Safe and sound

In the good old days of the offshore oil industry, when money was no object and the budgets were as big as the oilfields, the cry from those responsible for offshore safety would always be for bespoke solutions when it came to designing, specifying and building public address and general alarm systems.

The advantages of this approach were, people thought, clear for all to see. Bespoke was perceived as a euphemism for the best, and most advanced, system money could buy, guaranteeing reliability and offering the highest standards of safety and operational excellence. In reality, this was often not the case.

The vast majority of bespoke systems now in use are hard-wired. Although offering significant advantages, many of these systems are so heavily engineered to comply with customer specifications for system design, installation and servicing, as well as to meet the physical demands of the harsh operating environments, that they offer limited flexibility and use.

The main drawback of hard-wired systems is that any changes or on-site re-configuration needed to meet upgrades and network expansion requirements are difficult to undertake and invariably involve considerable cost.

Expensive technical expertise quite often has to be brought in to resolve problems and replacement parts never come cheap. In the most extreme cases it has been known for companies to completely scrap systems and replace them with brand new ones.

But the face of the oil industry is changing, and those responsible for offshore safety on oil production platforms and floating production, storage and off-loading vessels are now specifying to increasingly tighter budgets.

The knock-on effect is an increasing realisation that expensive, rigid, bespoke solutions are no longer the automatic choice. Low cost, off-the-shelf, modular products, which utilise the new generation of microprocessor-based operating technology, are gaining increased popularity – and credibility – as the way ahead for offshore public address and alarm systems.

The operational and economic arguments for the use of software-based technology are difficult to refute.

The new generation of equipment coming onto the market provides both the specifier and end-user with the levels of flexibility and unit cost being demanded by those responsible for safety and budgets.

Furthermore, with advancements in technology and software design, these types of systems can be easily designed and engineered to operate in the tough, remote and often inaccessible conditions found on oilrigs, while still complying with BS 5588 and BS 5839: Part 8.

It is generally recognised by safety experts that the safest and most effective way to declare an emergency is via clear, spoken messages, rather than noise-only sounders. That is why BS 5588 insists that a clear warning of fire is critical in the rapid and safe evacuation of buildings. It goes on to stress that "there should be a secure public address system complying with BS 5839: Part 8, whereby management can inform and instruct the public on the appropriate action to take".

Off-the-shelf pc-programmable products have developed so much in recent years that they now offer the same high standard of specification and operational benefits previously only available from bespoke systems, yet at a fraction of the cost. This is surely a major consideration in today's competitive economic climate? The use of Windows-based configuration programs provides simple graphical interfaces, allowing systems to meet the requirements of individual installations. These same interfaces provide diagnostic functions for fault finding, as well as function modifications when changes are made elsewhere on the installation.

The fact that proven software packages are used greatly reduces the chances of faults. This, together with the modular approach to the hardware set up, cuts maintenance downtime and increases system reliability.

Integrated voice evacuation and alarm systems are now coming onto the market that are fully compliant with BS 5839 Part 8. Units incorporate an input system with the pre-programmed ability to broadcast a message appropriate to the zone.

One or more fire microphones provide complete system command, with live voice instructions to control any situation. Advanced system design features include inputs for general paging and background music, with a priority override for emergency broadcasts.

Space per watt of power is reduced because parallel banking requires fewer standing amplifiers. This produces a standard product that is, in terms of cost per watt of power, significantly lower than a bespoke system.

The latest systems available provide capacity for up to 12 zone coverage, while enabling up to three messages to be sent at the same time to as many zones as required.

Amplifiers and input cards can be quickly and easily removed if an application requires less amplification or decreased zone coverage. Future upgrades can be provided simply with the addition of new cards for full coverage.

There's little doubt that the oil industry is changing, and as the search continues for deposits in ever more remote corners of the world, there is clearly a need for those responsible for safety to take a fresh look at the flexible and cost-effective alternatives to bespoke systems.