Abstract: An articulated two-boom support for a disc saw felling head. A first of the booms is pivotally connected to a base of a logging vehicle. The second boom is pivotally connected to the first boom at a pivotal joint and the booms are further joined to each other by a knuckle joint located below the pivotal joint connecting the booms. The knuckle joint includes two links pivotally connected to each other. The link connected to the first boom is also connected to the base by a locking hydraulic cylinder. An actuating hydraulic cylinder is linked to the first boom and base so as to rotate the first boom about the axis of its pivotal connection to the base. The arrangement is such that the disc saw felling head, mounted at the free end of the second boom, moves in a direction suitable for cutting a tree as the actuating cylinder is extended. The height of the disc felling head may be adjusted by altering the extended length of the locking hydraulic cylinder.