Looking at the after deck of Pampanito, it might seem strange that she is called a boat. Usually only small vessels are called boats, and she is 311 feet 8 inches in length, 27 feet 3 inches in the beam, and
displaces 1,525 tons in the surfaced condition. However, all submarines are called "boats" no matter how large they are. This is now an affectionate term left over from the early days
when submarines were small and nasty enough to deserve the name "boat".
structure is made up of three parts; an inner pressure hull, saddle tanks built around the inner hull, and a free-flooding superstructure. The saddle tanks contain either fuel or water ballast. The ballast tanks are flooded
with water to submerge the boat and compressed air is used to expel the
water to bring the vessel back to the surface. Once on the surface, low pressure air is used to finish emptying the ballast tanks.
A World War II submarine spent most of its time on the surface where it could travel quickly and more easily find its targets. She dove to make stealthy attacks or to escape from the enemy. To make it possible for the crew to walk outside the boat while on the surface, and to protect equipment that is not in the pressure hull, the main deck is built up over the pressure hull. The space between the pressure hull and the deck is the free-flooding superstructure. The many holes that are visible allow air to escape and water to flood this space. Any trapped air would slow down the dive. Pampanito can go from the surface to 60 foot depth in under 30 seconds.
The submarine's paint scheme
is designed to help make her less visible when on a war patrol. The vertical
surfaces are painted two shades of haze gray to blend in with horizon haze
when traveling on the surface. The horizontal surfaces are painted black
so the boat would blend in with the deep when she was submerged and viewed
from an airplane. This was very important in the clear waters of the Pacific.
Other Features In This Area:
Antennas: Three antenna wires which run
aft from the conning tower are used
to send and receive radio transmissions on the surface.
Engine Exhaust And Cooling Water Discharge: Two large, round exhaust pipes
on each side of the superstructure aft discharge exhaust gasses and sea
water which has cooled the engines' heat exchangers. Fresh water is circulated through the engines to move the heat into the heat exchangers.
Vents For Ballast Tanks: Located under the superstructure on
top of the pressure hull are the vents for the ballast tanks. They could
be hydraulically or hand operated. Opening the vents allows water to flood the tanks in order to submerge the submarine.
Air Salvage System: Air fittings and valves allow salvage divers to blow the compartments from an external source in an emergency. They also served to conduct fresh air and warm liquids to cold submariners trapped below. The deck plates for this system are individually
marked by numbers of bumps and ridges so the individual air connections
can be identified by touch in the darkness of the sea.
Main Air Induction Valve And Piping: A 36-inch diameter valve
is located in the aft conning tower superstructure below the 40mm gun which
supplies all the air for breathing, air systems, and the engines.
Large supply pipes run aft from the induction valve under the superstructure
to the engine rooms. Air was also supplied to the maneuvering room
for cooling the electrical cubicle. This valve had to be shut before
submerging and was opened when it was safe after surfacing.