All in all, the test on KH- 350 "Persistence" went well. As planned, we didn't launch, but tested while still tethered to the trailer. It floated off the deck a few inches but couldn't go anywhere.
We have the trailer workings and getting it in the water smooth. It takes a bit of time to unhook, add in the extension rod and then rehook, but not bad. After that, it's not much different from launching any other boat. It was a little strange standing up with my head out of the conning tower while the sub pitched and rolling around me. Strange because for three years I've been in and out of it while it was sitting on the shop floor and it didn't move a bit.
We put it in very slowly, watching all around as we proceeded. The first problem we encountered was air leaking from every bolt that passed through the forward and rear Main Ballast Tanks. I have a bumper / hand rail running around the sides of it and never gave a thought to sealing around each bolt that passed through. I also had a few bubbles coming from the seal where the forward MBT mates to the hull. All this can be fixed with a few dabs of silicone. Those were the only leaks. As far as I could tell in the hour it was in the water, there were no water leaks. It has been so long since I put in some of the thruhulls that I wasn't positive I did the final assembly with the O-rings in place on all of them. Guess I did!
The main reason for the wet test was to run the thrusters in water. When I was purchasing the props, the prop supplier told me that they are a bit over sized but they are the nearest they have to fit my needs. The only way to know how well they matched was to test in water and monitor the amperage draw of the motors. I barrowed a heavy amp meter used to check automobile starting systems and had it in the sub while testing. They were right! My side thrusters are supposed to draw 20 amps and they drew 30. My rear thruster is suppose to draw 70 amps and it drew 110.
In the process of testing the rear thruster I smoked two power transistors on the motor controller but just happen to have two good ones from the last controller I smoked while I unknowingly reversed the polarity. Never throw away junk!
I played around with the sonar / fish finder and the air system and all worked well there.
All in all the test was good. The thruster results were expected and now I will build a jig to reduce the pitch on the props and also mill them down a little. After that I will borrow the amp meter and retest to see how close I come to the proper current draw.
Still on for a launch on June 6th.
Dan H.