Delete comment from: Dark Roasted Blend
They have huge chains for towing (I think). I'm not quite sure myself how it moves over the seabed, but the "pods" you see at the bottom in the Eiffel tower comparison are basically suction cups. They open up valves on the top and let the structure sink into the murky seabed. Then they close off the valves which will anchor the structure to the ground (try to lift it and a vacuum will be generated, sucking it to the floor).
The band that is halfway up the legs is specifically tailored to change the resonance frequency of the platform. This is to prevent the platform from "breaking" due to the frequency generated by wave action (resonance is what causes bridges to "flail" about violently; in that case due to wind action).
I was actually offshore in September doing commissioning work on the Gjøa platform (the semi-submersible with green legs), and this summer I enjoyed 10 days of warm weather on a boat laying in between Statfjord A and B some hundred meters away :) will hopefully get to visit Troll A and the other massive condeeps later on as well (I'm a rookie petroleum engineer from Norway ;)
The "3 meter waves" has got to be a typo :P that's probably somewhere in between 10-15 meters. 4-5 meter waves is common during the autumn and winter.
At New Years Eve 1995 a freak wave of 25.6 meters (84 ft!)/significant wave height ~18.5 m, hit the Draupner field. I can't even imagine seeing that. (http://en.wikipedia.org/wiki/Draupner_wave)
Thanks for a nice article.
Oct 26, 2010, 5:21:43 PM