Prefabrication experiments - 252 - Operation Breakthrough - 03 - Dano Modules - on site megastructure

The vertical stacking of modular volumetric boxes in multiple configurations forms a common thread of many high-rise proposals in Operation Breakthrough. Piling, clustering and juxtaposing ready-made factory produced boxes was considered as a simple building block strategy for affordable housing. Each proposal in its own way tries to underscore this simplicity while offering various strategies for structuring the necessary, sometimes complex, cost intensive and redundant secondary support structure which makes it possible to stack identical volumes. From megastructures to prestressed skeletons, carrying individualized stacked units is one of the challenges of volumetric modularization. 

 

Dano-Modules, a precast producer from Chicago Illinois addressed the support structure in a most innovative way. Each profiled volume was designed as the formwork of an on-site cast superstructure. Defined as the building’s «hardware», each concrete cast unit with a modular dimension of 8 ft (2.4 m) x 12 ft (3.5 m) was based on standardized spatial/room arrangements and regulated transportation limits. The basic container would be easily delivered by truck from the factory to the building site. Interiors «software» could be adapted to any use and determined by the end-user. 

 

Two 6x8-inch (150x200mm) rib-like perimeter beams were factory-cast in the 12-foot direction of each unit’s face. When stacked or juxtaposed, the aligned ribs created a type of mega-Vierendeel space frame, a network of open spaces or chases for running mechanical equipment, plumbing, ductwork or wiring. The open chase also determined voids for the on-site casting of reinforced concrete. When filled with steel reinforcement and concrete, the monolithic structure braced the boxes horizontally and vertically and secured all components in place. Before being filled with concrete, certain voids would be pinpointed for prefabricated mechanical racks distributing services vertically or horizontally. Cited as an advantage, the reinforced concrete megastructure would save 50% of the required formwork when compared to conventional construction. Once cast in place, 16 inches (400mm) - 20 inches (500mm) of concrete would separate each unit. 

 

Certainly innovative in its construction, technology outperformed architectural design criteria as the Dano-modules linear organization created a standard and monotonous double-sided planning module with living spaces on one side and sleeping spaces on the other. Further, the massive concrete megastructure would definitely impede any changes or time-based evolution of the structure. 

Dano module stacking creating a vast formwork

 

Prefabrication experiments - 251 - Operation Breakthrough - 02 - Alcoa's Tension Frame Structure

Although Operation Breakthrough did not radically change the way housing was built in the USA, its enduring legacy as an exercise in industrial collaboration is underscored by the amount and variety of corporate consortiums that proposed housing systems, procurement options and integrated supply chains. George Romney, owing to his background as an industrial lobbyist was able to federate his brand of «cooperative capitalism» evident in partnerships that resemble industrial clusters. Emphasized in a proposal by Alcoa, the Aluminium Company of America, the list of affiliate companies included partners ordinarily portraying a fragmented building industry, however they were brought together to develop a horizontally and vertically integrated business model for a three-tier housing scheme for low-density, medium density and high density through 12 different building possibilities. 

 

Mass-produced service cores and storage wall modules were common to the twelve systems. Each process type displayed a particular approach to cost and product optimization with basic component sharing and modular coordination. Eleven systems in Alcoa’s proposal were conventional interpretations of either panelized or componentized parts over steel or reinforced concrete skeletons.  The most ambitious plan was Alcoa’s tension-framed high-rise system composed of steel mega-trusses cantilevered from a concrete core. Illustrated in the image below in a historic downtown core, it symbolizes the type of a-contextual, technology at all costs, consenting high modern ideologies seen in a majority of Operation Breakthrough’s proposals.

 

The 10-30 story structure’s plan was determined by vertical circulation and mechanical ducts rising with a reinforced concrete core.  Steel cantilevered trusses formed the gallows of this tower-crane building. Cables attached to the mega-cross beams would simplify raising manufactured volumetric dwelling capsules into place. Each volume suspended from the central core could be recessed or cantilevered horizontally or vertically over its neighbouring unit varying the exterior massing.  The reinforced concrete and steel lift literally hung dwelling modules in order to avoid the usual structural constraints associated with stacking and reinforcing individual modular boxes. Edge framed in steel or aluminium, the dwelling units would be completed in a factory and the proposal’s proponents argued that less staging areas would be required on-site making this mega-structure particularly well-suited for dense urban environments. 

