Customer: Draeger Safety / London Fire Brigade

Product: Bespoke intrinsically safe (IS) radio transceiver module

Application: Fire fighter personal monitoring

Industry/vertical: Emergency Services

Issue:

In a working environment when people’s lives are literally dependent on a radio communication system, standards-based ‘one size fits all’ short-range solutions like Bluetooth or Zigbee can struggle to deliver the level of specialisation required.

This is especially the case in the extreme and hostile environments in which fire fighters find themselves. When Draeger Safety, a leading international safety technology company, sought to provide wireless telemetry for fire crew monitoring, it chose to partner with Wood & Douglas to develop the necessary bespoke personal radio transceiver technology.

Traditionally, a UK fire tender would have used a simple tally board to enable the tender chief to monitor when team members entered a fire, providing an estimate of when they would need to be withdrawn when oxygen levels run low. However, this fails to account for an individual’s varied rate of breathing or exertions, meaning air supply could run out more quickly, unnecessarily endangering the life of the fire fighter.

Solution:

Wood & Douglas designed and manufactured an Intrinsically Safe (IS) wearable radio transceiver module for a fire fighter communications system. This met the reliability and flexibility required to deliver critical data in real time, whatever the challenging circumstances fire fighters find themselves in. The Wood & Douglas radio delivers accurate monitoring of an individual’s location and oxygen levels by creating a wireless connection between the tally board and the fire fighter.

The wireless data channel enables monitoring and measuring of the levels of oxygen that each fire fighter has left. This provides a far more accurate appraisal so the tender chief can deal in specifics and deploy their fire fighters more effectively. If a fire fighter is seriously endangered by low oxygen levels or local hazards, the Fire Chief is instantly informed. With the individual and threat identified, the fire fighter can either be made aware of the imminent danger by a highly-audible built-in alarm or two-way communication, or be extracted immediately by other nearby team members from the danger zone.

With an Intrinsically Safe design that needs to be battery powered, not only was each section of the transceiver required to be electrically isolated to ensure components do not overheat or burn out, it was also critical that battery energy could not be instantaneously discharged creating heat, or worse, a flame. Decoupling the battery from the rest of the circuit, without losing voltage supply, was a particular challenge that the Wood & Douglas specialists were able to overcome.

Because reliability is such a critical issue, Draeger and Wood & Douglas’ partnership extends from design and manufacture to include ongoing product refinement and testing. The latest generation of developments has moved the oxygen monitor from an umbilical dongle to being built between the air bottle and the respirator, raising the level of the antenna for improved communication, and connection to the electronic tally board that is used by the fire chief. This enables issues to be resolved quickly and effectively, ensuring London’s fire fighters and those around the globe remain safe, even in the most challenging situations.

• Intrinsically Safe bespoke radio design, manufacture, testing and refinement
• Delivers mission-critical reliability in the field for preservation of life

http://www.draeger.com/UK/en/