Back in 2010 the ultra deepwater drillship Stena Carron made a visit to the North Sea and drilled a well North of the Shetland Islands. It is a substantial craft with a dual derrick enabling it to drill ahead while carrying out other assembly or disassembly activities "off line". I seem to recollect that it was the subject of an investigation after a helicopter fell over on the deck. 

Here it is with a helicopter on the deck and the Maersk Detector in attendance, photographed by Scott Boulter and posted here on 7th September 2017.

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