"Our consumption of both potable and other household water (showers, washing machines, garden hoses, etc.) is increasing. Londoners, for example, use more water than the national average – 161 litres per day versus 150 litres – and the pattern looks set to be sustained as the capital’s population is expected to reach 8.89 million by 2031."
One of the companies tasked with meeting this unquenchable demand above is Thames Water. The largest utility in the UK, it serves more than 15 million customers across London and the Thames Valley region. “Our closest customer is three minutes away,” says Richard Hulley operations liaison engineer, as we are taken on a tour of the company’s Walton site.
The Walton works are a critical part of the London water supply network. A pumping station was built in 1898 to serve the various reservoirs and filter beds in the vicinity. In 1926, the site was expanded with the opening of the original water treatment works (WTW) – these were upgraded in 1995 to the Advanced Water Treatment (AWT) technique.
Today, Walton AWT treats between 80 million and 100 million litres of water per day, and is one of five AWTWs on the Thames Water ring main, ensuring that the ever-increasing demand for high quality drinking water is met.
Amid this effort, a recently installed digital radio system is playing an important behind-the-scenes role.
Problems with Analogue
As Hulley explains, the 15-acre site previously relied on a trio of radio communication solutions: analogue two-way radios, provided by long-term supply partner, Chatterbox, were used by staff for in-building communications; 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.
However, the nature and size of the site and the architectural mix of buildings had an adverse effect on the coverage capabilities of the system.
The previous solution did not provide 100 per cent site coverage – some areas did not support mobile coverage, while certain unique in-building conditions posed issues of interference making the radio handsets inoperable.
“We have various sensitive areas,” explains Hulley, “that don’t like radio frequency at all, and which could set off alarms. For instance, the parameters of the water quality monitoring system could be changed.”
Coverage in the Victorian pumping station was also restricted. Workers in ‘the crypt’, an area situated below the stairwell in the basement of the main pump house where several key services are located, can often work in isolation. In this location there was no radio signal and the noise of the pumps made any conversation inaudible, meaning communicating with personnel had to be physically carried out.
The previous system was also less accurate in terms of the location of workers. Then, the responsibility was on the individual to manually input which of the seven prescribed zones they were working in into their radio. Any alarms would be received on a pager, but when the pager system failed and could not be repaired, Thames Water turned to Chatterbox, for an updated radio solution with added functionality.
Migration to Digital (DMR) for 100% Coverage
Following discussions with the utility and evaluating site needs, Chatterbox identified an opportunity to improve the existing three device system, and initiated a migration from analogue to digital based on X1p hand-portables from Hytera.
Replacing the analogue system, the new DMR solution fills in the previous coverage gaps, providing 100 per cent coverage on the site, even in ‘the crypt’ and areas where traditional communications systems could negatively influence alarm systems.
In Walton’s complex and hazardous environment, the X1p handsets are delivering other benefits, namely in lone worker safety.
Walton AWTW is a key site for Thames Water and health and safety is taken as a priority, as Hulley explains. “The site is manned 24 hours a day, 365 days a year. We have lone workers, and workers on stand-by (out of hours), who come and work, by the nature of the environment, in conditions where they cannot readily be seen. It is key that the company ensures all workers are well looked after.”
With its blend of old and new, some listed buildings and new AWT processes, Walton’s infrastructure presents a wide range of physical and chemical hazards for workers. There are areas of deep, fast flowing water, and as Hulley adds: “Lots of high voltage, lots of water tanks – numerous areas where mobile phones don’t work, and communications are difficult. It is imperative to cover these areas as well as high risk areas where traditional radio systems would set off alarms.”
Because of such risks, the selected X1p is a rugged IP67 compliant handset that provides the much needed blanket coverage and safety through the integration of a third-party app – a localisation system.
A Lone Worker's Duties
Typically, a lone worker has to perform routine monitoring and evaluation duties to keep the site running. As Hulley describes, every four hours the staff member will have to leave the control room and test the lab equipment to prove that water quality sampling is taking place and is accurate. “Other responsibilities could be as diverse as cleaning leaves blown onto the screens and blocking the inlet ducts.”
In the event of an incident under the old paging system, the individual would receive an alarm on the pager, which they would act upon. However, if they had left the control room, such notifications may not have been received. This meant that the Walton site had to employ a ‘buddy system’ and double man the control room. This led to high overtime costs, especially during out-of hours (evenings and weekends). In addition, with an emphasis on the individual to manually input the areas they were working in into their radios, the risk of human error was great.
