US defence group Lockheed Martin has developed a hybrid airship that could potentially be used for transporting heavy cargo to remote construction sites.
The machines will not need mooring towers or runways to land, potentially enabling them to deliver to otherwise unreachable projects.
Lockheed is now ready to take orders through its partner Hybrid Enterprises for the design which can currently carry 20t of cargo and 19 people almost 2,400km at a cruising speed just below 112km/h. This version is around 130m long, which is less than half the size of its older counterparts, although it says it is working up to a model which can carry 500t which will be around 250m long.
Lockheed Martin airship
The airships are ‘heavier than air’ meaning the helium that provides their lift is not enough to support the craft’s entire weight. The inert gas provides 80% of the lift required and the rest is generated by aerodynamic lift from its tri-lobe hull design. The body of the airship is made from a material called Vectran which is commonly available and foldable – an important feature in the manufacturing of such massive vehicles.
“It’s similar to carbon fibre in its strength to weight ratio, but better suited to airships,” says Lockheed Martin hybrid airships program manager Bob Boyd. “Compared to the rubberised cotton they used to use, it’s two magnitudes stronger than it was.”
On safety, Boyd says that there are actually very few airship disasters and that it is a misrepresentation to say that they are not safe.
“What you find is that airships are extremely safe,” he says. “Airship accidents almost never happen, and when they do, they end up in a parking lot and no one really gets injured or dies. We’ve designed the ship so that even if we lost all power, it will just float down to the ground at lower than parachute speed and everyone will walk away.”
He also adds that modern technology and better weather prediction also help to make the ships safer.
Lockheed P791 first flight
To take off with a full load, the airships needs around 760m by 250m of clear space but this does not need to be paved, just clear of obstacles. Because the engines can rotate, their thrust can be directed to generate extra lift meaning they can take off vertically when not fully loaded.
The hybrids land on a cushion of air like a hovercraft with a gentle pressure of around 0.7kN/m2 and the fans in the system can be reversed to create suction to moor the vessel to the ground. All they need to land is a flat area of sand, gravel, snow or even water allowing cargo to be then unloaded on small beaches if necessary.
It’s this accessibility that is making it attractive to the oil and gas, and mining industries which often have to undertake huge infrastructure projects in very remote areas just to get to a potential site.
Lockheed Martin airship
“It really changes the way you plan a project in these remote areas,” says Boyd. “Take one site, for example, where a company had to build a 700km rail line just to get to a mine site. That took about three years and then they had to dig the mine, so it was five to six years before they were producing any goods.
“But with the airship you can plan it so you can go directly in to where there were tunnels to dig and start digging them right away. This could cut two to three years in the programme.”
He thinks that the barriers for moving over to the ‘new’ technology will be simply that it’s a very different way of doing things.
“Change makes people nervous, and that’s fair because these are big billion dollar projects,” says Boyd. “It’s a difficult decision for a project manager to make to step into a new activity like this, so we spend a lot of time talking to them about what we can do and what we can’t.
“However, with the cost benefits, time benefits and improved safety aspects, I believe within 5 years that this will be the industry standard.”
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