Design project overview and implementation

Iron Bridge was conceived of and erected for the extremely pragmatic purpose of allowing travelers and tradesmen to cross the Severn Gorge which is part of the River Severn at Ironbridge Gorge. Prior to its construction, the only way to cross this river was by ferry. Iron Bridge is located in a village of Iron Bridge, which is one of several villages in England's Shropshire. Due to the increasing commercial traffic from the village to other parts of England, the construction of Iron Bridge was viewed as an economic necessity and herald of the modern period of industrialization.

The original designer of the bridge was Thomas Pritchard, whose construction plans were finished in 1775. The rest of the project was largely overseen by Abraham Darby III, Pritchard's design was to utilize cast iron, which Darby went on to finance after the former's death in 1777 (Ironbridge Gorge Museum).

Design

Iron Bridge is approximately 60 meters long and rises about 100 feet above water level at its central span (Images of England). It is the first arch bridge in history that is constructed of cast iron (Haan). A fortuitous occurrence that enabled the construction out of the bridge in this material -- which was previously deemed too costly to carry out -- involved the utilization of a nearby blast furnace which significantly lowered the cost associated with casting the iron. Darby, who was an iron master working in nearby Coalbrookdale, oversaw the casting of the iron at his foundry. Since this bridge was the first of its kind to utilize cast-iron as construction materials, there was no example to base the design and construction procedures of the bridge upon. The smaller pieces of the bridge were cast with the usage of wooden patterns, while the more spacious ribs were cast with excavated moulds in a casting sand. The majority of the pieces of cast metal were made individually, giving the separate pieces an individuality that fused into the form of the bridge.

1.3. Construction

The Iron Bridge was built over a period of time spanning from 1775-1779. Although the bridge was novel in its construction approach due to its utilization of iron casting, it also implemented more traditional methods of construction for this pre-industrial age time period, which included conventional masonry abutments. Darby had to shoulder a cost of 3,000 pounds for the bridge's creation, largely due to the 379 tons of iron required and fees associated with the assemblage of the individual components.

The construction method was primarily based on carpentry, which required fastening the individual pieces cast in iron with woodworking through the means of blind dovetail joints and as well as those with mortise and tenon. Altogether, there were 800 iron castings roughly fit into 12 different cast types. The half-ribs, some of which exceeded five tons, were bolted together at the crown of the arch.

It is noteworthy to mention that after the bridge was completed in 1779 (and available for use in 1781) that several defects in the craftsmanship appeared such as cracks in the cast iron and in the masonry abutments. Many of these defects are attributed to a surfeit of cast iron used in the construction process.

1.4. Significance

The overarching significance of Iron Bridge is attributed to the fact that it was the first arch bridge constructed out of cast iron. As such, the design and construction techniques of Darby were novel, and helped to pave the way for future cast-iron work and structures that were able to not make many of the same mistakes (primarily using too much cast iron) in employing this type of craftsmanship. Despite its obvious defects, Iron Bridge should be commended for the efforts of its designers and workers to further the construction process by utilizing the latest technological advances.

Iron Bridge Bibliography

de Haan, David. "The Iron Bridge -- How Was it Built?." BBC History. 2011. Web. http://www.bbc.co.uk/history/british/victorians/iron_bridge_01.shtml

No author. "Ironbridge Gorge Museum." Web. http://www.ironbridge.org.uk/collections/our_collections/item.asp?cid=5&scid=60&tid=72&itemid=538&imagecollection=category

No author. "Images of England:. English Heritage. 2007. Web. http://www.imagesofengland.org.uk/Details/Default.aspx?id=362203

2. Menai Straits Suspension Bridge.

2.1. Background

In many ways, the history of the Menai Straits Suspension Bridge is the history of its architect, Thomas Telford, who built a number of significant bridges in the United Kingdom including the Craigellachie Bridge, the Conway suspension bridge, and an iron bridge at Buildwas. The construction of this particular bridge was highly utilitarian in its purpose, as it was able to connect Wales to the island of Anglesey. There were significant economic reasons for improving transportation from this island to the mainland, as the valuable cattle that were sold on Wales were traditionally transported by ferry -- a slow method that could yield considerable profit by updating the system of transportation.

