In a message dated 9/15/2009 10:20:07 A.M. Pacific Daylight Time,
vbra676539@aol.com writes:
After that, it's a waste of payload.
Hi Vance. That makes sense. I was a little concerned how difficult it would be to install/remove the drop weight mechanism if it was 750 lbs. I had designed the release screw long enough to "grab" the weighted keel and suck it up to the hull. With the rollers on the keel I can position it under the sub. I'm thinking too much weight used as a drop weight just adds difficulty to that task, and a lot of expense if I have to drop it and can't get it back later.
On the corrosion around the underfloor weights......I'm making contoured pans from sheetmetal to fit into the various odd shaped pockets under the floor. These pans will get lead poured into them and an indentation in the top for an embedded handle. This will make it simple and convenient to pull the leaded pans out of their pockets to dry out any condensation gathered there, and do any touch-up painting when needed.
The pockets are formed by the stiffener plates making a kind of "grid" pattern on the bottom of the hull interior. The floor plates will be bolted down to keep the leaded pans in place. I sure don't want anything rolling around loose inside.
I need a sliding weight inside because of the difference in my MBT sizes. Submerged it balances good front-to-back but surfaced the larger MBT in the back will push the nose down. The sliding weight will re-balance for surface level. I'll find out just how much sliding weight is needed once all the components are finished and I can actually weigh them.
So far, the front and back frame work matches pretty close. The rear ballast tank is getting pretty heavy and should end up around 275 pounds. Rear fairing is near 100 pounds, two motors with rudders at about 30 lbs. each. Add the spare scuba tank, and rudder actuators for another 50 lbs. and then balance the whole front assembly to match.
The tube steel frames have threaded ports in them so I can add weights as needed for balance. Some will get Argon gas to keep them light but prevent corrosion, some will be oil filled, and I may need to fill some with lead shot and oil if I need more weight to balance front-to-back. I'm pretty sure the two lower legs on the front will need that. The ballast tank and FRP fairing in the front are lighter than the rear components. Total weight of front and rear modules needs to match so it stays level when submerged.
I gotta take all these parts down to the scale once they're finished to get accurate weights on them. Then I can adjust with the fill-up material.
Frank D.