Submarine pen (Red Alert 1)

The submarine pen is the USSR's ship construction facility during the Second World War.

Background
The sub pen is a solid building, composed of a concrete, tetragonal triangle shaped dome built on eight supports embedded in the seabed with shipmaking facilities located underneath. Usually, they also hold data about the locations of all subs in active duty in the surrounding area, making them high priority targets for spies in operations that involve naval engagements. Should a spy infiltrate the building, the data can be accessed and a single sonar pulse discharged.

With the expanding of Soviet navy force during Third World War, it was phased out and replaced by the new Naval shipyard. During the Psychic Dominator Disaster, Yuri adopted its design into his own submarine pen.

Game building
The pen allows for standard submarines and their missile variants to be constructed as well as hover transports. It is also used to repair them.

Trivia
A fake Sub Pen exists in the game files, but is unused in-game.