An excavating apparatus having a prime mover with a longitudinal centerline and a main frame with an engine, a ground drive system and an excavation boom operatively attached thereto wherein the excavation boom has a first end and a second end. The first end of the boom is operatively pivotally attached to the main frame along a main frame pivot axis. The main frame pivot axis is transverse to the longitudinal centerline of the prime mover. A head shaft operatively rotatably attached to the second end of said boom and is operatively pivotally attached to the second end of said boom. Also, the excavation drum is mounted onto the head shaft in a manner that the excavation drum cooperates with the excavation chain and a fixed cutter pattern of the excavation chain to stay in consistent alignment with the fixed cutter pattern of the excavation drum.