Airships: dawn of a new golden age

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By Steve Elliott our Science and Health correspondent

[PART II]

The skies were full of airships in the 1930s till faster, more war friendly, heavier than air planes usurped their command of the skies.  Is a new golden age of the airship dawning? 

Yes and no: yes, in the sense that large gas-filled transportation carriers may soon be our most important form of transportation; no, in the sense that the new generation of ships of the air will most likely be Hybrid Air Vehicles (HAV) having as much in common with a 1930s airship as a penny-farthing has in common with a 21st century Grand Prix Super race bike today

By Steve Elliott our Science and Health correspondent

[PART II]

The skies were full of airships in the 1930s till faster, more war friendly, heavier than air planes usurped their command of the skies.  Is a new golden age of the airship dawning?

Yes and no: yes, in the sense that large gas-filled transportation carriers may soon be our most important form of transportation; no, in the sense that the new generation of ships of the air will most likely be Hybrid Air Vehicles (HAV) having as much in common with a 1930s airship as a penny-farthing has in common with a 21st century Grand Prix Super race bike today.

A hybrid ‘airship’ is a general term for an aircraft that combines characteristics of aerodynamic (heavier-than-air airplane or helicopter flight) and aerostatic (lighter-than-air gas lift) technology. 

A team from Cardington in Bedfordshire (home of the original R-101 airship industry in the 1930s) developed the HAV, made of ultra-lightweight, super-strong materials on top of a hovercraft landing system, it can take off and land just about anywhere and travels about ~115mph (100 knots).  The design is principally a huge single aerodynamic aeroplane wing.  It’s a new kind of vehicle – a hybrid combining helium lift, aerodynamic lift, a hovercraft landing system and vectored thrust – and it is the likely future of flight haulage transportation.

An HAV is in fact ‘slightly heavier than air’ (~60% of its lift power comes from helium) using forward engine thrust combined with the vehicle’s engineered aerodynamic shape to provide its own lift (the maths involved in the engineering is quite literally mind-boggling).  The air that rushes over the curved top of the vehicle creates a low pressure vacuum that pulls the whole thing up due to the upwards push from the higher air pressure on the underside of the craft.

The Cardington team’s technology is so robust and impressive that the LEMV (Long Endurance Multi-Intelligence Vehicle) – a scaled up version of the successful prototype – has been ordered by the US military.  The Bedfordshire HAV company and their partners Northrop Grumann won the contract worth $517m to supply 3 LEMVs and provide the mission operation support for the craft over the skies of Afghanistan.

The LEMV can be manned, or remotely piloted, is able to hover above battle-zones at 20,000ft for 21 days at a time without refuelling (using approx. £16,000 of fuel in that time); can react quickly to surveillance demands and be repositioned more readily than a satellite.  The idea is to provide what the US military calls persistent intelligence, surveillance and reconnaissance.  The aircraft carries its instruments and sensors in a 40-foot long, 15-foot wide area behind the cockpit.  The craft’s sensor payload is 2500lbs, it draws 16 Kw of power and is equipped with super-powerful cameras that can read a signature on a letter from four miles away.

The control cabin would be familiar to any air pilot offering not only flight pitch and roll control but also yaw (180° clockwise/counter clockwise horizontal craft rotation) because the vector propeller thrust system operates in both horizontal and vertical axes – making efficient vertical upward lift possible. 

HAV’s Scottish test pilot Dave Burns says: “It’s just, it’s a feeling of freedom.  And the detail you can see: you can fly over the field out there a hundred times and see different things every time.  All you need is about 30 knots to get her off the ground and she’s away.”

The ‘landing-gear’ is a hovercraft landing system consisting of 4 Air Cushion Landing System (ACLS) pads.  On landing, air is blown downwards landing the craft gently, then the AVLS doubles in ‘grip-mode’ as a suction anchor fixing the airship to the ground – producing a stable craft even in shifting wind conditions avoiding the requirement for mooring towers, tie downs and ground crew.  The ACLS pads allow the HAV to take off and land on a variety of surfaces including snow, desert, grass and even water.  Floating over normally impassable terrain, delivering payload direct to its destination, giving ready access to remote areas without roads or transportation infrastructure.  The vehicle is the length of a football pitch at 290ft and the imposing bulk of the LEMV will produce a craft that is stable in windy flight conditions, rather like an oil tanker carries on through stormy waters.

Lockheed Martin has a near identical HAV design called the P-791 which gives a fairly clear idea of how the Cardington LEMV operates:

One concern about the LEMV hovering over battle-zones is that intuitively a white balloon hanging about (even high up) in the skies above war zones would seem to be vulnerable to attack; the Cardington engineers cite experience countering this gained from Northern Ireland during the Troubles.

They tested a full-sized airship against a range of artillery including a Russian mounted machine gun filled with .22 calibre armour-piercing incendiaries and a SAM-7 surface to air missile.  What transpired was an airship is almost invincible to attack.  Missiles need something hard to connect with if they’re going to explode, but an airship is accommodating, not hard-shelled.  The hull is made from a mixture of laminate fabrics including Kevlar, the material used in body armour.

