What to do when your head gets stuck

Microtunneling machines have encountered a variety of conditions that prevented advance of the machine. The problems that have stopped advance of the machines can be grouped into two categories: things that can be controlled by the contractor, such as lubrication techniques, overcut, and dewatering; and things over which the contractor has little control, such as buried obstructions or mixed face soil conditions, The conditions which have prevented advance of the machine are discussed, along with the methods that were used to remedy the situation on each of the projects. Evaluations of the remedy procedure an discussed, along with recommendations on what could be done on future projects to prevent these situations from occurring. This paper is meant to present positive solutions to challenging problems for the improved success of microtunneling projects.