In Metropolis - the
famous 1927 science fiction film by Fritz Lang, airships criss-cross
the skies of a futuristic mega-city. In real-life, unfortunately,
they have not been popular since disasters like the Hindenburg and
R101 burned unforgettable images of catastrophic failure into our
consciousness.
However, over the
decades, airship technology has improved, and the replacement of
inflammable hydrogen with inert helium as the lifting gas has made
them very safe forms of transport.
The government's former
chief scientific adviser, Professor Sir David
King gave a presentation at the World
Forum on Enterprise and the Environment in Oxford that massive
lighter than air vehicles - blimps (non-rigid) or airships (which
have a structure) – would replace aircraft as a key part of the
global trade network as a way of reducing global warming emissions.
In Europe 22% of greenhouse gases are from transport, and the
freight-carrying capacity of airships would be able to replace
conventional aircraft for most of the slower cargo. With a speed of
125kph (78mph), much lower fuel costs, and a carrying capacity
potentially many times that of a Boeing 747, airships could in future
carry much of current air freight. A German firm, Zeppelin NT has
reentered the airship business with five flying now.
Most of the fuel used in
conventional heavier-than-air craft is burned up in takeoff, and this
does not happen in an airship as the lifting is done by the helium
gas and only the forward motion needs engine-power. There are
downsides, the bulky craft are slow. Helium is a rare gas, usually
coming from finite fossil fuel sources, so it might become scarce and
expensive. The biggest problem is that helium is a very small atom,
and can leak out from any containment, so airships will need "topping
up" with gas regularly.
A recent report on mobility by Professor King quoted an estimate
by one developer, UK-owned SkyCat,
that it could carry twice the weight of strawberries from Spain to
the UK of a standard cargo plane, with a 90% reduction in greenhouse
gas emissions, much of which is from avoiding the huge fuel burn a
jet engine uses to take off.
Other benefits included
the possibility that airships would not need to use airports if they
were fitted with "lifts" to pick up and land cargo. This in
turn would reduce the need for trucking goods to and from transport
hubs, and allow less well-connected areas, perhaps in inland Africa,
to take part in international trade, said King. For the same reasons
the blimps could also be used to reach devastated areas in need of
humanitarian aid, he said.
SkyCat also have a craft
on the drawing-board which transports Natural Gas as both a payload,
and ingeniously, provides most of the lifting gas - which is pumped
out at the destination.
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