Lidar-equipped drones to survey Scottish sewers
A combination drones and laser technology adapted for use in the waste water Industry is being deployed by the utility to survey sewers for potential problems by flying the drones inside them, often to parts of the network that traditional surveying methods can’t reach.
Using the new techniques will enable the water company to more accurately assess the sewers’ condition and make key decisions about investment in maintenance or rehabilitation work to improve them.
This will, in turn, make the sewers more resilient, improve Scottish Water’s service to customers, and reduce the risk of leaks, collapses and environmental pollution.
Replacing teams of up to 15 workers with just two operatives using drone and lidar scanning and measurement techniques will also reduce carbon emissions from sewer surveys by as much as 80 per cent, helping Scottish Water towards its target of reaching Net Zero Carbon emissions by 2040.
In a move which uses bespoke drones to fly into sewers, effectively replacing workers in challenging and dangerous underground conditions, the innovative application of the two technologies will enable Scottish Water to survey its network of more than 33,000 miles of sewers more accurately.
The more accurate surveys will cut the cost of repairs and maintenance, reduce the risk of flooding and pollution, improve the utility’s ability to target investment, and enhance workers’ safety.
Many of the sewers, some dating back to the Victorian era, have previously been difficult to access but much more of the network is now reachable following the collaboration between Scottish Water, its alliance partner Caledonia Water Alliance (CWA), civil engineering trenchless specialist Environmental Techniques and drone manufacturer Good Friday Robotics.
The adapted technology was used together for the first time on a large brick sewer in Bath Street in Glasgow city centre in July and is set to be rolled out and used at other locations in Glasgow, Edinburgh, Aberdeen and some rural areas.
Sewer inspections, which seek to identify issues such as cracks, holes, partial collapses, infiltration, and root ingress, are needed to enable Scottish Water to make decisions on investment and the earlier any repairs and maintenance work is carried out, the lower the costs are to the company.
With the aim of improving sewer surveys and making them safer by reducing the number of workers needed to go below ground, Environmental Techniques, which provides trenchless drainage inspection, cleaning, and rehabilitation services to the water industry, has developed the drones and associated software with CWA and Good Friday Robotics.
The drones and lidar provide substantially better video quality, defect confirmation and location accuracy than traditional techniques. The drone carries the LiDAR and camera onboard as it flies inside the pipe.
A worker controls or pilots the drone as it flies along the pipe and uses video for visual inspection and lidar for measurement. The outputs are then manually reviewed by operators to spot and code the defects.
The drones were adapted specifically for sewers and are made of carbon fibre to reduce their weight and extend battery life.
As we are working efficiently using this technology we are making significant carbon savings by not using any plant and people resources unnecessarily. Those who would have been doing these surveys in a traditional ‘worker-entry’ way will be redeployed to other tasks where we can still use their skills.
Iain Jones, Risk and Life Cycle Planning Manager at Scottish Water, said: “This is the first time we’ve used drones adapted for sewers and LiDAR together for sewer surveys and we are really excited about it.
“We want to improve the accuracy of our surveys and, for safety reasons, we want to reduce the number of workers needed to carry out survey work inside sewers. The drone does both and they will also help us in our aim to reach net zero carbon emissions by 2040.
“Factors such as depth, flows and debris can significantly slow down a worker entry survey in a way that does not affect the drones.
“Because of the reduction in the number of workers involved, a large number of site vans and vehicle deliveries are not required and so carbon emissions are reduced.”
Shauna Herron, Director of Environmental Techniques, said: “We’re delighted to be working with Scottish Water, CWA and Good Friday Robotics on the adaptation of these cutting edge technologies to help maintain and improve the network of sewers under the streets of our cities and towns. The fact that it will also improve workers’ safety and reduce carbon emissions is really important.”