It's not sampled or looped. "On the Run" was created entirely using a VCS-3. No crazy tape tricks beyond a few overdubs.
Thought I might expand on that a bit.
The Floyd were indeed pioneers in the control room, but not quite at the technical level that is generally assumed. Check out this article for some pictures of some early electronic music pioneers and the processes you're describing. These practices were already well established by the time the Pink Floyd came about.
As far as miles of tape loops ranged across the studio floor, the terminology probably creates a bit of confusion. I think they meant the total amount of tape used for all the loops. Since we're probably talking about 15 inches of tape per second, those loops can get pretty large. For example the loop of sound effects at the beginning of "Money" is about 4 seconds, which makes it about 5 feet long. Considering all the loops present in the entire album, that's an awful lot of tape.
As far as the tape being ranged across the studio floor:
That's how loops were done back in the day. Tape was very expensive, it's not something you'd want literally touching the floor.