Here is the Prelude FLNG, soon to be located offshore Australia by Shell as the world's first floating gas processing platform, at the Prelude Field. Its statists are amazing being nearly 500 metres long and having a deadweight of about 600,000 tons. On location it will be moored with a number of extremely large chains and able to weathervane due to the turret built in Dubai Drydocks. I think (but don't actually know) that the gas carriers will tie up alongside.

Photograph by Kenny Polson earlier this year and posted here on 8th December 2016.