Strength Analysis and Sea-Fastening Design of Container Crane Structure for Heavy Lifting Sea Transportation

Abstract

This paper discusses heavy-lifting sea-transportation of 831-ton container-crane in Indonesia from Surabaya to Kupang. Structural strength analysis is carried out to ensure the safety of the crane during the transportation process. The purpose of this analysis is to design the sea-fastening construction capable of redistributing the excessive stress that might occurred, to avoid structural failure. The first step is to model the crane structure and barge under certain various drafts. This is important because selection of the proper draft will determine the suitable righting moments of barge and hence to ensure good stability. The selected drafts under investigation are taken between 0.25 T to 0.75 T. The result of the structural strength calculation shows that the static load is found around 8150 kN. Loads due to motion of barge for heave, roll, and pitch motions are 116 kN, 7424 kN, and 232kN, respectively. Location of the high stress due to the motion is identified at the bottom of the crane structure so that the design of sea-fastening constructions will be concentrated in the vicinity of this position. The values of Unity Check after fitting the sea-fastening construction are reduced to 0.940, 0.704, and 0.702, respectively. It is concluded that the structure of container crane under such sea-fastening design is proven to be capable of overcoming the loads during transportation process.