19.1.1 General

This chapter looks at the future trends in overhead line design, construction and maintenance and also at draft regulations and how these may affect the current situation. The future is something that can be anticipated and precautions taken current data can be extrapolated and the present situation gauged in terms of overhead line supply quality and economic performance. For the future, the challenges of climate change and new regulations and practices require preparations now. The future trend for overhead lines has to be based on two areas what sort of environment the overhead line is likely to face for the next 50 years and how supply quality can be maintained costeffectively.

19.1.2 Scope

This chapter will therefore look at four areas:

1. new products

2. climate change and how it affects overhead line design in the UK

3. the present protection armoury, before considering the new techniques becoming available

4. finally, the chapter will see how these new developments can best be put to use to provide a total environmental protection design package.

19.2.1 Composite materials

The introduction of composite materials on to overhead distribution networks can be traced back to the early 1960s when the first composite insulators were introduced.

These insulators offered many advantages over existing porcelain and glass systems. Some of these included a greater resistance to damage from vandal attack, lighter weight and most significantly an improvement in performance in polluted environments. Unfortunately, these early insulators were...