What are these engineers doing sitting on a large format drawing of B-47s aircraft?
As commented by Anilv, they are examining a factory production layout/plan. They most likely are attempting to resolve a production or supply problem, though as Anilv suggests, they may also be planning the factory layout.

Listed below is an example of the B-17 Flying Fortress Factory Production Layout used by Boeing in WWII. Note the arrows which show the production procession and parts/sub-assembly entry and exit.


Source - Boeing