STORMLAMP - STructural behaviour Of Rock Mounted Lighthouses At the Mercy of imPulsive waves

Historic rock-mounted lighthouses play a vital role in the safe navigation around perilous reefs. However their longevity is threatened by the battering of waves which may be set to increase with climate change. Virtual navigational aids such as GPS are fallible, and reliance on them can be disastrous. Mariners will therefore continue to need the physical visual aids of these strategic structures. The loss of any reef lighthouse will be incalculable in terms of safety, trade and heritage.

Plymouth University has trialled the use of recording instruments to capture limited information on the loading and response of Eddystone Lighthouse, with the support of the General Lighthouse Authorities (GLAs) having legal responsibility to safeguard aids to marine navigation around the British Isles. The study evaluated the extreme logistical constraints of lighthouse operations and the feasibility of using instrumentation to understand the response of the lighthouse to wave loads, with results strongly encouraging a comprehensive study of the load and response environment.

Hence a full-scale project is proposed whereby field, laboratory and mathematical/computer modelling methods, novel both individually and collectively, will be used to assess six of the most vulnerable rock lighthouses in the UK and Ireland. Depending on the findings the investigation will then focus on extended full-scale evaluation of one lighthouse for the following two winters.

The field instrumentation run by University of Exeter, and which will include modal testing and long term instrumentation will require novel procedures and technologies to be created to deal with the challenging environmental and logistical constraints e.g. of access, timing power.

The modal test data will be used to guide the creation, by UCL, of sophisticated multi-scale numerical simulations of lighthouses that can be used with the data to diagnose observed performance in the long-term monitoring.

The numerical structural model will also be linked with advanced physical modelling at Plymouth University's COAST Laboratory, and numerical (computational fluid dynamic) simulations.

Finally, based on the structural and wave loading models, the long term monitoring will be used to characterize the wave loading in-situ at full scale.

Outcomes of the project will be used to inform the comprehensive structural health monitoring of other lighthouses both in the British Isles and further afield through the International Association of Lighthouse Authorities. This will lead to the identification of structural distress and reduction in the risk of failure through preventative measures. Methods developed will also be of relevance to other masonry structures under wave loads so the project team includes a number of industrial partners: AECOM, Atkins, HR Wallingford and the Environment Agency who have interests in this area. As the UK has a large number of ageing coastal defences whose vulnerability to wave load was demonstrated in the winter 2013/14 storms, the applicability of the STORMLAMP findings to these structures is an important additional benefit of the project.

As an island trading nation experiencing some of the world's strongest storms, the UK is particularly vulnerable to maritime navigation failure, and loss of one strategic lighthouse will have incalculable effect on safety and trade. The impact of STORMLAMP technology will be to reduce the likelihood of structural failure by characterising the loading and performance so that operators can integrate objective performance information with subjective visual assessment.

Impacts are expected through lighthouse authorities and associated business in UK and worldwide, the community of seafarers, coastal engineering and heritage agencies and due to the fascinating extreme engineering and historical significance, to schools, the general public and heritage agencies.

For national lighthouse authorities: STORMLAMP will primarily impact the General Lighthouse Authorities of the British Isles, e.g. Trinity House, who have internationally sanctioned legal responsibility to maintain the visual navigational aids of which offshore rock lighthouses are a vital component. Modern and efficient tools will be researched and tested to help them continue this vital role and preserve the structures. STORMLAMP investigators have a working relationship the GLAs who are necessarily project partners and provide all possible means of support and access.

For international agencies: Beyond the British Isles, STORMLAMP has the support of the Chair of the International Association of Marine Aids to Navigation and Lighthouse Authorities. STORMLAMP thus has direct access to and can provide input to the technical committee that provide guidance to its members, who include overseas lighthouse authorities and associated businesses.

For mariners: The Nautical Institute provides a direct impact route to seafarers and practical maritime professionals, via its international journal Seaways as well as wide range of technical guidance notes and opportunities for lectures.

For the UK coastal engineering industry: STORMLAMP has capability to generate broader benefits to other types of marine structures where the nature of structure/seabed interface leads to enhanced wave loading. AECOM, Atkins, HR Wallingford and the Environment Agency have specific interest in STORMLAMP outcomes for this application.

Other routes to technical impact are through the EPSRC-funded Collaborative Computational Project on Wave Structure Interaction and a range of (journal and conference) publications and presentations targeting academia and industry.

Public and educational: Lighthouses feature prominently in British literature, art, and film as well as in children's books and television, and the STORMLAMP project will be used to promote the engineering and cultural heritage aspects and the context as a maritime nation. This includes international coverage e.g. through National Geographic documentaries.

Schools: The Institution of Civil Engineers is interested to base educational material for school and other public engagement activities, to be delivered by ICE STEM Ambassadors in the format of talks and workshops.

Heritage: UK's Victorian era lighthouses are of great historic significance, so the project would provide interesting case studies to international heritage agencies. STORMLAMP will also work with Historic England and Historic Scotland on publicity on protecting this heritage.