Prefabrication experiments - 248 - measuring devices – 09 – Aircrafts and the Wonder Arch

Proportions and exact units for composing, measuring or coordinating architecture and building systems are normally articulated to functional requirements for fitting or harmonizing shapes, pieces or furnishings. These elements outline part-to-whole dimensions while determining standards, patterns and types over time. While not an explicitly categorized unit of measure, large spans serving the three military branches, army, navy, air force, in a way charted structural geometries as a function of wingspans, ship building sizes or spaces for armoury protection.   

Aircraft wingspan, above all, shaped architectural exploration and engineering invention to achieve the required open and free spans while reducing component and building dead loads. Konrad Wachsmann, Buckminster Fuller and Pier Luigi Nervi’s work underscored how military requirements influenced modern architectural and structural forms, specifically in the understanding of space frames, domes and form resistant structural shapes. All three inventors explored spanning large distances using reticulated structures made from prefabricated, manageable and arithmetically coordinated parts. 

Industrial development was an equally influencing factor in devising pre-calculated and prefabricated kits for large-spanning hangars or sheds. Manufactured for various storage needs, the steel barrel vaulted Wonder Buildings made use of their permanent versatile arched systems to invent formwork for a large-scale bomb-proof air-craft hangar. The wonder building’s semi-circular barrel vault is a compressive shape that reduces tensile forces and makes use of corrugations to offset potential localized buckling within the vault’s thickness. The undulated shape performs like a folded plate while its overall transversal curvature is basically a parabolic shell, which reduces horizontal thrust and bending through vertical rise. 

Known as the «Wonder Arch», the framework is made from transportable corrugated steel rib strips that are juxtaposed and aligned to create the half-cylinder hangar plan. Each narrow width curvature is composed of 9 identical steel panel voussoirs (circular segments) affixed in a semi-circular pattern.  The structural arched ribs are then bolted to the adjacent ones in a longitudinal pattern tailored to any length. Once fixed together, the building system is complete and could be used as is as a type of Quonset hangar. The Wonder Arch, however, was designed as permanent formwork. 500mm of reinforced concrete was poured in a perpendicular corrugated pattern over the vault to create a reinforcing trellis and make it bomb proof.  The Wonder arch was deployed during the Vietnam War and was a formidable structural achievement in bomb resistant shell structures. 

Wonder Arch ribbed section

Prefabrication experiments - 247 - measuring devices – 08 – Le Corbusier’s Modulor

Equally applied in traditional architecture and construction or via the invention of new manufacturing methods, standardizing and unifying measuring units and formulae make it easier to share knowledge about building or determining dimensional or functional requirements. Classifying ergonomic principles and their factorization into larger or smaller parts is the basis of architectural composition. The golden section “rectangle d’OR” is the prime example of a mathematical premise employed for the analysis of classical architecture and its geometric harmonic relations. The golden ratio (1 : 1.618) can be observed multiplied or divided into regulating proportions for decorative elements, overall building dimensions as well as structural proportions. 

Associated with refuting ornament and classical composition, these underlying geometric and numeric themes were hidden within modern architecture’s dogmas. Replaced and inspired by production standards, modernists concealed their classical penchants for the same Palladian ideal shapes and plans behind their new regulating orders. Sometimes these principles were derived from traditional architecture, such as Schindler’s use of the Japanese tatami or the Ken. 

Perhaps the most famous modern unit of measure, Le Corbusier’s Modulor (Module + Or) was specifically articulated to the concept of standardizing industrial processes to conceive architectural spaces that would be easily produced by modern methods. Based on his idealized understanding of human form which he deconstructed according to the golden ratio determining his basic sets of human to space configurations. The 226 cm height of the ideal man with his hand stretched out standardized floor to ceiling dimensions for a regular room or space. This 226 cm height was a multiple of the 1 to 1.618 golden ratio and exposed the architect’s perplexing relationship with classical proportions and themes.  Divided into multiples or different scales for directing a logical sequence to each particular design, the Modulor was for the iconic modern architect a type of slide-rule for encoded design skilfulness. Le Corbusier himself wrote about the Modulor in modest and humble terms. It was a tool for designing without having to refer or think about dimensioning. The Modulor allowed good design and its standardisation to be achieved efficiently; sitting, leaning, standing, stretching and all interrelated human activities defined by a harmonic measuring device. 

Le Corbusier's Modulor

Prefabrication experiments - 246 - measuring devices – 07 – Gridded measurement system for construction materials

Measurement tools and principles in architecture and construction invoke both the patrician idea of classical proportioning and all manner of tricks of the trade to help in anchoring or positioning building components and elements. Particularly within the spectrum of do-it-yourself aids, many geometric overlays and templates exist to simplify calculations and assembly of premade pieces. The 4x8 modular sheet is one specific example determining building dimensions and their constituting units. Modular production of building products is the basis for categorizing layers or systems and to ensure that components fit together in a rational manner. 

A gamut of apparatuses, hangers, supports, pegs are available in any hardware store. These anchors of every size and shape are precisely profiled to the dimensions and thicknesses of components such as joists and studs to standardize their joinery. Industrialized connectors pre-dimensioned according to materials have made the light timber frame the system of choice for do-it-yourself builders. 

