EVERETT, Washington (AP) — The forward and centre fuselage sections of Boeing Co.'s first 787 look lonely at one end of the sprawling factory. There are no overhead cranes that lower pieces of the plane into position, no huge fixed tools scattered across the length of the production line.Instead, Boeing has designed a unique set of mobile assembly tools that move around the factory floor as they fasten together pieces of a mostly prefabricated jet.

For the first 100 or so planes, Boeing expects each Dreamliner to spend just six days in final assembly. That should be reduced to just three days when the production line ramps up to full speed.

On the 777 line right next door, the same process takes 18 days after workers put together the fuselages and wings piece by piece, then stuff planes with all their electrical wiring, hydraulic systems and other "guts".

The 787 is the first commercial jet that will be made mostly of light, sturdy carbon-fibre composites instead of aluminium. Large chunks of the plane, including the fuselage sections, wings and the horizontal stabiliser that's part of the tail, are being made in faraway factories, loaded up with all their wiring, and flown to Boeing's widebody plant on an enormous modified 747 to be snapped together.

On Monday, the company kicked off final assembly of the first 787, giving reporters their first peek at the factory bay where two fuselage sections sat waiting to be joined by giant blue assembly tools — one of them aptly named "Mother of All Tools Tower".

The MOATT, as Boeing calls it, acts like a clamshell, closing on the rear end of the plane and lifting it into position so it can be joined with the fuselage sections. Two other tools hug the circumference of the fuselage in front of and behind the wings.

A four-wheeled mobile gantry crane, nicknamed the "boat loader," takes large pieces of the 787 from a 118-foot (36-meter)-long cargo loader that drives major parts of the 787 to the factory after they're delivered by the 747 Dreamlifter.

All the major pieces of the 787 get joined together at the first stop on a final assembly line that has four slots lined up nose to tail.

Once the main pieces of the body are joined, the plane moves forward to slot No. 2, where the engines, landing gear and interior fixings get installed, and the plane's structure and wiring undergo testing. Final installation and testing take place at the third slot.

There is a fourth slot that won't be needed for every plane at first, but Scott Strode, vice president of airplane development and production for the 787, said it's designed to allow room for some contingency work to be done if needed and could eventually be used to boost production.

Boeing is relying heavily on dozens of suppliers scattered all over the globe. Boeing decided to fly in major sections of the first few planes before suppliers had stuffed them with all their wiring, rather than risk falling behind schedule. Workers here will install the wiring on the first few planes, and Boeing said the first one will spend about seven weeks in final assembly.