Case Study : Thames Water

Thames Water

Ensuring Lone Worker Health & Safety at Walton AWTW

thameswatermewbannerChatterbox has been an approved supplier for Thames Water for over eight years. We have installed two-way radio systems in several of the company’s sites, finding solutions to challenges using the benefits offered by new technology in this sector. Below we discuss how our CALM systems have improved lone worker health & safety at one site and created an early warning alarm at another.

In March 2014 Chatterbox, an approved supplier for Thames Water for over seven years, installed CALM+ (Chatterbox Alarm Location Monitoring) at Walton AWTW (Advanced Water treatment Works), a system they have developed using their years of experience and industry knowledge.

CALM+ has delivered:
•Improved worker health & safety
•Accurate worker trackingpdf_download_icon
•Significant cost savings


The Customer

Thames Water’s Walton AWTW covers over 15 acres. It incorporates a Victorian pump house, modern blocks housing processing areas, decommissioned sand beds and smaller ancillary buildings.

The Challenge 

Thames Water’s previous solution for achieving communication coverage throughout this extensive site comprised three elements: operational personnel used analogue two-way radios supplied by Chatterbox to communicate with other colleagues working inside on site. For communication outside, where two-way radio coverage was not achievable, personnel also carried mobile phones. Finally pagers were used with a SCADA (supervisory control and data acquisition) system to raise alerts on equipment failures etc.

Through discussions with Thames Water Chatterbox identified an opportunity to streamline and improve the existing three-part system, to improve worker health & safety and achieve cost savings. Thames commissioned the proposed CALM+ solution.

A Modern, Streamlined Solution

Using Bluetooth beacons in internal areas and the GPS facility on the Hytera X1p and X1e hand portables for external areas CALM+ achieves the required coverage using just radios, dispensing with the need for mobile phones.

The text function of the Hytera X1p has also made the SCADA pager system redundant as messages can now be received on the radios. Additionally the radios allow a longer message than the pagers so standard alerts are less abbreviated and more readily understood.

Using CALM+, personnel at Walton now carry one compact, robust two-way radio instead of three communication devices.

“The Hytera radios are very simple to operate – if you can use a mobile phone you can use one. Chatterbox took time during the installation to ensure that our operatives were familiar with the system so that it could be used as soon as it was installed.”

Richard Hulley,  Operations Liaison Engineer, Thames Water

Central Control

Inside the control room CALM+ integrated software shows three key visual displays of the system:

The location of the two-way radios covered by the system is shown on-screen on two plans of the works, one for internal areas (covered by beacons) and one for the external areas of the facility (covered by GPS). As personnel move around an icon for the radio they are carrying tracks their position on these screens.

A third display screen shows the communications element. Using this screen and connecting the PC to a microphone allows control room staff to communicate with Thames operators (who use the Hytera X1p) and contractors (using the X1e which has no screen and does not receive alarms). The system allows one-to-many and private calls.

Improving Health and Safety

Inside buildings CALM+ automatically tracks personnel movement using Bluetooth beacons picking up radio signal. Unlike GPS tracking, which provides a location in 2D, Bluetooth provides a 3D location making it possible to see which floor the radio user is on. GPS, which tracks operatives outdoors, is automatically disabled within the Bluetooth area and resumes when leaving. The previous internal system required operatives to manually input which one of seven prescribed zones they were working in to their radio, this manual input is no longer required so there is less likelihood of human error.

Following a site survey and working with site plans and Thames Water personnel Chatterbox engineers identified the optimum sites for the system’s beacons to ensure that the location of operatives within the works buildings could be tracked at all times on the PC based software. The facility required 95 beacons in all, programmed by Chatterbox for Thames Water’s requirement.

“The new system is a godsend. The previous system was far less accurate in terms of location of workers. This one offers real peace of mind.”

Ian Privett, Process Controller, Thames Water

The new system even achieved coverage in ‘the crypt’, an area situated below the stairwell in the basement of the main pump house where several key services are located. ‘The crypt’ is below ground and very noisy. Previously no signal could be achieved and no conversation would have been audible however the use of beacons and the superior audio quality of the Hytera X1p made communication from here possible, and therefore working in this area far safer.

As operatives are often working alone the Hytera two-way radios have been programmed for lone worker, they sound a regular alarm to which the operatives respond; should they fail to do so an alert is raised. The radios are also programmed for man down monitoring; an inbuilt mercury switch triggers an alert if the radio is horizontal for an extended period of time. In both situations the alert, including the location of the operative, will be received by CALM+ in the control room. Out of hours CALM+ will send texts and alarm calls to all off site personnel providing cover.

