How drones are transforming the railways of the world
A growing flock of drones are being deployed by rail networks around the globe to perform inspections of infrastructure, ensure safety and security and to produce contour maps of areas where new lines are proposed. But the benefits could yet extend so much further. 2020 Could see the rise of the railway drone.
Drones have the potential help railway operators save billions and perform dangerous tasks usually undertaken by humans. If you would like to explore the option of adding drones to your business you can speak to one of our experts here.
The core benefits of using UAVs (Unmanned Aerial Vehicles) on the rail networks of the UK and the world are:
- Higher efficiency and reduced costs
- Increased frequency and level of detail of data collection
- Improved safety for railway personnel in the inspection of assets, particularly in remote or dangerous locations
- Maximising the potential of the rail network to bring added value
- Automating areas of rail operations
Drones and railways – overview
Track inspections, spotting trespassers, accident investigation and monitoring vegetation by the trackside – think “leaves on the line” – could be a thing of the past – these are just some of the ways in which Network Rail and others like them around the world are already harnessing drone technology.
But railway applications for drones extend far beyond aerial inspection, surveying and security. The future of the ‘railbot in the sky’ offers opportunities which could see the biggest revolution on the tracks since Thomas the Tank Engine learned to talk.
Danger, danger – drones for inspecting high-voltage electrical lines
Drones are already being used to perform inspections of high-voltage electrical lines.
The distribution and transmission of electricity through overhead power lines requires a continuous flow. Damages on the power lines can lead to power outages. That can shut down entire sections of the rail network and impact upon travellers, commuters and the wider economy.
Regular maintenance is needed to ensure this does not happen. RGB and thermal sensors mounted on a drone flying along the route of the power lines perform a precise analysis and diagnosis to identify potential defects and faults.
UAVs are being used to identify broken insulators, identify faults in the wires and check the condition of pylons. Drones are particularly useful for inspecting power lines along the route of a railway where the infrastructure is difficult to access, for example where there are long bridges or the track is separated from road access by rivers or gullies. There are sections of railway lines which simply do not offer safe refuge points for maintenance and inspecting staff. These danger hotspots can be overflown by drones to negate the need for personnel to enter them.
Drones have also been used to wire voltage lines from one pylon to another which is safer and faster than the usual methods of using a helicopter or manually performing the task with humans and elevating platforms.
Leaves on the line – drones to monitor line-side vegetation
There are over six million trees growing on the estate owned by Network Rail and a further seven million on private land adjacent to UK railways. There are around 500 reported “vegetation events” on the railways of Great Britain every year. Many of these result in delays or cancellations.
Leaves falling from trees onto the railway reduces a train’s grip and affect its braking to cause disruption to services and increase stopping distances considerably. Overgrowth can cause “tree arcing” which is a cause of electrical power outages. Fallen branches can block overhead line equipment entirely or bring down power lines. Overgrown trees and shrubs can cover up signals and pose a danger to drivers and passengers.
There are also many possible sources of ignition in railway operations. This includes sparks from brakes, diesel engines, wheels, overheated bearings and the operation of rail-grinding equipment. These sources of ignition combined with dry vegetation and weeds in hot, dry conditions are a fire hazard, with the potential to harm the public or damage buildings, property and the environment.
UAVs returning LiDAR data can be used to regularly survey dynamic, fast-growing plant life to evaluate risks, survey sites which are difficult or dangerous to access and create Digital Surface Models (DSM) to determine location, volume and risk level of vegetation.
Network Rail have also employed drones to conduct surveillance of water-related risks such as water-ponding and saturation near rivers and lakes. Without adequate track drainage, track formation may become saturated leading to weakening and subsequent failure and can cause softening and loss of support for tracks. Drone monitoring of potential hazards created by water can proactively identify where works are required to reduce the risk.
Drones for inspecting tracks and switching points
It is estimated that European railways alone spend approximately 20 billion euros a year on maintenance, including sending maintenance staff, often at night, to inspect and repair the rail infrastructure. That can be dangerous work that could be avoided with drones assisting the crews’ efforts. Drones can fly in darkness using suitable sensors and powerful LED lighting to illuminate the areas they are imaging.
There are is around 16,000 km of rail track in Great Britain. It has been estimated that a fleet of a few hundred drones could be capable of inspecting 200,000 km of railway tracks. That presents an enormous efficiency saving.
There are stringent safety protocols in place to minimise manual track inspection risks, but they can involve costly track possession or occupation to sections of rail lines. This results in line closures, trains being re-routed or being subject to speed restrictions during the operation.
