March 9, 2010 – Weighing as much as a small elephant and spanning more than 57 feet, the largest of the 747-8 fuselage panels that Marshall Street assembles could barely fit inside a tennis court. Imagine loading it into a rail car. A similarly large shipment is Section 48 which consists of the upper and lower lobe, the pressure dome or bulkhead, and the aft body. 

From a manufacturing standpoint, one of the biggest changes on the 747-8 versus the 747-400 is the increased size of the fuselage panels. This feature had the biggest impact on Vought as the company had to reconfigure both the Marshall Street site and the Hawthorne site to accommodate the larger size. 

Marshall Street also assembles the 747-8 vertical stabilizer/upper rudder, the horizontal stabilizer/ elevators, and the floor beams. This totals 10 separate railcar shipments for each ship set. 

Fuselage Panels, the skins for these panels come from Hawthorne and are loaded via rail system into customized vans for their trip to Texas. A matching lightweight monorail system was installed at Marshall Street for safe and efficient unloading and staging of the panel assemblies when the site made its transition to 747-8 production. 

Fast forward and the frames are fastened to the skins, final installations are done, and the panels are ready for painting. The heavy monorail takes the panels to the painting area where they are painted while still hanging on the monorail. This same rail then takes the panels to the shipping area where they are loaded into new shipping fixtures configured specifically for these panels. They are then loaded into the rail car with the use of overhead cranes and forklifts. It is interesting to note that the railcar is actually parked inside the building. 

Resembling a gigantic bowl, the pressure dome is another piece that is assembled piece by piece and evolves into the final structure you see in the photo on next page. “This structure is used to plug the rear end of the pressurized cabin and is assembled by a four person crew with over 60 years of combined aircraft assembly experience,” said production supervisor Tony Richie. Because of its function and to keep the weight down, the pressure dome is made of very thin metal. This is an important feature to keep in mind when packaging it for transport. “If it is nicked or dinged,” said Industrial Engineer Gary Monnette, “there are very limited repair options.” 

		The upper and lower lobes are made up of 22 bulkheads or frames and assembled much like the fuselage panels discussed earlier in that they are fastened to the skins, but they are not automatically riveted. “The upper lobe sits just beneath the vertical stabilizer, or what looks like the tail and is mated with the lower lobe and aft body upon delivery to Boeing,” Gary said.  Shipping fixtures made specifically for the Section 48 structures are used to package them for transport. The upper lobe and the pressure dome are loaded into one fixture and the lower lobe and aft body are loaded into its own specially-made shipping fixture and both are loaded into one custombuilt railcar.  Finally, the vertical stabilizer and the upper rudder are shipped from Marshall Street in one ship set. The left and right hand horizontal stabilizers, left and right hand inboard and outboard elevators combined with the horizontal center box, comprise the “Horizontal” shipment. The center box is the mating structure which is used to connect the left hand stabilizers to the right hand.  Ninety floor beams make up another delivery from Marshall Street. “The floor beams create the floor grid for the cargo decks in a 747-8 freighter” said Gary. “To a casual observer they may all look alike, however, each possess unique fastener patterns and bracketry.” The floor beams are the only delivery routinely transported by truck. All other shipments are made via rail.  There doesn’t seem to be anything standard when it comes to the 747-8. And when it comes to assembling these structures at Marshall Street, custombuilt and specially-made tools, processes and transportation methods are the norm rather than the exception.
Top: 747-8 aft body Marshall Street Bottom: 747-8 pressure dome