Alcoa's Tension Frame Structure illustrated in context and in action

Prefabrication experiments - 250 - Operation Breakthrough - 01 - George Romney

  

Protagonists have had a significant and advocating role in the history of prefabrication. The storied narrative of off-site construction is full of operatives, often coming from parallel industries to architecture and understanding the prospects for increasing productivity in a long-stagnating construction sector. By federating politics, funds and trade associations, industry leaders have been central to channelling romanticized transformations in the construction industry. 

 

The following ten blog posts will look into several selected proposals for Operation Breakthrough (1969), established by the department of Housing and Urban Development as an initiative synchronized with the Fair Housing Act, a framework for affordable housing and its desegregation in America. The main proponent of Operation Breakthrough, George Romney, embodied the posture of an industrial operative encouraging new materials, methods and opportunities for increased efficiencies and productivity in bringing about low-cost housing for all. 

 

From lobbying for Alcoa and aluminum, steering the Automotive Committee for Air Defense or being named Chief Executive of American Motors, George Romney was well versed in manufacturing potentials and parameters. After being nominated by Richard Nixon as Secretary of Housing and Urban Development, Romney initiated one of the largest industrial based cooperative efforts to stimulate new ideas for affordable housing. Linked to his experience as a lobbyist, Romney challenged builders, manufactures and professionals to come up with efficient factory produced building systems. Although none of the proposals were massively produced or built, the program did succeed in showcasing the potential for cross-pollination between industry players. 

 

From over a hundred proposals, 22 systems and eleven test sites were set up to build and showcase prototypes. From conventional to utopian and fascinating proposals Operation Breakthrough highlighted the type of cooperative capitalism that Romney preached for and is underscored by the consortiums set up to achieve each integrated application. At once Inspired by and critical of building programs in post-war Japan and Europe, the program encouraged streamlined procurement, centralized design, mass-production along with the concept of open systems to achieve product variety based on component repetition. Not just another failure in the history of industrialized architecture, some of the proposals were perhaps too innovative for the American public who had comfortably settled in the timber platform frame as the reflection of their basic on-site construction culture of building.

Operation Breakthrough test sites

Prefabrication experiments - 249 - measuring devices - 10 - NENK modular planning grid and floor system

Through funding of infrastructure, large-scale building programs or housing construction stimulus, governments sustain crucial economic and social industrial sectors, especially during periods of crisis. The post World War II building programs in industrialized nations affected and distressed by years of conflict epitomize how governments braced and maintained economies while preserving specific types of production in the event of other conflicts. Optimizing construction, increasing productivity, applying military efficiencies and lessons to modern building are just a few topics that underscored government programs. 

Housing policies provided a framework for monitoring the building industry, highlighted areas that offered opportunities for productive change and mandated building and resource agencies to ensure building construction would benefit from technological advances. The Directorate General of Research and Development at the Ministry of Public Buildings and Works in the United Kingdom in the early 1960s would express this industrial advisory role through their sponsorship of one of the era’s most detailed, flexible and adaptable modular building systems. The NENK system was named after David Nenk, an architect who had been in charge of the Architects and Buildings branch of the Ministry.

The modular steel-framed skeletal kit integrated efficient steel component production within a reticulated geometric lightweight floor system. Assembled from repetitive and lightweight tubes and struts, the floor structure is ultimately a large spanning (36-foot (12m x 12m)) planning grid. Parts are multiplied, aligned and patterned to outline any space.  The basic unit is a 4-foot (1.2 m) inverted pentahedron, a square-based pyramid with a 16 foot-square area (1.44 m²). Placed and lined up on their apexes the bolted square-bases frame the floor grid, while the 2-foot (600mm) height from apex to base structures an open network of webs for passing ductwork, piping or wiring. Tie rods link all the pyramid tips shaping a rigid three-dimensional space frame. The four-foot planning grid was designed for varied column positions: centered on the apex, on each of the base’s vertex corners or at an edge’s mid point, this variability increased the number of design variables. First used to construct army barracks in the 1960s the grid system could be deployed for any use.

Nenk's assembled pentahedron floor modules