Subsea 7 subsidiary Seaway Heavy Lifting has completed what it says is the first ever installation of an offshore monopile from an unanchored semi-submersible crane vessel.
The company installed the tubular at the site of Vattenfall’s 1.5GW Hollandse Kust Zuid 1-4 complex off the Netherlands to test a new dynamic positioning system it has installed on its Seaway Strashnov vessel.
The company has spent several years developing the system, which it hopes can slash the time taken to install tubulars offshore by removing the need to lay and remove anchors at each foundation location.
Data from the installation will be analysed to establish the angles of vertical achieved.
Depending on results SHL will use the unanchored method to install the 140 foundations at Vattenfall’s 1.5GW Hollandse Kust 1-4 complex off the Netherlands from 2022.