View Single Post
Old 03-10-2019, 11:04 AM   #2
Onkel Neal
Born to Run Silent
Onkel Neal's Avatar
Join Date: Jan 1997
Location: Cougar Trap, Texas
Posts: 19,649
Downloads: 451
Uploads: 209


Crash dive

1. Order: "Alarm!" Alarm bell activated by Chief.
2. Helmsman switches from diesel to electric motors, then orders ahead flank.
3. Captain closes voice tube on the bridge, descends into conning tower.
4. Navigator takes a depth sounding, reports depth under keel.
5. Navigator marks on chart where boat’s location is at the start of the dive.
6. Captain closes conning tower hatch, says “Conning tower hatch is closed"
7. Helmsman silences alarm bell.
8. Dive Officer sets dive planes to forward hard down.
9. Captain orders “Flood”
10. Helmsman opens the forward MBT #4 vent valves allowing seawater in the main ballast tanks.
11. Navigator opens the aft MBT #2 vent valves allowing seawater in the main ballast tanks.
12. Captain opens the Negative vent valve allowing seawater in the negative tank.
13. Captain sets depth with order “Go to depth, xx meters.” (At the front usually to 80 meters)
14. Once the down angle indicator indicates the boat has a down angle, hold: 8 to 15
15. Helmsman closes vent valve for negative tank and blows tank to control dive before desired depth is reached. After execution of the order "Flood" and the boat has a noticeable descending tendency, the negative buoyancy tanks are expressed (blown by compressed air), by the Helmsman, who will call out, “Express”. It is critical that the Helmsman perform the crash dive operation competently, otherwise the boat could dive out of control, below safe depth, or with a dangerous down angle.
16. The ordered depth is achieved by the Dive Officer’s operation of the dive planes.
17. After the report of Dive Officer's: "Boat is at xx meters", the order always follows, Captain: "Close vents".
18. Helmsman and Navigator closes MBT vents valves.
19. Navigator reports any leaks or problems, “No leaks detected, Herr Kaleun”.
20. Navigator checks compressed air level and reports, “Compressed air at xx millibar, Herr Kaleun”.
21. Captain orders new speed, course as necessary.
22. Helmsman reports battery status, “Both batteries at xxxx amps, Herr Kaleun”.
Sonar reports any contacts.
Onkel Neal is online