(Above image top left by Ajmir Kandola, Wikimedia Commons)

If you have been following me, you will know that I am counting down the decades, one per month, having started in January with 120 year-old structures completed in 1897 and aiming to finish with 10-year old structures in December.

This month's selection include some pretty well known ones, and certainly a few well known designers. I hope you find them interesting.  

1 Geodesic Dome by Buckminster Fuller, Montreal, Canada

I had to start with this one!  The famous Montreal Biosphere started life as the American Pavilion at Expo '67 in Montreal and is by the famous American architect Richard Buckminster Fuller.  He has effectively given his name to such structures, often simply called a Buckminster Fuller Dome.

Montreal Biosphere
(Image source: Wikimedia Commons, Hamidreza)

The futuristic structure caught the imagination of architects and engineers around the world, including the young Norman Foster who apparently employed Fuller as a consultant for a period.

Buckminster Fuller was in fact much more than an architect, and is also known as an inventor, theorist, and writer, but his claim to fame is undoubtedly the geodesic dome which he patented. The early small scale ones used aluminium aircraft tubing with a plastic skin, but they became more impressive from there, leading ultimately to this one, on which he collaborated with architect Shoji Sadao to design the U.S. Pavilion at the 1967 World Fair in Montreal.

The geodesic system divides a spherical surface into equal triangles resulting in a form that is structurally efficient, strong, lightweight and easy to construct. Buckminster Fuller's original idea was to use this system to mass produce simple, low cost, efficient and lightweight modular housing units using much smaller domes, but apart from a set commissioned by the US military, this idea never really took off. Instead, several large domes were constructed and this one is perhaps the most famous.

The building originally formed an enclosed structure of steel and acrylic cells, 76m in diameter and 62m high. For those who know about such things, it is a Class 1, Frequency 16 Icosahedron. The acrylic cladding system initially included a complex sun-shading arrangement to control the internal temperature, which was an attempt by the architect to reflect the same biological processes that the human body relies on to maintain its internal temperature, but it failed to work properly and was eventually disabled.

During structural renovations in May 1976, a fire burned away the building's transparent acrylic skin, but the steel truss structure remained. In August 1990, Environment Canada purchased the site for $17.5 million to turn it into an interactive museum showcasing and exploring the water ecosystems of the Great Lakes-Saint Lawrence River regions. The museum was inaugurated in 1995 as a water museum, and is a set of enclosed buildings designed by Éric Gauthier, inside the original steel skeleton.

The sheer visual drama and excitement of Fuller's geodesic domes have been celebrated in popular culture, including the 1967 James Bond movie, You Only Live Twice.

2 Habitat 67. Montreal, Canada

Sticking with Expo 67 in Montreal, I am intrigued by this modular housing complex which uses precast concrete boxes arranged on top of each other. Designed by the Israeli/Canadian architect Moshe Safdie, it was originally conceived for his master's thesis at McGill University.  After leaving to work with Louis Kahn in Philadelphia, Safdie was approached by his former tutor to develop a proposal for Expo 67 based on his Master's thesis. In spite of his youth and inexperience, he was awarded the project – an opportunity he later described as "an amazing fairy tale".

Habitat 67
 (Image source: Wikimedia Commons,  by Skeezix1000)

Habitat 67 comprises 354 identical, prefabricated concrete boxes arranged in various combinations, reaching up to 12 stories in height. Together these units create 146 residences of varying sizes and configurations, each formed from between one and eight linked concrete units. The complex originally contained 158 apartments, but several apartments have since been joined to create larger units, reducing the total number.

The development was designed to integrate the benefits of suburban homes with the economics and density of a modern urban apartment building. It was believed to illustrate the new type of development that people would live in as cities became increasingly crowded around the world. (How different that high density concept looks today!) However, Safdie's goal for the project to be affordable housing largely failed since demand for the units made them more expensive than originally envisaged. In addition, the existing structure was originally meant to be the first phase of a much larger complex, but the relatively high unit cost meant that enlargement of the scheme never occurred. 

Housing was one of the main themes of Expo 67, so Habitat 67 became a thematic pavilion visited by thousands of visitors from around the world. During the expo, it also served as the temporary residence of the many dignitaries visiting Montreal.

Amazing what you can do with a simple concrete box!

(Image source: Wikimedia Commons, by rokker)

3 German Pavilion for Expo 67, Montreal, by Frei Otto.

And we have one other notable structure from Expo 67. (These events tend to produce extraordinary structures, but arguably none more than this one in 1967.) I could not really leave this one out as it is one of Frei Otto's most famous tension net structures, and perhaps the one that initially brought him worldwide recognition. He is, of course, well known now for his tensile canopies and cable net roofs, including the structures for the Munich Olympics in 1972 which, like the Expo structure, were engineered by Leonhardt, and he had been experimenting with tensile roof structures for some time prior to the World Fair in 1967. That event in Montreal brought together such an extraordinary collection of futuristic structures in one place, including my previous two examples, and in many ways, the Expo 67 pavilion was a turning point in Otto's career.

Otto’s fascination with tensile structures dates back to his experiences during the Second World War. Captured and imprisoned in a POW camp in France, he worked on constructing tent-like shelters using the limited material resources at his disposal. After the war ended, he converted these ideas into a full-time architectural pursuit, investigating the potential application of minimal resource tensile structures on an industrial scale. His simple design idea of creating an architecture based on resource conservation, structural intelligence, and construction efficiency found favour in the stringent economic times of the 1950s and 60s.

Sensitive to the need for building adaptability, Otto also promoted the concept of using temporary structures that were easy to assemble, and just as easy to take down and recycle. With few components, all of which could be adapted to virtually any site and terrain condition, his systems of masts and canopies were a radical simplification of traditional building methods that valued rigidity and permanence. Once it had been designed and pre-fabricated, the German Pavilion in Montreal was assembled on-site in a mere six weeks, only to be dismantled shortly after the fair.

(This 1967 video shows a remarkable aerial view of the tent-like Pavilion, before sweeping over other fascinating structures that featured at the Expo)

The canopy itself was constructed of a pre-stressed steel cable mesh covered in a translucent, polyester textile membrane. At several points within the perimeter of the pavilion, the surface of the tent dipped to the ground in dramatic funnel-like cavities, only to rise up again to the soaring height of the masts. Otto’s system was technologically sophisticated yet conceptually simple; the pavilion was little more than a big tent – arguably mankind’s most primitive structure!

Throughout his career, Otto always built physical models to determine the optimum shape of a form and to test its behaviour. Engineers in his studio were early adopters of computers for structural analysis of his designs, but the basic input data for these calculations came from the physical form-finding models.

4 Liverpool Metropolitan Cathedral, UK

Officially known as the Metropolitan Cathedral of Christ the King but often referred to fondly as "Paddy's Wigwam", this building is the seat of the Archbishop of Liverpool and the mother church of the Roman Catholic Archdiocese of Liverpool.

Earlier proposals for the cathedral included one by Sir Edwin Lutyens (1869–1944) who was commissioned to provide a grand design in response to the Neo-gothic Anglican cathedral designed by Giles Gilbert Scott, which was being built further along Hope Street. Lutyens' design was intended to create a massive structure that would have become the second-largest church in the world. It would have had the world's largest dome, with a diameter of 51m, compared to the 42m diameter on St. Peter's Basilica in the Vatican City. Construction of the Lutyens design began in 1933, but funds were tight, and in 1941 the restrictions of World War II and rising costs forced construction to stop. In 1956, work recommenced on the crypt, which was finished in 1958, but thereafter, Lutyens' design for the Cathedral was considered too costly and was abandoned with only the crypt complete. 

After the ambitious design by Lutyens fell through, Adrian Gilbert Scott, brother of Giles Gilbert Scott (architect of the Anglican Cathedral), was commissioned in 1953 to work on a smaller cathedral design with a much smaller budget. He proposed a scaled-down version of Lutyens' building, retaining the massive dome, but his plans were criticised and the building did not go ahead.

The present Cathedral was designed by Sir Frederick Gibberd (1908–84) who won a design competition held in 1959. The requirement was firstly to accommodate a congregation of 3,000 (later reduced to 2,000) all of whom should be able to see the altar in order that they could be more involved in the celebration of the Mass, and secondly for the Lutyens crypt to be incorporated in the structure. Gibberd achieved these requirements by designing a circular building with the altar at its centre, and by transforming the roof of the crypt into an elevated platform, with the cathedral at one end. The construction contract was let to Taylor Woodrow. Work began in October 1962 and was completed less than five years later. It was consecrated on the Feast of Pentecost in May 1967.

Liverpool Metropolitan Cathedral
(Image source: Wikimedia Commons by Chowells)

The Cathedral is built in concrete with stone cladding and an aluminium roof covering. It has a circular plan with a diameter of 59m, and with 13 chapels around its perimeter. The conical shape is surmounted by a tower in the shape of a truncated cone, supported by 16 boomerang-shaped concrete trusses held together by two ring beams, one at the bend line and one at the top. Flying buttresses are attached to the trusses, giving the cathedral its tent-like appearance. Rising from the upper ring beam is a lantern tower, containing windows of stained glass.

Unfortunately, soon after its opening, it began to exhibit problems, including leaks in the aluminium roof and defects on the mosaic tiles, which began to come away from the concrete ribs. Repairs have been carried out, but the mosaic tiles were difficult to repair and were replaced with glass-reinforced plastic, giving it a thicker appearance, and the aluminium in the lantern was replaced by stainless steel. But in spite of these difficulties the building remains popular today, and is one of Liverpool's most recognisable landmarks.

5 Reliance Controls Factory, Swindon, UK

This simple factory building may seem unremarkable, but it defines something of a turning point in industrial architecture and is a showcase for efficient and economic structural engineering. The building was designed by Team 4, the famous architectural practice set up by Norman Foster and Richard Rogers, with structural engineering by Anthony Hunt Associates.

Reliance Controls Factory
(Image:Foster + Partners)

In the 1960s there was still a strong tradition in industrial architecture of the segregation between management and workers, but for the Reliance Controls Factory, the designers sought to introduce a radical new approach. The result was a democratic pavilion where management and employees shared a single entrance and a single restaurant, a practice unheard of at the time. With the electronics industry then in its infancy, the building was regarded as a light-industrial prototype, its organisation and design implying new democratic standards in the workplace.

Reliance Controls Factory detail
(Image: Foster + Partners)

The client's brief demanded economy and speed of construction. There were strict cost guidelines and a requirement that the building be ready within ten months: it was finished early and to budget. 

The designers set out to deliver a simple low cost flat roof office/assembly building using ‘off the shelf’ standard products. In fact, the structure uses only four elements as a welded steel frame: column and crosshead, main beam, secondary beam and diagonal bracing. Profiled steel sheet cladding spans 3.6m top to bottom for the walls (considered daring at the time), and the profile steel roof decking is double fixed to eliminate plan bracing. All services run through the floor slab via a central duct, and the whole building was designed for simple future extension. (In fact it was subsequently extended with minimum disruption.)

The idea of the building was clearly expressed in its structure, with everything contained within the grid of the steel frame and sheltered by one large roof. The emphasis on prefabricated metal components allowed the structure to be built in less than a year at very low cost. The structural steelwork was celebrated both inside and out. Indeed the structural members were painted white to contrast with the grey, plastic-coated, corrugated-steel cladding. 

The building is considered to be an early example of so-called High Tech Architecture, or Structural Expressionism that emerged in the early 1970's. This is an architectural style that incorporated elements of high-tech industry and technology into building design. 

6 I-35W Mississippi Bridge, Minneapolis, USA

I was not going to include any particularly exciting or dramatic bridge structures this month, as although I could find several bridges completed in 1967 none stood out to me as particularly remarkable.

However, this bridge will be known to many of you because of its sudden and tragic collapse during the evening rush hour ten years ago, so I felt that it needed a mention.

The bridge was located in Minneapolis, Minnesota's largest city, and was designed by Sverdrup & Parcelto. Construction began in 1964 and the bridge was completed and opened to traffic in 1967. The bridge had fourteen spans in all, with a 3-span continuous steel truss girder structure crossing the river with a main span of 140 metres and two side spans of 81 metres. The depth of the two main trusses, one on either side, varied from 18.3 metres above the supports down to 11 metres at midspan and 9 metres at the outer ends. At the time of the collapse in 2007, the bridge was Minnesota's third busiest, carrying 140,000 vehicles per day.
I35W Bridge
(Image source: Wikimedia Commons, Todd Murray)

At 6:05pm on Wednesday, August 1, 2007, with rush hour bridge traffic moving slowly across the bridge, maintenance works having reduced the number of available traffic lanes, the central span of the bridge suddenly gave way, followed by the adjoining spans. The structure and deck collapsed into the river and onto the riverbanks below, the south part toppling 25m eastward in the process.

111 vehicles were involved, sending their occupants and 18 construction workers into the river and onto the river banks below. Northern sections fell onto railways, landing on three unoccupied and stationary freight trains. 13 people were killed and 145 injured.

I could write a whole lot more about the causes of this collapse which are now fairly well known , but this is not the place for that. You might take a look at the short video obtained from a nearby security camera which captures the horror of the event:

Within a few days of the collapse, the Minnesota Department of Transportation planned a replacement bridge, the I-35W Saint Anthony Falls Bridge, which was very rapidly designed and constructed.  It opened to traffic just over a year later on September 18, 2008, which just goes to show what can be done when needs must.
I35W Bridge post collapse (Image source: Wikimedia Commons, Tony Webster)


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