 Pipeline networks are modeled in a similar manner to power grids, for example through distributed source transmission line models that provide the pipe-to-soil potential at any point along the pipe (Boteler, 1997; Pulkkinen et al., 2001).These models need to consider complicated pipeline topologies, including bends and branches, as well as electrical insulators (or flanges) that electrically isolate different sections.From a detailed knowledge of the pipeline response to GIC, pipeline engineers can understand the behaviour of the cathodic protection system even during a geomagnetic storm, when pipeline surveying and maintenance may be suspended.