25 03 2010

Light Rail Channel

“…Project Stephenson, the task of connecting the outposts and mining stations, was the largest planetside undertaking since the construction of Charlotte Station.  Channels were carved through the uneven landscape to provide protection from meteor showers and to streamline loading and unloading of minerals and equipment required elsewhere across Fram.” 

The rail project was the next logical step in the effort to connect the four colonies with each other, and with the various installations scattered about the edge of the main crater. Project Stephenson was prioritised by the First Congress, and work began mere weeks after the close of that meeting. The project represented the most significant capital investment yet undertaken by our fledgling Colony; our other great undertakings – such as Charlotte Station, Port Mayflower, and the cable which connected them – had all been constructed using prefabricated materials, and according to designs drawn up in Sol.

The Stephenson rail network would be almost entirely produced from resources mined from Fram, and designed by us.

The highways of carbon sheeting had been a temporary measure, and one inconsistently applied at that. Each of the colonies had been connected to the central hub, Charlotte Station, although none was directly connected to another. Nor were the open-cut and COIL mines, or the solar field and launch complex, connected to the highway system. Moreover, these were surface roads, with all the problems entailed therein: windstorms would deposit regolith across the carbon sheeting, and these drifts could cut access until they were ploughed to the side.

Light rail was an elegant solution, though not one commenced without thorough consideration. For example, the Conference rejected the use of maglev systems. Most persuasive of the arguments submitted in favour of a light rail electrification scheme was the conservation of power and comparative ease of construction. A magnetic levitation system would involve the construction of high-temperature superconductors and magnetic shielding; moreover, the levitation and propulsion systems would have to be carried onboard the train, reducing cargo space and increasing weight. A light rail network could be connected to and powered by a Colony-wide power board.

We began by digging trenches ten meters deep and thirty meters wide. The inside faces of the channels were strengthened with inlaid carbon mesh. We modified one of our enormous UC-104s: its utility crane was stripped from the chassis and, instead, installed were two load-bearing arms ending in a single rotary bore attachment. Its legs locked in place and the body hung low as its arms dug up the regolith, eerily like a Martian handling-machine plucking victims from the ground in a Wellsian novel.

Our priority, as with the carbon highways, was to connect each of the colonies to Charlotte Station. The elevator ground station was located between each of the colonies and served as a natural terminal. We had to dig over eight kilometres of channels just to fulfil this limited objective.

The closer that we dug to Charlotte Station, the more difficult that task became; Charlotte was located in the base of the large crater in which all the colony pods had landed, and as such there was less regolith between the surface and the bedrock. In places we also struck fractured basalt sheets. Here KOVTARs equipped with portable COIL rigs broke up the densest materials.

It was important that the channels be deep and wide. Deep trenches afforded better protection from meteorites, and we would add a further parapet of exhumed material to the western lip of each channel. The trenches would be widest for the main lines of the network, those between the colonies and the Charlotte Station Terminal – on these lines we would lay two tracks, one for each direction. When we began construction on the ancillary lines, to the spaceport, mines and reactor, we would lay only a single track to accommodate comparatively less traffic.

Three rails were installed for each track. The Stephenson network used a third rail to provide 1,200 V of power to the trains. The conditions of Fram and the depth of the rail channels precluded the use of catenaries and overhead wires, thus necessitating the third rail. Here we used a covered, bottom-contact rail to prevent the kind of disruptions caused by wind-driven regolith that had plagued the carbon highways.

Yet the geographic conditions also gave us certain benefits. The distances between terminals were short – Charlotte Station was no more than three kilometres from any colony – which meant that there was no need to construct feeder stations along the line. Furthermore, our channels followed the general decline of the crater; trains running to Charlotte would run downhill. Our trains would be built with regenerative breaking equipment, which would generate power while breaking and return that power to the rail network for use by trains travelling uphill. Excess energy would be converted to heat and vented into Fram’s atmosphere – our first, if somewhat insignificant, terraforming effort.

But first we had to dig the channels, lay the track, and build the trains. That was many months of work. Still, our impression upon this ancient and dusty planet grew more profound…




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