Best known for modern, innovative passenger catamarans, Astilleros Unidelta SA of Buenos Aires is currently building an innovative tug. The aziumthing stern-drive (ASD) ship-handling tug is now being built at the Argentinian yard. The first, in an anticipated series, will be for the maritime group SIPSA. The boat will have twin Cummins QSK60-M propulsion package. Each of the Cummins mains will deliver 1958 kW at 1800 RPM to a Rolls Royce Z-drive with 2400 m/m diameter propellers in nozzles. This combination is designed to give the ASD tugs a 61-ton bollard pull. The double-chinned hull, designed in-house by the Unidelta naval architects, features a nearly full-length skeg and finely tapered stern to optimize ship-handling capabilities.