Hytera X1p – Geolocation and more
The selection of the Hytera X1p enabled the deployment of a new geolocation system. In doing so, it removed the need for extra staffing levels. Deployed around live operations, PMR Products’ SafetyNet Locator is a real-time mapping system which tracks and records the location and movement of radio users in both indoor and outdoor environments, based on a network of beacons.
A module in each X1p handset automatically detects a radio user’s movements via the beacon. The Locator Receiver processes the beacon updates and sends position information over the radio to a centrally located decoder. Bluetooth is used for indoor data transfer, while GPS is automatically activated when outdoors.
There are nearly 100 beacons strategically placed around the site. According to Chatterbox’s Richard Blackwell, the company worked closely with Thames Water on a site survey to identify where radio users were operating, for the purposes of management of staff movements, security and safety needs. Areas where coverage already existed, and zones carrying a need for antennas were also ascertained.
Each battery-powered beacon is built into a standard cube enclosure, which can be physically attached to a surface such as a doorframe or stairwell through captive screws under the main lid. They can also be glued to a vertical surface, and this approach was necessary at some locations on the site. “Some of the older works contain asbestos,” explains Blackwell. “At these locations, resin was used to bond the beacon instead of screwing it in place. This avoided problems of dust.”
Chatterbox has online access to the system to remotely monitor the network and provide maintenance. “We don’t wait for an issue,” says Blackwell. “In real life, you know you have an issue when something happens. We can pre-empt it.”
How the Beacon Works.
The beacon system collects and displays updates of movements and changes of operational status of radio users within an area. The information is sent back to the control room and displayed on a PC. The control room at Walton typically deals with around 1,700 alerts a day, from SCADA, BMS and operatives, requiring varying responses.
On the main monitor in the control room, the location, time and date are also displayed – a valuable function according to Hulley.
“The time-stamped feature is useful for auditing purposes. Radio communications through the system are automatically logged and recorded. If there is an event – not just health and safety related – such as a burst pipe or a power dip, rather than having to log all the details, you can simply talk into the radio. You can then play it back later to capture what was happening at the time.”
Alarms can be raised by the operative pressing the alarm function – a panic button – or the radio being motionless for a set time. The handsets 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.
“Once the radio signal is received by the control room, if it is manned and there are people on the site, you can easily locate those individuals and send the relevant help. If an incident occurs out of hours, and it is the controller themself who is in trouble,” Hulley continues, “the signal is echoed out to staff on standby on mobile devices as an issue. They can then contact the controller directly. If they are unable to reach them, and it may well be a false alarm but all alarms are treated as real, they can attend the site and locate them directly without having to search across the 15-acre site.
The X1p handsets are also integrated into the main telephone system so that calls can be transferred to the radios, which can also receive voice messages. Blackwell explains that this is especially useful when the radios are accidentally taken home or found to be in a prohibited area. “A beacon on a gatehouse or in a zone the radio is not supposed to be will recognise the radio and send out a voice message, basically saying ‘Put me back’.”
A Visible Difference
With the new solution in place, combining a state-of-the art location network and digital radio system, Thames Water operatives now have a compact, handheld device they carry with them that does ‘everything’, replacing three communication devices. The ease of installing the beacons meant the system was installed in days and operating shortly thereafter with minimal training, although Chatterbox was on hand during the commissioning to respond to questions.
The whole solution is Windows-based and very intuitive, according to Hulley. “You can walk up to it and in five or six minutes be able to do what you want it to do. If you can use a mobile phone, you can use the Hytera handsets.”
The simplicity of the system and the on-going advantages of digital radio are encouraging Thames Water to consider rolling it out across other water treatment plants so there is a common network across the whole of West London.
Approaching the Victorian pumping house, Hulley remembers an incident from some years back. “About 20 years ago, work was being carried out in a nearby farm and they uncovered an unexploded bomb – 2,500lbs. About 2,000lbs was removed, but the rest was detonated. The windows in the AWT plant were blown out and there was lots of debris across the site. In the pump room, there was one cracked window and a door was blown open!”
A resilient marvel of Victorian engineering which now sits side-by-side with a very 21st century radio communication solution.
Let’s raise a glass of water to that!
* Photo courtesy to Internet