P.N. Daly's scientific contributions

Publications (2)

Article
This invention relates to methods and apparatus for pipe replacement. From one aspect the invention provides a method comprising moving a mole through an existing pipe, the mole having rotatable elements for engaging and fracturing the pipe. The method may comprise moving a new pipe into the fractured pipe whilst fracturing the existing pipe. Grout...
Article
This invention relates to methods and apparatus for pipe replacement. It is known to replace a gas main by moving a mole along the main, the mole fracturing the main and towing with it a new main or a liner for the existing main, the liner to act as a sleeve for the new main. Such a mole may include blades movable outwardly to fracture the existing...