Coöp Himmelb(l)au

The “maverick Viennese partnership” Coöp Himmelb(l)au (literally, the “Sky Blue Cooperative”) was established in May 1968 by Wolf D. Prix and Helmut Swiczinsky. Their architecture has been called expressionistic, spontaneous, irrational—all characteristic of the Deconstructivism that followed them. Why should they be included in an encyclopedia of architectural feats? Because they were the archetypal challengers, not altogether without success, of orthodox architectural thinking at the end of the twentieth century.

Until the late 1970s, when they took a “technological stance,” drawing “airy therapeutic machines,” their practice focused mainly on interior architecture. Twenty years later they unabashedly aimed to unsettle and create unrest, reacting mostly against

the history-plundering aspects of postmodernism. Such contradiction of what were held to be architecture’s “eternal truths”—harmony, unity, and clarity—must be seen as neo-Mannerism, playing it for kicks, so to speak. Their interior spaces and elements of their facades, thrust through with girders, giant needles, or spikes, create esthetic emotions of discomfort and disturbance rather than once-prized beauty. Someone has described their work as “an architecture of the chest spiked by the steering column.”

Early designs of this kind included the Reiss Bar (1977) in Vienna, whose interior is split by a fissure ostensibly held together by massive turnbuckles. The front door is pierced by two huge spikes. The Red Angel Bar (1980–1981), also in Vienna, uses “tin, steel and glass block [to] embody the form and soul of the hovering angel, the wails of the sinners, and the protests of an antiestablishment youth.” To enclose the space, wings spread out from the diagonal spike that forms the structural spine—a frequent motif in their buildings.
This approach climaxed in a number of projects and buildings, including a prizewinning master plan for the new town of Melun-Senart, near Paris, France (1987), a proposed city center for St. Polten, Austria (1989–1990)—urban design schemes in which the excitement of polemic eventually gave place to the pragmatics of city bylaws—and a hilltop studio for Anselm Kiefer in Buchen, Germany (1990). It can be found also in the Funder Factory 3 in St. Veit/Glan, Austria (1988–1989). There, Coöp Himmelb(l)au “dissolved” what might easily have been a boring long-span industrial shed into “an amalgam of more sculptural, functionally differentiated elements,” with spectacular results: a main building with a red entrance canopy, a power plant with three 75-foot-high (23-meter) chimneys that lurch drunkenly, and an assembly-line building whose corner is an exploding structure of steel and glass. The same dynamism may also be seen in a strangely compatible penthouse addition (1984–1988) to a neoclassical building in Vienna. It has been described as “biomorphic … an exposed exoskeletal structure” whose boardroom looks like a “dissected ribcage.” Outside, it looks very much like a huge beetle with spread wings, scrabbling for a foothold on the roof.
In June 1989 Coöp Himmelb(l)au won (with locally based Morphosis and Burton and Spitz) first prize for a pavilion in a Los Angeles performing arts park. Opening an office in the U.S. city, they secured several commissions in southern California. In 1993 they won a competition for the Jussieu Campus Library of the University of Paris and were commissioned to design the east pavilion of the Groninger Museum, Groningen, the Netherlands, completed in 1995. The following year they represented Austria at the International Architecture Biennale in Venice. They have recently completed the eight-theater UFA Cinema Center in Dresden, Germany (1993–1998), and the SEG Apartment Tower in Vienna, a complex of residential and other towers and a school (1994–1998). Working with a staff of twenty-seven, they undertook a project to convert the shell of a former Vienna gasometer into a multipurpose building; another complex in Hamburg, Germany; an entertainment center in Guadalajara, Mexico; and a building for Expo 2001 in Biel, Switzerland, all between 1995 and 2000.

Further reading

Gruenberg, Oliver, Robert Hahn, and Doris Knecht, eds. 1988. Coop Himmelb(l)au: Power of the City. Darmstadt, Germany: G. Büchner.

Peter Noever, ed. 1991. Architecture in Transition: Between Deconstruction and New Modernism. Munich: Prestel.

Steinbauer, Jo, and Roswitha Prix, trans. 1983. Coop Himmelb(l)au, Architecture Is Now: Projects, (Un)buildings, Actions, Statements, Sketches, Commentaries, 1968–1983. New York: Rizzoli.

Confederation Bridge, Prince Edward Island Canada

The 8-mile-long (12.9-kilometer) Confederation Bridge, which crosses the Northumberland Strait between Jourimain Island, New Brunswick, and Borden-Carleton on Prince Edward Island, is the longest bridge over ice-covered water in the world. Its daring conception, the quality of its engineering, and the logistics of its realization are among the factors that make it one of the great constructional feats of the twentieth century. The project is also environmentally, politically, and culturally significant.

