Another question...pump controllers and WTC builds

[Thorbrandr]

All,

I know I have a sudden burst of questions. it's sub running season here in WI, and I have been trying to make the most of it. I have the Marline rebuilt and running well, my 212 mostly dialed in. The R10 will be going out next month. I am planning my winter builds.

The rebuild on the Marlin ended up taking me in the direction of replacing WTC plexiglass to deal with a crack in shipping and to move the ballast tank CG, replacing the ballast pump and plumbing (which was flooding the forward compartment), etc. I have also updated the main tube on my 212. I now have my south bend lathe running for working with the WTC size materials, and am looking at my own WTC build.

What pump controllers are out there, and what should I use?

I am looking at possibly doing a high pressure dive system, but I admit the low pressure is easy. I just would like a way to blow the tank wheel fully submerged, as I am in a location where I can run my boats deep.

Thoughts?

T

[Subculture]

What do you mean by a high pressure system?

[type7]

Nautilus Drydocks sells Kevins McLeod's pump controller if you want to set up a system like Merriman's sub-drivers. His sub-drivers are about the most efficient power and packaging. A 20 amp or more ESC will power a pump like R&R cylinders which is pretty simple to implement.

[Thorbrandr]

What do you mean by a high pressure system?

Using Bob's terminology (p 17 in his book), something like the OTW system where the air in the WTC is compressed. I like the fact that I can bottom my OTW R10 in 6', then bring it back up. I would prefer to avoid the issues with water getting into a dry compartment however.

T

[Subculture]

Recirculating or non aspirated system is a better terminology. These systems typically run at a few psi, running too high pressures inside a WTC will compromise seals anyway. Some OTW systems compress air inside the ballast tank like the Sheerline system. Typically half the tank volume is used to give 1 atmosphere pressure increase inside the tank, quite a bit higher than the OTW system that vents air into the rest of the cylinder. The draw back with this arrangement is increased pressure meaning a more stout ballast tank has to be constructed, plus a larger ballast tank, as you can only fill it so far before pressures get a bit scary, so you need to be more mindful of slosh or baffle the tank carefully. You also need a pretty decent pump to stand up to the higher duty.