fig1 connected to the legs of a fork 9 constituting the outermost part of a crane beam otherwise not shown the common axis of the pivots 8 passes through the centre of the imagined sphere in which the bowl 7 is included as a segment and moreover such axis extends in parallel to the plane of the edge of the bowl the bowl 7 may be pivoted by means of two hydraulic cylinders 10 each mounted between a crane beam leg 9 and adjacent end of the yoke 6 in fig1 the bowl saw has been shown in an inclined position before the sawing through of a trunk 11 the intended cut is indicated by dash dotted lines 12 and it is evident that a major portion of this cut may be located below the ground surface 13 an endless saw chain 14 fig2 and 5 of the kind used in portable chain saws has after bending laterally to the required conical form been inserted in a peripheral groove 15 fig3 at the edge of the bowl 7 in other words the chain has been bent such that as far as possible its conical form constitutes a continuation of the profile of the bowl 7 owing to the rather small height of the saw chain the difference between such conical form and a corresponding segment of a sphere will be very insignificant and may be neglected in the embodiment shown the edge portion of the bowl 7 is turned down to a rather thin fin 19 and two rings 16 and 17 are by screws.