engineering – Professional Mariner

21 Feb

Study links small propeller defects, increased cavitation

Rich MillerMaritime Newsengineering, propulsion, shipbuilding

(OTTAWA, Ontario) — The slightest deviation in the machining, polishing and finishing of ships’ propeller blades could result in underwater radiated noise and cavitation, even if defects are within the maximum tolerance allowed by classification societies and the ISO 484-1 standard. A Canada Transport-funded study on the impact of manufacturing tolerances on propeller performance – carried out by Memorial University…

01 Dec

Advanced props, rudders provide new efficiencies below the waterline

Professional Mariner StaffShipbuilding, Trends and Currentsengineering, propulsion, technology

It took a decade or two from the invention of the marine propeller in the 19th century for the technology to become widely accepted. Thereafter, adoption has been nearly universal, but progress toward improved efficiencies has come in fits and starts. Now, though, a combination of factors — ranging from advances in computer numerical control (CNC) machining and modeling software…