A numerical study on the value of response forecasting for offshore construction work

Response forecasting is used for offshore decision-making by continuously evaluating wave conditions using the forecasted numerical wave spectrum. While forecasted wave spectra come directly from mathematical models, forecasted wave parameters undergo meteorologist inspection, are corrected based on measured wave data, and may be available at higher spatial resolution. This paper compares decision-making using forecasted numerical wave spectra against conventional lookup of forecasted wave parameters by simulating responses in an offshore construction vessel and applying two different response criteria at two locations in the North Sea and the Norwegian Sea. Five years of forecast and hindcast data, including operational forecasted wave parameters and spectra, are used. Results show that response forecasting reduces uncertainty and aids decision-making under some circumstances but may not necessarily result in both reduced risk and increased operability. However, response forecasting significantly increases operability for a particularly sensitive case at the end of the installation season without additional risk. Still, none of the considered methods guarantee against severe misclassifications that could result in operational failure. Decision-makers should rely on multiple sources of information to avoid such situations, and improved methods for accounting for forecast uncertainty should be investigated by the industry.