There's a subway running under my apartment, so I'd have to do some testing before I could commit to owning the L shelving system. Other than that, I admire designer Juan Pablo Quintero's brilliant idea of using a single tabbed-and-slotted shape to create an infinitely scalable bookshelf, no tools required.
"L" is a modular shelving system based on a unique piece. Like fish scales, the modules are superimposed one after the other to generate a useful surface slightly inclined to prevent books from falling. This system allows for increased storage capacity by adding new modules.
Assembled according to the taste of each user. Easy assembly using no screws or fasteners, almost as if it were a game. It is delivered disassembled.
I suppose that fully laden, gravity would do to keep the shelves in place, even under mild vibration.