Ladies, Gentlemen,
My apologies in advance if this turns out to be an old issue, as I have only recently joined the list, but haas anyone ever attempted to make sense of the Bayernese passenger airships?
I find I have to rewrite the Bayernese airships because they don't make much sense as described in the books I have on hand (Castle Falkenstein, Comme Il Faut, and Steam Age). For example, the largest, the Princess Sophie (no relation :-) is "almost 200 ft long" (which would be about the length of a 747), with "12 decks" - guessing at a deck height of 10 ft, that's an ugly block of 200 ft x 120 ft... Consider that the Hindenburg was 804 ft long, just 78 ft shorter than that other ill-fated craft, the Titanic! To strike a balance, I suppose, I am thinking of making the Parsifal (the airship I am using in my Adventure Entertainment) some 122 m long, or about 400 ft. With decks of about 3m or 10 ft (a bit skinny, but it'll work), that makes the hull about 150 ft (45 m) high (including cargo space.) Does this sound reasonable? Does a clever Dwarf Engineer have better stats to propose?
What I believe they are actually talking about is the length of the passenger section of the Bayernese aeroliner. If they are (which I believe they were) the text is a bit muddled in sections. The passenger/control gondola for the Graf Zeppelin was 98 1/2 feet long by 20 feet. The passenger quarters for the "Hindenburg" and "R-101" were both larger and more luxurious than the Graf's, so the facilities of these aeroliners would be very deluxe.
200 feet is hardly longer than the Goodyear blimp. The dimensions must not include the gas cell, which would be proportionally sized to lift the ship. Without regard for the picture in Steam Age, I would venture that the aeroliners do not look like matchboxes attached to basketballs, apply some artistic license.
One of the Call of Cthulhu scenarios is set on an airship and comes with a layout.
Not wanting to burst one's balloon (pun intended), it would be incredibly illogical to believe that the Bayern is the only one to own and operate this type of airship. The Zeppelin Company of Prussia would probably be operating (though the good old Graf came from the Kingdom of Wurttemburg), air travel would be more reliable to places like eastern Russia or easier, though expensive, in between the nations of North America. As in the beginning of "Those Daring Young Men in Their Flying Machines", Britannia rules the wave and it must now rule the air. Lord Thompson was right in that one of the best ways to connect the British Empire together is by air. Flying the "All Red Route" between dominions and colonies (for a good idea of this read M. Moorcock's Warlord of the Air).
My dear Sophie, one thing that you have not taken into account (or perhaps you were not aware of) is that most of the height of the airship is not involved in the passenger accomodation, but the diameter of the gas cells.
I haven't done any research in airships such as the Hindenburg, but I have done a lot into the German Naval Air Service Zeppelins of World War 1. From about the middle of the combat life of the Zeppelins to the end, the hydrogen gas used to lift the ship off the ground was at least 1,000,000 cubic feet. Towards the end of the war, the Germans were building the "Height Climber" Zeppelins, which had a gas volume of around 2,000,000 cubic feet of hydrogen. The Hindenburg was, if I recall correctly, built with a volume of 7,000,000 cubic feet.
The main body of the ship, which is visible from the outside is made from a frame work of a lattice work of duralum (sp?) metal (which is a lightweight alloy of aluminium). Inside this framework are hung a number of gas cells (I think, from memory, the R-Type Zeppelins, which began with L31, had 19 separate gas cells hanging inside the frame. But don't quote me on the type of the Zeppelin though).
In the wartime ships, the engines and controls were all carried in small cars situated *outside* the main frame of the ship (the engines used in the Zeppelins were notoriously unreliable as well, but that is another story). In later passenger Zeppelins, such as the Hindenburg or the Graf Zeppelin, the controls and engines were moved inside the main frame of the ship, improving the streamlining.
The diameter of the frame of the wartime Zeppelins was around 96 feet. I remember reading somewhere that the Hindenburg had a frame diameter of 138 feet, although I could be wrong on that score.
At the bottom of the (wartime) zeppelins, there was a triangular part of the frame in the keel. This was used as a walkway for the crew members who had to move around inside the aircraft during flights. This was also where all the ballast and bombs were held. As another aside, the wartime zepps used water as ballast, and we constantly having to adjust the trim of the ship as the petrol was consumed. The larger passenger Zepps got around this problem by using a gas fuel, which had the same density as the air - burning it up didn't affect the trim of the ship. It's possible they used water as ballast to help offset the bouyancy of the gas, but I don't know about this one.
The passenger ships, again if I recall correctly, had only two or maybe three decks, stretching for a reasonable portion of the length of the ship. And I very seriously doubt that a single deck would have a ceiling height of 10 feet. 7-8 feet would probably be a more reasonable height for a single deck.
