When a road needs to be resurfaced, it is cordoned off with access restricted. However, resurfacing an entire airport runway is a much more complicated engineering affair, with challenging logistics. The Northern runway at London Heathrow (LHR) is currently being replaced during the night, around the 1,300 combined take-offs and landings, in order to remove embedded aircraft tyre rubber. The project will be completed over three months, by 230 specialist workers, using around 130 different maintenance vehicles.
How do they do that?
At 10.45 p.m, a waiting convoy of vehicles wait for the last aircraft to leave LHR. They will have a five hour window to set up a construction site, dig up and resurface about 75 metres (246ft) of a runway section, before incoming aircraft are due to land from abroad.
Just like on a road, workers set up cones and measure and mark out lines with spray paint. The old surface is removed by a milling machine (and will later be recycled by the construction industry or used to make local roads). The surface is then prepared for new asphalt which needs to be ready with an exact type and thickness (and is more difficult to lay than highways). This asphalt has already been mixed in plants on-site and 25 wagons transport the lower layer for laying. Then the wagons collect the next 500 tonnes for laying the surface course material. This is all then compacted and sealed and once it is cooled to the right temperature, new paint markings can be applied. As most aircraft weigh around 200 tonnes and are travelling about 140mph when landing, the material has to be able to withstand incredible pressure.
The team need to be ready to leave at 04:30 a.m. in order for the operations team to carry out a foreign object debris safety inspection. The runway is then handed back to air traffic control by 05:45 a.m, to enable them to vector in the first aircraft at 6 a.m.
Critical asset
Alistair Awcock, LHR’s infrastructure delivery and strategic planning director told the BBC:
“It’s a scheme that we undertake about every sort of 10-12 years, based on the condition of the runway. Obviously, our runways are our most critical asset, it is the thing that keeps our business operating. So, we’re willing to invest to make sure that this stays operational all year round. It is a big job.”
The delivery project manager, Gawaine Yates emphasised how the skilled work is practised, trialled, improved and fine-tuned. A recovery truck is on site every night, in case of the “rare occurrence” where equipment breaks down and needs to be removed from the runway. He adds:
“The public have not known any dramas from here, because we’re dealing with it on the night…fingers crossed, we haven’t had any operational issues. The implications of not handing this runway to our operation is not just an impact to Heathrow but would impact the whole of the UK airspace.”
At the end of the project, the specialist teams will replaced around 200,000 tonnes of asphalt. According to website The measure of things, that is more than eight times heavier than the United States’ Statue of Liberty, or about 2,000 blue whales. That is no mean feat, considering this essential maintenance work occurs without disrupting the operations of the United Kingdom’s largest and busiest airport.
Are you impressed by this high-pressure maintenance work that happens overnight at LHR? Let us know in the comments below.
