Application of 3d Scanning Technology in Restoration of Heritage Site Damaged by Natural Disaster

Abstract. Duddell Street Steps and Gas Lamps in Central, Hong Kong (hereafter “the Steps”) is a small site with outstanding heritage value to the city and was therefore declared a monument by the heritage authority in 1979. In 2018, Super Typhoon Mangkhut hit Hong Kong, causing significant damage to the Steps. The Steps were broken into 280 pieces in total. The Antiquities and Monuments Office (“AMO”) set up its 3D Laser Scanning Survey Sub-unit (”3DSU”) in 2016 with the objective of utilising latest technologies to drive innovations in the surveying, recording and conservation of invaluable built and archaeological heritage. Fortunately, a laser scanning survey of the Steps was conducted in early 2018. This went a long way towards facilitating the success of the restoration work, as the project team had a baseline dataset showing the Steps’ original state. The ensuing restoration proposal could make reference to the 3D survey data, thus ensuring a complete and faithful restoration. Given the sheer number of broken pieces involved, it was decided that 3D scanning technology would for the first time in Hong Kong be used in parallel with traditional craftsmanship, guided throughout by the highest conservation principles, to help restore a heritage site badly damaged by a natural disaster.This paper illustrates how 3D scanning technology facilitated the restoration works. This project also perfectly exemplified the importance of ‘conservation preparedness’ for heritage sites facing unpredictable risks from natural disasters.