. These are switched off only by special order of the Commander.

The light voltage is regulated down to 90 to 100 volts (the latter for the gyro-compass transformer).

198. In the boat there are only whispers, even as required orders are conveyed by voice and telephone. Even the slightest noise must be eliminated, e.g., rattle of pots, required movements take place silently.

199. The command for ending silent running is:

Commander: "End silent running".

Link: http://www.uboatarchive.net/Diving/DivingRegulations.htm

So it seems the way noise is handled in this game needs to be re-considered.

One area of ambiguity here is the gyro-compass. How noisy was it? The regulations say "even the slightest noise must be eliminated, e.g., rattle of pots". This suggests crew noises were far noisier than the gyro-compass.

And this is confirmed in the noise test data listed in the Type VII-C manual (page 24):

Boat lying on the bottom
Sound from auxiliary machinery at 250 meters distance
Operating: Underwater Telegraphy converter and gyro compass

Not heard:
Gyro compass - circulation pump
Gyro compass - converter
Dive planes electric drive
Dive planes (hand drive)

Link: http://www.uboatarchive.net/Manual/Manual.htm

[kimdownunder]

I must say I wondered about the gyro compass too. It is not something one can just switch on and off like a light bulb. Maybe the Devs can remove the necessity of turning it off? Ought not to be a hard “fix” but I’m guessing the sound profile will need some adjusting.

[AcceptYourDeath]

Originally posted by urseus:

Ahead 1 isn't silent running. Even with everything turned off I have to not move until depth charging. As soon as I turn on ahead slow they make a beeline directly for me

It was even worse for me yesterday. I did a Black Pit patrol. I got in trouble with a bunch of destroyers although I had everything turned off and the "eye icon" only showed 88dB noise for the lowest forward speed or 0 during engine stop they could still attack me with depth charges.

From what I can tell the problem was I had still 100% sonar reflection since I couldn`t dive to the ground. I went 160m deep and still couldn`t see it. So if they got close to me by chance all circeling around over my head they found me and attacked.

You are pretty much F`ed in this scenario. 88db seems to be enough for alerting destroyers close by and you can`t mask your hull with the ground layer.

[Pyrrhus]

DD with sonar still can detect you while you have everything off or stopped, including propellers, sitting 150m under abandoned C3. They'll still try hit you with depth charges but they cannot charge through a drifting ship doing so. This can be useful to have DD run out of depth charges before they give up and move on.

[Lipi]

I always wondered if going below 160m or so rewards you with better sonar avoidance in these scenarios.

[Dewgle]

The loading screen hints refer to a 'shadow zone' that you can use to hide from enemy sensors. The game is referring of course to the thermocline and in vanilla Uboat you can only reach the thermocline by diving deeper than 260 meters.

Obviously this is a very dangerous depth and you want to spend as little time that far down as possible or risk sprouting a potentially fatal leak.