VESSEL CONVERSION | HOS Rocinante – Platform supplier rebuilt as maintenance vessel for Hornbeck Offshore

The Eastern Shipbuilding Group (ESG) based in Panama City, Florida, has completed and redelivered HOS Rocinante, a US-flagged commissioning service operation vessel (CSOV) belonging to Hornbeck Offshore Services (HOS).

Originally built by ESG as an offshore supply vessel, the 300-foot (90-metre) HOS Rocinante has undergone an extensive conversion at ESG’s Allanton and Port St Joe Shipyards in Panama City.

The project transformed the vessel into an CSOV engineered to support technician accommodation, safe personnel transfer, and multi-day offshore operations in harsh, open ocean environments — capabilities essential for offshore wind farm construction and maintenance, as well as traditional offshore energy projects.

Complete transfer and warehousing fitout

Key conversion elements include: installation of a walk-to-work motion-compensated gangway and other personnel transfer solutions; enhanced dynamic positioning and propulsion capabilities for precise station-keeping; upgraded accommodation and workspace capacity for offshore technicians with single-person staterooms; improvements to cargo handling and client warehousing/storage systems; and an energy storage system for enhanced power reserve and improved failure mode operability.

ESG said the CSOV is uniquely positioned to support both offshore wind development and petro-energy operations, offering HOS greater flexibility to meet the evolving needs of domestic and international energy customers.

The working deck has a total area of 4,300 square feet (400 square metres) and can transport assorted payloads totalling 508 tonnes. Approximately 2,150 square feet (200 square metres) of warehouse space is also available for cargo requiring protection from the elements.

The working deck has an Uptime motion compensated gangway with a stepless personnel and cargo lift, a Motus 3D offshore crane, a Red Rock stores crane, and space for a 15-person fast rescue craft. A flight deck capable of handling an S-92 or similar helicopter is also fitted.

Propulsion setup ensuring flexibility

The CSOV is powered by four Cummins QSK-60DM 1,825kW (2,450hp) main engines that drive two Schottel azimuthing L-drives to deliver a top speed of 12 knots and a cruising speed of nine knots. At cruising speed, the vessel consumes 155 gallons (587 litres) of fuel per hour.

Bilge keels and two passive anti-roll tanks help keep the vessel as level as possible during transfers and platform maintenance.

The propulsion arrangement also includes two Schottel side thrusters and one from Brunvoll and a Corvus Orca Energy 870kWh battery pack that will enable hybrid operation. Fuel is fed from tanks with a combined capacity of 267,408 gallons (1.012 million litres) while the freshwater tanks can hold up to 174,618 gallons (661,000 litres).

Full electronics suite and broad selection of amenities

The CSOV can also be employed in emergency response thanks to the installation of two firefighting monitors with a total flow rate of 10,568 gallons (40,000 cubic metres) per minute.

The vessel boasts a comprehensive electronics suite consisting of an AIS, an anemometer, an autopilot, CCTV cameras, a depth sounder, GPS, AIS, an area A3 GMDSS, gyroscopic and magnetic compasses, VHF radios, X-band and S-band radars, a speed log, and a public phone system with loudhailer.

The accommodation includes 45 client cabins and 29 crew berths that can house a total of 119 personnel; three client offices; a 30-person briefing room/cinema; a TV lounge; a fitness centre; a hospital; male and female changing rooms; a drying room; a client mess with 44 seats; a crew mess with eight seats; a conference room; and a laundry area.

Work on the interior spaces was undertaken by Maritime Montering.

HOS Rocinante is classed by the American Bureau of Shipping.