Analysis the Effect of Freeboard on a Ferry Ro-Ro Ship Stability Based on the Weather Criteria

Lukman Bochary; Mohammad Rizal Firmansyah; Muhammad Akbar Asis; Wihdat Djafar; Wahyuddin Wahyuddin; Rosmani Rosmani; Nasruddin Nasruddin

Lukman Bochary Departemen Teknik Perkapalan, Fakultas Teknik, Universitas Hasanuddin, Indonesia
Mohammad Rizal Firmansyah Departemen Teknik Perkapalan, Fakultas Teknik, Universitas Hasanuddin, Indonesia
Muhammad Akbar Asis Departemen Teknik Perkapalan, Fakultas Teknik, Universitas Hasanuddin, Indonesia
Wihdat Djafar Departemen Teknik Perkapalan, Fakultas Teknik, Universitas Hasanuddin, Indonesia
Wahyuddin Wahyuddin Departemen Teknik Perkapalan, Fakultas Teknik, Universitas Hasanuddin, Indonesia
Rosmani Rosmani Departemen Teknik Perkapalan, Fakultas Teknik, Universitas Hasanuddin, Indonesia
Nasruddin Nasruddin Departemen Teknik Perkapalan, Fakultas Teknik, Universitas Hasanuddin, Indonesia

Keywords: Ferry Ro-Ro; Freeboard; Weather criteria;

Abstract

Weather criteria is one of the IMO standards that must be met before the ship operates. Ferry Ro-Ro ship which operates in Indonesia tend to have a small freeboard. The small freeboard affects the stability of the ship. The smaller the freeboard, the arm stability will be smaller as well and vice versa. This research analyzes the stability of a Ferry Ro-Ro ship based on the weather criteria at the design stage. Analysis was conducted by varying KG value with Breadth (B) and Draught (T) or B/T ratio and freeboard (fb) ratio with Breadth (B) or fb/B. The ship models are analyzed using two weather criteria which are based on IMO recommmendation and on the characteristics of Indonesian waters. After testing the ship stability based on the weather criteria, maximum KG value resulted for ship ratio B/T = 5 and ratio fb/B = 0.04 at 1.0H is 3.456 m. At fb/B ratio = 0.06 on 1.1H of ship height, maximum KG value is 4.118 m. At fb/B ratio = 0:08, maximum KG value is 4,435 m at 1.1H while at fb/B ratio = 0.1, maximum KG value is 4.752 m at 1.1H.