Years ago on my elderly dawes galaxy I rode over a section of the Cairngorms, bike handled it OK but I was paranoid about the dished 126mm OLN rear wheel. Now I thought I'd like to do more off road touring but didn't want a new bike at the time so I thought about a tringle speed.
Build a rear undished SS wheel which would be nice and strong and use a compact 5 arm chainset on the front with 20/32/44T rings. I reckoned that would have given me a decent gear spread for the desired task whilst the bike would be well tough.
Never did it, wish I had
I can see the point of the original posters idea, if you cant shift on the fly you effectively are a singles peeder in any given situation untill you stop and become a different single speeder.
I applaud the idea