2.2. Design

The Menai Straits Suspension Bridge is 98 feet tall, 39 feet wide, and 1,368 feet long. It contains eight arches. One of the principle reasons for the bridge's significance is the fact that it is widely regarded as one of the first modern suspension bridges in existence. There were several aspects of this bridge that were based on the previous work of T.F. Pritchard and ____ Derby, who composed the ____ bridge in 1779 by employing a five cast-iron ribs to build a single semicircular arch. Telford was able to incorporate this concept into the overall design principle of suspension, that hung a roadbed via wrought-iron chains over towers that were mired in a foundation of rock at either end.

2.3. Construction

The Menai Suspension Bridge was built over a period of six years in the early part of the 19th century. There were several ingenious techniques that Telford utilized to erect this edifice, not the least was his propensity for rust-proofing the construction links by pre-treating them in warm linseed oil and drying them by stove. Furthermore, Telford made use of (wrought) iron as a construction tool, which was another technique the architect had previously employed as the following quotation from Colvin denotes. "…as a bridge-builder he was not slow to realize the possibilities of iron, already demonstrated by T.F. Pritchard at Coalbrookdale, and his iron bridge at Buildwas was one of the pioneer structures of its kind" (970).

Additionally, Telford attempted to imbue the Menai Suspension bridge with a distinct flair for aesthetic which was also highly utilitarian. The metal reinforcements on this construct were decorated with a variety of designs and masonry abutments that reflected an artistic sensibility. In addition to utilizing iron with the principle of suspension, Telford's construction techniques were renowned for their picturesque appeal as well, prompting to Kostof to remark that "Telford's distinction was to endow metal bridges with architectural grace" (599).

2.4. Significance

The primary significance attributed to Telford and his work on the Menai Suspension bridge pertains to his merging of the relatively new principle of suspension with construction utilizing iron. Works of iron were becomingly increasingly popular at the time that the architect erected the Menai Suspension Bridge, yet this particular edifice represented iron building on a larger scale than that which was previously done -- particularly than that which was previously done with suspension techniques. There are other significant aspects of Telford's work on this bridge that allude to the grandeur he endowed iron wrought construction that utilized suspension, which the following quotation from Kostof regarding the former's penchant for reinforcing the Menai with pieces of metal makes abundantly clear. "Telford's contribution, again, was to approach this as an architectural problem, making it feasible on a large scale" (599). It is not consequential that subsequent to Telford's work on the Menai Suspension bridge, that his technique of supporting the structure with metal would be refined to the practice of supporting structures with cables or wire ropes. The Menai Suspension Bridge can be considered a forerunner of this technique.

Menai Suspension Bridge Bibliography

Colvin, Howard. A Biographical Dictionary of British Architects: 1600-1840. 3rd Ed. New Haven: Yale University Press, 1995.

Kostof, Spiro. A History of Architecture: Settings and Rituals. Rev ed. New York: Oxford University Press, 1995.

Kovach, Warren. "Menai Strait Bridges." Anglesey History. 2012. Web. http://www.anglesey-history.co.uk/places/bridges/

3. The Crystal Palace (1850-1851)

3.1 Background

Originally, the Crystal Palace was constructed to host the Great Exhibition of 185, which was a glorified showcase of many novel products from countries around the globe. To that end, there were a number of aspects about the building's design and construction that were for aesthetic and not utilitarian purposes. Queen Victoria's husband, Prince Albert, worked in tandem with Henry Cole to organize the exhibit and to facilitate the construction of the building that would house it. The Great Exhibit was conceived of for commercial purposes, so that the Crystal Palace was essentially designed as an economic tool. More important, the exhibit was a testament to man's newfound achievements in the industrial age. The Crystal Palace, therefore, was created as a structure that was modern enough to be demonstrative of the industrial age, and the developing constructions techniques of the time which were primarily the use of iron and plate-glass.

