... the rear tube on my Dawes went "POW!" and I walked after that. Actually, I walked a mile or so, then Ellen picked me up with the car.
The tire is a brand new Swift Sand Canyon. I presume it was intended for hook bead rims, and that the Dawes has straight beads. In my defense, this happened earlier on the ride, I let out enough air to reseat the tire, then walked to a nearby bike shop and squirted in about 40psi of air. I kept the pressure down because I figured I was dealing with a hooked/not hooked situation. I didn't have time to check it out when I got home because I needed to pack to go out of town. So I brought my Eisentraut instead.
I rode this bike with some cheap Schwalbe's with no problem for several years and just replaced them with the Sand Canyons a couple weeks ago. Maybe the extra width was a problem. The Schwalbe's were (I think) 28mm. The Sand Canyons are labeled 37, but they really are only 31mm wide when inflated.
When I get home in a week or so, I'll scout around for some more modern 27-inch rims. I have no idea what the current rims are, but I suspect they are original to the bike.