From Larry Niven's novel Ringworld.
Almost only used for intestellar travel, this statoreactor device allows for a "permanent" refueling of the engine: an electromagnetic field supplied by autorecharging batteries and built around the prow captures interstellar hydrogen atoms and carries them back to the huge front overture, mouth of the main reactor; this field compresses the hydrogen particules until they reach fusion point –this power source allows propulsion. See a cargo variation here: [link]
And a tri-reactor version there: [link]
Reaching distant stars requires travel of hundred of years: it makes sense that the crew is made of entire families living inside the ship during several generations, breeding their own successors who, in turn, will inherit the vessel. This design concept is partially inspired by the Kevin O'Neil model of space habitat [link]
: a 7 to 8 kms long and about 2 to 3 kms wide cylinder rotating around its main axis (where is located the statoreactor device) to provide artificial gravity. Inside the hull is reproduced a biosphere to allow the crew to live like on Earth. Occasionnally, the inhabitants of the ship will encounter social troubles and/or technical issues which will drive the onboard micro-society to collapse and/or evolve into a very different direction than expected (like in Brian Aldiss' novel Non-Stop)
Made with pencil in 1996