The Crystal Palace was designed by Joseph Paxton. Paxton's design was largely influenced by the greenhouses he remembered from his previous work as a gardener at the Chatsworth House. During his tenure there he initially worked with the technology that he would use on the Crystal Palace, cast place glass that supported the structure of greenhouses in combination with supports made of iron. Paxton was selected as the designer for the Crystal Palace after the committee selecting designers had rejected all of the entries of an international competition to design the structure. Paxton's design was selected in part due to the affordability and the expedience that the materials he proposed to use, iron and glass, could be assembled. Interestingly enough, Paxton was one of a few designers to submit a proposal based on the construction materials of iron and glass (Hitchcock 184). The engineer was Sir William Cubitt. Sir Charles Fox, who founded the engineering company Fox and Henderson, was contracted for the iron work.

3.2 Design

The height of the interior of the Crystal Palace was approximately 39 meters high; the building's length was approximately 564 meters. The width was approximately 139 meters. The palace encompassed 990,000 square feet. The ground floor encompassed 71,794 square meters (Hunt et al. 685).

The most significant aspect regarding the design of the Crystal House is the fact that it was designed via the use of prefabricated materials, most of which were iron. Prefabricated materials are those that can readily be disassembled and taken elsewhere, which allowed for a new mobility and flexibility in the construction process. Additionally, it was due to the use of prefabricated materials which were relatively easy to assemble that the construction process took less than two years. Kostoff writes, "the casting process was geared to prefabrication in bulk, so that members could be shipped to the site ready-made and assembled with ease" (594). The levity of the parts used for this structure allowed for expedient transportation of the materials, which could then be put together in a variety of fashions to suit construction purposes, a fact which Nuttgens alludes to with the following quotation. "there was no reason why it should not be made bigger of smaller, longer or wider" (246).

Another practical innovation credited to Paxton and his work on the Crystal Palace was his employment of an internal skeleton consisting of wrought- and cast-iron beams and stanchions. The designers use of these iron materials helped to usher in the iron age of construction, and was widely replicated by a number of architects and structure in the ensuing years. Iron structures were used to make the framework and columns that supported the Crystal Palace.

A number of the special features that were contained in the Crystal Palace alluded to Paxton's gardening background. An eight meter tall crystal fountain was located near the central exhibition hall; the latter quartered a number of fully grown elm trees in a spacious park. The Palace itself housed several different cascading fountains, a pair of jets approximately 76 meters high to maintain the irrigation system. The water towres were located at opposite ends of the structure (on the south and the north sides, respectively). Three reservoirs were needed to supply the water for the palace and all of its cascades and foliage.

Other design innovations attributed to the Crystal Palace included the installation of public toilets for a facility of this size -- which indubitably added to the supply of water to maintain the building.

In a final tribute to the usefulness of the design principles introduced by Paxton to create the Crystal Palace, it is noteworthy to mention that the entire structure was dismantled following the six-month Great Exhibition and moved to Penge Place that had once sat atop Sydenmahm Hill as part of Penge Common, where it was promptly reconstructed. It continued to host an assortment of festivals and exhibitions until it was eventually destroyed by a fire in 1936.

3.3. Construction

The absence of conventional masonry techniques was readily apparent in the Crystal Palace. The building's roof was glazed and the floor was tiled with clay. Additionally, an the wood-framed glass sheets (Hobhouse 34) were supported by iron latticework, which typified the construction technique of this epoch. The glass was largely provided by a Smethwick, Birmingham company known as the Chance Brothers, which utilized sources of labor as far away as France to fulfill what has been estimated to be approximately 84,000 square meters of glass.

By utilizing the new technology of prefabricated parts, the Crystal Palace was built in roughly six months with the help of 5,000 navvies. Significantly, no more than 2,000 navvies were employed at the construction site at a time, which is a further indication of the degree of efficacy Paxton achieved in his design for the palace. The original construction of the edifice cost 150,000 pounds, which has been estimated at 13.1 million pounds by contemporary standards. After the palace was subsequently rebuilt in Sydenham, the construction cost was additional 1,300,000 pounds -- roughly equivalent to almost 100 million pounds in today's market -- which is due in no small part to the expanded nature of the palace. Desite the fact that many of the same construction materials were used in the updated version of the Crystal Palace, which was rebuilt in 1854, there were definite modifications including the fact that the dimensions of the building had significantly expanded.

