AIRFRAME MANUFACTURE AND ENGINEERING EXCHANGE

This essay studies engineering exchange within the context of American aircraft manufacture during World War II. At issue is the nature of engineering knowledge within the manufacturing firm and how this is transferred among firms. While technology normally finds its way between competing firms (often surreptitiously), this period is interesting in that companies broadly encouraged technology transfer. Wartime mobilization brought both pressures and opportunities for firms to establish cooperative links, eventually leading to the establishment of product – oriented and industry-wide cooperative structures.1

The methods of technology transfer and the kinds of information sought teach us much about the nature of engineering knowledge and the process of exchange. What becomes obvious in this history is that traditions of practice unique to each manufacturer obstructed technology transfer. The difficulty of exchanging engineering knowledge had less to do with legal and proprietary boundaries than it did with technological cultures, a firm’s unique methods of designing and producing aircraft. In some cases these practices were so different that even when firms attempted to manufacture identical products, they were simply unable. While individual components of a manufacturing system might be adopted across firms, production systems themselves remained highly localized and the result of idiosyncratic philosophies. An examination of the design and manufacturing process reveals that design information was not only lost or changed as it proceeded from the drawing board to the factory floor, but that it continued to be created along the way. While engineers might have believed that all design information began with them and could be transmitted completely through drawings, the imposition of different tooling and production groups from outside companies exposed the degree to which engineers were also imbued with specific traditions of production.2

Within these constraints (many of them initially unknown to the manufacturers themselves), firms established varied means for communicating technological knowledge. Before mobilization, technological information normally found its way through engineering and trade journals, scientific and technical societies, and user- producer relationships.3 This is exemplified through the story of the Guerin process, a metal stamping technology that began at Douglas Aircraft and diffused across the industry through journals and machine tool suppliers. With the advent of cooperative wartime structures, the ease, urgency, and rapidity of information flow increased dramatically. Manufacturers established methods for exchange, including tooling transfer, central data repositories, committees, publications,

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P. Galison and A. Roland (eds.), Atmospheric Flight in theTwentieth Century, 259-285 © 2000 Kluwer Academic Publishers.

inter-plant visits and standards-setting bodies. While conclusions about the success or failure of this transfer are elusive, the quantity and persistence of exchange throughout the war testify to some measure of achievement. In addition, the types of material exchanged, from explicit design data to more tacit shop-floor information, as well as the mediums of exchange, suggest a diversity of engineering knowledge and reaffirm the assertion that engineering knowledge was embedded within a firm’s culture.4

A brief look at the historical treatment of engineering knowledge discloses two recurring strands. The first is the importance of design, and the second is a design trajectory that posits a movement from idea to finished product. Originally, the notion of engineering knowledge emanated in part from a desire to reject the applied-science definition of technology, and to characterize engineering as a distinct and valued branch of knowledge. By asserting that technology extended beyond material artifacts, engineering could be placed on a par with science rather than serve as a translator of theory into artifact. More important to historians of technology was the function of design in what was considered to be a knowledge­generating activity or process. Engineering knowledge was not simply distinct from scientific knowledge in its content, but also embraced creativity. This was original knowledge, not reconstituted theory. In design and creativity, engineers could lay claim to the kind of prestige normally reserved for scientists, while some historians underscored engineering’s relation to the arts. Edwin Layton’s oft-cited 1974 article “Technology as Knowledge” emphasized the role of design as an ideal within American engineering and as a distinguishing characteristic from science. Furthermore, he described a trajectory that began with an idea (rather than a scientific theory) and eventually culminated in a product. He writes:

The first states of design involve a conception in a person’s mind which, by degrees, is translated into a detailed plan or design. But it is only in the last stages, in drafting the blueprints, that design can be reduced to technique. And it is still later that design is manifested in tools and things made…. We may view technology as a spectrum, with ideas at one end and techniques and things at the other, with design as a middle term. Technological ideas must be translated into designs. These in turn must be implemented by techniques and tools to produce things.

