Pipelayers & Side-Boom Tractors

Pipelayers (side-boom tractors) lift and lower long sections of heavy pipe into trenches. The boom sits on one side of a crawler tractor, balanced by a counterweight. Tipping, dropped pipe and workers caught in the trench or under the load are the major dangers on pipeline and utility jobs.

• Pipelayer Operators
• Pipe Crews
• Utility Contractors
• Riggers & Signal Persons

How pipelayers work

• A pipelayer is a crawler tractor with a side-mounted boom, hoist winch and a counterweight on the opposite side. It lifts the load beside the machine rather than from the front or back.
• The machine's rated lift capacity depends on boom angle, load radius, counterweight position, ground conditions and track extension. Use the manufacturer's load chart and operator's manual. See Load Charts.
• Pipelayers may be covered by OSHA's cranes and derricks rules (29 CFR 1926 Subpart CC) when used for lifting, depending on how they are used, as well as the equipment rules of Subpart O and the excavation rules. Follow your employer's program and the manual. See Crane Basics.

Main hazards

• Tipping: overloading, extended load radius, soft or sloping ground, trench edges, travel with the load, and misused counterweights can tip the machine toward the load.
• Dropped or swinging pipe: failed slings, poor rigging, shifting loads and sudden stops can crush workers. See Rigging Basics.
• Crushed in the trench: workers placing and aligning pipe are in a cave-in and struck-by danger. See Trenching Basics.
• Trench edge collapse: the machine's weight near the edge can collapse the wall or tip the pipelayer in. See Excavation Edge Protection.
• Power lines: boom or pipe contact with overhead lines. See Cranes & Power Lines.
• Run-over and blind spots: the operator can't see all around the machine. See Backing & Spotters.
• Rollover on slopes and uneven right-of-way. See Slopes & Unstable Ground.
• Pinch points in tracks, hooks, and between pipe and trench.
• Gas lines and live utilities: contact with existing lines. See Utility Strikes.

Lifting and traveling safely

• Only trained, qualified operators may run the machine, with a pre-use inspection of boom, cables, hooks, counterweights, brakes and controls. See Operator Training & Evaluation and Crane Inspections.
• Know the weight of the pipe including coatings, water and rigging, and stay within the chart. See Estimating Load Weight.
• Keep the counterweight set correctly and the tracks at the proper position and extension per the manual. Don't change them with a load on the hook.
• Work on firm, level ground. Keep tracks parallel to the trench and a safe distance from the edge as the plan and soil conditions dictate. Use mats or cribbing where needed.
• Use proper slings and spreaders, and attach the load so it stays level and under control. Use tag lines to control swing. Don't use damaged slings. See Sling Inspection.
• Lift slowly, keep the load low when traveling, avoid sudden swings or stops and don't travel with a load on slopes or soft ground unless the manual and plan allow.
• Never drag, side-pull or lift loads that are stuck or buried. Don't exceed the rated line pull.

Crew safety around the machine

• Stay out from under the load and out of the swing area, and keep outside the pipelayer's tipping zone. Pipe crew should stand in agreed safe positions and approach only when the load is stopped.
• Use a qualified signal person and clear signals, with radios when needed. See Crane Hand Signals and Signal Person Qualification.
• Workers in the trench need protective systems (shoring, shielding or sloping) and safe access, and should only enter once the pipe is stable and the operator has paused. Never be between the pipe and the trench wall when it moves.
• Use hand tools and guides, not hands, to align pipe ends. Keep fingers clear of joints. See Protective Systems.
• Wear hard hats, high-visibility clothing, safety glasses, gloves and steel-toe boots.
• Keep away from overhead lines and have a spotter watch clearance. Maintain 20 feet or the required distance.

Pipelayer checklist

• I know the pipe weight and stay within the load chart
• The machine is on firm, level ground, a safe distance from the trench edge
• Rigging is inspected and tag lines control the load
• Nobody is under the load, and trench workers are protected
• I use signals, watch power lines and keep the load low when traveling

Last updated: October 5, 2026