Topcon intelligent solutions get Brussels Airport ready for take-off
Runway 25 at Brussels Airport had reached the point of requiring some attention, with a full resurfacing needed; something that Topcon Positioning have a wealth of experience in delivering.
Smooth runways are vital for large international airports – not only do they increase safety, but they also provide optimal comfort for airline crews and passengers, and an increased degree of efficiency. In order to guarantee seamless operations in busy hubs, as well as safe landings and take-offs, runways must be resurfaced at regular intervals in their life cycle, especially at high-traffic destinations.
In July 2020, the 3.3 kilometres long, 45 meters wide runway 07L/25R at Brussels Airport required a complete renovation. The airport’s operations team knew that this renovation would have to be conducted quickly, accurately and safely, meaning that an efficient, all-encompassing solution would be key to the project’s success.
This is where Topcon Positioning’s intelligent milling and paving solutions came in, alongside the expertise of cold planing specialist Top-Off, which supported general contractor Willemen Infra on the renovation.
A Quick Turnaround
Despite numerous challenges facing the project, not least the constraints associated with minimising airline disruption, the runway was ready for operation again in just over one month.
Phillipe Grevendonck, project development manager at Topcon, said: “When Top-Off asked us to assist them with this renovation project, we didn’t hesitate for a second. The time pressure was extremely high, because the runway closure had to be kept to an absolute minimum. The quality requirements were, of course, exacting: the runway must ensure safety, and we had to extend the life of the asphalt layer by preparing a flat foundation and ensuring an optimal milling finish.
“We helped Top-Off with the preparation and start-up at the worksite, as well as with the calibration of the machines. Where necessary, we also carried out the position checks, because milling obviously requires the utmost precision, whilst remaining on standby during the work, to support Top-Off as necessary. However, once the work was in full swing, Top-Off’s team had this well under control, and we were not needed!”
Milling made easy
The volume of milling was significant. John Vastmans, CEO of Top-Off explains “We placed two new layers of asphalt on the runway, which amounted to 222,000 square meters and about 60,000 tons. The work had to be 90% done in just five days. That is to say: we milled at a rate of more than 10,000 tons a day.”
Top-Off’s team started by milling the old asphalt layer off the runway in order to apply the new asphalt onto an optimal terrain model. Grevendonck explains: “The 3D model supplied by Brussels Airport Company ensured the best possible sub-foundation for the new asphalt layer – and if there’s one place where an even, flat layer is important, it’s on a runway.”
When it came to milling, Topcon’s solutions had a significant impact on the efficiency of the project’s turnaround, with its 3D millimetre GPS system ensuring the inevitable airport hustle and bustle was far less disruptive than it might have been. The solution combines the advantages of laser (multi-user & high vertical accuracy) with GPS (multi-user & 3D), transmitting a 10m tall sheet of light to map a more accurate picture of the site, with a diameter of up to 600m.
Vastmans said: “We’ve worked with Topcon for years, and since our first discussion, around 10 years ago, Topcon has truly earned our trust. It was only thanks to their millimetre GNSS system that we were able to complete this project so quickly and efficiently. Imagine if we had to perform this kind of milling work with an optical system. There’s always some kind of obstacle – a worker, a van or even a plane – that interrupts the visual connection, causing the device to search for the prism again. With millimetre GNSS, we had the advantage that all the machines could make use of a single laser, which not only made the system easy to use but also saved significant costs.
“If the laser beam is interrupted, the system can continue to operate for about four seconds based on its last corrections. If it takes longer before the obstruction clears, the use of the rotating laser allows a connection to be established again immediately. The biggest advantage of this is the huge time savings. In the vertical plane we have a 10-metre window in which we can work with a single laser. So, in that regard, we have almost no restrictions.”
Bumps along the way
Laying asphalt is always a complex process, and requires a steady flow of heavy machinery for the ongoing transportation of materials.
John Vastmans added: “Repaving with new asphalt had its challenges too, mostly because at the Brussels Airport worksite there was non-stop movement: transport vehicles passing by, cranes in full operation – you name it. That’s where Topcon’s technology was absolutely of added value.”
Grevendonck elaborated “There was a point where there were 20 excavators, 30 dump trucks, 20 trailers and five milling machines all there at the same time… An immense amount of traffic. There were always five lasers set up on the project. All machines could select a laser of choice within reach. One laser could give guidance to multiple milling machines simultaneously. So, we actually tackled our biggest challenge with millimetre GPS technology.”
Work also had to be conducted on the sewer pipes, which imposed an even tighter deadline. Vastmans added “With the solutions utilised, milling out of the contours for the sewer basins also went very smoothly.”
Landing ahead of schedule
Thanks in part to the high levels of efficiency achieved with the help of Topcon’s MM GNSS system, the project was completed ahead of schedule. John Vastmans reported, “In the end, the entire project was delivered 24 hours before the deadline.”
“It went very well,” says Jan Eikenaar, site manager for Top-Off. “We finished ahead of schedule. That’s always a favourable position to be in. The customer is very satisfied. Our work was grade-checked, and we remained well within the error margin.”
Phillipe Grevendonck summarises: “As a technology provider, there really isn’t any greater affirmation than when a company like Top-Off, Belgium’s largest cold planing company and therefore also the reference in that field, relies on your solutions for their most complex projects.
“We were always confident that Top-Off’s project would succeed, but we are always particularly happy when our solutions help to deliver a top-quality end result before the agreed deadline.”