Similarly, Walter Vincenti’s work What Engineers Know and How They Know It also emphasizes design, and characterizes the process as a movement from the abstract to the physical.5

Both Layton and Vincenti were well aware that while design was an important quality of engineering knowledge, it was not everything. Furthermore, they understood that the process was much more complex than the idealized and sometimes reductionist versions they portrayed.6 This is especially so in the case of the manufacturing firm.

As an organization that generates large quantities of engineering knowledge, the firm cannot be treated in the same way as an individual engineer. Outside of a small number of gifted individuals who have designed both the product and the production process, these activities are normally carried out by different communities of engineers.7

It should be evident that the design trajectory, the movement from an idea through increasingly material stages, does not fit neatly into the factory. Production, as a stage in this process, is not simply downstream from the idea stage. It is itself the operational stage of a different design process. Layton appreciated this relationship, stating:

The designs for the final products of technology do not exist in isolation. They are intimately asso­ciated with production and management, which, as Frederick W. Taylor insisted, also require design. The innovations of Eli Whitney and Henry Ford were less in the final products, whether muskets or automobiles, than in the design of systems of production and tooling.8

While we may idealize the creation of a product as a linear process, in practice it is much more circular, since production techniques feed back and change the original design. Vincenti alluded to this in his study of flush-riveting, which he termed “production-centered.”9

Changing our perspective to incorporate all the engineering activities of a manufacturing firm serves to eliminate some of the strict distinctions between design, production, and operation, as well as notions that this is a linear process. In reality a manufacturer is usually doing all three; it does not necessarily follow that one begins with design, and moves on down the line to production and operation. Rather, in a company practicing design and production, there is a negotiation between different groups of engineers and managers. The aeronautical engineers are but one group, and they may well conceive of the process as linear. But the tooling engineers will have a different understanding, since they are designing a process in which the product is not an aircraft, but a quantity and quality of aircraft under certain limitations of machinery, material, and labor.10 Figure 1 illustrates this relationship in a simplistic fashion. The actual circumstance would incorporate far more communities of engineers (aerodynamics, structural, systems, weight, etc.), a

Figure 1. Relationship between Tooling and Aircraft Engineers.

web of feedback loops, as well as inputs from labor, materials, and machinery. The two dimensions given here are sufficient to make the point that what an aircraft factory does is a negotiated result of multiple design models.

As products and production processes grow more complex, an intermediate group appears, namely production engineers, who mediate between product and process designs. The World War II period saw a blurring between design and production as aircraft came to be “designed for production.” The history of Ford’s Willow Run facility reveals how an aircraft, the Consolidated B-24, was redesigned, not around performance specifications but around manufacturing specifications.

The idealized design trajectory itself exists only in a extremely contorted fashion within the manufacturing firm. For example, tooling engineers begin with a product and work backward to design a process. And while they certainly operate under a set of fundamental design concepts, it is more appropriate to discuss traditions of practice. A tooling engineer, confronted with a novel product, is going to have at his or her disposal a range of well-known production techniques that can be applied to create a production process. He or she does not necessarily return to abstract fundamental concepts each time a new production process is to be made. In the end, it must be concluded that depending on what technology is under consideration, there may be a whole range of models for the description of engineering knowledge. Layton’s warning in this regard is appropriate, “We need not assume that technological thought is a single monolithic whole or that it can be uniquely characterized in any single formula.”11

Comprehending the nature of engineering knowledge within a manufacturing establishment is difficult, not only because much of it is tacit or proprietary, but also because some of it involves seemingly non-technical issues. Engineering practice in a company is not only a body of collected knowledge; it is part of a culture or tradition of practice. Just as companies may have distinct business cultures with their own internal momentum, so may firms have distinct engineering cultures. These traditions of practice count, and they are embedded not only in the engineers, but in the technicians, the workers, the managers, and even the equipment. Engineering within a large company is far richer than traditional notions of engineering knowledge allow. When it comes to understanding the nature of engineering exchange among companies, many non-technical issues impinge on the flow of information. As will become clear, ideological and practical differences regarding the optimal form of manufacture resulted in three different systems for the production of the same aircraft. Transferring the Boeing aircraft company’s system to the Douglas and Vega aircraft companies would have involved far more than the simple exchange of technical information; it would have bordered on the wholesale adoption of a tradition of practice.