Another thing to consider when you are designing an airship is that it cannot (and should not) be anywhere as luxurious in appointments as an ocean going liner such as the Titanic (which had marble fireplaces and the like). On board an airship, weight is a premium. I cannot for the life of me remember what the lifting strength of a wartime Zeppelin was, but I do remember that the vast majority of the capacity was used up by the rigid framework. Also, the number of passengers is going to be far less than an ocean liners, again, primarily due to weight restrictions.
I find it interesting you have decided to name your ship the "Parsifal". During WW1, there was a type of dirible called a "Parsifal" (or at least a name very similar to that). It was basically not much more that a cigar shaped rubber bag, filled with hydrogen with a net thrown over it to contain it.
Of course, this is all real world stuff. The world of Falkenstein has slightly different rules about physics. If we stick too hard to the truth, the Bayernese aerocorvettes would not be possible, despite being one of the coolest things in the game. But considering that the lifting capacity for a Bayernese ship still comes from the gas, I don't think it is going to be possible to build a 12 deck floating Titanic, even if it is ensorcelled hydrogen.
Another piece of Zeppelin trivia - the gas cells were basically great canvas bags, lined with "goldbeater's skin". This strange sounding material is one of the few substances known during WW1 that was able to contain hydrogen. It comes from the insides of cows. If I remember this right, it is a membrane between the skin and the body of a cow (although it could be something to do with the stomach of the animal). A single wartime Zeppelin required the Goldbeaters skins from at least 100,000 cows. I can't remember the exact figure, but I am pretty sure it was in that sort of range. Most of these came from South America, again if I remember correctly.
(Most of this information came from a really good book called "The Zeppelin At War" by Dale Robinson. Unfortunately, I don't have access to it anymore, as it belongs to the Australian Department of Defence. As I ceased working for them over a year ago, it makes it a tad difficult).
Here's one for Mike P. In the main CF rulebook, it states (although as I don't have it with me, so I am working from memory here), that the Bayernese airships use ensorcelled hydrogen as a lifting mechanism. It's ensorcelled so that it won't catch fire. Which is fine by me. BUT. The ship is driven by a magnetic sorcerous engine which latches onto the Earth's magnetic field and pulls the ship along. What stops the engine from unravelling the spell on the gas, given as you explained last year that there is but a finite amount of magickal energy in a region, and it gets locked into long term spells and stops other mages from using it).
Sorry, Mike, this is pure baiting, I know, and I apologise unreservedly. I just hate that rule.
Geoff Skellams wrote:
> The ship is driven by a magnetic sorcerous engine
which
> latches onto the Earth's magnetic field and pulls
the ship along. What
> stops the engine from unravelling the spell on the
gas, given as you
> explained last year that there is but a finite amount
of magickal energy
> in a region, and it gets locked into long term spells
and stops other
> mages from using it).
>
Funny you should mention that - it was going to be my next question. For the Sorcerers of New Europa, wouldn't having the Sorcerous Engines fly overhead be like the worst kind of sonic boom? The passenger line has only four ships, of course (Princess Sophie, Parsifal, King Maximillian, and Siegfried, according to "Comme Il Faut"), with fairly regular timetables, so to a certain extent New European sorcerers could plan their day around that schedule. ("Drat! I am sorry, Lord Auberon, but I cannot help you with that spell, right now; the Siegfried is due any minute!") However, military ships wouldn't give any warning. Of course, this is a good plot device to interrupt a power gamer in the middle of levelling a capital, but it seems a bit clumsy. You'd think all the sorcerers would form a Union and blast those ships out of the sky!
Also, in practical terms on board, the Bayernese must be intent on keeping the technology out of foreign hands. They would have to have defenses against Sorcery (although the Engines may fulfill that function just through their working), but also against Faerie powers of all kinds. I can hardly believe that the wall around the Engine room are made of Cold Iron! (although I suppose they could be laced with it.) I'll have to go and hunt down for spells related to observing or countering Faerie activities...
Ah, now a civilized conversation to which I can contribute!
Mr. Skellams, I thank you for the fascinating discourse on the particulars of airship design. With respect, I would now like to contibute some small meansure of knowledge from my own area of expertise.....
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From: Geoff Skellams
Date: Thursday, June 18, 1998 3:08AM
At the bottom of the (wartime) zeppelins, there was a triangular part of the frame in the keel. This was used as a walkway for the crew members who had to move around inside the aircraft during flights. This was also where all the ballast and bombs were held. As another aside, the wartime zepps used water as ballast, and we constantly having to adjust the trim of the ship as the petrol was consumed. The larger passenger Zepps got around this problem by using a gas fuel, which had the same density as the air - burning it up didn't affect the trim of the ship. It's possible they used water as ballast to help offset the bouyancy of the gas, but I don't know about this one.
