# 1985 York
Since 1969, when polyethylene pipe systems were first used to distribute gas in the U.K., the vast majority of joints have been constructed using heated tool fusion techniques. The jointing processes involved require a high level of operator participation. The paper describes the development of fusion jointing techniques which are less dependent upon the "human factor" and more likely to result in a better operating efficiency in difficult working environments. The jointing methods have been evaluated experimentally and theoretically using heat transfer calculations.