A friend of mine in college was studying to be a nuclear engineer and after graduating headed off to the Navy to do his tour of duty on a submarine. At the time I could not comprehend what 6 months on the sub really meant. I probably still don't fully understand although having the opportunity to tour the USS Santa Fe (SSN 763), I have a much better appreciation. Leading up to the tour, the identity of the submarine was not revealed to us until we got to the docks where a torpedo weapons retriever would shuttle us to the waiting sub out in Pearl Harbor. We boarded in the protected waters of the harbor over a gang plank and down a hatch. I couldn't help but notice how the surface of the sub looked like a soft cushioned surface. I was later told this was anechoic material to minimize acoustics reflection. Once in the vessel, the outside world is shut off except for what is received through instrumentation. To provide a sense of what the inside of the USS Santa Fe looks like this cutaway of a typical Los Angeles class attack submarine is a good orientation. Our first stop was the Wardroom where COB (Chief of the Boat) John Davis, LCDR Mike Beckette and Ship Doc Rob Lazarin provide the overview of ship operations. Right above the wardroom is the Control Room and Attack Center. This is the hub of activity on the submarine. Steering and navigation is located here, along with the periscopes and sonar room. It is here where Commander Dave Adams ran through maneuvering capabilities of the sub and an attack exercise. During the maneuvering exercise he took the vessel into an incline which felt like a 30 degree angle. You can see here where Nathan Kam and Melissa Chang are both standing at a forward slant. CDR Adams then took it into a decline of 30 degrees and you could feel the opposite affect of leaning backward. Quite radical when you think about it. It is like being in a bus but moving in 3 dimensions. We then did an attack simulation on a surface target. Although the sub is equipped with torpedoes and Tomahawk cruise missiles this exercise used a water slug, basically a torpedo tube filled with water. The crew provided precise readings from sonar and the sub surfaced to periscope depth. The periscope was used to visually acquire the target and made multiple short viewings to confirm. Once the target was secured the CDR gave the "fire torpedoes" command and the water slug was launched. You could hear the expulsion of water and the change in air pressure within the control room. One cannot visit a submarine without a tour of the torpedo room. This is on the deck below the wardroom. In this photo you can get a relative size of the torpedo (in green) along side Melissa talking with LCDR Dave Benham. The torpedoes are position such that they can slide into the facing tubes. The USS Santa Fe was equipped with about 30 torpedoes mounted on a sliding mechanism that allows loading into the tubes. This is not a trivial feat in such close quarters. We did not see the vertical launch tubes for the Tomahawk cruise missiles which I assume were pre-loaded. It's one thing to load horizontal torpedoes. With the limited space on the sub, vertical missiles need to be stored within the launch tube. Another area I found quite interesting was the air handlers in the submarine. Being underwater for extended periods of time requires special monitoring of carbon dioxide and replenishing of oxygen. These CO2 scrubbers remove the carbon dioxide from the air in the sub. Right next to it is the electrolytic oxygen generator. It takes seawater, purifies the water by removing all the salts and minerals, then adds potassium hydroxide as an electrolyte. The water mixture is then electrolyzed separating the hydrogen from the oxygen. This oxygen is then added into the air mix replacing the carbon dioxide and replenishing the depleted oxygen. The air is constantly being monitored to maintain the right mixture of oxygen, nitrogen and carbon dioxide. Stay tuned for more as I have a video I plan to post of our visit to the sail area when the USS Santa Fe surfaces. You can also check out the set of USS Santa Fe photos on Flickr.