The Berk plant is a "sort of" production line. They have a two pair of rails in the floor similar to two parallel railroad tracks. The tracks are about 200-300 feet long and are just far enough apart to match the front and rear axles on the FL chassis.
So, they drive each raw chassis in and position it on 4 "wheeled dollies" (one for each chassis wheel) that roll on the tracks. Basically as the coach is built in phases, it is pushed sideways (by hand) on the rails from one "station" to the next.
I counted about 18-20 of these "stations".
At each "station" a different phase of the build process takes place; for example, one station is for plumbing, one for electrical wiring, etc...
As the plumbing crew finishes their job, they push the chassis (sideways) down to the electrical crew, whom in turn have pushed their (electrically) finished unit on to the next station (crew).
So, they have roughly 18-20 coaches under production at any one time (in varying stages of completion). Right now they're rolling about 8 finished coaches off the last station every day, and of course rolling 8 raw chassis' in onto the first station.
There is a overhead door even with the first station to bring the raw chassis in, and another overhead door on the other side of the building (even with the last station) where they drive the finished coach out.
EDIT: I said 8 per day; maybe it's 8 per week..... Not really certain right now.