Happy Thanksgiving to all you Steampunks South of 49!
Found this photo on G.D. Falksen's  page.

Keep your sightglass full, your firebox trimmed and your gravy warm.
KJ

Train of Rubbish

This fascinating site has a wealth of interesting info.
Created and maintained by Lee Jackson  check out...

The Dictionary of Victorian London

From the site:

... a vast website - it would run to thousands of pages in print - containing primary sources covering the social history of Victorian London. This includes extracts from Victorian newspapers, diaries, journalism, memoirs, maps, advertisements &c. and the full text of several dozen books. These sources are arranged by subject area and can be browsed and searched at will.

The site has been used extensively by scholars, genealogists, authors, and the general public for the last decade - it was most recently cited by Anthony Horowitz, as a key research resource for his Sherlock Holmes novel The House of Silk.

In addition to the Dictionary itself  Lee also has a companion blog:

The Cat's Meat Shop is a blog containing pieces of source material from my current research, pending updates to the Dictionary of Victorian London, reports of visits to buildings in London — recent visits have included the St. Pancras Renaissance Hotel and The Royal Society of Arts — and anything else that catches my eye. 

A recent blog entry contained this gem from  1892:
----

Train of Rubbish

One day last week a friend of mine walked down Piccadilly behind a lady who was wearing a dress fitted with the long train now in vogue. Opposite St. James's Club she got into a cab. She consequently left behind her on the pavement all the rubbish which her skirt had collected as it swept down Piccadilly. My friend, being of a scientific turn, proceeded to make an inventory of the collection, and he has been good enough to send it to me for publication. I give it below. In the days when germs and microbes play such an important part in social life, I question very much whether these trains should be permitted by law. This lady left her street sweepings on the curb-stone; but it might be remembered that many convey them into their own or their friends' houses:-

2 cigar ends.
9 cigarette do.
A portion of pork pie.
4 toothpicks.
2 hairpins.
1 stem of a clay pipe.
3 fragments of orange peel.
1 slice of cat's meat.
Half a sole of a boot.
1 plug of tobacco (chewed).
Straw, mud, scraps of paper, and miscellaneous street refuse, ad.lib.

Lady F.W. Harberton, "Symposium on Dress," Arena, vol. 6. New York, 1892, p. 334.

----

A highly recommended site for Victoriana, quirky, entertaining and informative.

 

Keep your sightglass full, your firebox trimmed and your water iced.

KJ

To Fly Amongst the Clouds

Heavenly Nautilus by *voitv

In the previous articles in this series I talked about some of the ways that airship flight was controlled and the constraints that those ways imposed on flight duration. With the fantastically powerful energy source at the heart of our airship, I have concluded that using steam as the lifting gas essentially eliminates those constraints.

Besides, what better steampunk airship could we have than one that flies and is propelled using steam!

Later in this series I will attempt some calculations, to do a kind of "reality check", for the overall design. However to make sure that I wasn't too far off base, I did some quick calculations using the specs of the Hindenburg to see if steam lifting gas would result in useful lift. For an airship the size and dead weight of the Hindenburg, steam does indeed allow a small payload. You may recall that my buddy Grant's calculations had shown that in order to fly it would have to be 25% larger. But she was saddled with passenger accommodations and infrastructure to handle 40 or more people and their baggage, and since our airship is a military/exploratory one, not a commercial passenger ship, we have a lot of weight that can be re-allocated to our power and propulsion systems.

In a conventional gas filled airship the static lift system is independent of the propulsion. In the case of the great rigid airships like the Graf Zeppelin or Hindenburg, the lift was provided by hydrogen and the propulsion by diesel engines. In our case, courtesy of our power source, we can unify these systems with the attendant benefits I discussed last time.

So how would this work in practice?

First I'll talk a bit about one way to make use of our power source to handle both lift and propulsion. Then I'll discuss a way to bring the power out to the propellers so we can begin our grand voyage. In my next post in this series I'll talk about how all this can be laid out in the hull and perhaps what form that hull will take.

