@MattB & @ChasB46
Sorry for my gobbledygook ;) - ChasB46 explained already, thanks for that, but SOV means "Service Operation Vessel"
Here you can see, how such a gangway is connected to the platform http://www.shipspotting.com/gallery/photo.php?lid=3180369

Excellent shot

Thanks ChasB46 & Baltic Sailor

SOV supply offshore vessel
DP Dynamic positioning ..computerised system to maintain the course or positioning using propellers / thrusters

Could you translate that statement into English please ;-D

I made this picture, while the SOV was proceeding towards the turbine in DP mode to pick up the maintenance team via the Ampelmann (hydraulic compensated gangway)

Interesting photograph to see what goes on in these wind farms. There appears to be two persons on that structure. I wonder if they used the landing pad to step off - looks like it's the right height.