Holistic Approach In Human Error Management
Authors: Shetty Kishan Prasad , T.S Subramanian , Al Awadhi Ibrahim 
Published: December 2021

Despite all safety measures taken in oil and gas plants, serious vehicular accidents happen during maintenance/ shutdown activities, due to human errors such as inadequate planning, improper decision making/ behaviour etc. affecting structural integrity/ process safety, resulting in catastrophic events. In most of such incidents, swift safety measures need to be undertaken to control the extent of damage and limit additional risks cascading from the main event. This paper presents the case study of a vehicle impact incident on an existing main piperack located in the process plant, its root causes and immediate actions adopted in controlling major hazard and ensuring uninterrupted plant operation by maintaining structural integrity.

Prime factors considered while arriving solutions to structural damages due to the vehicular impact include, incident cause, extent of damages, availability of restoration material, execution feasibility under plant operating conditions and skillsets of work force that carries out the restoration activities. Due to various constraints, solution arrived are temporary, averting multiple structural failures/ major accident. Further investigation and studies were required to identify root cause of the incident and enhance the implemented solution that would reaffirm long-term integrity of the piperack structure.

The vehicular impact loads are generally not accounted in general structural design, since necessary safety measures are considered while finalizing the plant layout. Such unanticipated vehicular impacts on the structural system can result in local/ global structural damages such as failure of critical pipe supports, consequential damage to adjacent pipes, other structural components etc. In this case, although there was a warning signboard (installed on the pipe rack) indicating maximum permissible height, contractor tried to drive the container vehicle having height more than the stipulated height. Since the vehicle passed through first obstruction (beam) located at much higher level, driver negligently moved the vehicle further ahead hitting internal beam located slightly above the limiting height thereby damaging structural beam supporting critical piping.

In this incident, site surveys to inspect the damage, data review, structural assessment and details of material in stock are some of the common steps followed for swift restoration of structural integrity.

Based on the same, temporary support to prevent further structural damages and restoring operational integrity was designed and implemented in a short time. Other main activities followed were,

Walk through the incident to derive the root cause Review work instructions and communication protocol Human factors pertaining to the incident Review the application of management and administrative control Permanent solution for structural restoration

Ensuring safety of critical assets is the top most priority for the asset owner. Further, any accident related to safety shall be dealt swiftly to control major hazard, maintain asset integrity and ensure process safety. Such incidents could happen in any industrial facility, oil and gas or other industries. The lessons learnt from this accident and fit for purpose swift actions employed for restoration can be shared with the industry professionals to ensure 100% HSE in projects, operations and maintenance activities.