Gulf of Mexico Shelf Region
SAFETY ALERT
Proper Grounding During Welding Operations
No. 2013-09-26
Date:
Thursday, September 26, 2013
Issued By: John Poole – EHS Specialist, Areas 3-5
Apache Corporation, Gulf of Mexico Shelf Region
Subject:
Safety Alert; Recommended methods for attaching Ground Return Cables for welding
The following incident occurred on an Apache facility. There were no serious injuries or spills associated with this incident.
However, serious consequences could have resulted. Please review this Safety Alert carefully and take necessary precautions as
outlined below to help avoid this type of incident in the future.
Incident
Welding Machines were placed on the top deck of a facility for a welding job on the +10 level. The Welding Cable (“Welding
Lead”) was run from the top deck to the +10. The Ground Return Cable (also referred to as “Ground Lead” or “Working Ground”)
was attached to a steel handrail toe-plate on the top deck. The handrail was mounted in sockets along a wooden deck. Due to
poor continuity in the handrail mounting sockets, an arc was created at the top lip of the socket when the welder struck an arc
for his work on the +10. Sparks and embers from the arc at the socket landed on the wooden deck boards catching them on fire.
Contributing Factors
• Workers mounted the Ground Return Cable on the toe-plate because the top deck beams (rig beams) had no space for
installing the clamp.
• The ground return cable was mounted in a location far from the welding activity. This made it impossible for the Ground
Return Cable to be monitored by the personnel performing the work.
Recommended Practices to avoid this occurrence
•
•
•
•
•
•
•
GROUND RETURN CABLES MUST NOT BE ATTACHED TO SOCKET-MOUNTED HANDRAILS OR OTHER NON-WELDED
COMPONENTS.
Welding machines should be placed where they can be frequently monitored when in use.
Welding machines shall not be run/operated in classified areas.
Whenever possible, the Ground Return Cable should be run along with the Welding Cable to the worksite. The Ground
Return Cable should be mounted in reasonable proximity to the worksite so it can be monitored during the welding
operation.
When the Ground Return Cable must be mounted in a location away from the welding site, it shall be mounted on a
welded structural component.
Workers must ensure that surfaces are properly prepared before installing Ground Return Cable clamps.
All Ground Return Cables must be mounted in locations that can be verified to have unbroken continuity between the
ground clamp and the welding site (Refer to OSHA 1926.351(c)).
Summary of Findings
This incident shows the importance of the location chosen for mounting the Ground Return Cable. Welders should not rely on
their ability to strike an arc as an indication of the quality of their ground. In this case, the scenario was re-enacted to confirm
the source of ignition. There was no indication at the welding site that the continuity of the ground was poor. During the reenactment, several sparks were thrown from the handrail onto the wooden deck boards. This could easily happen at any point
between the Ground Return Cable clamp and the welding site. By keeping the clamp near the welding site, and by only attaching
the Ground Return Cable to welded structural components, the chance that an arc might happen near a fuel source (i.e.
classified area, deck board, etc.) is greatly reduced.