Define the interfaces and resources required to build a lunar rail network.
Establish a critical list of foreseeable cost, technological and logistical risks.
Identify prototypes, demonstrations and analyses of a fully operating lunar rail system’s concept design and architecture.
Explore concepts for constructing and operating the system with robotics, including grading and foundation preparation, track placement and alignment, joining and finishing, inspection, maintenance and repair.
Gravity or lack of gravity means cannot use earth type RRs. Any change in direction either horizontal or verticle train goes off track. So, locos and cars must have some kind of positive contact up and down and sideways with rails at all times to prevent lift off of rails. But the rails and cross ties then would also need to be anchored for every crosstie & rail to solid moon.
No cooling available from air causes major engineering work for propulsion, friction, and braking.
For tractive effort and braking best use a rack RR.
For rails cannot use CWR as kinks and pull aparts due to extreme temperature changes with alternate 14 days of sun and then 14 days dark. Miter joints every 20 feet?
Don’t be silly; this is military-grade rocket science, involving some of the finest engineers in the world. Of course it will be orders of magnitude less expensive than CAHSR.
The Moon isn’t an asteroid – it has very efffective gravity, just weaker than Earth’s. The obvious way to increase ‘curving speed’ is to use increased superelevation… with vacuum-cementing of ballast and so on.
One approach is to use a Fell-style method on a reaction rail – two sets of sprung wheels bearing on the web and underside of the railhead. Provide the electromagnetic braking either side of these wheels if you want to keep this separate from the ‘running’ support rails…
Gravity would hold them adequately, presuming correct design at the ends of the ‘ties’ – but I suspect that’s not what would be used; it would be some kind of cast slab-track in sections, with positive anchoring as well as shims allowing the counterpart of top-down alignment of the rail structure.
Propulsion would probably be hydrogen fuel cells, with the water exhaust serving very nicely if something is needed for heat transfer. Radiators are VERY effective in the lunar environment, where one side will always be dark at effectively hundreds of degrees below zero. You will certainly not be using air brakes, or even hydraulic brakes, but eddy-current braking is completely adequate (even if you need coordinated inverter drive for the axles).
As noted, the Fell system is better than a lateral rack, and of cou
I remember thinking about what it would take to build a railroad on the moon and one of the first challenges was how to deal with thermal expansion/contraction. It then occurred to me that rocks would have similar problems - repeated thermal cycles would break the surface into little pieces. My next thought was: that’s why the lunar regolith is a coarse powder.
I like OM’s idea of “snowshed”, especially if there is a heap of lunar regolith on top. The heap of regolith would accomplish two things. First is the thermal mass would even out the temperature underneath. Second is that a meter or two of regolith would be a passable radiation shield providing some protection against the normal background radiation levels of space as well as solar flares. The earth’s atmosphere is roughly equivalent to 15 feet of concrete with respect to radiation shielding.
I forget how old I was when I came across Neil Ruzic’s ‘The Case for Going to the Moon’, but I became convinced then, and still am, that sensible Lunar development ought to be undertaken… as long as it doesn’t devolve into the usual kinds of finance oligarchy. I note that the current thinking does call for ‘surface construction’ of a network of lines, rather than in deep tunnels or even with the overburden Erik mentions against flare or CME events. Be interesting to see what detail design and options they come up with.
I confess I’ll be eagerly watching for Don Oltmann’s ‘railroading in 2060’ blog post about a typical day’s work up there.
The problem with the idea of exploiting lunar resources is the assumption that any single entity or country “owns” the resources. There is no law for the Moon, no agreed upon international treaties, etc. Wild Wild West. No guarantee that if you build it someone won’t take it or tear it up, etc.