Drednot.io Wiki

Dock Springs are found in Freeports. They prevent your Spaceship being pushed around by other Spaceships. This can help prevent theft when ejecting items out of your Cargo Ejector.png Cargo Ejector.

You can easily dock your Spaceship by landing(touch) one of these Dock Springs, and easily undock by flying away from it. Once docked, your Spaceship will have a slight pull towards the Dock Springs. It's noticeable. They also disable your thrusters saving fuel.