Power Core

At the heart of our airship is the core, a dense block of "something" generating very large amounts of heat. (Personally I prefer to treat this core as a fission type nuclear reactor.) Since for our purposes it is our one major fantastical element, we don't have to deal with the pesky details of how it actually generates so much heat. We do however, need to deal with the practicalities of using it.

To keep things simple the core is either an "on or off", "feast or famine", deal. Once running this core continues to generate heat, whether we need it or not, therefore cooling of the core is a priority. The core is mounted in the center of a large tank of water. Thermosyphoning of the tank water around the core, where it is turned into low pressure steam, carries away this heat. This steam is used as our lift gas. In flight, we only need to generate steam to balance that which is condensed and collected from the gas bags inside the hull. This will not be enough to prevent overheating of the core, so a large radiator ,or condenser, is mounted on the top of the hull to condense any excess steam. This radiator is a primary structural component making up a significant portion of area of the hull itself. The radiator is air cooled, sending excess heat to the atmosphere.

In the event that the hull condenser cannot handle the excess steam, or in case of an emergency, steam will be sent directly to the atmosphere through a couple of elegant funnels on the upper hull. (Just cause it looks so damn cool.)

In practice the Chief Engineer (me) and his staff would constantly monitor the heat balance of the main tank, along with the balance of lift steam and condensate reboil, directing excess steam to the condenser as required to keep things stable.   

The main tank also serves to shield our crew from any adverse effects of the core itself. Water is a good shield for ionizing radiation. Two meters of water is sufficient to handle the gamma ray flux of a typical spent fuel rod from a modern reactor for example.

Power Generation

My proposal is for our airship to use a Tesla type electrical power system to drive its main propulsion engine. This power is generated in the engine room by the use of a similar system to that found in a modern nuclear reactor.

Given the very large amount of heat being produced continuously, the interior of the core itself is much hotter than its surface.  A coil of steel pipes built into the structure of the core when it is made, carries a dense mineral oil into the heart of the core. Here the oil picks up the intense heat, and being under very high pressure, does not boil but remains liquid itself. This high pressure, very hot, oil is directed to a more or less conventional boiler outside the main tank. Here it is used to boil water, supplied from the main tank, to make steam. This steam is used to run a high speed turbine in the engine room. Exhaust steam from the turbine is directed to the hull condenser and thence back to the main tank.

Why not have water in the coil and simply flash it into steam directly? 

To keep things simple. If the coil and boiler are arranged and sized correctly, no mechanical pumps are required to maintain the fluid flow through the core, and therefore the heat flow to the boiler. The density effects of temperature will cause the oil to flow in the loop. We want to minimize the amount of things that can fail INSIDE, or close to, the dangerous confines of the main tank near the core. Also it is likely that the fluid used in the loop will become dangerous (radioactive?) as a result of its close exposure to the core. With no mechanical pumps in the loop, there is no need to open the piping for repair or maintenance with the risk of exposure to any contaminated fluid.

The turbine is connected to one of Tesla's high powered AC generators. This power is used to run the main propulsion systems.

Propulsion

Tesla's wireless power transmission system, a kind of tuned resonance, is used to transfer this power to the main engine without wires. The engine drives large counter rotating props at the stern of the airship. These props, by counter rotating, do not induce any rotational torque on the hull. A similar system is used to drive water torpedoes.

Auxiliary engines and propellers are mounted on the hull for use in maneuvering at low speeds during takeoff and landing. These engines also receive their power via Tesla's wireless system.

A side benefit to using Tesla's power system is that lighting and auxiliary power can be taken from the same system without the use of wires, thus helping to minimize weight.

The core gives us both lift and power for propulsion. There are no mechanical pumps necessary to control the primary system, minimizing the points of failure when we are far from our base. With such power at our command we can truly fly amongst the clouds, traveling the world in the search of adventure and in service of Her Majesty, HUZZAH!

