Here is an example of a pedestrian walkway on a mountain, on Tianmen Mountain (YouTube) in China. The video shows the walkway, tram, and road. The walkway is near the beginning.
This walkway winds around the face of a cliff. How could workers establish the foundations for the walkway supports when there is no infrastructure and really not even a place to stand?
Just a guess but they could do it by drilling into the cliff face and establishing a support point. From the looks of the supports they did the drilling about 10 feet below the walkway. After drilling they could hammer steel into the cliff face and build on that.
Think of how a climber can climb up a steep surface, hammer a support into the side of the cliff and set up a tent Example.
Now if one of those climbers hauled a hammer drill and some re-bar up the face with them they could create a support that sticks out from the wall. laying on that support they could drill more holes vertically and with multiple trips and enough time they could lay the foundation for a deck.
And to start the drilling you can rappel down from the top with your drilling equipment and start establishing the attachments to the rock face. You can do a lot while hanging from a rope. You could use a platform like window washers use to work for extended periods of time.
Some of the workers on Hoover Dam did this sort of thing. They were called high scalers. They were primarily clearing the canyon walls of loose rock using hand tools, steam jackhammers, and dynamite - all while hanging from ropes.
Very carefully.
You can look for Youtube videos, for example
https://www.youtube.com/results?search_query=construct+walkway+cliff
https://www.youtube.com/results?search_query=build+walkway+cliff
or whatever.
Although the few I look at don’t include constructing the support points.
Exopy … lots and lots of epoxy …
Have you forgotten the Boston Big Dig ceiling collapse–partly blamed on the epoxy:
For rock climbing at least, titanium bolts with pure epoxy-based glue are supposed to offer good corrosion resistance.
Not enough exopy … one can get more epoxy in by drilling the hole deeper and using an even longer shaft …
Exopy isn’t perfect … we still have the anchor bolt system we’re using … and the exopy really helps … the exopy also is a big help keeping our iron from rusting away … it’s good stuff, just a major hassle using it … easy to do it wrong … [wolfish grin] …
In places like Zion, some trails are just ledges hacked out of the side of the cliff face, like this section of the Hidden Canyon trail.
Roads too. There used to be roads in Hawaii just hung out of the sides of cliffs in some places.
Is exopy better than that epoxy stuff I’ve been using?
Spelting is overratted …
Somehow I think trying to build a secure walkway on a spelting cliff face is a bad idea.
That was uncomfortable to watch. Fascinating, but uncomfortable. And then as the hiker reached the end of the trail (knowing he has to return), we see that it had started to rain…
At least they could have installed the chain for the entire length of the shear cliff walk.
Brrr.
maybe when I was younger and didn’t know better.
We just hiked the Angel’s Landing trail this spring, lots of fun. Angel's Landing - Scariest Hike in America? Steep Drop off - Zion National Park, Utah - YouTube