chain saw cherry picker danger ear muffs extension Harness height helmet looking down lopping men men at work noise reduction Noisy pruning raised platform safety safety harness tall tall tree tree tree loppers tree lopping up high work workmen professional branches chipper chipping chipping-machine chips cover covered covering dangers equipment feeding helmeted helmets high-pressure improvement machine machinery maintenance men-at-work outdoor-power-equipment power-equipment protection protective-clothing protective-gear pushing risks risky safety-colours spray sunlight sunshine tools tree-branches tree-loppers tree-lopping wood-chipper wood-chipping wood-chipping-machine chain-saw ear-muffs ear-protection grinder stumpgrinder work-clothes workers workman