“Operatives at Walton work in high-risk areas on a daily basis, often alone. Health & safety is a priority for Thames Water, and we believe that it is important to invest in technology that improves the safety of our staff. The new system tracks where operatives are; we know their safety is covered and they know that we are looking after them.”

Richard Hulley, Operations Liaison Engineer, Thames Water

“The new system means that anyone in any part of the works, whether it is the furthest edges or the deepest part, can stay in communication.”

Mark Collier, Health & Safety Advisor, Thames Water

Achieving Man-hour Cost Savings

The control centre at Walton handles in the region of 1700 alerts a day, from SCADA, BMS and operatives, requiring varying responses. At times the site could effectively be manned by one person however, under the original communication system, as routine checks necessitate leaving the control room, a second operative was required to ensure someone was present to receive critical alerts and to page out relevant information so that appropriate action could be taken.

Integrating the Hytera X1p digital radio CALM+ allows operatives to receive SCADA and BMS alerts direct to their two-way radio wherever they are on site so the whole site can be manned by one operative. With the need for a control room to be staffed 24/7 removed Thames Water has been able to significantly reduce overtime spend.


CALM+ goes beyond the provision of two-way radio communication to incorporate other functions offered by two-way radios and the systems that can be integrated with them. Solutions are bespoke to each customer and their requirements. Experienced Chatterbox personnel consider the customers existing way of working, listen to their requirements, look at the technology available and build a solution appropriate to the customers business needs.

Working with Chatterbox 

The Chatterbox account team responsible for the installation and continued support at Walton include an account manager, a technical solutions engineer, who has online remote access the system to provide support to on site operatives, and a legislation specialist.

“The Chatterbox team is knowledgeable and helpful and we have developed a good working relationship.” 

Richard Hulley, Operations Liaison Engineer, Thames Water

Chatterbox offers customers in depth knowledge of two-way radio communications and related technologies, a range of products from the World’s leading companies in two-way radio communication, and an unparalleled level of service with a committed account team for every CALM+ customer.

For a free systems evaluation and to discuss what CALM+ could do for your business call 0800 387 760


System Features

  • Hytera X1p two-way radios with GPS and Bluetooth
  • Recording function (which provides evidence of location when recording was made)
  • Indoor location monitoring using Bluetooth beacons
  • GPS tracking
  • System integration with BMS and SCADA systems
  • Integration of radio and telephone systems so that calls can be transferred to radios
  • Lone worker and man down monitoring
  • Text and phone messaging to offsite personnel
  • Online remote access for support

The Hytera X1p Digital Two-way Radio

  • Compact (21mm thin), robust design
  • Complies fully with European Telecommunications Standards Institute (ETSI) open standard
  • Built in Bluetooth
  • USB port
  • Complies with IP67 requirements, withstanding up to 1m submersion for 30 minutes or more.
  • Large-size Colour Display 1.8″ TFT LCD display (65536 colours), allowing good visibility even under outdoor strong sunlight

System Benefits

  • Improved health and safety provision
  • A streamlined system – one device instead of three
  • Improved radio coverage and sound quality
  • One operative required instead of two with resulting cost savings


Read Land Mobile magazine’s article on Thames Water Walton’s CALM+ system 


Watch Land Mobile’s video interview


Thank you to Richard Hulley and his team at Walton for their help in collating the information for this case study.

Photos: Peter Crane 2014



Since installing the CALM system at Walton Chatterbox has installed similar systems for Thames Water at Hampton and Ashford, Middlesex.


Using Two-Way Radios as an Early Warning Alarm at Kempton AWTW

Thames Water Kempton AWTW (Advanced Water Treatment Works) uses analogue two-way radios supplied by Chatterbox. These provide audio communication and are also programmed for lone worker safety. The radios sound a regular alarm to which the worker needs to respond. Should they fail to do so, for example if they have been injured or rendered unconscious, the control centre would be alerted, and a text message would be despatched to a team of duty managers. The radios can also be used to summon assistance at the discreet press of a button or left open to broadcast to other radios on the network.

Kempton AWTW uses chlorine gas for water treatment, which is extremely harmful if inhaled. For the health and safety of staff and residents living in proximity the facility therefore requires an early warning alarm system. When the original hard-wired public address system needed updating Thames Water commissioned Chatterbox to replace it.

Building on the existing two-way radio system Chatterbox installed 23 two-way radios in protective boxes on site and around the perimeter. Transmissions from these radios are amplified with horn speakers. In the event of an emergency gas sensors notify the control room and a pre-recorded announcement can be transmitted at the press of a button leaving personnel available to deal with the situation or they can choose to make live announcements. To minimise the risk of accidental or improper use the system must be operated from the control room.

Thames Water Kempton now has a wireless public address system ensuring the safety of its on-site employees and members of the public in the immediate vicinity.