Maritime and Port Authority of Singapore

Recognising the need to enhance safety of navigation by improving the conspicuity of aids to navigation (AtoN) against strong background lighting, the Maritime and Port Authority of Singapore (MPA) in a public-private partnership with Zeni Lite Buoy Co., explored the use of Dual Intensity Lanterns (DILs) along the approaches to the Singapore’s terminals where there is strong background lighting over three phases of trials from 2017 to 2020. The objectives of the trials were to review the feasibility; advantages and disadvantages; and practicability of DILs in improving detection, recognition and identification of AtoNs in these environments

We observed that the intensity of the rotating light character of a lighthouse varying from nil to peak which allowed the marine AtoN lantern to be more distinguishable from a normal marine AtoN lantern. This simple yet effective concept of varying the light intensity made the light more distinguishable and attracted the human eye to visually detect, recognise and identify easily. Thus, the use of a marine lantern with two different peak intensities (i.e. DILs) to improve the conspicuousness of AtoNs against strong background lighting was tested.

DILs were installed on selected AtoNs. Survey forms were provided to harbour pilots and mariners during the various phrases of the trials. 85% gave positive feedback and stated that DILs improves detection, recognition and identification for the selected AtoNs in the trial.

Following the successful completion of the trials, MPA and Zeni Lite Buoy Co., Ltd had submitted an input paper at IALA ENG 14. The input paper intends for the development of international specifications, recommendations and guidelines for the development, charting and usage of DILs, particularly for critical aids to navigation where strong background lighting interferes with the detection, recognition and identification. We hope that by sharing this enhancement, we can share knowledge and make an improvement to safety at sea!

View of the DIL

By AwEng Soon, Senior Assistant Hydrographer, Hydrographic Division, Aids to Navigation Department.

Rapporteur: Paul Ridgeway

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