Ballast Tank Size for OSCAR II

[ericpw8818]

Hello all,

I am on the quest for Oscar II, and have a SubDriver 3.5/2 and am not sure what size to cut the ballast tank down too. Any ideas out there Kevin ? or Wayne? Thanks in advance.

Eric
#1808

[wayne frey]

First, Have you already picked

First, Have you already picked up your hull? There are now two excellent sources. But since you are asking for Kevin or me, you probabably Know that.
Kevin is using this:

So, a 3.5 WTC of a home made design should be about right.
When mine comes up in que, I will likely use a 3.5 also. I am still debating an RCAB system, or a custom pump design like Subron 5 member Gail has built from scratch.
Email me.

[KevinMC]

Oooooo, that's an old photo...

I'm

Oooooo, that's an old photo...

I'm not sure what to tell you Eric- I lay up my OSCAR as light as I can above the waterline specifically to minimize the size of ballast tank required to lift it to the scale waterline. The length of ballast tank in the photo above is more than adequate for my hull, but I it's all a function of "weight above waterline" and I don't know how light/heavy-handed Vladimir is with his layups in comparison to mine.

The best recommendation I can make is to leave your D&E3.5/2 full length and add foam/weight to achieve a scale waterline in surface trim. Then if she's negative when you flood the tanks add above waterline foam until she's ballasted to your liking. If she's still positive with flooded tanks you'll either have to extend the ballast tank or accept a lower-than-scale waterline. (Which most people probably wouldn't notice anyways 'cause the OSCARs ride so high.)

Where are you placing your C of G?