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Technical and operational barriers: Acting to sustain the safeguards

Investigations into serious incidents and near-misses often cite breached barriers among the causes. The PSA is now calling for a collective effort to plug these holes.

This article was published in the publication "Safety - status and signals 2009-2010".


Human, technological and organisational interaction. Where human behaviour is a barrier function, technology and organisation must provide the operator with the necessary support to interpret conditions correctly and to act in accordance with the safety assumptions.

Avoiding accidents is a key goal for everyone involved in the petroleum business. Design of installations and plants, choice of technical solutions and the provision ofseveral levels of safety systems and barriers are vital elements in this effort.

The barrier concept embraces technical, operational and organisational measuresintended individually or jointly to reduce the probability of undesirable incidents or their impact.

A number of incidents both in Norway and internationally nevertheless show that one or more breaches of established barriers can have disastrous consequences.

The inquiry into the major accident at BP’s Texas City refinery in 2005 (see p 25) found that a series of barrier violations, each simple and apparently harmless, led to matters getting out of hand over time. 

And the subsea gas blowout on Snorre in November 2004 – one of the most serious incidents ever on the NCS – demonstrated what can happen if established protections are ignored.

The PSA’s investigation revealed that all the non-conformances would have been picked up and corrected along the way if the barriers had functioned.

While individual safeguards may become defective, it is very seldom that such a large number fail to work in different phases of an operation.

“Our investigation of this incident documents what can happen when barrier elements are breached,” explains principalengineer Einar Ravnås.

He is the PSA staffer primarily responsible for technical and operational barriers, which are one of the main priorities set by theagency for 2010.

“This commitment aims to help raise awareness in all parts of the industry, including top and middle management as well asthe actual workers, about the need for robust barriers which are maintained in a good andintegrated manner,” he says.

“Identifying technical barriers is relatively easy in our business. But serious-incident investigations often find a failure to grasp what operational and organisational barriers involve.

“This ignorance extends to the way safety can be compromised by breaches of or weaknesses in these safeguards, such as a failure to observe established procedures.

” Noting that barriers must accordingly be viewed from a human, technological and organisational (HTO) perspective, he also cites the safety culture in the companies as a key element.

“If it’s tacitly accepted that a job can be done in ways not described in the relevant procedures, such incidents as Texas City and Snorre show that the outcome can be dangerous.”

Barriers were also in the PSA’s spotlight during 2009 as a key element in its main priority of improving technical and operational safety.

“As part of this commitment, we carried out a number of audits which looked in part at company systems for establishing and managing barriers,” Mr Ravnås explains.

 “Experience shows that these protective functions can become even better. So we’ll be sharpening our efforts this year to raise barrier awareness in the companies.”

The PSA’s goal with this commitment is to help ensure that technical and operational barriers are maintained so well that major accident risk is minimised.

It will also encourage the industry to adopt a sound approach to protecting these safeguards on aging installations. Thatincludes factors related to extending production life, a main priority for the PSA in 2009.(See the article on page 34).

The HSE regulations for the petroleum industry are based on functional requirements, with the guidelines giving more details on how regulatory requirements can be satisfied.
But it is up to the companies to select technical solutions and to establish routines and systems tailored to the risk in each case.

“Our goal is to enhance understanding about the way barriers work and how they perform,” explains Mr Ravnås.
“Through audits, we will assess the standards set by the companies for these protections, how they are monitored and how they are improved. “As part of that effort, we’ll also be taking a closer look at the regulations and the way barrier requirements are followed up.”

Petroleum is an international business, and the PSA has benefited from the extensive and detailed work done on asset integrity by the UK Health and Safety Executive (HSE) over a number of years.

“A lot of good work has been done in both Britain and Norway, which we can build on further,” says Mr Ravnås. He urges the industry as well as companies and unions on land and offshore to make a collective effort over barriers.

“The most important consideration is that the industry actually manages to turn all its knowledge of barrier benefits and its experience from incidents into learning, so that we can stay ahead of the game and prevent accidents.”

By: Ole-Johan Faret