<The gas fuel would be pressurized into cylinders, and so would be much more dense than air. I think the advantage would be that, properly valved, the gas would continuously redistribute itself as it was burned, by the simple natural mechanism of pressure equalization; thus making separate ballasting unnecessary. Of course, bussing all of the fuel cylinders together has its dangers, too...>
The passenger ships, again if I recall correctly, had only two or maybe three decks, stretching for a reasonable portion of the length of the ship. And I very seriously doubt that a single deck would have a ceiling height of 10 feet. 7-8 feet would probably be a more reasonable height for a single deck.
<10 feet per deck may still be a reasonable estimate of the total height of the structure, taking into account the width of framing between the floors, and the space required for infrastructure (electrics, hydraulics, pneumatics, cabling,...); although certainly, the space from floor to ceiling would have been no more than necessary: seven or eight feet.>
Another thing to consider when you are designing an airship is that it cannot (and should not) be anywhere as luxurious in appointments as an ocean going liner such as the Titanic (which had marble fireplaces and the like). On board an airship, weight is a premium. I cannot for the life of me remember what the lifting strength of a wartime Zeppelin was, but I do remember that the vast majority of the capacity was used up by the rigid framework. Also, the number of passengers is going to be far less than an ocean liners, again, primarily due to weight restrictions.
<Absolutely true, that weight is at a premium - in fact, it is the primary limiting factor in all airship designs. Regarding the lifting power of the gas. The buoyancy force of a lighter gas (hydrogen) in an environment of heavier gas (air - admittedly a gas mixture, but still an "ideal" gas, at Standard Temperature and Pressure) is due to their difference in relative weight, by volume. Specifically, the weight-density of hydrogen at STP is about (2[g/M]/22.5[M/l]=) 0.089 grams per litre; that of air is about (14.4/22.5=) 0.64 grams per litre. That is, if I remember my chemistry correctly, and one Mole of ideal gas has an equalibrium volume of 22.5 litres -- I invite any corrections. Simple arithmetic tells us, then, that one litre of hydrogen in air has the buoyancy, or lifting force, of about (0.64-0.089=) 0.55 grams equivalent weight. Taking mass and weight as equivalent in most situations, one cubic metre (1000 litres) of hydrogen could support (1000*0.55/1000*2.2=) 1.2 pounds of balloon structure, passengers, ballast, weapons, etc. Of course, the higher the balloon goes, the thinner the atmosphere becomes, and so the lesser is the buoyancy of the hydrogen. The airship must be designed to have enough lift to support its own weight, at the altitude desired. I do not have the pressure profile of the Earth's atmosphere handy at present.
I hope this gives some small idea of the lifting force offered by 7 Million cubic feet, approximately 640 Thousand cubic metres, of hydrogen!!
In the real world, we switched to Helium, as the magick to render Hydrogen unexplodable is still beyond us. Helium, being a molecule four times the mass of Hydrogen, has approximately one-fourth the lifting force. Thus ended the Golden Age of airships.>
Another piece of Zeppelin trivia - the gas cells were basically great canvas bags, lined with "goldbeater's skin". This strange sounding material is one of the few substances known during WW1 that was able to contain hydrogen. It comes from the insides of cows.
<Fascinating!>
...latches onto the Earth's magnetic field and pulls the ship along. What stops the engine from unravelling the spell on the gas, given as you explained last year that there is but a finite amount of magickal energy in a region, and it gets locked into long term spells and stops other mages from using it).
<Pray, is this rule in the CF rulebook? I am not familiar.
[Sophie's Note at the time of editing of the page: It's based on the information in Comme Il Faut.]
>In the real world, we switched to Helium, as the magick
to render Hydrogen
> unexplodable is still beyond us. Helium, being
a molecule four times the
>mass of Hydrogen, has approximately one-fourth the
lifting force. Thus
>ended the Golden Age of airships.
A minor point, but the end of the Golden Age was due in part to the monopoly one nation - the United States - enjoyed on the inexpensive production of helium. Essentially all of the world's production comes as a byproduct of oil and gas production in the American southwest, and the United States declared the gas a strategic material and established a stockpile, restricting sales to other nations. This stockpile was often cited as an example of government waste in action during the 1980s, by the way - maintained at high cost just in case the American military decided to begin the construction of a huge airship fleet. Can't remember if it is still around, or finally got killed off in recent defense deparatment budget cuts.
One other point about airships - the Hindenberg disaster nonwithstanding, most airship losses (at least in peacetime) were due to weather, not fire. Big, lightweight structures do not take kindly to the stresses of wind shear and the like. Would make for a good adventure hook - what happens to the DCs when they are trapped on a crippled airship drifting towards the ocean, or enemy territory, or, horrors, EuroDisney?