Why prepare a jack-up for a storm that will not occur while she is on site? Many site-specific assessments (SSAs) are performed for the year-round extreme storm. In most areas of the world, the most extreme storm of the year can only occur within a three- or four-month period of the year. If a jack-up is planned to operate outside of this period, less stringent requirements apply.
About half of metocean design bases to cross our desks present environmental extremes per month. This enables assessment for the period of operations on site.
For those sites for which monthly extremes are not presented in the metocean design basis, these can be readily determined by the assessor based upon hindcast data. In modern day offshore engineering, hindcast data is straightforward to procure. The quality of the data and the probabilistic analysis is to be validated with respect to the metocean design basis.
Seasonal assessment has been shown to significantly enhance survivability of jack-ups operating in the more benign periods of the year.
.gif)
