The "Great Big Gun" is a heavy lift orbital launch system designed to "shoot" large payloads to LEO. This is the "railroad" to space designed to provide low cost delivery of materials and equipment into orbit.
Consisting of a gigantic floating catamaran supporting a 50 foot diameter cast concrete electrical mortar, the giant platform is nearly a mile long and 600 feet wide. Cast into the mortar tube are electromagnetic coils that propel huge 50 foot by 200 foot long "bullets" to a muzzle velocity of 9,000 meters per second. This giant rail gun mortar (5,000 feet long) will be built with bouyancy chambers to allow the tube to be flooded selectively and provide elevation control. The entire raft can be rotated to launch in any direction. A roller trunion allows the mortar tube to move freely.
Each "bullet" contains up to eight modular container sized boxes that are not just containers but are also habitat modules. A typical launch bullet will weigh 350,000 pounds. Each launch bullet comprises less than 10% of the payload and is made to be disassembled into general purpose structural members. Each container is rigged with retro rocket pack to provide a "gentle" landing on the Moon or Mars.
The ability to put earth moving equipment, tunnel boring machines, and other "impossible" loads into earth orbit will allow for some serious habitation possibilities. The goal is to put a pound of payload into orbit for less than $100 per pound. Currently it costs $10,000 per pound to orbit. Located on the equator, the "gun" will have a 6,000 mile launch range stretching across the Pacific Ocean. The nose cones will take the heat and pressure abuse from high speed launch. The "bullets" only need to survive for 15 seconds before breaching the atmosphere into LEO where a small steering motor takes over and guides it to rendezvous to the Interplanetary Shipyard where huge new spaceships will ferry people and equipment to the Moon and Mars.