“It’s a great example of our continued commitment to innovation across Gas Transmission and we’re proud to be at the forefront of such exciting innovation.”
A new generation of robot is set to revolutionise the way National Grid manages its assets. Project GRAID promises a world-first robot that will inspect the condition of previously inaccessible buried, high-pressure gas pipework – from the inside. Project lead Jon Lelliott shares the story so far.
Engineers are used to answering tough questions. And they don’t come much tougher than the ones we’re asking on Project GRAID. For example, how do you design a robot that can work inside high-pressure gas pipework without being blown to pieces by the 200kg force it faces at peak flow? Good aerodynamics are a must. Magnets too. And a whole lot more besides.
Project GRAID’s journey began in January 2015 and its objective is to create a robot that can inspect the condition of complex, buried pipework at our high-pressure gas installations.
It’s important because these assets are nearing the end of their design life. Up to now, the only way we could assess their condition was through above-ground surveys and asset life modelling. Occasionally inconsistent, these techniques have led to unnecessary excavations which are expensive and environmentally adverse.
Greener and leaner
GRAID will give us the inside story on the pipework’s condition, providing hard, reliable data that will allow us to target investment to manage, maintain and replace them more efficiently. At full operational capacity it is likely to save c.£60m over a 20 year period – and more than 2,000 tonnes of carbon annually. That’s equivalent to the emissions of around 500 UK households.
But there’s a lot of work still to do before we get there. We’re collaborating with three SMEs – Synthotech, Premtech and Pipeline Integrity Engineers – to make this world first in robotics reality.
The first stage of the project, called solution development, ended last October. As a result, three conceptual designs for the robot were produced and we selected a preferred design to take forward into stage two, where we’ll continue to test and develop its design.
Aerodynamic by nature
The design of our preferred robot is greatly influenced by the conditions it will face inside high-pressure gas pipework. Natural gas acts more like a liquid than a gas at high pressure as it becomes more dense. In these conditions, aerodynamics are critical. Another factor is that when gas flow peaks, an equivalent 200kg force will push against it. That’s like a big England rugby prop taking a run at you. So it needs to be strong.
To find the most aerodynamic shape for our robot, our engineers looked to nature for inspiration. And they found it in the dolphin. The dolphin’s shape – with quite a rounded, but wide front-end and then a slimmer body at the back – makes them incredible at cutting through liquid. Their shape minimises force against an opposing flow and our robot has been designed to do the same.
Along with its aerodynamic shape, the robot will use a magnetic system to keep it stuck to the pipe wall. Being magnetised means it will be able to drive around the full circumference of the pipe – rather than just staying at the bottom. So it can steer around any contaminants we might find in there.
Also, when we do see those peak flows, and it gets a bit tricky in there, the robot will be able to go firm, hunker down and wait it out. Once flow starts to drop again, it will come back to life and restart the inspection.
Another area where GRAID breaks new ground is that it will be operated by a human. Existing inspection systems are inserted at one end of the pipeline and they collect data as the flow of gas pushes them along and out the other end. This makes them unsuitable for use at high pressure installations due to the variable gas flows. GRAID has the extra flexibility of being user-operated. So an engineer will actually drive the robot through the pipework and they’ll be able to investigate specific areas they’re interested in. They can stop, reverse, turn around and zoom in on areas they feel need closer attention.
So that’s the concept for our robot. But there’s a long way to go before it carries out inspections. For the moment, it exists as a 3D-printed model, rather than a ready-to-go metallic robot. We’re in the process of developing all of its specific components, such as the drive, communication, vision and sensory systems.
Polishing the prototype
As testing progresses, we’ll start to manufacture the preferred design out of metallic components. This will then become the prototype that we take forward to physical trials in the next stage of the project.
Trials are essential, as they manage project risk by reducing the likelihood of the device failing in a live installation. So concurrent to our work on the robot, we’re exploring an offline test facility and also three trial sites in more detail.
For trials to be successful, we need to understand what the buried pipework looks like at these sites. So we’ve used laser scanning combined with existing design drawings to build up a computerised 3D model of what they look like. That’s important because we need to know what kind of features the robot is going to encounter as it drives underground.
This model also enables us to find the best access points and plan the best routes for the robot. To fulfil Ofgem’s success criteria, it will need to be able to travel a minimum of 100m and negotiate two bends, so we need to put it into a section of the pipe that will give us the distance and geometry we need to use the robot to its full potential.
We’re putting stakeholders at the heart of GRAID and have been busy sharing what we’re learning across the gas industry – and outside it. We want our work to inspire other stakeholders and stimulate further innovation.
We’ve sparked lots of interest and discussion at industry events including the LCNI (Low Carbon Networks and Innovation) conference, World Gas conference, United Kingdom Onshore Pipeline Operators’ Association (UKOPA) and Ageing Pipelines Conference. We also talked to the rail infrastructure industry at an event run by the University of Birmingham to show an alternative sector how robotics could benefit their asset management.
GRAID is also a great opportunity to inspire potential future engineers. We reached out to hundreds of them at the Big Bang Fair – an event which celebrates science and engineering for young people – and showed them our 3D prints to help them visualise the robot. We have an urgent skills gap to address in our industry and this kind of tailored engagement is one way of inspiring young minds.
Next on the GRAID calendar is further research into the best access points for the robot at our trial sites. We’re also exploring whether there are additional sites that could benefit from having trials conducted.
The future of the robot, in the short term, will be the further development of its sub-systems. As we move to stage three at the end of this year, we’ll then step into field trials. We’re also going to start the construction of an offline test facility and our launch and receive vessel, which will be used to insert the robot into the pipe. We’re on schedule and within budget, so everything’s progressing well.
We still have some significant engineering challenges to overcome, but through collaboration, innovative thinking and hard work, I’m confident we’ll succeed. Nothing like this has ever been attempted before and it’s exciting to be a part of such groundbreaking work.