Foo4You: Just in case someone doesn't want to use mods, here's what worked for me in the vanilla game: I just turned off Antialiasing in the graphic settings while I was in the Mechanist Level. I didn't have to change any other of my (high) graphic settings. No problems with looking at certain textures, no crashing.
aggusia: Not working. Any ideas?
I found this work-around while I was trying out different graphic settings to solve the crash problem.
When I first launched the game I had problems with the well-known crash bug during the intro, when you run from your house to the vault across that little bridge. I searched for a solution and found out, that you can switch off weapon debris in the graphic settings. I tried it and it worked for me. After the intro I switched it back on.
So when the problem with the Mechanist level occured to me, I started playing around with the graphic settings again, since it seemed to have something to do with the textures. Fortunately it was the first change (the Antialiasing-switch-off) that worked for me. If that doesn't work for you, maybe you could try the weapon-debris-swith-off or lower down the texture quality?