Sound the alarm – wireless audio and control for major accident hazard alert

Wilec / MSD Ireland
OpenNET 3000
Siren and public address control
Industry / Vertical:
Manufacturing / Healthcare


The most important criteria for security, fire and environmental equipment is the guarantee of continuous, reliable operation. Wilec (Fire & Security) Ltd, is an Irish specialist in the installation and maintenance of electronic fire, life safety and security systems. The company deploys integrated technologies and systems for complex, multiple sites and commercial, industrial and pharmaceutical high risk installations.

MSD operates such a facility in Co. Wicklow called The Rathdrum. The facility is considered a strategic site in the company’s operations, producing up to thirty active pharmaceutical products – such as vaccines and prescription drugs – for a global market. The Rathdrum’s production buildings, where 350 are employed, are classified as hazardous, due to the flammable and explosive nature of some of the materials being processed.


Wilec is contracted to assess, and where necessary, provide expansion and maintenance to the fire response and prevention systems for The Rathdrum. These systems include a Control of Major Accident Hazards (COMAH) siren system installed in 2008 by Wood & Douglas. The siren and public address (P.A.) system forms a crucial part of the system as COMAH regulations demand that organisations take all necessary measures to limit the consequences to people if a major accident involving dangerous substances occurs.


To ensure the system was up-to-date and properly maintained, Wilec approached Wood & Douglas to review the original system and make recommendations for improvement. Located on a hill above the site, the COMAH siren is an extremely large, very loud klaxon reminiscent of an air raid siren. It has six horns which issue a wailing tone to indicate an emergency, and a single all clear tone. In addition there are nine muster points located throughout The Rathdrum where staff gathers in an emergency. These muster points have their own P.A. system which replicates the emergency and all clear sounds, or can be used to deliver audio information to collective or individual points. Wood & Douglas originally deployed an OpenNET 3000 UHF radio network, linking the gatehouse control room with the COMAH siren and P.A. system.

To support Wilec’s maintenance programme, Wood & Douglas has incorporated an Ethernet hub on the base station of the OpenNET 3000 system, which now supports live diagnostics. Wilec maintenance crews can make use of a portable diagnostic HMI (human machine interface) whilst on site, or can obtain the data when off site via a web portal. This means they are able to remotely monitor the entire system at any time from an internet connected PC or smart device and review operations in real time, including the status of the power amplifiers, drivers, sounders, the RF communications, and the charge on the system batteries.

This significantly improves how the company is able to monitor and maintain the COMAH system on the MSD site. Maintenance can gauge the initial severity of any potential problem and plan a response before even visiting the site. When they do they are properly prepared deploying relevant staff with the necessary parts to affect rapid and cost effective maintenance. This improved system monitoring ensures Wilec is able to provide MSD with long term system reliability and staff safety should there ever be a major accident at the site.

  • Wireless control and transmission of alert signals and verbal audio via siren and PA
  • Meets COMAH regulations
  • Remote diagnostics for proactive and cost effective maintenance programmes


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