Aerial surveys of track can improve the precision of data received on the state of lines and cut down the time usually taken by maintenance operators to inspect the vast railway network.
When switch points become frozen, trains are unable to run. Railway operators use heating systems on certain parts of the network prone which are particularly to freezing conditions. Drones can monitor the operation of switch point heating units and identify those which have become affected by ice.
The ability to allow services to continue during surveys prevents the costly network closures required to permit people to access the track. Drone surveying also reduces the number of specially trained staff required to conduct surveys in difficult to access areas that might call for abseiling or climbing.
Getting on track – drones for mapping train lines
Drones can be used to map and plan for greenfield and brownfield rail projects. The ability to view an accurate digital picture of an existing railway or a planned one vastly decreases the cost and time required to undertake surveys of existing and planned rail routes.
Traditionally, mapping the railway network involves a lot of pouring over signalling plans, track drawings and a lot of paper. Drone surveys enable a real picture of the rail corridor to be generated incredibly quickly with high quality imaging and processing to produce 3D maps.
Equipped with RGB or infrared cameras, drones take thousands of pictures, each of which is geo-localised using an on-board GPS. The images are then post-processed with dedicated software and paired with a selection of ground control points alongside the track to create an accurate model of the entire rail corridor.
The digitally produced railroad can also be used to automatically verify the correct installation of railway elements on the track against various engineering rules as they are laid and installed.
Drones for guiding trains safely
Drones can help make the trains themselves more autonomous. Small drones with advanced sensors and AI could feasibly travel ahead of a train to guide it – just like a co-pilot would do.
With their ability to see ahead, UAVs could signal any problem or obstacle, including at road crossings, so that fast-moving trains would be able to react in time – much quicker than at present, particularly for a vehicle, livestock, a person or trees, landslides and other trains blocking the track.
Driverless trains are an emotive concept. But collision-detection and advanced intelligence provided in a real-time format to enable drivers and operator control centres to take aversive action in the event of potential dangers is a huge potential for drones.
Who goes there – drones for safety and security on the rail network
At present, the vast majority of open-air track has to be monitored by security guards and maintenance operatives. It would be prohibitively expensive to deploy fixed cameras along hundreds of miles of railway lines.
UAVs can be used to spot vandals and trespassers upon the railway lines. The drones, equipped with cameras, including thermal imaging cameras, are deployed on specific sections of the network to respond to incidents. Data is then fed back to the operator’s control centre and can be passed on to police.
Using aerial drones to carry out the arduous work of physically checking the tracks and fencing for trespassers or security breaches could improve the efficiency of monitoring operations while freeing up staff to look after higher value critical assets.
It has been proposed that UAV flights to respond to potential trespassers could be triggered by for example fence vibration detectors.
Drones are also being used to monitor sections of railway with high suicide incidences. It is a tragic fact that there were 271 fatalities in 2018/19 caused by people taking their own life on the railways of the UK. That figure is nearly five percent of all deaths by suicide in the country.
Other potential applications for drones and railways
The potential for drones to add value to railway networks is not limited to inspection, safety and security.
Drones can supplement the activities of freight operators – picking from trains for delivery to drop off points and back again.
Tests have already begun to use Unmanned Aerial Vehicles (UAVs) for making long distance deliveries using the path of rail tracks as safe transit corridors.
Battery life remains a key barrier to the introduction of drone technology to perform flights for long periods over long distances. One potential innovation could see the introduction of wireless landing charging points along the route of railway lines. Such points could also be used to download larger data files to overcome limitations of mobile telecoms or WiFi technology, particularly in more remote parts of the rail network.
The airborne railway crew – the bottom line
Drones can greatly increase the inspection of railways. The more regularly that railway infrastructures can be inspected, the more railway safety, reliability and on-time performance will be improved. Costs would be cut as a result and operations would be more efficient across the board.
Railway tracks cover huge distances – indeed that is the very reason the railways were originally developed, to enable the carriage of people and freight around the country at high speeds.
So the ability to add flight and airborne intelligence to the armoury of rail operators in order to perform all manner of tasks and provide enormous amounts of useful data is huge.
The use of drones in the rail industry is an example of its growing interest in ‘digital rail’. The opportunities are huge, as is the potential for cost savings and critical improvements in safety, both for railway staff themselves and the wider public. Only time will tell what exciting developments the future will bring for drones and train travel. If you would like to explore the option of adding drones to your business you can speak to one of our experts here.
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