Zero Speed Seakeeping Characteristics of a Causeway Ferry Consisting of Four Pontoons Connected End-to-End

摘要

Seakeeping experiments were conducted to evaluate the performance of a causeway ferry consisting of four pontoons connected end-to-end which would be used to transport cargo from a floating platform to the beach during container-ship off loading in support of assault operations where no port facilities exist. The aft pontoon contains propulsion units to drive the ferry with the forward three pontoons being assembled from standard watertight cans. Heave, roll, and pitch of the aft pontoon, heave of the forward pontoon, and the relative angular displacements between individual sections were measured in random and regular waves at zero speed for unloaded and loaded conditions. A spectral analysis of the random wave data was performed to yield transfer functions for comparison with transfer functions obtained form the regular wave runs. Values of significant double amplitudes from the random wave runs are also reported. In general, transfer function and significant double amplitudes results from the two displacements are not greatly different, although in the loaded condition, the causeway ferry did experience considerable deck wetness for headings between beam and bow quartering. Performance improved as heading angle increased and was best in head seas. (Author)