With some disappointment Carla looked through the downward slanting large windows: there was still nothing more to see than grey fog, a pea soup that seemed to touch the windows and that moved past with considerable speed. Of course she had it wrong, she realized, the ship was moving forward at one hundred twentyfive kilometer per hour and it was the fog that was stationary.

They had departed from Frankfurt yesterday and that had been an exciting experience. The ship had been moored to the landing tower at a height of about thirty meters and hundreds of people had swarmed below it. Commands and shrill whistle signals could be heard, hawsers were cast off, even a ship’s bell was sounded. She had heard a steady discharge of water – that was ballast, she was told. Then the ship had moved slowly away from the mast, going backward and upward in a stately manner, while the crowd below was cheering and waving. She had felt a shudder going through the mighty structure surrounding her, followed by a steady vibration when the engines took hold of the airship and started to propel it forward. The “Hindenburg” had freed itself from the airport departure site and had at first flown low over the city until it had begun to rise gradually into the clouds.

Obviously that’s where they still were at present. Carla had slept very well and after having been awakened by a light knock on the door, she had dressed quickly in order to hasten to the dining room with almost childlike impatience. Coming from the ladies’ rest room on the lower deck, it struck her that the corridor was sloping slightly downward toward the rear and that the ship was rolling and pitching lightly. Much gentler than an ocean liner, but, as she moved towards the tail, the movement became more noticeable. The engines hummed far away, not loudly and not bothersome, but rather emanating a feeling of security.

The breakfast room was empty except for two well-dressed gentlemen, most likely business men on their way to Brazil. As Carla walked past them to the large picture window at port, she smiled and exchanged a friendly “grüß Gott”. She had been hoping for a cheerful sunny morning, but outside there was only grayness. All the same, she peered out intently for some minutes as if to grasp the true meaning of the passing cloud patches.

She could not help overhearing the conversation of the two gentlemen. It also concerned the clouds.
“I think we’ll probably stay in the clouds today as long as possible,” said the larger of the two, a military looking man. “In that way the Captain saves his hydrogen gas. See, we are heavily loaded – the fuel tanks are almost completely full – we are near maximum weight. If we get out over the clouds into the sun, the gas cells will heat, the gas expands to maximum and it could well be that the safety valves will bleed it off. But, see, we can’t afford that – we need all the gas to stay afloat, especially during the night. That’s why we are staying in the clouds now. Do you want some more coffee?”
“Yes, please.”
“There is one more thing that shows that we are heavily loaded: we’re cruising with the nose slightly up. That means the forward speed gives the ship some lift on its hull, just like the wing of an airplane. If we were to fly horizontally, with static buoyancy, we might loose height gradually.”
“We could jettison ballast?”
“Yes, we could, that’s true, but we are at the beginning of the journey and the Capitan must make best use of his resources – we may get into a situation later where he needs the ballast badly. Don’t forget that the ship gets slowly lighter all the time because it uses its fuel. In a while we’ll get to a warm country with a much lighter ship. You wouldn’t want to be in a situation where you couldn’t descend because you were too light, would you now? Or where you kept going higher and higher? Haha!”

Carla felt a bit of a shiver – there was much more involved in this type of travel than she had ever suspected.
“But in that case he would valve off the gas, wouldn’t he?”
“Of course, I was only joking. But the essence is to maintain control of the airship in an optimal way by preserving as much as possible of both gas and ballast. Remember, we can use the resources – fuel, gas and ballast – only once. When they’re gone, they’re gone for ever. That’s to say, until we can land.”
“Same with water?”
“Less so. We can collect rainwater and condensation on the hull and replenish our stores. But that takes time.”

The weather outside cleared somewhat. The pea soup became less dense and wispier. Occasionally there were even clear spaces between the shreds of fog. The men behind her continued with their breakfast and the expert on zeppelin travel volunteered more information:
“On the other hand, of course it is advantageous to fly as high as possible.”
“Because there the air is less dense?”
“Yes, the air is thinner; the ship has less drag. That means less effort to propel it. So we can make the same speed with less fuel, or we can go faster with the same fuel – so we arrive earlier in Rio.”
“So, we should fly as high as possible?”
“Yes, but there are limits. First of all we get trouble breathing. Especially the older passengers may not find it very comfortable at two thousand meter. The engines also will have their problems; they deliver less power per liter of fuel. Then there is the cold, mind you. At two thousand meter it may start to freeze. So the ship has to be heated, for the passengers first of all, and that takes fuel again…”
“Yes, but if there are no clouds at two thousand meters, the sun will heat us. You said just now that the gas would get warm …”
“Indeed, by radiation, but the air temperature is low and the air will have to be heated!”
“What fuel do we use?”
‘Diesel, we have four twelve hundred horse power diesel engines.”

Carla no longer followed the conversation. Typical boy’s talk. Men were awful… They could go on and on about something technical. She was more interested in the clouds. They were unmistakably becoming less and less. Occasionally she could even see a small patch of ocean surface. Ripples in a grey sheet: waves seen from a great height. It was only for a moment that she could see the sea and the thought flashed through her that somebody on a ship could have seen the Hindenburg. She imagined being on a ship underneath an endless cover of clouds and then suddenly in an opening, an airship appears and is gone again immediately. A strange thought. Would there have been somebody, there at sea? Or were they the only ones present in this space: a surreal dining room at five hundred meters, surrounded by clouds? Was she dreaming? Did the sea down there really exist? And had the zeppelin been visible from the sea even if nobody had been there to see it? Was there a reality outside the things that you saw yourself?

Fortunately, at that moment more passengers entered the room and a friendly elderly couple invited her to join them. They talked about their destinations and where they came from and soon the disturbing thoughts were gone.

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ADDENDUM

Luftschiff Zeppelin LZ-129 ‘Hindenburg’ was the largest operational passenger airship between the wars in Germany. It had a length of 800 ft and a diameter of 135 ft.
Starting March 1936, it flew a regular airservice between Germany and South (later also North) America, until it was destroyed by fire
in May 1937 at Lakehurst, New Jersey, USA. In 1936, 17 round trips were made across the Atlantic, carrying an average of 65 passengers with a crew of 56. In that season the ship flew 192,000 miles, carrying more than 2000 passengers and 160 tons of freight and mail. A westward trip
took an averige of 65 hours depending on weather conditions; eastward it took ten hours less. The one way fare to the USA amounted to $400.–.

for more reading, see this most interesting Wiki site:
http://en.wikipedia.org/wiki/Lz-129

for books on airships:
www.Lindbergh-aviation.de