The S.C.A.F pipeline encountered by Isaac Clarke and John Carver following their crash landing on Tau Volantis was (Presumably) one of the many constructed by the S.C.A.F on Tau Volantis to supply Facility One.
The pipeline was supported by large square stands attached to the ground with large bolts. It appeared wide enough for a tram to drive through. On top and below of the pipeline are numerous habitation quarters, presumably for guards and workcrews maintaining the pipeline. Generators in the rooms powered equipment, heaters and lights. Lifts and ladders provided access to the top of the pipeline and sections which are covered with catwalks.
Due to 200 years of exposure to the elements, the pipeline broke apart in many places and was no longer filled with anything (It was unknown what the pipeline was used to transport, but the design was similar to that of oil pipelines).