Join me next time for some more details of how all this fits together within the airship's hull. An engineer's eye view if you will.

Keep your sightglass full, your firebox trimmed and your heat balance stable!
KJ

Click here for the next article in the series.

You can follow the full design thread by clicking on the tag "Flight Engineer".

I love watching engines run.
When they are made out of glass they are just so much more awesome!
From that font of all video wonders YouTube.


Glass steam engine made in 2008,named after the original made in the 1850s. The cylinder and valve housing are made of glass so you can see the action inside.


This Model of Stephenson's Steam Engine was made in 2008 by master glassblower Michal Zahradník.

Highlights:
* The crankshaft is glass.
* The piston is glass.
* The counterweight that makes the wheel spin evenly is glass.

* There are no sealants used. All is accomplished by a perfectly snug fit. The gap between the piston and its compartment is so small, that the water that condensates from the steam seals it shut!
* Notice the elaborate excessive steam exhaust system next to the piston.
* The piston is the most arduous part to make due to to extreme level of precision needed. Its parts have to be so accurate that no machinery is of use here. The piston and its cylinder must be hand sanded to perfection, and they are very likely to crack in the process! On average, three out of four crack.

Keep yous sightglass full, your firebox trimmed and your water iced.
KJ

This book is a real treasure trove of design ideas.

First published as Ornamentale Formenlehre in 1886 as a Folio sized edition in Leipzig, this book became the standard pattern book for designers of the latter 19th c. The first English version was published in book form in 1894 and rapidly became the bible for design in Victorian time.

With over 3000 detailed line drawings, in 300 plates, of classical and mediaeval decoration, this book contains the genesis of much of the design used in Victorian sculpture, architecture and graphic arts.

My edition was printed in 1974 and is a wide format beauty that allows for detailed examination of the figures.

The forward by the editor, Tony Birks, is a fascinating look at the enduring conflict between technological devices, with their spartan utilitarian looks, and the complex and intricate designs of neo classical and neo gothic design that became popular at that time.

Title
Myer's Ornament
Victorian Bible of Design
Originally
A Handbook of Ornament

Author
Franz Sales Myers
edited by Tony Birks

Publisher
Gerald Duckworth and Company
London


Date
1974
First English edition 1894

ISBN
0 7156 0713 8

Keep your sightglass full, your firebox trimmed and your water iced.
KJ

The Case for Steam

In the previous part of this series I talked about some of the details concerning how an airship flies.  In this part I will discuss the pros and cons of using steam as the lifting gas for our airship.

You can get some of the technical details of why steam makes a good lifting gas at this website:
The Flying Kettle. They are actually working on a free balloon that uses steam and have dealt with a lot of the practical details, a fascinating site definitely worth a perusal.

There are lots of different gases that can be used for generating static lift for an airship. In the real world the best one is hydrogen, followed by helium then pure methane. Of these three, hydrogen and methane are explosive when mixed with air and helium, while being non-flammable, is expensive and relatively rare. Ordinary steam is a surprisingly good lift gas being between helium and methane in lift capacity, plus steam is easy to make, cheap, and non-flammable.

This table from Flying Kettle has the properties of various lift gasses.

GAS	M.W.	Temp. (‹C)	Density (kg/m3)	Lift (N/m3) in ISA	Safety	Cost	Ease of provision	Buoyancy control
H2	2	15‹	0.084	1.140 11.19	bad	fair	fair	no
He	4	15‹	0.169	1.056  10.36	good	very high	very bad	no
CH4	16	15‹	0.676	0.549  5.39	bad	low	fair	no
NH3	17	15‹	0.718	0.507  4.97	fair	low	fair	no
hot air	29 (avg)	110‹ (avg)	0.921 (avg)	2.980.327  2.2.98 (avg)	good	very low	good	yes
steam (H2O)	18	100‹	0.587	0.638  6.26	good	very low	good	yes

From the chart you can see that pure steam at sea level and 100C only has the ability to lift 6.26 N/m3 which is better than pure methane but only about 60% of the lift available from helium. My buddy Grant, who is an engineer in real life and also a member of our crew, has calculated that, given steam's lifting capability compared to hydrogen, an airship with the weight of the Hindenburg would need to be about 25% larger in volume to fly!  That is a significant difference and could easily kill the use of steam for any "practical" design on that basis alone.

