Request for comment - ballast system

[fbradasc]

[color=#000000]Hi all,
could this ballast system work ?



1) The water pump, which mustn't be tight, could be a simple propeller inside a duct (the L duct in the drawing) and should have the power]

[smwarships]

Hello ,
I am working on

Hello ,
I am working on a ballast tank system right now and I am
thinking about using 2 winshield washer pumps to fill my
ballast tank which will vent through a brass tube and out
through the conning tower .
The windshield pumps are gear driven and when shut off
the do not allow water to flow back out . The motors have
their own sealed containers so the pumps can be put in the
free flood area .

Any thoughts or suggestions ?

Darle

[dietzer]

2) WSW1 and WSW2 are

[color=#000000]2) WSW1 and WSW2 are wather switch used to detect when the pump must be switched off]

Hello,

It's not clear to me whether WSW1/2 are simply switches or whether they are valves.

It seems to me that without some kind of valve, your MBT will lose air when submerged, and result in completely full MBTs. Was that the intent ?

Carl

[fbradasc]

It's not clear to me

It's not clear to me whether WSW1/2 are simply switches or whether they are valves.

WSW1/2 are simple water detector (electrical contacts)

It seems to me that without some kind of valve, your MBT will lose air when submerged, and result in completely full MBTs. Was that the intent ?

When submerged the MBT is completely full but the top of the snorkel must be slightly above the water line when you need to surface the boat

[fbradasc]

So then, could this system

So then, could this system work ?

[koeze]

Of course it can work.

[color=#000000]Of course it can work. Provided]

[keving]

Hello
What you are proposing is

Hello
What you are proposing is the typical Pump Ballast System. I have used this method very successfully in my DeBoer Skipjack for years. I would suggest removing the water sensing switches and keep the system simple. Use a 3 position momentary switch to operate the pump. (Up-empty, Center off, Down-fill.) In submerged trim the top of the sail is above water and a little water will escape the ballast tank vent port signaling you to shut off the pump. In surfaced trim you will see the boat at the proper waterline and you can often hear the pump suck air. This will signal you to shut off the pump. You want to run the ballast water out completely and hear the gurgling sound or water in the flood line will siphon back into the tank causing the boat to slowly submerge again. This is not a catastrophy. Just use you transmitter to signal the boat to run the pump to vent the tank.

On my boat the submerged trim is half way up the sail and it works great.

Good Luck

Kevin

[jeffg]

Seems alot like the system

Seems alot like the system Skip Assay uses in his two finw kits. The ballast system works great. I add a subsafe to blow the ballast in case radio signal is lost. Also from Skip

Jeff Groseth

[bobcowan]

Try the bladder system. Simplest

[color=#000000]Try the bladder system. Simplest and most robust of them all. Use a medical IV 'bladder' bag with an automotive windsheild washer pump or preferably a peristaltic pump. This system is closed so you can sit on the bottom and it meters water in and out in such a way that hovering is a breeze. It also has a built in 'sub-safe' because if you lose radio contact or have any other on board mechanical failure pressure will eventually take over forcing water out of the bag and your boat to surface. (this will take a number of agonizing hours). Every system has it's advantages/disadvantages and I have used gas and a piston ballast but returned to the pump/bladder bag this summer with my 1]

[fbradasc]

I would suggest removing the

I would suggest removing the water sensing switches and keep the system simple.

Kevin, I thought to use a micro controller to start/stop the pump for surfacing/submerging, so, from the R/C I need only one push button to command the sub for the diving operations.

Try the bladder system

Bob, the bladder system must be designed to support high pressures for the pump and the hoses, also, lesser the pressure higher the volume occupied by the air pressure bottle inside the WTC. It's right ?

Thank you all