Further experiments have followed elementary dimensional standardization to imprint materials with notes, grids and cut-lines to reduce on-site estimations and increase precision. A patented system by inventor Glenn Robell (US Patent US5673489A) proposed that all types of surface and sheet materials used in construction, from sheetrock to plywood and cement panels, be manufactured with a graphic veneer which inscribed onto the material surface a system for measuring. In a sense this gridded measurement system would be equivalent to adhering a large piece of graph paper over the material. This grid could include any number of measurement scales and notations to inform users of elements to avoid, such as nailing to close to edges or other constraints and care taking measures. The information could normalized and conform with structural or even code requirements. A simple example: bold lines could represent structural spacing of studs, while lighter lines could represent nailing / screwing distances. 

The precise gauging and cutting of materials on a job site is a particular problem for novices or self-builders. Robell’s method suggests specific / generic lines of productions for different building types and methods with different notations (metric and imperial) to imprint dimensional specifications on a material or product. 

US5673489A patent drawing

Prefabrication experiments - 245 - measuring devices – 06 – Dimensional Coordination and Elementhus

The pursuit of low-cost, quality housing has determined government programs and funded research activities with similar frameworks in wide-ranging settings. Often championed by large corporations or philanthropists much of this compiled research shaped and mapped out the construction industry’s progress. In the years following World War 2, in Sweden, large construction industry leaders such as Skanska financed the Home Building Research Corporation in an attempt to democratize cheaper but improved housing. This investigation considered modular coordination as the primordial standardization to bring about large quantities and streamlined production methods.  

Architects Lennart Bergvall and Erik Dahlberg were charged with the task of reporting back to the Research Corporation with specific gauges and metrics to help reform housing production. Their reports became the basis of additional investigation and controls published by the Modular Building Group in the 1960s. Further, out of this research partnership, the architects founded AB Elementhus, a factory built housing system based on the basic principles of modular and dimensional coordination: the assembly of a few continuously produced and interchangeable building elements and parts. 

Inspired by previous and similar studies, principally Bemis’ 100mm (4-inch) building matrix, the Elementhus components used a 200mm module (8-inch). Nominal 200mm x 200mm vertical and horizontal box beams were developed to structure walls, floors and roofs. The box beams, rectangular prisms cut to varied lengths, were laminated from hardwood veneer plywood and a sawdust/woodchip insulating core. Each box beams’ extrados and intrados flange was tongue and grooved and simply attached with dowels. The kit included bearing and spanning units and shorter lengths for below or above windows or around other openings. The patented assembly method and dimensions regulated the whole modular grid for arranging housing patterns. The factory produced nearly three houses per day and a total of 18 000 housing units during its operation. An emblem of streamlined manufacturing processes with a minimum number of interchangeable parts, the process used 100% of all its timber, for the panels, their insulation and fuel for heating and running machinery. Elementhus idealized modular coordination and symbolizes the type of dimensional and modular theories that were applied to the problem of accessible housing. 

Elementhus components

Prefabrication experiments - 244 - measuring devices - 05 – Transport and the mobile home

Ordering tenets in architecture are based on geometric compositions. Regulating lines and guides generate shapes and their interaction. Guilds and master builders shared knowledge and rules for modulating building and structural components. These ruling lineaments developed master works and their geometric indications: the golden section in classic architecture, the tatami grid as the datum of traditional Japanese dwellings or the Fibonacci series as the basis for subdividing wholes into smaller parts. Industrialization introduced manufacturing methods as rules for defining and normalizing precise measurements. A notable example of an organizing principle in industrial architecture was the standardization of shipping dimensions from rail to truck and to international naval shipping. 

The containerization of shipping has been a regulating force in dimensioning parts and components for building. The Iso standard shipping container and the standardized shipping pallet coordinate and optimize intermodal transport. Determined by the evolution of railroad dimensions and later by the regulation of truck transport the 2.4-meter wide by 4.4-meter high (including wheel height) and 10-meter long standard circumscribed the mobile home industry. This towing capacity and limitation informed the industry’s early development until Elmer Frey challenged this norm with his 10-foot singlewide (3 meters) in 1954. Its transport was subsequently permitted as an oversized-load requiring special permits. The 10-foot singlewides and later the 12-foot models (3.6 meters) Frey produced were more flexible and made it easier to arrange and define day and night spaces. 

Both early mobile homes and today’s shipping container homes share the common history of shipping’s dimensional standardization. If the hand regulated the modular brick as many have written, then road widths and possible wheelbase structures shaped the modern mobile home. The industry’s progress in truck transport both in terms of towing capacity and highway breadths made it possible for mobile homes to become wider, 14-foot and 20-foot models became possible in the 1970s and 80s. While the early mobile home was a definite result of transport efficacy, today’s manufactured house continues to be determined by shipping concerns - less to do with width and more to do with weight, structure and manufacturing details and parameters. 

An example of a 2.4-meter singlewide (late 1930s - early 1940s Shult Trailers)