As far as i know Zeppelins were abandoned because they were not safe, back in time. Is it still the case in 2011 though? In my opinion it is more economical to operate a Zeppelin than a plane and they are more stable as there is less acceleration so the interior has tables and chairs etc.
The problem is we are running out of helium. Liquid helium is used in the MRI and other applications. It is also profligately wasted on party balloons. So the prospect for helium lofted dirigibles is not good. Also the US in the 1930s built some helium lofted dirigibles, which were destroyed by storms. So they are not entirely safe, as they are pretty vulnerable to weather.
They are safe now that they use helium.
There exist zeppelins for special occasions. During the Olympics in Athens in 2004 there was a Zeppelin hovering for the news cover. There existed some by GoodYear for advertisement purposes some years ago.
They are not used for transport because of economic choices. I think time is the important factor in plane travel, and they cannot compete there. There are tourism uses.
There was a German company CargoLifter that wanted to build commercial zeppelins to transport heavy weight goods. However the company got insolvent. In the german Wikipedia article it is mentioned that Boeing is working on some transportation craft similar to a zeppelin.
In my opinion it is more economical to operate a Zeppelin than a plane
Why would it be more economical? Why would the energy required to propel a large unaerodynamic balloon a certain distance be less than that required to propel an equivalent cargo in an aeroplane?
As far as i know Zeppelins were abandoned because they were not safe, back in time.
I'm pretty sure they were also abandoned because they're slow and uneconomical.
If I think about the scaling of the aerodynamic drag at a fixed speed with size. A heavier than air airfoil scales linearly with mass, because of the need to generate lift. A Zepplin's area should scale as the 2/3rds power of its size. So for a large enough Zeppline, it should be more efficient.
I am agreed, about the high vulnerability to weather events.