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/Testing the Sub

2012 Feb 21

By Chris Hames

(The sub has no wings in these pictures – they weren’t necessary at this stage of testing.)

The past week was full of excellent progress on the project. Our submarine started a series of tank and on-tether sea testing near our shop and performed better than expected.

We were testing out of the Alameda Naval Air Station (famous for also being where the Mythbusters do many of their more dangerous tests) near Oakland, CA. Over two full days of testing we verified the operations of all the major systems of the submarine, and conducted tests of our sustained life support, ballast weight release systems, lifting/loading best practices, and sustained propulsion systems. We were also able to refine our safety and operational procedures.

On Day One, after some important safety discussions, we performed a series of land-based tests mostly dealing with the ballast system. There was a lot of heavy lifting involved as we were wrangling multiple sets of 200 pound ballast weights into position under the sub, and lifting and securing them into the release mechanisms. This series of tests got us, the sub wranglers, used to maneuvering the weights on dry land and helped give us a feel for the system so we will be able to load them successfully when we are at sea and on station ready to dive. The tests also showed that all the safety and release mechanisms were working as designed. Near the end of the day, we prepped all of the CO2 scrubbers by filling them and installing them into the sub so it would be ready first thing in the morning for our life support testing.

On Day Two, we prepped the sub for her first swim test, to be conducted in a large tank that was available at the location we were using. Since Chris would be in the sub for this, we figured it would be a good time to do the life support testing as well. We loaded our Chief Pilot, Chris Welsh, into the sub on land and began the life support test. The crane then lifted Chris and the sub into the tank, and we tested the ballast release systems to ensure that they performed equally as well while submerged in water. Initially, we had planned on also testing the propulsion systems in this tank, but there was not enough water depth in the tank to keep the propellers submerged when under power, so the decision was made to bring in a bigger crane so that we could lower the sub into the San Francisco Bay. By this point, Chris had been sealed in the sub for three hours without problem, an excellent show for the life support system. After re-adjusting ballast configurations, we were successful in submerging the sub enough to stress test the motors and batteries to a point well beyond what we expect to encounter during the dives. The systems performed significantly better than expected, and in addition Chris was in the sub for nearly an additional three hours, for a total of six hours of life support testing accomplished over the day without incident.

One lesson we learned during this testing is that the sub definitely needs some more “comfort” additions for the pilots, such as padding for elbows and knees. But, beyond this small issue – a very successful first “piloted” test for our sub. We look forward to our first un-tethered shallow sea trials coming up next month. Stay tuned!