The SY-4-FI Shipyard, also known as the Shipyard IV or SY-4, is built upon the same technology and design of the Shipyard I. Over ten times larger than the Shipyard I, the Shipyard IV is a network of individual production bays similar to the Shipyard I's making it capable of producing small and intricate equipment such as fighters as well as heavier starships. What makes this shipyard design far more potent, however, is its ability to drop its compartmental doors, permitting production of capital ships such as the Mammoth-class Heavy Hauler, or deploying its industrial equipment outside the station itself to construct even larger starships such as the Super Star Destroyer. Because of their ability to assemble such large ships, these shipyards are generally tasked with building the flagships of the major navies in the galaxy.
The ability to use an open bay and exterior production capability is unique to the Shipyard IV, generally making it a primary target during a raid. Given the obviousness of the Shipyard IV being a high priority target, the designers realized that to lightly arm such a station could prove disastrous. As a result, the station itself is well shielded, heavily armed, and quite capable of defending against even some capital ships without as much need for the picket fighters traditionally used for station defense. Nevertheless, few are willing to leave such valuable assets without dedicated protection from combat ships or defense stations.
Because of the high cost of building even a single Shipyard IV, these ship producing behemoths are a rare sight in the Galaxy. With lower costs and the ability to produce most ships, the Shipyard IV's smaller cousins are far more common in the ship building industry.