Computational and experimental analysis of trawl winches barrels deformations

The necessary use of heavy duty trawl winches can cause plastic deformation of winch barrels, known as “rolling”. Numerical analysis shows that the main reason for such deformation is pressure from layers of cable, while other reasons – a “rolling spot” of stress near the rope-barrel contact point, barrel bending and torsion – play a small role. The influence of different factors (barrel sizes, material properties, rope properties, and load levels) on the strain accumulation rate is analyzed. The described method provides a barrel design for new winches and load constraints for existing winches. New rope tension gauge and special software are developed to help the trawler master predicts situation that can lead to barrel plastic deformation.

► Increase of trawling speed and depth cause increase of loads on deck machinery.
► Trawl winch is the part of deck machinery that cannot be repaired offshore.
► Displacement accumulation and cracks in trawl winch barrels restricts lifetime of the winches.
► Numerical analysis of these processes helps to overcome the problem.
► New rope tension gage is developed to help trawl master keep barrel deformations acceptable.