The General Products Hull is a basic spacecraft body, impervious to all forms of matter and electromagnetic energy (except visible light).[1]

After the dissolution of General Products, the limited number of GP Hulls remain the safest transport bodies in the Known Space.[1]

There are four types of Hull and can be further customized by the user.[2]

  • The No. 1 hull is a sphere about the size of a basketball, used for automated spacecraft.
  • The No. 2 hull is "a cylinder three hundred feet long and twenty feet through, pointed at both ends and with a slight wasp-waist constriction near the tail".[3] Louis Wu's Lying Bastard and Beowulf Schaeffer's Skydiver were based on No. 2 hulls.
  • The No. 3 hull is a cylinder with rounded ends and a flattened belly about 110 feet across. The Hot Needle of Inquiry,[4] used for the second Ringworld expedition, was based on a No. 3 hull.
  • The No. 4 hull is "a transparent sphere a thousand-odd feet in diameter". According to Beowulf Schaeffer, "no bigger ship has been built anywhere in the known galaxy". They are so expensive that only governmental colonization projects use them, with the exception of the Long Shot, which was mostly filled with the experimental Quantum II Hyperdrive.

Properties and limitationsEdit

Antimatter can degrade the Hull (like any other substance); gravity and other forces can be fatal to the inhabitants.[1]

The hulls are advertised as being capable of flying through the upper atmosphere of a star unscathed, although the contents will be cooked; as a protection against this particular contingency, the Puppeteers also provide a stasis field as well.

When a GP Hull was exposed to a constant stream of diffuse antimatter during a visit to a star system with some exotic qualities it unraveled (whereas a conventional hull made of metal, would simply have ablated under these conditions). This was because that a GP Hull essentially consisted of a single incredibly large, highly complex molecule. Once a sufficient number of the atoms which constituted the molecule were annihilated by the antimatter, the molecule could not remain stable, and thus degenerated into a selection of less complex compounds and elements, effectively causing the hull to vanish in an instant. Fortunately, the vessel's pilot was sufficiently paranoid to be wearing a vacuum suit at the time, and survived, as did the owner of the ship.[5]

Baedeker once revealed (apparently unintentionally) that the manufacturing process was extremely sensitive to gravity and impurities, that the hulls are constructed from a single supermolecule constructed using nanotech, and their strength is reinforced by an embedded power plant that reinforces the inter-atomic bonds. These facts provide the clues that allow the tourists to later destroy a GP Hull from the inside and survive.[6]

Another way to destroy a Hull was to direct a high energy visible light beam through the hull to overheat the integrated hull strengthening power plant. This would force it to shut down whereupon the air pressure inside the hull would be enough to burst it like a soap bubble. This was addressed in newer GP hulls where a hi gain diffusion tubing network was established in the hull to rapidly disperse excess heat away from the powerplant. This prevented any quick destruction of the hull. Secondary methods of destroying the GP hulls which cannot be completely protected against are the Gw'oth method, and a deliberate point blank laser used to reprogram the powerplant. The Gw'oth method involves getting a ship with a hyperdrive shunt close enough that the bubble of normal space taken by said ship into hyperspace bisects a portion of the GP hull. Anything disconnected from the central hull power plant is reduced to a weak husk. The reprogram method is a back door left by the GP designers themselves for repairs, the laser needs to send highly precise program instruction from a range of a hand scanner to cause the hull to shut down and break apart.


  1. 1.0 1.1 1.2 Concise Encyclopedia
  2. Database
  3. "Neutron Star"
  4. The Ringworld Engineers
  5. Flatlander
  6. Fleet of Worlds
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