UK CLIMATIC CONDITIONS APPLICABLE TO THE DESIGN OF TYPE B(M) PACKAGES

For Package Design, TS-R-1 2009 Edition specifies insolation parameters considered acceptable for application throughout the world, and specifies the assumption of an ambient temperature of 38ºC. Prior to its withdrawal, a British Standard, BS3895:1976, recommended, for Type B(M) packages travelling solely within the UK, an ambient temperature range of -10ºC to +26ºC to be assumed, and for insolation, permitted 50% of the values given in TS-R-1, which would give reduced cost in design and substantiation of packages. In response to climate change, and to better inform guidance for package designers and regulators, a requirement was identified to study the range of temperature and insolation values likely to be experienced in the UK in order to ensure nationally accepted standards remained safe. This paper evaluates current and predicted climatic conditions throughout the UK, focussing on major transport routes, including motorways, main roads and railways. Comprehensive temperature data from 1961 to 2010 was analysed. Key statistics included: maximum, minimum and mean temperatures over 8-hr, 12-hr and 24-hr periods annually and for each month. Data analysis then predicted estimates for high and low extreme values experienced in a 1-year, 10-year, 100-year and 10,000-year period. Insolation was considered, albeit with a much smaller dataset, to give 8-hr and 24-hr statistics annually and for each month, and to consider the ratio of exposure between vertical and horizontal surfaces at Northern latitudes of 51-54° (equivalent to the UK). General temperature and insolation trends were then extrapolated over two decades to estimate future temperature ranges and profiles. The output of this research indicated previous assumptions were no longer valid, so guidance was developed with industry and other regulators providing for a more flexible approach for package design that incorporated risk of operational availability as part of the design, to be balanced against development costs; for example a package intended for near constant utilisation may now focus its design for a limited range of conditions that have a high degree of probability of occurring in the UK, without meeting the more demanding Type B(U) requirements. Regulators are better able to assess the adequacy of a submission for a proposed operational role.