"Bringing the technology from the factory to the ship has been demanding"
When the Navy/RAF’s new stealth fighters enter service in 2018, they will launch from the Navy’s two new massive aircraft carriers to provide what the Government calls a “formidable fighting force”.
Currently the most advanced jets in existence, the F-35B Lightning II fighters will take off from a short ramp and land vertically on the decks of the warships. But the heat and force of the exhaust gases from the jets are so extreme, this demands innovative technology to protect the decks of the aircraft carriers: the traditional coatings aren’t tough enough.
Engineers have devised an innovative thermal “paint” (actually metal spray) to withstand the extreme high temperatures from the supersonic jets. It’s a metallic compound of aluminium and titanium which is melted and sprayed on to parts of the four-acre deck of the carrier. So resilient is the thermal coating, it can withstand temperatures of up to a staggering 1,500°C.
But applying it hasn’t been easy, says David Thomson, flight deck and coating manager at the Aircraft Carrier Alliance, which is responsible for building the carriers. The Scottish weather hasn’t always behaved.
He’s been working at Rosyth Dockyard where HMS Queen Elizabeth and HMS Prince of Wales are being built by the Alliance, which includes BAE Systems. His team needs to keep temperatures stable and the air dry.
“It is a challenge,” admits Mr Thomson. “We’ve had to maintain tight environmental controls: we’re working on open decks and it rains a lot in Scotland”
The team has been working in an enclosure which is kept at 22°C and at a humidity below 60 per cent in all weathers. “We’ve made 10 air changes an hour through extraction, to make sure the air is kept clean,” explains Mr Thomson. “We spray on the coating but it generates aluminium dust which is flammable, so it needs to be removed.”
Specialist machinery has been developed in order to apply the coating. Robots fire powdered metal through a jet of plasma at temperatures of around 10,000°C. The molten droplets then flatten and solidify, creating a tough coating.
A first application ensures the “paint” sticks to the steel deck, a second coat is for strength, and the third application has added sand to provide non-slip friction, both for the jets and crew.
It’s a laborious process and has taken a year to complete. This type of durable coating has been used in the oil industry to protect rigs from corrosion from salt water, but this is the first time it has been used on the deck of warships.
According to the engineers it will protect decks throughout the carriers’ 50-year lives. Rather than coat the complete deck, the team has protected three landing spots. “The high standards of the aviation sector have required lots of independent testing,” says Mr Thomson. “Bringing the technology from the factory to the ship has been demanding.”
The first of the two warships, HMS Queen Elizabeth, completed sea trials in 2017 and then flight trials in 2018, before its sister ship, HMS Prince of Wales, went through the procedure. The new fighter jets, meanwhile, employ stealth technology to avoid radar detection, and the RAF plans to have 24 aircraft available on the two new carriers by 2023.
