Boeing has revealed details of its plans to implement a moving production line at Renton, Washington for the 737 - and has for the first time acknowledged similar plans for the 757.

News of the initiative came after Boeing announced its intention to move 757 fuselage assembly to Wichita, Kansas, as part of efforts to boost efficiency by streamlining production. Boeing says that "over the next two to three years" 757 fuselage fabrication will move to Wichita, where the 737 fuselage is built, and will be manufactured using the more advanced robotic technology developed for the 737 Next Generation family. The fuselages would then be transported to Renton by train.

The move dovetails with efforts to introduce a moving production line for both models at Renton. Although the 757 will not be "moving" in the same sense as the 717-200 line at Long Beach, California, Boeing says it expects automated tugs to tow aircraft between positions. Even though this movement will not begin until next year, the company expects significant benefits from the lean manufacturing techniques being implemented to support the transition. Benefits expected by December include a 17% reduction in final assembly days, a 7% improvement in inventory turns, a 17% cut in direct labour hours and up to an 11% reduction in support labour.

The 757-200/300 aircraft in final assembly are now aligned nose-to-tail, instead of the traditional slant positions. Boeing says "simulation" of the moving line process on the 757 has just begun, whereas the simulation for the 737 changeover began in late 1999 on one of the three assembly lines.

After the success of the simulation on the initial line (line number two), Boeing has also begun the same process on the last two positions of a second assembly line. A temporary winch was rigged to pull aircraft to simulate a pulsed line while automated tugs designed for the 757 are expected eventually to be used on the 737 line.

Boeing says that, unlike Long Beach, where a chain drive was installed in a trench for the 717 in a "green field" site left empty by the closure of the MD-80/90 lines, the frantic pace of 737 production at Renton has required a different approach. "The challenge has been how to implement a moving line when you already have a full-up production rate," says the company. The 717 is currently in a pulsed mode, but is expected to become fully moving in August.

Source: Flight International