Danger from the deep: Take a look inside the WWII-era USS Pampanito

After a distinguished career, the USS Pampanito now sits as a museum ship in San Francisco. 

For more about this ship, check out Undersea battle star: Inside the USS Pampanito. 

The Pampanito is a Balao-class diesel-electric sub, launched in 1943.

The Pampanito had six patrols in the Pacific during World War II.

She's 311.5 feet long, or about 95 meters.

I began the tour descending stairs that were retrofitted when the sub was converted to a museum ship. This is the aft torpedo room. 

The Pampanito had 10 torpedo tubes, 4 aft and 6 in the bow.

The top right shows the inside of a torpedo where the warhead would normally be.

The torpedo's propellers would rotate in opposite directions to help maintain direction.

The next compartment forward is the maneuvering room. 

The Pampanito has four electric motors that, through reduction gears, drive the propellers.

Submerged, top speed was around 10 mph, or 16 km/h.

The next compartment forward is the aft engine room, where you'll find two of the four 10-cylinder opposed-piston engines. 

Diesel engines need to breathe, and this is one of the main ways that was done. A big snorkel that could supply fresh air when the sub was on the surface. This was usually done at night.

The four engines, with electrical generators, were used to recharge the ship's batteries.  

The diesel engines weren't connected to the propellers; they were just used to generate electricity. 

Water was desalinated on board but was always at a premium. The crew would rarely shower.

The next compartment forward is the other engine room, with two more 1,600-horsepower Fairbanks-Morse engines.

The Pampanito had around 80 men on board. There wasn't a lot of privacy. 

Many subs squeeze crew bunks wherever they fit. The Pampanito has a whole compartment for the majority of the crew. 

The crew hot bunked (or hot racked), which was common for subs of the era. In this case, two beds for every three men.  

The crew's mess was one of two places the crew could relax, the other being their bunk. 

There was a radio, board games built into the tables, and lots of coffee.  

On modern nuclear subs, food is the only major limiting factor as to how long a patrol can last.

It is said submariners have the best food in the armed services, and you'd hope so, given how isolated they were.   

In here is the radio room. The "typewriter" is a state-of-the-art encryption device.

Not just for show, the Control Room would use red lighting at night to help maintain the night vision of the officers on watch in the conning tower above.

The Pampanito had five patrols in WWII, sinking six ships and disabling four more.

On the surface she had a range of 13,000 miles, or 20,000 kilometers. Submerged, she could run at maximum speed for about 30 minutes, or at a crawl for 16 to 18 hours before oxygen depletion became a problem for the crew.

Before you submerged you'd better make sure your panel was green.

Beneath the control room is the pump room, with the machinery to help the sub maintain depth. 

Balao-class submarines could submerge to a depth of 600 feet (183 meters).

The USS Tang, one of the Pampanito's sister ships, went even deeper. 

Like nearly all submarine museum ships, you can't go up into the conning tower. However, a selfie stick can help give a peek. You can see the periscope tubes and various sensor and electronic equipment.

Looking the other way, the blueish light is sunlight coming through an open hatch at the top of the tower.

During her third patrol, in 1944, the crew of the Pampanito rescued 73 British and Australian POWs out of the South China Sea, survivors of a cargo vessel sunk by one of the Pampanito's sister ships several days prior, having not known there were POWs aboard.  

Even under the sea there's paperwork.

The chief petty officer's quarters. No hot bunking here.

The commanding officer's quarters.

The officers get their own "lounge."

And their own mess.

The Pampanito served from November of 1943 to December 1945, then again as a training vessel from 1962 to 1971.

Early in the war the Pampanito had the troublesome Mark 14 torpedo (as shown earlier in the aft torpedo room), but later received the electric Mark 18, seen here with a clear casing. 

The six forward torpedo tubes.

Note the escape hatch (with sunlight coming through) at the top of the image.

The top here is the flat deck, with the curved pressure hull underneath. That hull is 0.875-inch (22.2 mm) thick.

The Pampanito's turn on the big screen was in 1996's Down Periscope where it starred as the "USS Stingray." The actual USS Stingray was a Salmon-class submarine, but we'll let that slide for such a cinematic masterpiece.

For most of WWII, deck armament consisted of a 4-inch 50-caliber gun, a 40mm anti-aircraft gun, and a 20mm anti-aircraft gun.

Hard to lose your binoculars when they're hard mounted.

In 1945, right before the end of WWII, Pampanito got an overhaul that included some new weaponry, including a 5-inch 25-caliber gun, and a doubling of the 20 and 40mm AA guns. Only one of the latter is shown.

Also on the pier is the Liberty ship SS Jeremiah O'Brien, which was part of the D-Day invasion.

Notice the broom at the top of the tower? That was to signify a successful mission when the sub returned to port.

It's easy to find the USS Pampanito, right next to Fisherman's Wharf in San Francisco. It's well worth a visit. 

For more about this tour, and the sub, check out Undersea battle star: Inside the USS Pampanito.