[PSUBS-MAILIST] Ballast water valves on single hull subs with bow and stern tanks was AW: Uc3 Nautilus

[MerlinSub@t-online.de via Personal_Submersibles]

I like to explain how the ballast water system on UC3 and on Euronaut works. 

UC 3 
One hull sub with a bow ballastwater tank and a stern ballastwatertank. 
One ballast butterfly vale on top of each tank - tanks on the bottom open to the sea. 
Mechanical linkage from the valves to a troughhull to inside the sub to a mechanical hand lever. 
The position of this hand lever shows the position of the butterfly valve. 
Pretty simple and easy. No backup system - if you turn the two hand lever - the boat dive. 

Euronaut
One hull sub with a bow ballastwater tank and a stern ballastwatertank. 
One ballast ballvale on top of each tank - tanks on the bottom open to the sea. 
Mechanical linkage from the valves to a troughhull to inside the sub to a eletrical servo. 
Servo can be drop off in case of a electrical error and replace by a hand lever (a pipe)
Troughhull angel indicator gives you a green light if vale is closed, a red for open. 
Dashboard has four green and four red lights for the two ballast tanks valves and the 
two eletric remote controled hardtank valves. Servos only operates if you switch the converter on. 
You have to press the buttons for 15 Seconds before the ballvalves are fully open. 
This give you some time in case you can not read the labels proper and press maybe the wrong button.. 
In harbour or surface drive only mode the ball valves a sealed by metall plates -so even opening the valves will not flood the tank. These metall plates have small check screws - so you can test the vales function safe in harbour without to dive the boat. This test will be done any time before leave the harbour to ensure that both ballast valve are working. 

Problem with one hull sub with a bow ballastwater tank and a stern ballastwatertank are: 
If only one vale open and the other is still close the boat will half dive under an very heavy angle.
To prevent any mistake like that we only operate the valves only after a harbour check and only with closed hatches. 

Saftey procedure: 
What ever goes wrong with the system - first close the hatch and endsure the pressure hull tightness (seal the exhaust system).  

A submarine is only a submarine if the hatch is closed. 
In all other cases it is just a motorboat with a very low freeboard. 

vbr Carsten