The installation vessels
We used a variety of specialist vessels to transport and install the foundations, turbines, substations and cabling for London Array. Some of the vessels were also used to accommodate our offshore construction team, who stayed on site whilst the wind farm was built. A hotel ship is still onsite accomodating the technicians who are carrying out commissioning activities on the wind turbines and a variety of array cable vessels will be onsite until the summer, using ROV’s to bury the array cables.
The newly built ‘Stemat Spirit’, first launched in March 2010, was used to lay the wind farm’s export cables. Built by leading Dutch maritime services company Stemat, the ‘Spirit’ is a DP2 special service workboat that can accommodate 60 crew members and has a top speed of around 10 knots.
We used a variety of vessels and ROV’s to lay the wind farm’s array cables. For shallow water locations these included:
- Stemat 82
- Stemat Oslo (below, left)
- ROV Otter (below, right)
In deep water locations we used:
- Pontra Maris (below, left)
- Normand Flower (below, middle)
- ROV’s Atlas (below, right) and Excalibur
A variety of vessels will be used to bury the array cables at London Array.
Foundations and turbine vessels
Another brand new vessel, the ‘MPI Adventure’ (below, left) a purpose-built vessel for constructing offshore wind farms was used to install some of the foundations at London Array. Launched in August 2010, the ‘MPI Adventure’ has a top speed of 12.5 knots, a maximum operating depth of 40m and can accommodate 112 crew and workers.
The MPI Discovery, another brand new vessel, was used to install some of the wind turbines at London Array. The vessel can lift 1,000 tonnes, operate in waters 40m deep and has six jack-up legs, providing a stable platform from which turbines can be safely installed.
A2Sea Sea Worker
The ‘A2Sea Sea Worker’ (below, right) is a modern jack-up barge that’s been specially designed for the offshore wind industry. We used this vessel alongside the ‘MPI Adventure’ and ‘MPI Discovery’ to install monopiles, transition pieces and turbines for London Array. ‘Sea Worker’s four 73m long legs enable it to work at depths of up to 40m and its onshore crane can support weights of up to 400 tonnes.
The HLV Svanen was also used to install a small number of foundations at the London Array site.
Offshore substation vessels
This specialist heavy lift vessel (below, right) has been used, alongside A2Sea’s SeaWorker, to install the foundations for London Array’s two offshore substations.
The Rambiz (below, left), a multi-purpose heavy lift vessel with a lifting capacity of 3,300 tonnes, was used to install the offshore substation topsides, each weighing over 1,200 tonnes.