The first use of the original Rouge building was not to assemble automobiles but rather submarine chasers. Henry Ford had convinced the government that he could mass-produce submarine chasers, called Eagle boats, using the same principles he used to make the Model T. The government agreed to finance construction of the building in early 1918, and Kahn proceeded to design a building 1,700 feet long and 255 feet wide. The building was ready for operations in May 1918, and Ford launched its first Eagle boat in July. After the war, the company converted the building, designated "B" Building in the River Rouge complex, for use in assembling Model T cars and Fordson tractors.
This steel-framed structure designed by Albert Kahn is the oldest extant building in the Ford River Rouge Complex. Situated immediately north of the River Rouge Turning Basin Slip, this edifice was designed for the mass production of sub-chasers or Eagle Boats. When completed in May, 1918, the one-story structure measured 350 by 1700 feet and was 100 feet high. The production area was divided into five huge aisles, each of which was 51 feet wide and 1700 feet long. Two of these aisles had a continuous railroad track for moving parts and materials while the other three aisles had tracks used for actual assembly of the boats. After the war, the structure was used to build Model T bodies and Fordson tractors and from 1927 to 1932, Model A's were assembled here.
Over the years the building has been modified somewhat to accommodate new production techniques. Although this structure is generally considered to mark Henry Ford's commitment to single-story factory construction, around 1919 it was converted to a two-story facility in order to fully utilize its height which would otherwise have been wasted. Over the years, its size was increased, and it presently measured 520 by 2600 feet in 1977. It still exhibited, much of its original exterior architectural vitality, and the interior had a number of original features such as support posts and wood block flooring in certain sections. Exterior walls are constructed of brick on the lower levels while asbestos-clad metal is used on the upper levels. Steel sash windows and butterfly monitors on the tile roof provide much natural lighting for the interior. In 1977, the building was used to assemble Mustang II's, which roll off the 1,200-foot assembly line at the rate of one every 53 seconds.
Production at this building continued through 2004, and the building was demolished in 2008.