The material has the flexibility of a plastic bag; make a hole in it and it almost immediately shrinks inwards.  If it were hit by a missile then it could still float for several days until it was recovered because the helium pressure inside is very low.  Helium is an inert gas, so it doesn’t explode – a little helium may be lost but at high altitude the pressure between the inside of the hull and the outside is not very great so that when a hole is made, say by a bullet, air seeps out slowly rather than rushing out catastrophically.  The inert helium is at such a low pressure that even if the blimp is holed by bullets it would take days to seep out.  Missiles bounce off without exploding and the ship cannot be detected by radar.

One defence industry official who saw the tests conducted on a prototype said: “We shot at it with 120 half-inch armour-piercing rounds and, three days later, the balloon was still flying. It’s a remarkable piece of kit.”

A BIGGER LEMV:
Looking forward to the near future as a heavy lift vehicle, it provides a more effective method of delivering military payload, i.e. once scaled up in size to between 5 and 7 times its present bulk, the gondola (airship cargo bay) will be capable of carrying hundreds of tonnes per voyage.  Basically a flying aircraft carrier except that it can go and pick up its load of tanks, troops, weaponry, military supplies from wherever they are and deliver them anywhere, anytime, quickly and efficiently – a far simpler logistical challenge. 

A CIVILIAN HEAVY LIFT VEHICLE:
Bedfordshire HAV hopes to sign a commitment with a customer to pursue heavy lift cargo transportation.  Although, most international haulage is performed by shipping, with lighter than air vehicles the bigger the craft is the more efficient it is and HAVs offer the ability to fly for extended periods without refuelling and carry 15, 20, 30,000lbs.  The cargo could be picked up from the sender and delivered directly to the customer with greater efficiency and speed than combined road-shipping haulage.

The company has just signed a multi-million-dollar contract with Canada’s Discovery Air to supply a brand new range of heavy-lift airships costing between $30m and $50m that will carry 50-tonne payloads to remote areas of the Arctic, where roads are non-existent.

They will be used mainly in the mining industry to ship in heavy equipment and take away raw material from some of the most remote communities in North America.  The first generation of heavy-lift vehicles will be able to lift up to 20 tonnes.  There are plans for vessels that could lift 10 times that.

CIVIL AIR TRANSPORTATION:
HAV is currently discussing building passenger transport vehicles with Canada’s Discovery Air.  Stephen Newton, director of business development at Discovery Air, said the company was planning to place an order for between 10 and 45 vehicles pending the successful certification of the craft.

Mr Newton: “We already have more than 130 operational aircraft so we look at the airship as a natural extension of our fleet.”

Jets vs. HAVs:

Of course a jet is faster than an HAV but a cramped, stressful, noisy tiring voyage to New York can take an air passenger 10 to 15 hours, including getting to the airport, checking in, passing through security, traveling (with limited baggage), landing, checking out, finding your baggage if it’s not lost, traveling into the city…

Speed:
Compare this to the HAV, at 100 knots it takes 30 hours to travel from Regent’s Park to The East River in New York and for European travel, it’s only a matter of a few hours between Norway and Spain. 

The voyage:
You will: travel in comfort; sleep in your own berth; dine in a restaurant; roll the casino dice; wander in public areas; enjoy the view in the observation deck; no pressure relaxation; land without jet-lag.

Safety:
Should catastrophic engine failure occur, the HAV won’t drop out of the sky like dead-weight stone and a terrorist bomb wouldn’t cause the HAV to crash and burn.  The HAV would glide down to the Earth with plenty of time to warn emergency services. 

Fuel efficiency:
Compared to a jet-plane, the HAV is relatively green (it does use diesel fuel for its forward thrust) and more fuel efficient: e.g. the HAV is estimated to be able to carry twice the weight of strawberries from Spain to the UK of a standard cargo plane, with a 90 per cent reduction in greenhouse gas emissions, much of which is from avoiding the huge fuel burn a jet engine uses for take off. 

Helium:
The Kevlar-reinforced semi-rigid balloon loses less than 3 per cent of its gas every year but it does require helium gas replenishment.  There’s plenty of helium gas available but it would require about $1bn to get helium production up and running in order to produce enough helium for all the HAVs required to replace aircraft – a drop in the ocean compared to oil platform drilling.  Helium supply is no longer confined just to the US.  Russia has large supplies and in Qatar a new natural gas well has a remarkable 12% helium concentration.

What parents wouldn’t prefer HAV travel with all that in mind?

Another possible airship pasenger cruise liner:
In the planning stages, The Aircruise – a towering airship packing 330,000 cubic metres of hydrogen gas (Hmmn…?), anyway, it’s capable of lifting 396 tonnes – travellers will be able to float through the clouds, literally.  The Aircruise combines solar power with a primary hydrogen fuel cell drive for a cruising speed of around 90mph and leaves no carbon footprint whatsoever.

http://www.youtube.com/watch?v=2L4TjbzqPuc

So the future looks balloon-like, bringing with it a possible downside, a sky filled with blobs, lots and lots of them but they do strike one as possessing a natural air of romance not seen since, well…

Those Magnificent Men In Their Flying Machines.
They Go Up, Tiddly, Up, Up.
They Go Down, Tiddly, Down, Down.