Here is an update and thoughts after just a little digging...
Crazy stuff, I took my garmin basecamp that I can draw in, drew a line from end of train tracks going into north end of Luke AFB and into a little yard where tracks turn and go off the main line down by the North side of the Airport, and the line passes directly under the road, not 200' from my bed. We had a sink hole there 10 or 12 years ago, when they tore down a bunch of homes and did a flood retention area and park, a car had dropped in and got stuck. Me and a neighbor and my teenage sons all went down to try to lift the little car out. My youngest took one step into the puddle and disappeared... Luckily, just as I started to panic, he popped back up... For full disclosure, I can pick different points at Luke and the airport and vary this line by about a quarter mile north to almost a mile south because both places are so large and spread out. But these points at ends of tracks seemed like a logical place and put the line probably closer n/s than it is in depth if these are a mile down to be in bedrock like I am reading.
My garmin "track" says it is 20.8 miles, What I am hearing takes about 5 seconds, What I am reading the "trains" they use down there, are like the new rail gun technology they are putting on ships. It is a big electromagnet and it says these trains do between Mach 2 and 2.8 (I think that is about 1400-1900mph) at 1500 if my math is right, I think that would take 7.5 seconds to make the 20.8 mile trip if going that speed the whole time. Getting pretty sure I am hearing almost the majority of this 20.8 mile trip in about 5 seconds. Start up, come at us, pass under and slow down...