[samwichse]

Interesting tidbit from the conference call, summarized from a comment in this slashdot story:

We all know the story of how Tesla's original plan for GA3 (General Assembly 3) was to have an automated conveyor belt system transport parts from the warehouse to each of the assembly workstations. Unfortunately, it just didn't work; they had to tear it out and do the transport manually. However, when general assembly became a bottleneck, they built a whole new line (GA4) in a Sprung structure, partly out of scrap - including said conveyor system, which now transports the cars down the line as they're assembled.

What we found out today, however, was that they had a problem with the conveyor system in the engineering phase: since it was designed for transporting parts, not whole cars, it wasn't up to the job. It could hold a car fine, but the motors weren't strong enough to move it reliably. Their solution? Let gravity give them a boost. The GA4 line is built at a 1% downward grade, which reduces stress on the motors to within their design tolerances.

Interestingly enough, the Sprung structure solved the warehouse transport problem on its own. Since it's a long, narrow structure surrounded by roads, trucks could just back up to each workstation and unload their boxes of parts right there - no centralized warehouse needed, and no redundant unloading / reloading work