Energized 13.8 kV Line and Covered Conductor Claim
A 40-ton rough-terrain crane is working in a utility yard beside an energized 13.8 kV overhead line. The line is owned by the utility and has been fitted with orange insulating line hose over part of the span; the utility says it is covered but will not de-energize during the day. The crane must lift a 6,500 lb pump skid over a 6 ft fence, and the planned boom tip path will come within 9 ft of the nearest conductor at its closest point. The crane has a proximity alarm set to 10 ft, and a dedicated spotter is assigned. The operator proposes to keep the boom below the line and use a tag line. Two workers will guide the load near the fence. The load chart permits the lift at the planned radius.
1. Does the planned 9 ft clearance comply with the minimum approach distance? Does the insulating line hose change the answer?
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No. For an energized 13.8 kV line, the minimum approach distance in OSHA 1926.1408 Table A is 10 ft for lines up to 50 kV. The planned closest approach is 9 ft, so the lift is non-compliant even if the alarm is set at 10 ft. The orange line hose is not a substitute for de-energizing or maintaining the MAD; it is not a rated barrier for crane contact, and it may not cover the entire span. Boom deflection, load swing, and tag-line pull can reduce the 9 ft further.
2. What are the acceptable ways to proceed with this lift?
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Acceptable options are to have the utility de-energize and visibly ground the line, or to relocate or re-rig the crane so the boom, load line, load, and tag line cannot get closer than 10 ft under any expected motion. A dedicated spotter and proximity alarm are supplementary controls, not the primary means of compliance. If neither option is possible, do not make the lift. Barricade the area and keep workers from contacting the crane or load.
3. What should the spotter and operator do if the boom drifts to 9 ft or the alarm sounds?
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On the alarm or at 9 ft, the spotter gives a clear stop signal. The operator stops smoothly and moves the boom away from the line, without slewing the load toward workers. No one touches the crane, load line, or load. If contact occurs, the operator should stay in the cab unless there is fire, warn everyone away, and call the utility. The lift plan should be suspended until the clearance is corrected and the plan is reviewed.