Comparison of longitudinal and transverse cutting heads on a dynamic and kinematic basis

Some dynamic and kinematic characteristics of longitudinal and transverse cutting heads on boom tunnelling machines are described and compared. A dynamic and kinematic analysis was carried out for the both cutting head types under the same operational and design conditions. The results were compared with those of long term in situ trials of longitudinal cutting heads.

The cutting head design was found to have a significant effect on the performance of both cutting head types. The resultant boom force reaction was found to act perpendicular to the boom axis for a longitudinal head, whilst it tended to act parallel to the boom axis for a transverse head. The change in the magnitude of the resultant boom reaction was also seen to be relatively high for the transverse heads during transitions from arcing to lifting. It was further emphasized that the consistency in the produce size of a transverse head is likely to be higher in arcing than in lifting.