Castoro Sei

The Castoro Sei (Italian for Beaver Six) was a column stabilized semi-submersible pipelay vessel. She had an overall length of 152 m, a width of 70.5 m and an operating draught of 7.8 to 15.5 m.

The Castoro Sei was equipped with 2 rotating gantry cranes 134 tonnes capacity, three 130 tonnes pipe tensioners and a 400 tonnes abandon and recovery winch for pipelaying. She provided accommodation for 354 people.

The firing line comprises the fixed pipelay ramp, enclosed in the central housing, running along the longitudinal centreline of the vessel. It is connected to an internal and external ramp, both of which have adjustable inclination to facilitate pipelay in varying water depths. A ramp extension unit is available for use in deep water or for severe seabed conditions.

The Castoro Sei was built in 1978 by Fincantieri at Trieste yard, and was owned and operated by Saipem. Her port of registry was Nassau, Bahamas.

It has been used for laying a number of pipelines in the Black Sea, North Sea and Mediterranean Sea, including Blue Stream, Greenstream, Medgaz, Trans-Mediterranean, Europipe II, and BBL pipelines. The vessel also laid most of the Nord Stream 1 pipeline in the Baltic Sea.