The Great Light, Belfast

The Great Light is one of the largest optics of its kind ever built in the world, and is around 130 years old. Weighing 10 tonnes and measuring 7 metres tall, the optic is a unique maritime heritage object with significance to Belfast's economic, maritime and industrial past. It is totally irreplaceable and is an exceptionally rare maritime artefact. It produced one of the strongest lighthouse beams ever to shine - a truly GREAT LIGHT. Design ID were responsible for the civil and structural design for this project. The site is located at the end of Victoria Wharf in the Titanic Quarter, land reclaimed from Belfast Lough in the 1800's during the Belfast ship building boom. Traditionally all structures in this area have been piled due to the risk of settlement on the reclaimed land, however the cost of piling and dealing with contaminated material would have represented approximately 25% of the overall budget so a raft foundation solution was developed. We undertook a detailed desk study of the anticipated ground bearing pressures and predicted settlement beneath the raft, taking into consideration at least 130 years of consolidation of the fill material. Insitu testing of the ground was undertaken by monitoring settlement of Kentledge blocks over a period of months - this proved the ground was stable and suitable for the raft solution. Rather than default to piled foundations which would have exceeded the budget and stalled the project, we designed a pre-construction settlement monitoring regime to assess the load bearing capacity of the made ground considering it has 100+ years of consolidation. This allowed us to assess and understand the risk of adding what is a lightweight structure with a rigid raft onto the made ground. We clearly communicated the low risk associated with this solution to the client to allow an informed decision to be made. https://youtu.be/3hKkg4BNem0 link to Time Lapse Camera- Titanic Time Lapse Camera.