“Caltex is on fire” (don’t worry — it’s not)
The importance of following a permit to work system
By Michael Wright
In the Major Hazard Facility (MHF) Team, we tell a story of the day an Inspector called a colleague and exclaimed “Caltex is on fire!” from the now closed Chatswood SafeWork (then WorkCover) office.
The view from the Chatswood office was the best in SafeWork and on a clear day, the lucky inhabitants could see as far south as Wollongong. It was while admiring this view from the lunchroom a few years ago that an Inspector called the MHF Team after they noticed a large flame on the eastern edge of Sydney near the airport. The phone call set off a sequence of events that found a well-meaning shift supervisor and an undocumented open valve had inadvertently shut down production at one of Sydney’s largest chemical manufacturers.
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Caltex was a refinery at the time, located in the southern Sydney suburb of Kurnell and it wasn’t on fire, it was just hard to tell this from Chatswood. The Senior Safety Analyst who took the call in the MHF Team knew he couldn’t ignore it and began to make his own inquiries. He rang a friend who worked in the industrial park near Sydney airport. The friend looked out his window and was a little surprised to see a large ball of fire over a nearby chemical manufacturer. That was the start of an investigation that led to a fairly innocent variation from a permit to work that could have been disastrous.
The flare was actually in the suburb of Banksmeadow at an MHF and was caused by a loss of instrument air that resulted in the plant failing to safe and venting hydrocarbons to a stack. How this happened is a reminder in how variations from a permit to work might have unintended and sometimes disastrous consequences. A contractor had obtained a permit to work that involved jack-hammering with his own compressor but discovered his compressor was faulty. The plant manager helpfully advised the contractor to use the plant’s factory air to power the jack-hammer, which he did, however, the volume of air consumed by the jack-hammer quickly depleted the factory air. Although it was not known until after the incident, the factory air was also cross-connected to instrument air, which was not shown on any of the plant drawings. The result was a loss of control of the plant and an uncontrolled shutdown. Fortunately the flare, which is the final layer of control, functioned as intended leading to a safe but spectacular shutdown. In this instance, the only consequence was an expensive interruption to production and, much more difficult to quantify, reputational damage.
The investigation of this incident reinforced the importance of following the permit to work procedure and if an unexpected variation is required, to reassess the risk using this procedure. The factory air should never have been used without reassessing the risk through the permit to work system and further controls should have been put in place to advise plant operators of the use of factory air which would have given an early warning as the instrument air pressure dropped.
Multiple layers of protection are required in process safety because of the extreme consequences of failure. On this day, the final layer of protection functioned as intended but it should be a reminder to develop safe systems of work and follow them, even when and perhaps especially when an unusual circumstance arises.
For more information on permits to work at Major Hazard Facilities in NSW, see the Safe Work Australia Guide for Major Hazard Facilities or call 131050.
