AWARDS 2024 | Best Medium Escort Tug – Signet Sirius – Robert Allan Ltd
The Robert Allan Ltd (RAL)-designed Signet Sirius is a cutting-edge escort tug for navigating large crude tankers through the Port of Corpus Christi’s channels.
The 31.48-metre-long, 31.86-metre-wide vessel features a triple-drive propulsion system with three engines, each delivering 1,920 kW, and thrusters, achieving a 90.5-ton bollard pull for superior towing in congested waters.
Its innovative design ensures exceptional omnidirectional manoeuvrability, redundancy, and precise close-quarters handling for ships up to 300,000 DWT.
"The structure was designed in 3D and ABS approved the 3D model as opposed to traditional 2D drawings," Hongling Zhang, Project Manager/Senior Naval Architect at RAL, told Baird Maritime. "This successful model-based design project opened an avenue for 3D projects. The approach is widely accepted now by class societies, shipyards, and operators."
Zhang added that the tug also incorporated the patented triple Z-drive propulsion layout and is capable of omnidirectional manoeuvrability. The construction also applied a new lightweight fendering system and chemically strengthened windows to reduce weight and enhance efficiency and safety.
"USCG tonnage regulations required consultation and clarification of the rules and their application at a very early stage in the design development process," said Zhang. "Significant effort was put into making the structure easier and faster to build."
She added that operator Signet had set high expectations for outfit and arrangement. In particular, the tug was designed in accordance with Signet's requirements covering sourcing, lifecycle, economical operation considerations, and emissions reductions.
"The client also wanted spacious crew accommodation areas, which has a significant effect on tonnage. In the end, compromises were made to stay under the tonnage limits."
Zhang explained that the tug must meet the stability requirements, resulting in a hull form with a broad beam, a wide sponson and a deep draught, but again staying within the tonnage limits.
Lawren Best, RAL's Director of Design Development, said 2024 was another strong year for the company with almost 100 vessels built to its designs, the vast majority being high performance ship assist and escort tugs.
"We continue to be thankful for the continued trust from our strong relationships with shipyards and operators and our investments in escort tug safety, increasing vessel performance and decarbonisation continue to drive growth and provide us the opportunities to support their business," Best told Baird Maritime.
"The tug industry continues to adopt high bollard pull compact ship assist/escort tugs to support the large ships visiting ports. Over the next few years, the tug industry is poised for continued transformation driven by technological innovation, environmental regulation, and evolving operational demands."
Best said decarbonisation will remain a prominent trend with the continued shift toward greener propulsion systems, including use of biofuels and hybrid and fully electric tugs. He also expects increased investment by operators in new vessels and technologies that bring operational efficiencies and increased reliability and safety.
In Zhang's view, the North American workboat market appears focused on supporting the large number of potential new terminals and terminal expansion projects as well as fleet renewal efforts to replace ageing lower power tonnage.
"Most of these vessels look to be diesel-fuelled, but there are still some opportunities for battery electric vessels [under] the right conditions (i.e., support, power availability, etc)."
For a list of the 2024 "Best Of" award winners, please click here.
