A massive, arsenal-type Metal Gear inspired by the US Navy's Arsenal Ship program. It houses and protects GW, a large-scale data management system designed to control information on a global level. Arsenal Gear is a nearly-invulnerable mobile fortress armed with several thousand missile weapons and guarded by a swarm of Metal Gear RAYs (unmanned), a force of Tengu Soldiers armed with high-tech weaponry patrols its interior, which is divided into Stomach, Ascending Colon, Ileum, Rectum, Sigmoid Colon, and Jejunum sections. It can take command of all four US armed services through its tactical network. However, it requires military support for long-term operations.
The top-secret Arsenal Gear development project was carried out by the Patriots in the "Big Shell" ocean cleanup facility. In 2009, during the occupation of the Big Shell, Solidus Snake seized control and activated Arsenal Gear. However, damage to GW caused him to lose control and it crashed into lower Manhattan, destroying Federal Hall.