VESSEL REVIEW | Aesen 116H – Singapore operator's new hybrid crewboat for oil and gas field use
Singapore-based offshore services provider Aesen (formerly Miclyn Express Offshore) has taken delivery of Aesen 116H, a hybrid fast crewboat developed for personnel transfer and logistics support within producing oil and gas fields.
The aluminium monohull was launched on June 2. She is flagged in Panama and classed by Bureau Veritas with the notation I ✠Hull – Mach Crew Transfer Vessel, Sea Area 3, Electric Hybrid (PB, PM, ZE), Smart (M1)
The crewboat has an LOA of 42.2 metres (138 feet), a moulded beam of eight metres (26 feet), a moulded depth of four metres (13 feet), a loaded draught of only 1.9 metres (6.2 feet), and a gross tonnage of 346.
Aesen owns and operates more than 70 crew vessels across Southeast Asia and the Middle East. Company chief operations officer Tan Wee How said that analysis of the fleet's operating data showed most of its crewboats run at less than 20 knots, while conventional designs are built around transit speeds of up to 30 knots. The company therefore set out to design a vessel around that real operating profile while keeping high-speed capability, safety, and redundancy for when they are needed.
Developed in line with contemporary offshore energy support requirements
“Importantly, the objective was never simply to introduce hybrid technology for its own sake,” Tan told Baird Maritime. “The brief was to leverage Aesen's decades of operational experience and fleet data to develop a vessel that better reflects real-world operating profiles while maintaining the safety, reliability and performance standards expected by our clients.”
Propulsion for Aesen 116H is provided by two Caterpillar C32 main engines, each rated 1,081 kW (1,450 hp) at 2,300 rpm. The engines drive two fixed-pitch propellers through ZF 335 gearboxes.
A permanent magnet synchronous motor is coupled to each gearbox PTI/PTO shaft and is supplied by a Lehmann Marine air-cooled lithium iron phosphate energy storage system.
Three Caterpillar C4.4 generator sets of 86 ekW each complete the arrangement, which was integrated by Stin Global.
The diesel mechanical mode delivers maximum power, giving a top speed of 24 knots at full power and a service speed of 22 knots at 85 per cent MCR.
Diesel-electric mode is ideal for lower-speed interfield transfers, manoeuvring and routine operations, matching energy use more closely to actual demand. Full electric mode will cover time alongside and hotel loads, reducing engine running hours, noise and local emissions.
“The electric system also enhances operational resilience by providing an additional source of propulsion and power redundancy, including support for certain emergency response scenarios without the immediate need to start the main engines,” said Tan.
Aesen estimates savings from a single infield test vessel's service cycle under its own operating assumptions. On that basis, Tan said the vessel is expected to cut fuel costs by approximately 40 per cent. He put the resulting savings at around US$700,000 in operating costs and 1,750 tonnes of CO₂ per vessel annually.
Tan added that actual results will vary with duty cycle, utilisation, loading, speed, sea conditions and the time spent in each mode.
Ample personnel capacity coupled with external firefighting arrangement
The vessel seats 80 passengers in business class seating and accommodates 10 crew. Her 120-square-metre (1,300-square-foot) deck is rated at 2.5 tonnes per square metre and can carry up to 60 tonnes of cargo.
Tank capacities are 96,000 litres (21,000 gallons) for fuel oil and 30,000 litres (6,600 gallons) for freshwater. These are served by transfer pumps rated at 20 and 30 cubic metres (4,400 and 6,600 gallons) per hour, respectively.
The vessel also carries a FiFi 1/2 external firefighting monitor rated at 1,200 cubic metres (260,000 gallons) per hour. On the bridge, Smart Window technology provides a clearer view of critical work areas around the vessel.
Aesen 116H is "probably the world's first purpose designed infield hybrid crewboat," Tan told Baird Maritime. Her daily work will include transport of personnel between installations, interfield transfers, and carrying mission-critical cargo and equipment.
The crewboat is also equipped for emergency response support, security escort, and node handling.
Pilot testing of Aesen 116H with selected national and international oil companies is expected to begin in Southeast Asia during offshore personnel transfers and infield logistics work.
