Interesting Infrastructure

I’m continuing to rifle through old HDs in search of historic artifacts…

Today’s find was a series of photos I took on October 25th, 2014 while out investigating curious things I spotted in Google Earth.

See, Colorado is just chock-full of weird things you can only see from space. This is because back before easy satellite imagery, sparse civilization, hilly ground, and lots of acreage was all you needed to hide things. And Colorado has those things in abundance.

Anyway, back in 2014 I found this weird structure out in the middle of nowhere in Google Earth…

Google Earth, 2014

It vaguely looked like a particle accelerator as seen from space, but I was pretty sure there weren’t any of those in Colorado… So I took a road trip to find out.

The place was surrounded by fencing, but the fence near the road was down so I walked in to have a look around…

Standing at the west-side junction of the two loops, looking north

Same place, looking south

The large structure on the west side of the oval

Each loop was about ten feet wide with a shallow trench about eight inches wide cut into the middle of it, and I’d estimate the larger of the two loops as being about a mile around.

I puzzled over this thing for about a week or so before assuming it was probably a light rail test track.

Today I spent more time on it, and after digging through the Internet for clues for a few hours I finally found out what it really was…

In the late 1950’s and early 1960’s, a group at General Motors Research Laboratories had been working on ground-effects machines for the Army. These were air-suspended vehicles that could run on a variety of surfaces, but with such low power on paved roads that air suspension appeared applicable to transit. Since an air-suspended vehicle made no direct contact with the roadway, a new type of motor was required that did not use wheels for traction. The logical choice was the linear induction motor (LIM), and thus the combination of air suspension and LIM propulsion was born. The development program was impeded at General Motors because of anti-trust laws that made it difficult for GM to be involved in development of transit systems. As a result, the air-cushion-vehicle (they called it Hovair) development group separated and formed a corporation they called Transportation Technology, Incorporated. TTI developed the idea into what became one of the leading candidate PRT systems. They carried their system to full-scale testing in Detroit in 1969. In 1971, they became a wholly owned subsidiary of Otis Elevator Company. They demonstrated at Transpo72, then for political reasons moved to Denver where they constructed a second test track and participated in the AGRT program until its funds were withdrawn.

Some Lessons from the History of Personal Rapid Transit (PRT)
J. Edward Anderson, Ph.D.

The Hovair system used a linear induction motor (LIM) and hovercraft-like air-cushion systems. Neat stuff.

“Popular Mechanics” March 1978, Page 18

Anyway, having seen US DOT reports on the first test track – a more linear track with turns at either end that was re-purposed for winterization testing in the 80’s – it turns out that what I’d found was a second test track.

The second track was built in the mid 80’s by Otis Elevator in accordance with US DOT AGRT (Advanced Group Rapid Transit) requirements for funding. This section of a Congressional document from 1985 shows Otis asking the government to release allocated funds to finish the second track…

Department of Transportation and Related Agencies Appropriations for 1985

AGRT was primarily designed to research automated / computerized command and control systems to improve rail or guideway traffic. It’s not clear on how that all worked out by the end of the 80’s though.

These days though you can only see a small portion of the track peeking out from under a Martin Marietta asphalt plant…

Because we can’t pave the planet without more asphalt

And with that yet more interesting history gets bulldozed by ‘progress’ – but at least I have a ton of cool photos of the place in 2014!

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