There’s nothing worse than rushing to put out a fire only to find the hydrant isn’t working. How do you make sure the hundreds of fire hydrants in a city are working properly?
Typically hydrants are inspected manually, but that is a slow and costly process whose results are often out of date. It's now possible, though, to remotely monitor hydrants for malfunctions or vandalism without having to spend a fortune.
Designing IoT-enabled hydrant system
Consider a small city such as Des Plaines, Illinois, which illustrates the challenges involved with monitoring and repairing hydrants. The city extends over 14 square miles and has 3,600 fire hydrants. It could take a few months for a small team of inspectors to manually inspect each hydrant.
Since there's no electricity nearby, a monitoring solution has to be battery powered and run for years without a battery replacement. The hydrants also have to transmit their status to a monitoring station several miles away.
How should the hydrants communicate?
Deciding how the fire hydrants should communicate is a complex decision like most IoT projects. Here's a checklist to select the right mode of communication:
- How many devices need to communicate?
- How much data will each device be transmitting?
- How frequently does the data have to be transmitted?
- How far do endpoint devices have to communicate?
- What form of obstructions or interference could impact data transmissions?
- Is power available for the sensor or does the sensor have to be battery operated?
- Will devices only send data or is the communication bi-directional?
- What’s the budget per device to enable it to communicate?
- How important is security of the data transmissions?
- Does the endpoint device have an IP address?
- Does the firmware in the device have to be updated frequently?
Cellular or LPWAN?
There are two main options for device connectivity: cellular or Low Power Wide Area Networks (LPWAN). LPWAN devices work on radio signals and send small amounts of sensor data over large distances. As a result, the devices use very little battery power. In fact, they are able to conserve power by going into a dormant mode and only wake to transmit their sensor data.
Cellular coverage vastly exceeds LPWANs, as it is used for voice communication and data streaming.
TALIS hydrants include monitors
Valve and hydrant maker TALIS has added monitoring to its hydrants. It selected SIGFOX, a LPWAN, to transfer data from the hydrants to a management console. The company selected SIGFOX because:
- The updates sent by the hydrants on their status are very small in size
- There is a low frequency of updates (four times a day)
- The communication is unidirectional (only to the management console)
- The data transmission has to cover a long distances with very little power
- A large number of hydrants had to be monitored
A ruggedized sensor from Bayard Copernic is embedded in each hydrant to report any malfunction and the water pressure. A lithium battery that can last up to five years is used to power the sensor. The location of each hydrant is geotagged on an online map with the help of an RFID tag on each hydrant. This helps route repair work orders to the closest service technician.
The Tagua Asset Management system is a web-based solution to keep track of hydrants and create maintenance work orders. In France, many municipalities use it with the SIGFOX radio network to manage hydrants. Alerts are sent via the SIGFOX network when a hydrant is being opened, closed, tampered with or isn’t working properly.
“Copernic enables cities and municipal water suppliers to reduce costs and improve services,” said Hervé Dumont, head of marketing at TALIS. “The SIGFOX network helps us easily connect thousands of hydrants to the Internet of Things because there is no network infrastructure to be deployed during installation of the fire hydrants. The network offers low energy consumption, reduced costs, easy integration and, most of all, comprehensive coverage in France.”
The Things Network demonstrates the potential of LPWANs and IoT to improve daily activities and launch new services. It's a crowdsourced IoT data network across Amsterdam that connects a wide range of objects through a service with low battery usage, long range and low bandwidth.
Fighting fires is a dangerous but vital task. SIGFOX-connected fire hydrants help ensure firemen always have the water they need to fight fires.
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