Surely this has to be the REM "island", the platform and tower?
The last four issues of Offshore Echos, 210 to 213, has been covering this achievement.
And not least the erection of all the towers on the Ross after the big mast came down.
1st the temp stuff, then the heavier sections taken to the ship as described in Butterfly, and put up at sea. The double masts.
They stood till they were taken down so many years later in port......
And signals were still being broadcast as most of the work was taking place......