In-depth Suezmax study makes CAPEX case for T-BOSS® sterntubeless shaftline system

A recent evaluation conducted by Hydrus Engineering and reported by gCaptain highlights the financial and logistical advantages of adopting the T-BOSS sterntubeless shaftline. The study utilized data from a 274-meter Suezmax tanker to compare conventional oil-based systems against seawater-lubricated alternatives. Findings suggest that shipbuilders can reduce labor and installation expenses while gaining significant design flexibility due to a shorter shaft requirements. The research indicates that the system creates approximately 660 cubic meters of additional cargo volume. This extra room allows naval architects to reposition engines or install shaft generators, potentially aiding in carbon credit acquisition. The study notes that these technical advantages allow designers to "enhance layout flexibility at the early newbuild design stage" while simultaneously offering a more efficient stern arrangement to prospective vessel owners. Operating costs are also impacted by the removal of sterntube lubricating oil. Eliminating initial oil purchases and yearly lubricant expenses provides significant savings, while lower friction in polymer bearings further reduces annual fuel costs. Additionally, the system simplifies maintenance by allowing for bearing inspections and replacements while the vessel remains afloat, removing the immediate necessity for drydocking and lowering overall lifecycle expenditures. The T-BOSS solution was a collaborative development involving Thordon Bearings, Wärtsilä, the National Technical University of Athens, and the Shanghai Merchant Ship Design and Research Institute. By removing the risk of oil leakage, the system helps operators meet international environmental mandates without the need for specialized lubricants, positioning the technology as a safer and more economical choice for modern maritime logistics.