Passive Restraint System for Floating Docks with Large Water-Level Excursions

Abstract

Anchorage of a recreational two unit floating dock, a gangway-deck configuration, is achieved using a combination of a fixed pile and fixed-length mooring lines. Attached to the floating gangway is a guide that rides along the pile during fluctuations in water level. For a 15.2-m (50-ft) gangway and a pile inclined toward shore at a critical angle of 10.55° with the vertical direction, two symmetrically placed shore-anchored mooring lines attached to the deck corners and diverging at 45° remain at nearly constant length during extreme water-level excursions. Experiments employing a scale model of such a design, together with the observed behavior of a recently installed prototype system in a flood control reservoir, serve to validate the practicality of this passive restraint system for inland water applications.