Range marker is an important guideline for ship navigation. In order to cope with the special geographic environment of Taichung Port and development of wind power industry, this project has introduced the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) international standard, which significantly reduces the deviation factor (the linear relationship between offset distance and the width of navigation channel) and improves the sensitivity of range markers at the design phase, thereby enhancing their adaptability and visibility for large vessels and conforming to the international standard. This project is characterized by its innovation and comprehensiveness. According to IALA regulations, the sensitivity is calculated using 3D visual simulation at the design stage. Based on the location of the old range markers, suitable sites were identified at the backline of each group of old ranges. The existing front and rear ranges, which were originally 13m and 18m, were significantly increased to 55m and 65m to increase the visibility of the navigation ranges. The old navigational ranges were originally single-pole structures. Considering the impact of strong winds in the port area, we adopted a steel tube structure to provide a strong and tough structure. We also configured staircases and platforms within the structure to facilitate maintenance, which is a sound concept of "government procurement lifecycle".
Regarding details of the project, the steel structure is designed with flanged joints, and all welding work will be completed in the steel factory, with all bolts being locked in place. Considering that the conventional twist-off bolts are prone to corrosion, this project adopts a tension indicator, which can determine the bolt torque up to the design standard via visual inspection, which is convenient for the quality control and gives due consideration to the weather conditions of the port area. The duplex system of painting or powder coating over hot-dip galvanized steel greatly improves the future maintenance operation of the steel structure. Moreover, the coating materials are all commonly used in public works, and thus eliminating difficulty in replacing the coating materials.
The five reconstructed ranges are located at the hinterland of Pier No.105 (2 units), hinterland of Pier No.36 and at the back of Pier No.20B Mitsui Outlet Park (2 units), as well as behind Wuqi Fishing Port (1 unit), etc. The project started in September 2021 and completed in March 2023. The project team successfully overcame the challenging conditions such as dense fog, strong winds, and limited space of Taichung Port, and the project was carried out as scheduled and in good quality. The project scored 85 and 86 points respectively in 2022 and 2023 MOTC project inspection, and received "2022 Public Construction Excellence Award" by MOTC. This project was also recommended by MOTC and had won Excellent Award in Facilities Engineering Category of 23rd "Public Construction Golden Quality award" after the initial evaluation and re-assessment by the professional evaluation team of Public Construction Commission of the Executive Yuan. This award is a recognition of hard work and dedication to the quality of the project. Taichung Port will keep on upholding the responsibility to establish a safe yet well-organized environment for vessels.