Significance

The erection of the Crystal Palace helps to usher in the age of iron in construction. Additionally, its liberal usage of glass helped to distinguish this construct, and the ensuing epoch in construction it heralded, from the Victorian age, a fact attested to by Middleton and Watkin who wrote "iron and glass were not generally applicable to Victorian architectural needs" (359).

Another highly noteworthy aspect about the Crystal Palace is the fact that it was one of the first pieces of construction of this magnitude to utilize prefabricated parts. This innovative construction technique would be instrumental in the speed in which projects could be carried out, and revolutionized the building process for the simple fact that prefabricated parts could be disassembled and transported to erect the same structure in a different location. Worksites become more expediently mechanized, which directly resulted in the large contractors replacing the work typically done by craft guilds. Additionally, prefabricated parts allowed for the implementation of novel internal systems, which Nuttgens refers to by stating, "the needs of industry led to the development of new technical services in heating, ventilation and sanitation, which began to be applied to domestic architecture as well" (245). 430

Lastly, there was a rippling effect of the repercussions of Paxton's innovation in internal skeletons -- consisting of cast and wrought-iron beams and stanchions -- that immensely benefitted Western Civilization as Paxton's technique, which involved the creation of columns out of iron, would be consistently utilized by posterity. These three facets of the building of the Crystal Palace helped to issue a revival in this field following the Gothic Age, "when mass production was beginning to alter the age-old habits of the building industry" (Kostof 594).

Most significantly, however, was the fact that the design, the construction materials, and even the initial purpose of the Crystal Palace -- to host the World's Exhibit of Industry and Commerce and a plethora of new tools utilizing cutting-edge technology for the time -- signaled a transition from the remnants of the Dark Age that the Gothic era symbolized into the industrial revolution: which was a definite precursor to the 20th century. Although considered passe by today's standards, the innovations of iron and plate-glass that Paxton utilized for the Crystal Palace were considered by many to be the most radical advance in building material technology since the Roman practice of utilizing concrete in construction (Kostoff 595). During the 1850's the world was definitely changing, and one of the most tangible markers of that fact was the transportable construction materials associated with the Crystal Palace. Although the technique for plate-glass was developed in the 1840's, it was not until the 1850's that glass glazing, such as that found on the roof of the Crystal Palace, was made possible alongside other fairly modern innovations such as the construction of highways and the expansion of railroads and steam engine use, all of which typified the industrial age.

Crystal Palace Bibliography

Hitchcock, Henry-Russell. Architecture: Nineteenth and Twentieth Centuries. Harmondsworth: Penguin Books. 1977. Print.

Hobhouse, Hermione. The Crystal Palace and the Great Exhibition of the Works of Industry of All Nations. London: Athlone. 2002. Print.

Hunt, Lynn, Martin, Thomas, Rosenwein, Barbara. The Making of the West: Peoples and Cultures. New York: Bedford/St. Martin's Press. 2009. Print.

Kostof, Spiro. A History of Architecture: Settings and Rituals. Rev ed. New York: Oxford University Press, 1995.

4. Eiffel Tower (1887-1889)

4.1. Background

The Eiffel Tower was initially conceived with visions of grandeur. This construct was specifically built as one of the primary attractions at the 1889 World Exhibition in Paris -- during which time the tower enjoyed the status as the world's tallest structure. To that extent, the building was chiefly erected for the sake of novelty and to attract attention to the exhibition. To construct the edifice, a contest was held in 1886 in which over 100 designers and architecture firms competed for the prize of being able to build the tower. The winner was Gustave Eiffel, whose namesake the monument bears and who had created a career prior to the contest building viaducts and railways around France through the employment of arched wrought-iron bridges.

4.2. Design

The antenna pinnacle of the Eiffel Tower is approximately 300 meter high (King 175); the roof of the structure is just over 300 meters. The initial conception for the design of an observation tower of this magnitude can be traced to Richard Trevithick, who proposed such a structure as early as 1832 (Steiner 117). Trevithick's original design included cast-iron panels and an elevator located in the center of the structure.

