A branch drain accepting waste products delivered to it vertically, by gravity, from one or more similar but usually smaller fixtures, and conducting them horizontally to the primary disposal drain.
When the Minuteman III retires, the silos and launch facilities at Malmstrom Air Force Base in Montana, which oversees 150 nuclear ICBMs scattered across a 13,800 square miles, will have been buried for 70 years.
The SM-65 Atlas was the first US ICBM. An intercontinental ballistic missile (ICBM) is a guided ballistic missile with a minimum range of 5,500 kilometres (3,400 mi) primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads).