Railroads

Railroads are one of best methods of moving materials over landscapes. In the short run they are expensive to build yet over the long run they prove to be very valuable. Your other options are to go over the rough or paved surface in a vehicle or to mix your material with a liquid or gas and send it through a pipe.

Lunar Environment

The Lunar Regolith consists of extremely fine crushed rock. This acts like abrasive powder and will electrostatically adhere to anything in contact with it. Vehicles traveling over the open surface will experience wear at an accelerated rate. Paving a road with dust free materials does not solve the problem because the sunlight will cause the dust to climb up and over structures to about a meter in height.

One solution to this problem is an elevated railroad supported above what the dust can reach. The costs of building elevated railroads and other structures on Luna as compared to Earth are less because of the 1/6 g gravity on Luna, metals such as magnesium and calcium can be used as electrical conductors without corroding, lunar soils provide a firm base, and weathering will not damage the structure so it ought to last a long time. The costs are greater because of the general difficulty of operating in a vacuum, the necessity for dust control techniques during construction, the radiation environment preventing the direct presence of human laborers for any routine outdoor tasks, the inability to use any fossil fuel burning air breathing engines, and the lack of infrastructure in general on Luna. This last problem might be reduced until at some future time all desirable infrastructure is available.

Mars

With such a thin atmosphere and no oxygen, Mars has essentially the same dynamics as the moon only with more gravity (better cornering).

Asteroids

All asteroid like objects have a gravitational force insufficient for traditional railways. The modifications necessary are two fold. An upper track must be added like roller coaster to be able to go a reasonable speed without jumping the track. All materials must be securely fastened with either lids or binding clamps.

Cargo Type Iteration Development Model

Bulk Iteration

In the soil of the moon there is metallic nickel iron (as opposed to oxides) that can be collected and is a strategic resource. At a concentration of only a few kilograms per cubic meter, it makes sense to build a railway to open up new regions once the local soil has been processed. This need not be a major railway as the amount of material that can be passed over even a model gauge can be hundreds of tons a day. The rails can be made from local iron. Operating costs would include interest on the capital investment, maintenance and electricity to power the system.

Freight Iteration

Once you have a sizable base and need higher volumes of material, you simply leverage the existing facilities to build a larger railway. Railroads are suitable for automated delivery and could conceivably be launched like carrier pigeons to far off secondary bases. A lunar railway of about a meter wide would be able to transport virtually any freight.

Passenger Iteration

For passengers and large more fragile freight, you will need protection from radiation as well as the extremes of the solar insolation. A railway with tracks several meters apart (wider than on earth) should have the desired characteristics of fast travel in secure accommodations. Once you have a developed network of railways the need for vehicles to drive on the surface is reduced to a local level. Railways are far less to maintain and last significantly longer.

Design Issues

Thermal expansion issue

Switching issue

Derailment avoidance issue

Vestibulation issue

Gauge

Rail System Solutions

Number of Rails

The number of rails may vary. Does the system go with a monorail solution, a two rail solution, or a three rail solution that provides external power?

Rail variations

A smooth rail is the tried and true Terrestrial solution refined over an extended time period. Any proposed alternate type of rail would need to prove its capabilities to exceed the safety and performance in Lunar gravitation. A possible point of concern is that with lower gravitation the risk of derailment may be greater.

Maglev solutions have been experimented with on Earth and may have value, especially after the infrastructure needed is in place.

A toothed rail and wheels might be able to provide some additional stability.