Other inspirations for the design of the Eiffel Tower involved the work of Henri de Dion on the Galerie des Machines. In particular, Eiffel patterned the base of his tower on the rigid frame truss of de Dion's work "in which there is complete union of 'staunchion' and 'beam'" (Steiner 95) and for which the foundation weight was "less than that of a stone wall nine meters high" (Steiner 119). This design principle enabled the tower to incorporate a degree of levity that did not sacrifice any of its strength and durability. Of this effect Echols states, "the tower was designed so that the structure applied a foundation load no greater than that of a person sitting in a chair per square unit of measure" (229).

A particularly eminent feature regarding the design of the Eiffle Tower which is immediately noticeable is its open spaces, which were configured by Eiffle to account for the presence of the wind -- which could be considerable in that part of France, particularly in light of the tower's looming height. Echols states, "Eiffel resolved this potential problem by providing diagonal framing within the structure, and by incorporating a system of windbreaks" (229). These measures were able to minimize the need for the structure's wind resistance, particularly due to its open spaces which allows the wind to harmlessly pass through without sacrificing stability or structural integrity of the tower. While some have argued that the unique design of the Eiffel tower was created for aesthetic purposes, Echols reveals, "the mathematical precision of the tower's components and the lightness of its lacy design made the tower a sophisticated product much ahead of its time" (229).

4.3. Construction

The Eiffel Tower cost approximately 260,000 pounds to build; most of those funds were paid by the government of France and by Eiffel himself (Ryan). As a testament to the efficacy of the design advocated by Eiffel, the construction of the Eiffel tower took less than two years. According to Echols "under the architectural preparation of Maurice Koechlin and the guidance of structural calculations by Emile Nougier, workers began construction on the Eiffel Tower on 26 January 1887" (229). The frame of the Eiffel Tower was built with the employment of four piers and sixteen iron ribs, each of which was placed upon a foundation composed of concrete and stone. The foundation -- which borrowed principles from de Dion -- utilized a stratum of plastic clay that was placed 16 meters beneath the ground and solidified with sand and gravel. The foundation was planned in accordance to the particular needs of the soil on the building site.

A number of the more important points in the construction of this edifice have been denoted by Steiner (Steiner 199-20). Derricks and windlasses were used to build the initial 25 meters of the tower in cantilever. Eiffel's men used a timber scaffolding as the basis for the first level, which structurally bonded the piers, and used the scaffolding in conjunction with piered elevators to raise the rest of the construction materials.

The construction process consisted of building four "legs," which would eventually be joined together to provide the basis for the tower to stand upon. The legs were built atop concrete slabs, the slabs were installed via the means of compressed-air caissons [21]. The builders placed a block of limestone on each of the slabs to provide a "shoe" for the ironwork of the legs.

What was remarkable amount the iron work was the fact that most of the pieces utilized for the legs of the Eiffel Tower were actually created offsite and fitted together before being transported to construction site. This was largely due to the precision of Eiffel's designing, which denoted the exact specifications of the materials that would merge together to form the legs. With the majority of the 18,038 pieces of puddle iron (23) arriving to the construction site in sub-assemblies, the pieces were bolted together and later riveted to form the legs.

One of the critical components in building the tower was the joining of the four separate legs that holds it together. Provisions were made to do so with the use of hydraulic jacks attached to the base of each of the legs

4.4. Significance

There is no disputing the notoriety of the Eiffel Tower, which was attended by almost two million viewers during the Paris Centennial Exposition of 1889 (Plumley). The most significant aspect of the Eiffel Tower was the brief amount of time that a structure of this magnitude was constructed in. The efficacy of Eiffel's design process was a testimony to the changing times and the adaptive technologies of iron and metal works that allowed builders to erect structures more efficiently. The architect built the Eiffel Tower specifically to reflect the changing times and the technologies that shaped them (Loyrette 116).

Eiffel Tower Bibliography

Echols, Gordon. "Eiffel Tower." In International Dictionary of Architects and Architecture, ed. Randall J. Van Vynckt. 2 Vols. Volume 2: Architecture, 227-29. Detroit: St. James Press, 1993.

King, Mary. A History of Modern Architecture. New York: Hill & Wang. 1967.

Loyrette, Henri. Gustave Eiffel. New York: Rizzoli. Print. 1985.