Ampcontrol VoiceCom Telephone

  • 2015

  • Product
    Commercial and Industrial

Designed By:

  • Tiller Design Pty Ltd

Commissioned By:

Ampcontrol Pty Ltd

Designed In:


Ampcontrol’s VoiceCom Phone is an Intrinsically Safe telephone, providing essential communications in harsh coal mining environments.

Wired telephones form the ‘last line of defence’ in underground mining operations and are the principal means of communication in normal operations and emergency situations.

In keeping with Ampcontrol values, the Voicecom Phone has been developed with the highest standards of rigor and attention to detail. An extensive research effort informed every aspect of the design, and user feedback has been overwhelmingly positive.

The Voicecom Phone is a profound advance in available offerings. It meets every challenge of the coal mining environment in a fit-for-purpose unit.

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  • Ampcontrol's previous offering had more than 20 years of service history, and was end-of-life in its product life cycle. All the telephone products available weighed over 10kg. Weighing under 2kg, the Voicecom Phone is a welcome change for users. In ever-expanding operations, the Voicecom Phone's ability to operate over 20km from the surface means significant savings compared to alternative products which are capable of only 10km. They require large infrastructure outlays to support growing mining complexes. Unlike competitors, Voicecom offers the intuitive use of a normal telephone. This means that users in stressful emergency situations do not have to rely on workflows to maintain communications.

  • A coal mine is a challenging environment for tradespeople to deploy and maintain equipment. Users deploy units in difficult terrain, carrying up to 8kg of other equipment. In some cases, they need to traverse uneven muddy ground for several kilometers to install and service telephones. To meet these difficulties, Voicecom employs several key features. At less than 2kg, carrying the unit is no burden. A retaining spring ensures that the handset remains cradled during transport. The integrated handle has a subtle feature; it has been shaped to enable a tradesperson to easily carry two units back-to-back in one hand. Critically, this frees the remaining hand for other tasks or for carrying other equipment.

  • The Voicecom Phone is cognizant of the dynamic nature of the mining environment. Installation must be quick and easy. A feature of the modern mine is that the geological strata is stabilized using 'rib' bolts. They are several meters long and installed at regular intervals. The detail on the underside of the Voicecom Phone handle exploits these rib bolts for mounting; a feature welcomed by users as they do not need additional hardware to mount the phones. For more permanent installs, an M5 screw may be used. Wiring is achieved using spring-cage terminals via integrated glanding into a terminal compartment. The terminal compartment is under the mouthpiece cradle and accessed via a single retained screw.

  • Visual cues are important in dark, noisy working areas. A flashing beacon and an audible ringer ensure effective signaling of an incoming call; and a unique aesthetic. Bright yellow colouring and reflective telephone symbols allow quick identification. Careful consideration of user characteristics drove key operating features. Use of the familiar 'off-hook, dial, speak, hang up' workflow was key, and distinct from competitor products. If a handset is not correctly returned to the cradle, the Voicecom Phone automatically hangs up after 30 minutes to ensure critical communications remain possible. For safety-critical operation, the inclusion of a dedicated Emergency Call button simplifies emergency procedures.

    Coal mines are harsh environments, and equipment is handled roughly. The choice of high-impact-resistant plastic maximizes the robustness of the Voicecom Phone. A subtle design feature is that the outer flares of the enclosure are effectively sacrificial; any damage sustained on the sides does not reduce the environmental rating of the product. An IP rating of IP67 ensures no contaminants can degrade the performance. The keypad design includes electrical redundancy to allow emergency use even if keys are deliberately damaged. A common failure mode of telephones in coal mines is abused handset cords. A field-replaceable handset is employed allowing repairs to made in situ.

    The Voicecom Phone meets or exceeds all the regulatory requirements for use in Australian coal mines. The electronics include substantial fault tolerance, low power consumption and no energy storage. Anti-static polymer prevents static discharge creating an incendiary spark into a methane, coal dust rich space. These characteristics allow certification to internationally recognized explosion protection standards, achieving IEC Ex ia (intrinsically safe) in Group I. The Voicecom Phone is able to be used in Zone 0 areas, the most onerous conditions which equipment may be subject to. The Voicecom Phone also exceeds standard requirements of temperature resilience, fire resistance and ingress protection.