Investigation on Service Years of Large Rubber Marine Fenders

Abstract

Estimating the life of rubber marine fender (fender) is an important concern in the maintenance of a port facility. From the supply record of the Circular-Shaped Buckling (CSB) fender with panel contact, the actual service life was from 15 to 35 years. The compression tests of the fenders returned from ports showed that the reaction forces increased moderately due to the years in service. Other than some visible signs such as cracks and deformations, invisible signs of aging including uneven buckling, increased reaction force, and the growth of cracks were observed. The material tests results indicated that the deterioration of physical properties were limited to the rubber surface; the center of rubber bodies were still considered to be elastic and flexible. The performance in the first compression cycle of the test showed that the used fender exhibited a higher reaction force than the value stated in the catalogue -that is a value equivalent to the average of the second and third compression cycles. This increased reaction force during the first compression cycle (after a long interval from it's last compression cycle), for example, if used as inventory stock, could potentially be a concern to the berth structure and/or the vessel's hull.