Another big disadvantage of steam as a lifting gas is that it condenses when the temperature goes below that necessary to keep it as vapour. That temperature is just over 100C at sea level of course, but lower at higher altitudes. As time goes on during a flight the steam will condense back into liquid water, primarily due to heat loss through the envelope, which will reduce the volume available to generate lift. Essentially the airship will constantly be "leaking" lift gas by this condensation.

To maintain flight this condensate must be re-boiled and returned to steam constantly, plus any leakage through the envelope that contains the steam must be balanced somehow, just like a normal gas filled airship must balance against the leakage or venting of lift gas by the dropping of ballast. In a conventional airship the energy that would be necessary to re-boil the condensate must be supplied by fuel and boilers that take up payload capacity.

So why am I proposing the use of steam given these disadvantages?

What really tips the issue in favour of steam for our airship is the power source we are using. In part one I mentioned that the main fantastical element of our airship was this power source, the exotic core of Verne's Nautilus. I prefer to think of this source as being like a fission type reactor core and will treat it as such for this design. Part 4 and 5 of this series will deal with the design decisions that such a power system requires. For the purposes of this discussion here, the key elements we are concerned with are that such a reactor uses up no fuel with time, and it generates prodigous quantities of heat continuously with a very high power to weight ratio.

This power source neatly deals with the disadvantage of condensation as it can easily re-boil any condensate and return it to the envelope.  Liquid water can be boiled to make up any leakage through the envelope to the atmosphere as well.

I am a big fan of simple systems, especially mission critical ones. Since we have an almost unlimited supply of heat available with our power core, we do not need much complxity to generate large volumes of low pressure steam. Thermo syphoning through the core may be all that is required for lift gas production. I will look at some proposed details of how the core and steam production can be controlled in following articles.

Let us now look at the three constraints to airship flight duration I discussed in the last article.

The three constraints are: lifting gas supply, ballast supply, and fuel supply. These are constraints because as a flight continues, the need to balance the buoyancy by releasing ballast and venting gas to account for changing conditions, place a limit on flight duration. Venting gas to lower buoyancy must be balanced eventually by dropping ballast to increase it again. As fuel is consumed the airship gets lighter and gas must be vented to adjust for that as well. In the case of a conventional gas filled airship both of these actions, venting gas and dropping ballast, were irreversible. Once the ballast supply was used up no further adjustments were possible. Ditto once the volume of gas vented reduced the airships buoyancy below that necessary to maintain lift. At that point the voyage was over!

So how does steam as a lifting gas, with our power core, handle these constraints?

The Case for Steam (almost)

In part one of this series I talked a bit about why I'm working on a "practical" design for an Airship.  I also mentioned that one of the main fantastical elements was the super powerful energy source that will power the ship.  So in this article I will start to make the case that given this very good energy source the best lifting gas system to use is simple steam.

I thought I would be able to get right to making that case, but first we need to talk a bit about how a conventional gas filled airship flies.

Graf Zeppelin 1933

An Airship is not simply a balloon with an engine and propeller attached. Anybody who has ever tried to throw a kids balloon knows that a balloon has no directional stability at all. Airships tend to have shapes akin to those of the underwater profiles of ships, or the hulls of submarines. This enables some longitudinal stability when moving through the air.


