Function
The substation installation vessel transports and lifts the offshore substation into position on the pre-installed foundation (fixed or floating).
What it costs*
This is included in the substation installation contract.
- Day rates for most substation installation vessels are about £230,000
- Semi-submersible vessels may have day rates greater than £450,000 but if the oil and gas market is quiet then rates may be more competitive.
Who supplies them
Bonn & Mees, Heerema, Huisman, Saipem, Scaldis Salvage & Marine, Seajacks, Seaway 7 and ZPMC.
Key facts
If the substation is transported separately and assembled on-site at the wind farm, four main types of installation vessels can be used. These include:
- Barge
- Heavy lift vessel
- Semi-submersible vessel, and
- Sheerleg crane vessel.
In this case, the choice of these vessels will be driven by market factors and, especially if vessels serve other markets like oil and gas.
In the case where floating substations are assembled on the construction port and towed to the windfarm site, the vessels used are:
- Heavy towing tugboats with at least 300 mt bollard pull.
- Anchor handling vessels.
These vessels are supplied by companies like Solstad, Boskalis, FOF subsea and Vard marine.
Heavy lift vessels used in offshore wind include Rambiz, Sleipnir, Stanislav Yudin and Samson.
Crane ratings required for substation installation vessels are from 900 t to over 3,000 t.
What’s in it
- Auxiliary cranes
- Crane
- Dynamic positioning system
- Gangway
- Helideck
- Propulsion systems