Abstract: A pipeline replacement system incorporating an expansion and line replacement mandrel and having a power system for imparting linear movement and rotation to the mandrel. Within the scope of the invention, the mandrel may be pushed or pulled or both pushed and pulled through an existing buried pipeline by the power system while being rotated by the power system. The mechanism, in a single pass, breaks up the existing pipeline, forces the broken fragments of the pipeline into the surrounding earth and positions a replacement pipe of the same dimension or larger dimension in place of the existing pipeline. A swivel system allows the replacement pipe to be moved linearly into the expanded passage behind the mandrel without rotation. The power system includes a mechanism or mechanisms for applying pushing, rotational and pulling forces to the mandrel.