Wolf Rock lighthouse

Wolf Rock lighthouse: Past developments and future survivability under wave loading

Raby, A. C. (Plymouth University)
Antonini, A. (TU Delft Coastal Engineering)
Pappas, A. (University College London (UCL))
Dassanayake, D. T. (Plymouth University)
Brownjohn, J. M.W. (University of Exeter)
D'Ayala, D. (University College London (UCL))

2019-10-07

Lighthouses situated on exposed rocky outcrops warn mariners of the dangers that lurk beneath the waves. They were first constructed when approaches to wave loading and structural response were relatively unsophisticated, essentially learning from previous failures. Here, we chart the evolution of lighthouses on the Wolf Rock, situated between Land's End and the Isles of Scilly in the UK. The first empirical approaches are described, followed by design aspects of the present tower, informed by innovations developed on other rocky outcrops. We focus on a particular development associated with the automation of lighthouses: the helideck platform. The design concept is described and the structure then scrutinized for future survivability, using the latest structural modelling techniques of the entire lighthouse and helideck. Model validation data were obtained through a complex logistical field operation and experimental modal analysis. Extreme wave loading for the model required the identification of the 250-year return period wave using a Bayesian method with informative prior distributions, for two different scenarios (2017 and 2067). The structural models predict responses of the helideck to wave loading which is characterized by differential displacements of 0.093m (2017) and 0.115m (2067) with associated high tension forces and plastic strain.

Lighthouses
Modal testing
Structural response
Wave loading
Wave statistics

http://resolver.tudelft.nl/uuid:b23a12b5-ad94-4314-8043-3f873c4d9470

https://doi.org/10.1098/rsta.2019.0027

1364-503X

Royal Society of London. Philosophical Transactions A. Mathematical, Physical and Engineering Sciences, 377 (2155)

Institutional Repository

journal article

© 2019 A. C. Raby, A. Antonini, A. Pappas, D. T. Dassanayake, J. M.W. Brownjohn, D. D'Ayala