Unlike a surface or underwater vessel however, the airship is moving through a medium that is more than 700 times less dense than water. A ship floats by displacing water equivalent to the weight of the vessel. Since water is so much denser than air a ship hull can be quite small and still be able to support a significant weight.  Plus there is a definite interface between the water and the air so a ship can act like a platform resting on this surface and have all it's "interesting stuff" exposed on top of the hull, in the air. A surface ship usually has a significant amount of reserve or excess buoyancy, which is why a ship floats on the surface and can carry useful amounts of cargo and armaments.

An airship also floats by displacing a volume of air equivalent to it's weight but, since air is so much less dense the volume required is correspondingly higher. There is essentially no "surface" to the air so an airship is more like a submarine than a surface ship. The airship is suspended INSIDE the air it moves through so it needs to be as close to neutrally buoyant as possible. That is, the buoyancy should be sufficient to allow the airship to be stable in altitude but not tend to rise or fall. If the airship is positively buoyant by too large an amount it will rise uncontrollably unless lift gas is vented or buoyancy is otherwise reduced. If it's buoyancy is too negative it will not fly at all or fall to the ground unless weight is reduced by dropping ballast.

In practice airships are usually slightly heavy relative to this neutral point, I'll explain why in a moment.

Since there is no surface against which an airship's hull can push, like a surface ship pushes against the water's surface, there is no "right-side up" except that determined by the distribution of weights in the hull. This distribution is critical, relatively heavy portions of the craft will tend to twist the hull until they are at the lowest point. Thus even though it is popular to show some  Steampunk Airships looking like airborne surface ships it would take a lot of external force, with complex engines and propellers , to keep them that way. Our airship will have the traditional weight distribution where the lowest part is filled with the heavy stuff, engines, power source, crew, cargo, cabins, and most weapons. The large volume needed to make the vessel float in the air will be above this.

The other thing that powered airships use in flight is what I call dynamic or form buoyancy. That is, the movement of the ship through the air generates some of the needed lift. This is in addition to the static lift supplied by the large volume of lifting gas, much like the passage of air over the wing of a heavier than air craft. In the case of the original Zeppelins, and current non-rigid airships, most altitude control in flight was by judicious use of the control planes to change the hulls angle to the airflow. They use the effect of the ships forward motion through the air to control altitude. That is the reason to keep the airship slightly heavy. By having the airship tending to sink in the absence of forward movement the pilots can play the opposing forces against each other which makes control easier.

Airship flight is a constant balancing act between the forces supplied by the vessels buoyancy and propulsion, and the external forces caused by air movement across the surface of the vessel, and any larger atmospheric conditions like winds, frontal systems, storms etc. In a traditional gas filled airship there were three constraints that determined the length of time an airship could operate. The three were fuel supply, ballast supply and lifting gas supply.    

Adjustment for external conditions, like altitude, temperature, humidity etc, required the release of ballast, usually water, to increase buoyancy, or venting of gas to decrease it. As fuel was consumed during a flight the vessel would get lighter with time so gas would have to be vented to maintain static altitude. Obviously there is a limit to how much ballast could be carried, simply to be dropped, and how much gas could be vented before the ability to control the buoyancy would get problematic.

Any emergency conditions, like being caught in a sudden updraft or downdraft near a weather front, could necessitate the dropping of a lot of ballast at once or the venting of a large amount of gas. A single such incident could result in the vessel being unable to continue its voyage, if she survived at all.

Here, finally, we can begin to discuss the case for steam as the lifting gas, because the use of steam essentially removes two of these three constraints! In our case our amazing power source also removes the third, completing the trifecta.

In my next post in this series I'll get to the heart of the Steam as Lifting Gas case.

Until next time here is another image from the Steampunk Art of *Voitv to inspire our airship dreams...

Postal Dragon

Keep your sightglass full, your firebox trimmed and your water iced.
KJ

Click here for the next part of this series.

You can follow the full design thread by clicking on the tag "Flight Engineer".