How thick is the fuel tank of a jet plane (Hercules)?

Question

In inches. And also, what are they made of?

Answer 1

I wasnt able to find exact numbers but base on experinece with other aircraft I would estimate the wall thickness between 1/4 to 1/2 inches

There are over 40 versions of the C-130 "Hercules' so its hard to say for ecah aircraft.

Hercules Tankers carry an additional fuel tank in the cargo compartment .. these are made of stainless steel.

The KC-130 tanker is equipped with a removable 13,626 L (3600 US gallon) stainless steel fuel tank that is carried inside the cargo compartment providing additional fuel when required. The two wing-mounted hose and drogue aerial refueling pods each transfer up to 19 L/s (300 US gal/min) to two aircraft simultaneously allowing for rapid cycle times of multiple-receiver aircraft formations (a typical tanker formation of four aircraft in less than 30 minutes). Tanker aircraft, when initially procured for the U.S. Marine Corps in 1958, were designated GV-1.

C-130E

The extended range E model entered service in 1962. The increased range was achieved by underwing fuel 1,360 U.S. gallon (5,150 L) tanks and more powerful Allison T-56-A-7A turboprops. The E model also featured structural improvements, avionics upgrades, and a higher gross weight.

Aircraft fuel tanks are typically composed of a structural container which surrounds an elastomer bladder. Such tanks typically include various access openings which are covered with bolted closures. In the design of such fuel tanks, one potential hazard is the potential for catastrophic failure due to foreign object impact damage and penetration of the fuel tank. It has been discovered that even using ballistic tolerant materials to produce the structural component of the fuel tank, it is possible that an object penetrating the tank wall at high velocity will generate a hydraulic pressure wave in the contained fluid. As the high speed object penetrates the tank and enters the fluid, it is slowed down due to drag forces. As it slows, the object transfers its kinetic energy to the surrounding fluid which generates an intense pressure wave. When this wave reaches the rigidly bolted closure, it is capable of producing catastrophic failure, stripping the bolts or fracturing the closure or surrounding structure. While additional strengthening bolts or other structures may be added to limit this type of failure, such structures add a severe weight penalty to the aircraft. Consequently, other means for avoiding instantaneous high pressure damage to closures on fuel tanks should be sought.

Answer 2

Having been a field engineer on C-130’s I can state in fact it depends on where you measure the thickness.  The aircraft has internal fuel cells in the wings and wing box.  It also has two wing tanks.

The thickness of the wing box can be ¾ -inch to a wing tank of 0.062 of an inch thick.

Answer 3

The fuel tank is an integral part of the wing.

Answer 4

The tank isn't that thick as far as the exterior metal is concerned. I can get you an exact measurement, but it'll have to wait until Monday. I doubt that it's over .090" though. The internal outer wing tanks are made of aluminum alloy, and they are coated to prevent leakage.

There are internal center wing aux tanks, but they use rubber bladders in those.

E-mail me if you want an exact figure.