Effects of Mooring Line Failure on the Wave Frequency Responses of Truss Spar Platforms

Experimental and numerical studies on a typical truss spar with
intact and damaged mooring line conditions are presented.
Physical model motions in surge, heave and pitch in addition to
the mooring line tensions were measured. A MATLAB code
named TRSPAR was developed for the dynamic analysis of
truss spar. The numerical predictions agree very well with the
measurements for the two structure conditions. Mooring line
failure has shown insignificant effect on the wave frequency
responses of the truss spar. However, for relatively low
frequency waves, surge responses for mooring damage
condition are lower than the corresponding intact mooring
condition responses.
KEY WORDS: Truss spar; responses; mooring lines; waves;
experiment; simulation.