Vuyk Engineering provided the basic design for Boskalis to convert the Windpiper into a 45,000+ tonne subsea rock installation vessel. Originally built for a different purpose, the Windpiper has been converted to execute offshore rock installation activities, with a cargo capacity above 45,000 tonnes, making it the largest vessel in this segment.
The design centres on a tower mounted inclined fall pipe system used to guide rock from vessel to the seabed. The cargo handling concept combines an arrangement of loading hoppers within the ship’s hull and feeders above deck that transfer rocks directly into the fall pipe, enabling a continuous and controlled material flow. Cargo holds were optimised to support bulk handling considering the location of the excavators and sizing of the hopper bulkheads. For this to work, multiple compartments of the original vessel were combined and opened towards deck level to allow direct loading and transfer.
Vuyk performed structural engineering for the modified cargo hold configuration, the tower which is supporting the inclined fall pipe and supporting (under deck) structures. Finite element analyses defined the required reinforcements in the existing structure to accommodate the increased loads from bulk cargo operations. Stability calculations were made to full fill the applicable criteria for a subsea rock installation vessel with the hoppers enclosed within the hull.
The general arrangement was developed to integrate the cargo handling system as one coordinated layout. Equipment such as hoppers, conveyors and excavators are positioned to support continuous material flow, while interfaces between systems were defined to ensure operability. Supporting systems, including overflow and bilge system, were incorporated together with the associated piping layouts.
The project resulted in an integrated engineering package supporting the conversion of Windpiper into a vessel capable of subsea rock installation, with a focus on cargo handling, structural modifications and system integration.
