A mobile apparatus, comprising: a self-propelled mobile carriage including a frame; a pedestal pivotally mounted to said frame for pivoting about first and second substantially orthogonal pivot axes (230, 232); a boom having a proximal portion pivotally mounted to said pedestal, said boom defining a boom lumen; a cutting apparatus; a connection apparatus rotatably connecting said cutting apparatus to a distal portion of said boom for rotation of said cutting apparatus about an actuator axis, characterised in that said connection apparatus being connected to said boom with a feed manifold positioned within said boom lumen, said connection apparatus including: (i) a rotary actuator having a housing defining a chamber, a shaft having first and second ends (72, 74) and extending axially through said chamber for rotation relative to said housing about said actuator axis; and (ii) a pressurized fluid circuit for delivery of pressurized fluid through said rotator actuator to said cutting apparatus, said circuit having the feed manifold at said first end of said shaft, a delivery manifold at said second end of said shaft, and first and second channels (110, 112) fluidically coupling said feed manifold to said delivery manifold axially through said shaft, wherein said feed and delivery manifolds (106, 108) are rotatable with said shaft relative to said housing. a self-propelled mobile carriage including a frame; a pedestal pivotally mounted to said frame for pivoting about first and second substantially orthogonal pivot axes (230, 232); a boom having a proximal portion pivotally mounted to said pedestal, said boom defining a boom lumen; a cutting apparatus; a connection apparatus rotatably connecting said cutting apparatus to a distal portion of said boom for rotation of said cutting apparatus about an actuator axis, characterised in that said connection apparatus being connected to said boom with a feed manifold positioned within said boom lumen, said connection apparatus including: (i) a rotary actuator having a housing defining a chamber, a shaft having first and second ends (72, 74) and extending axially through said chamber for rotation relative to said housing about said actuator axis; and (ii) a pressurized fluid circuit for delivery of pressurized fluid through said rotator actuator to said cutting apparatus, said circuit having the feed manifold at said first end of said shaft, a delivery manifold at said second end of said shaft, and first and second channels (110, 112) fluidically coupling said feed manifold to said delivery manifold axially through said shaft, wherein said feed and delivery manifolds (106, 108) are rotatable with said shaft relative to said housing. (i) a rotary actuator having a housing defining a chamber, a shaft having first and second ends (72, 74) and extending axially through said chamber for rotation relative to said housing about said actuator axis; and (ii) a pressurized fluid circuit for delivery of pressurized fluid through said rotator actuator to said cutting apparatus, said circuit having the feed manifold at said first end of said shaft, a delivery manifold at said second end of said shaft, and first and second channels (110, 112) fluidically coupling said feed manifold to said delivery manifold axially through said shaft, wherein said feed and delivery manifolds (106, 108) are rotatable with said shaft relative to said housing.