Propeller Guard Information Center

Following up on Hydrodynamics of Propeller Accidents Part 1, we now share some research work that looks very applicable to future hydrodynamic studies of human body / swimmer / man overboard interactions with boats, drives, propellers, and propeller guards.

We recently came across some hydrodynamic studies of whale interactions with ships, ship hulls, and ship propellers. One study was done at Carderock (the U.S. Navy lab facility we earlier suggested as a possible location to do full scale interaction studies with small boats). In the whale ship interaction study, they used a scale model of a huge containership with an elliptical bow bulb along with an instrumented model of a right whale.

The study is cited below.

Hydrodynamics of a Ship/Whale Collision.
Gregory K. Silber, Jonathan Slutsky, and Shannon Bettridge.
Journal of Experimental Marine Biology and Ecology.
Vol.391 (2010) Pages 10-19.
an Elsevier Journal.

Several quotes in the journal are strikingly similar to the needs of propeller guard hydrodynamic studies. The abstract contained the quote below:

“Factors influencing the incidence and severity of ship strikes are not well understood, although vessel speed appears to be a strong contributor. The purpose of this study was to characterize the hydrodynamic effects near a moving hull that may cause a whale to be drawn in or repelled from the hull, and to assess the acceleration exerted on a whale at the time of impact.”

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