Design of Tin Cutter Suction Dredger Ladder for Maximum Operating Depth 55 Meters

• Main Author: Budiawan Saputra, Matheus
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40618
• Institution: Institut Teknologi Bandung

Cutter suction dredger (CSD) is one of equipments for offshore tin mining operation. A CSD consists of many systems to support tin mining operation. As one of the main equipment of a CSD, ladder is a construction to mount cutter, pump, and pipeline, as well as to reach certain dredging depth. Ladder can be hoisted or lowered by means of a hoisting system in order to reach certain dredging depth. In one case, it is required to increase the ladder length in order to increase CSD maximum dredging depth. This final project is aimed at designing a ladder structure as well as its hoisting system based on the original design belonging to the existing CSD. In designing ladder structure, several design alternatives are proposed, analyzed, and finally selected as one design that is considered the most suitable one. The design of the hoisting system is based on, the heaviest ladder alternative. Strength and stiffness analysis of ladder structure are carried out with a finite element software, Abaqus 6.10 EF2. Design alternatives are analyzed in the most critical load case, i.e maintenance case (00) and maximum operating depth case (600). After trials and analysis on 6 design alternatives, an optimum design of ladder structure has been selected, with the estimated mass of ladder structure of 57.7 tons and the minimum factor of safety from its yield strength of 2.66. For the hoisting system, it is selected to have 75 HP electric motor with pulley system that consists of 9 pulleys with 765 mm diameter. For wire rope, 6 x 19 IWRC parallel laid- type rope is selected with a diameter of 30 mm.