Martian Cloudships

There is a diverse and exotic biosphere on the Mars of Space: 1889. Perhaps the most unusual evolutionary quirk is the ability to defy gravity without using wings or lighter-than-air gases. Certain kinds of Martian life developed the ability to float through the air by opposing the pull of gravity. One of these is a tree which produces 'liftwood'. The Martians have, for tens of thousands of years, used liftwood to build ships that sail among the clouds -- cloudships.

The Martians developed two types of cloudships. The oldest and still most common type are those powered by sails. They are often refered to as "kites." A relatively recent development is the cloudship propelled by an airscrew, called a "screw galley." The airscrews are turned by crewman turning handcranks, linked through mechanical gear boxes.

Click on thumbnail pictures for more about the following example of each type of cloudship.
Bloodrunner, A Kite.
Smallbird, A Screw Galley

I am very fond of the idea of cloudships (as evidenced by my building a model of one) but I do have a problem with the concept as it is used in Space: 1889 - they simply will not work. I am not talking about liftwood. Liftwood is the fantasy element of the story and I am willing to suspend my disbelief and accept that there is an organic material that can counter-act gravity. No, my problem is that adding sails to a lighter-than-air craft will do absolutely nothing to control its speed or direction. A free floating object, and that's what a cloudship without an airscrew is, will travel at exactly the same speed and in the same direction as the wind current in which it resides. Balloons control their direction (and speed, to a lesser extent) by rising or falling to find an air current that is going in the direction they want to travel. If no air current is going that way, then neither is the balloon. Adding sails to a balloon will not effect its speed or provide any control over its motion. The sails do absolutely nothing. Why do sails work on a boat and not on a balloon (or cloudship)? Because a boat exists in two media of different densities. The difference in density between air and water means that there are two forces acting on a boat, the drag of the water and the pressure of the wind (which is actually a form of lift generated by the airfoil shape of the sails). A sail boat balances these two forces against each other to allow the boat to control its direction and to generate speed. A sail boat can actually sail faster than the wind speed under certain conditions. The resistance of the water on the boat's hull is vital to it's control. A boat that does not have a keel that extends far enough into the water cannot sail into the wind but will be pushed across the water in the direction that the wind is blowing.

And that's the trouble with cloudships, they have no keel and no water for the keel to push against. Without that, there is no way for them to sail, they can only drift. There is a solution to this problem, though, and it can come from the same liftwood that allows the cloudship to rise into the sky. We know that liftwood is effected by planetary magnetic fields (the Venusian magnetic field accelerates the decay of liftwood), so it seems reasonable that one effect might be that liftwood resists crossing the magnetic field lines. That resistance would not be enough to slow the cloudship significantly but could provide the equivalent of the drag of water, and thus allow the cloudship to truly sail through the sky. Obviously, the magnetic resistance is different from drag in the sense that it is very directional, i.e. there would be less resistance when the cloudship is traveling with the field lines than when crossing them, but this is roughly analogous to ocean currents and, like their Earth ocean sailing counterparts, the Martian cloud sailors would long since have learned to use this effect and will have adapted their sailing techniques to not only compensate for it, but will have learned to use it to their advantage.

Kites are not the only cloudships with which I have a problem. Screw galleys, as portrayed in most of the game materials, also have a shortcoming. They are invariably shown as having only the air screw as a means of propulsion. This is not at all reasonable. Since the air screw is driven by man-power, this severly limits the range of the vessel. Hand turned cranks simply could not drive a cloudship over any but very short distances. A good Earth analog for the screw galley are the oared galleys used around the Mediterranean in the 18th and early 19th centuries. They mounted a few heavy cannon, usually in the bow, and the larger ones had over a hundred oars, each pulled by several men. These galleys never ventured far from their home ports and were essentially coastal defense craft. Even so, they were still fitted with masts and sails so that they could sail most of the way to the battle and reserve the strength of their oarsmen for the final maneuvering. It is also of interest that in 1889, a large percentage of the steam-powered warships of Earth's navies still retained their rigging so they could sail if they needed to. It seems reasonable to me that the Martian sailors would be just as conservative and practical as the sailors of Earth and their screw galleys would be rigged for sailing, when the speed and maneuverability of the screw was not required. I was pleased to note that the cover illustration for the re-release of TRMGS Vol 1 did feature a screw galley that mounted sails as well.

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Space:1889 is Frank Chadwick's registered trademark for his game of Victorian Era space-faring. He has granted permission for the use of the background of Space:1889 for the stories presented here. All text, illustrations, photographs and design are 2000-2013 Dan Thompson, except where otherwise noted.