I remember seeing an early photo of forge welding ship components together on the floor of the factory.  Large piles of coke with large blowers blowing into them, lots of jib cranes to move things around.

I had seen in several books.. one was industrial forgings and the other was on vintage forgings either a train shop or the like..   In each of them they had pictures of forges that were mounted on the ground with only a slight lip with a back wall maybe 6'X8' or more with back blast setups..  the forge itself was 6-8ft or more in widthXlength..

Basically same setup as you had mentioned..  They also had centrally located work platform and from what remember in the pictures were basically a round wagon wheel affair with a center forging location with forges surrounding this area in a circular pattern.. 

Later on I had seen a video on Anchor making where it became apparent why the setup this way.. I'd be guess as to my assumptions but in the video it showed the Main forging as they added stock to it to gain in bulk and once the main body was up to welding temperature,,  and the forge welding started they would walk up with bars at welding temp and they would be welded on, one after the other without adding back to the forge for a new welding temp..        Adding the bars in rapid succession kept it at welding temperature and was amazing to see.. 

Anyhow,  it's all pretty neat..  Be great if there was more early movie footage of such mundane acts..