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Type IV Coastal U-Boot

Background Info :
In 1937, Germany is building a large number of submarines to expand its navy. A new prototype of light unterseeboote is commissioned : Designated as "Type IV", those small vessels are perfect for coastal defence operations, crew training and stealthy strikes against an ennemy surface force.
The propulsion chosen for it is conventional. Fitted with two 5 Inline cylinders Diesel generators and a powerful electric motor for submerged travel, it can reach a top speed of 17 knots surfaced in calm seas, and up to 10 knots submerged, on electric power.
It's offensive power is composed of two unguided torpedoes, launched according to a previously calculated bearing, and a 88mm deck gun, with a reserve of 23 shells loaded under the deck and in the conning tower.
The range is estimated to 1100 Nautical Miles, or 2000 Km

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- CONTROL ROOM





- PROPULSION

HOW TO OPERATE THE DIESELS ENGINES :
Please refer to this video tutorial on how to start the diesel generators :
> HOW TO START THE DIESELS <

HOW TO OPERATE THE ELECTRIC MOTORS:

When SURFACED and on diesel power, use the "MAIN MOTOR"
> Turn on the "ELECTRO MOTOR RELAY" breaker at the back of the engine room in order to power the motors
> Set the clutch to 1 on the electric control panel
> Use the correct throttle

When DIVING and running on BATTERIES, use the "CRUISE MOTOR"

ATTENTION : When charging, the batteries will produce a small quantity of hydrogen. Turn on the ventilation system in the control room to avoid an explosion caused by hydrogen accumulation in the submarine's atmosphere.

- DIVING

HOW TO DIVE :

• Fill the MAIN ballast with ~14000 liters of water
  
• Fill the STERN ballast with ~7600 liters
  
• Fill the BOW ballast with ~9500 liters of ballast

The sub may start tilting because of an incorrect balance, adjust the quantity of water in the ballasts using the panel located near the valves.

HOW TO SURFACE :

• Turn on the air compressor until the pressure in the air banks reaches 40 bars -ATTENTION- The pressure needs to be above 20 bars to empty the ballast
  
• Open the "HIGH PRESSURE AIR BANKS VALVE"
  
• Open the ballast valves to let let air in, and blow water out

IMPORTANT INFORMATIONS
The map can be updated by pressing the "CHANGE MAP" for ~2 seconds
HOW TO USE THE TDC :
Although the torpedoes are unguided, you can easily calculate a bearing for a moving target :
-It is easier to do this procedure if you have a friend that can stay at the periscope!-

• First of all, go to the torpedo control pannel, at the front of the sub.
  
• Flood the tube until the needle indicates max capacity
  
• Open the outer door (in this precise order, otherwise you will compromise the balance of the sub!)
  
• Arm the torpedo
  
• Enter a depth for the target (The input is clamped between -1 and -35 meters)
  
• Enter a range for the target (Either known or estimated)
  Now comes the tricky part :
  
• As quick as possible, measure and enter the bearing of the target a first time using the attack periscope, or a hand held compass if you are on the conning tower
  
• After a period of time you've chosen, measure and enter the beargin a second time
  
• Enter the time period separating the two measurements
  
• Fire the torpedo rapidly after checking that estimated bearing

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Huge thanks to Maniac and Mallamar for their precious help. They created the hydrophone, as well as the TDC and helped me to test the thing at sea.
Thanks to the Subworks Discord[discord.gg] as well, for giving me precious feedback

As always, please report any issue in the comments below, and enjoy !