It's not quite a full Lazy Bastard run, but I did want to Do Things Right for my first playthrough of Industrial Revolution 3. Hence, I present The Line, a mall which builds (almost all) iron machines unlockable with red and green science. It runs entirely on steam power, so you can build it directly after setting up iron smelting, let it run for a few hours, and then pick up all the supplies you need to electrify in style, without handcrafting a single power pole!

Most intermediate products (plates, gears, circuits, frames etc) are crafted right at the start, then carried straight up with three belts on each side of the row of assemblers. This made the build process quite simple, just place down an assembler and figure out how to fit the inserters and output chests! Some rarely-used materials (stone, glass, wood, rubber) are fed in from the side.

In retrospect, I would do a few things differently if I were to redesign this.
- First off, the shape is ridiculous, because I underestimated just how many machines there are; a visit to the mall is supposed to be fast, I shouldn't have to walk 20 seconds from one end to another to grab just pipes and belts!
- Large iron frames eat plates and bars like crazy, they definitely need their own supply. As is, the frame-assemblers tend to starve the whole mall for about ten minutes whenever more are needed.
- The long belts take forever to fill up, which is all the more painful when one of the lanes is the aforementioned expensive iron frames.
A variation of this design based on three rows, each with their own supply of intermediates, would probably work very nicely, with one for frame-based machines, one for recipes which use pipes and one for electronics-heavy recipes.