Case study

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Retrofitting in controllable pitch propeller for trawlers

Customer: Pescanova, Deris, TASA, Iberconsa, Inpesca
Related services: Ship resistance & powering prediction, CFD simulation, adapted propeller design & supply
Scope of work

  • 3D model of the hull
  • Core and base measurements for current CPP
  • Hull analysis by CFD tools
  • Nominal wake calculation
  • Self-propulsion computation in conditions of drag and free running
  • Cavitation analysis
  • Propeller geometry design, adapted to vessel operational profile
  • Supply of blades compatible with the CPP core


Results
The retrofitting of CPP blades offers an interesting alternative for the replacement of controllable blades. Both in old equipment, as those who want to provide more efficiency or present problems of consumption, noise or cavitation.
For trawlers, the design of the paddles implies an added difficulty because they must take into account two well differentiated working conditions. On the one hand, the work en route to the fishing ground and on the other the trawling condition. However, thanks to the adapted design of the propeller we have achieved improvements of 5% compared to the original equipment. These improvements have allowed to increase the towing capacity of the vessel, as well as to reduce time on the routes to the fishing grounds.
During the self-propelled CFD studies for the design of the blades, special care was taken to avoid the appearance of erosive cavitation, thus preventing possible noise and vibration problems.
To ensure the compatibility of the manufactured equipment, a Vicusdt technician traveled to the shipyard. He made an exhaustive measurement of the base of the blade and checked gaps in the equipment. In this way, we achieved that the lace of the blades in the original core was perfect.
The base of the new blades, which can be manufactured in Cu3 bronze or stainless steel, is adaptable to any type of core. As a reference, we have already made substitutions in Kamewa, MAN, LIPS, SILLA and Wichmann equipment, among other brands.