Prince Edward Island, on Canada’s Atlantic coast, is the nation’s smallest province, with a population of around 130,000. It lies in the Gulf of St. Lawrence at an average of 15 miles (24 kilometers) across the strait from mainland New Brunswick and Nova Scotia. The strait freezes for up to three months every year, and links with the island historically were expensive, freight and passengers having to be moved by ferry. In 1912 the Canadian government decided to build a railcar ferry to run between Borden-Carleton and Cape Tormentine, New Brunswick, and the Prince Edward Irland was commissioned in 1917. In the first year she made only 506 round-trips. In 1938, as a response to wider automobile ownership, a car deck was added, and the vessel continued to operate until 1969. The subsequent decades saw improvements to the service, and new ferries now make the seventy-five-minute crossing at hour-and-a-half intervals. Prince Edward Island has become a vacation resort and by the beginning of the 1990s tourism had joined commercial fishing and agriculture as a mainstay of its economy.
Between 1982 and 1986 several consortia approached Public Works Canada (PWC) with proposals for a privately financed permanent link between the island and the mainland. Three were for bridges (the first estimated at Can$640 million), one for a tunnel, and another for a combined causeway-tunnel-bridge link. In December 1986, the central government instructed PWC to commission feasibility studies of fixed-link alternatives. By June 1987 twelve expressions of interest were in hand, and the acceptance of Strait Crossing’s proposal was announced in

December 1992. Strait Crossing Development (SCD), a consortium of Janin Atlas, Ballast Nedam Canada, and Strait Crossing, was established to develop, finance, build, and operate the Confederation Bridge.

The proposal, put before the island population in a plebiscite the following January, was generally supported, but lobster fishermen and conservationists raised concerns that led to protracted delays. Their conservation measures won for the contractors the Canadian Construction Association’s 1994 Environmental Achievement Award. Working with the Canadian Wildlife Service, SCD provided nesting platforms for endangered osprey in Cape Jourimain National Wildlife Area. The consortium also initiated a Lobster Habitat Enhancement Program, using dredged material to establish new lobster grounds in three formerly nonproductive locations. Construction work commenced in mid-July 1995.
The shore-to-shore Confederation Bridge consists of three parts. The 1,980-foot (0.6-kilometer) east approach from Borden-Carleton and the 4,290-foot (1.3-kilometer) west approach from Jourimain Island, New Brunswick, join the 6.9-mile (11-kilometer) main bridge across the narrowest part of the Northumberland Strait. Its two-lane carriageway rises from 120 feet (40 meters) to 180 feet (60 meters) above the water at the central navigation span. The bridge takes about ten minutes to cross at the design speed of 50 mph (80 kph).
Engineers designed for a 100-year life, taking into account the combined severe effects of wind, waves, and ice. In part, this was achieved by using concrete up to 60 percent stronger than normal in construction. The concrete employed in the 60-foot-diameter (20-meter) ice shields, designed to break up the ice flow at the pier bases, was more than twice normal strength. Because climatic conditions limited on-site construction to six months of the year, the bridge was designed to be assembled in the summers from posttensioned concrete components precast during the winters. The parts of the approach bridges were cast at a staging facility in Bayfield, New Brunswick, transported by land or water to the site, and assembled by a twin launching truss with a traveling gantry crane. Another staging facility was set up in Borden-Carleton to precast the 175 main bridge components. Some weigh as much as 8,000 tons (8,128 tonnes); the main box girders are 570 feet (190 meters) long, yet designed to be joined with tolerances of less than 1 inch (2.54 centimeters).
In August 1995 a purpose-built floating crane, the Svanen, began placing the components of the east approach bridge, completing it in November; the west approach was built the following spring. The main bridge followed, and by August 1996 the navigation span was the last to be placed. On 19 November the structure was complete: sixty-five reinforced concrete piers, founded on bedrock, supported the 8-mile (12.9-kilometer) superstructure which curves gracefully across Northumberland Strait. During the next six months, the finishing work—the polymer-modified asphalt cement road surface, traffic signals, emergency call boxes, weather monitoring equipment, closed-circuit television cameras, and toll booths—was carried out, and the bridge was opened on 31 May 1997. The estimated direct construction cost was Can$730 million.

Further reading

Macdonald, Copthorne, 1997. Bridging the Strait: The Confederation Bridge Project. Toronto: Dundurn Press.

Thurston, Harry, Wayne Barrett, and Anne MacKay. 1998. Building the Bridge to P. E. I. Halifax, Canada: Nimbus.

Colossus of Rhodes Greece

One of the seven wonders of the ancient world, the huge statue of the pre-Olympian sun god Helios stood at the entrance to the harbor of Rhodes on the Aegean island of the same name. The work of the celebrated sculptor Chares of Lindos, the giant figure, shown in some representations to be shielding his eyes as he looked out across the sea, towered 110 feet (33 meters) above the entrance to the Mandraki harbor. According to Greek mythology, Helios was the son of the Titans Hyperion and Thea, and brother of Selene, goddess of the moon, and Eos, goddess of the dawn. He was worshiped throughout the Peloponnese, and the people of Rhodes held annual gymnastic games in his honor.

The cast-bronze shell of the Colossus, reinforced and stabilized with an iron-and-stone framework, stood on a white marble base. It has been suggested that, in order to attach the upper parts of the monument, earth ramps and mounds were built. Work commenced around 294 b.c.—although some sources put the date at ten years earlier—and the statue took twelve years to complete. Its size is hard to comprehend, but some idea can be gained from Pliny the Elder, who wrote, “Few people can make their arms meet round the thumb.” From medieval times, artists’ romanticized impressions have shown the Colossus straddling the entrance to Mandraki harbor, towering over the ships that sailed between his feet. Given its height, the width of the harbor mouth, and the technology available to the builders, that construct is most improbable. The fact is that no one knows exactly what the statue looked like, nor where it stood. Recent scholarship suggests that it stood on the eastern promontory of the Mandraki, or perhaps a little inland.
Rhodes was an important island in the ancient civilization of the Aegean. The Dorians inhabited it in the second millennium b.c., and their city-states of Lindos, Camiros, and Ialysos were vigorous commercial centers with colonies throughout the region. In the fifth century b.c., it belonged to the Delian League, a confederacy of city-states led by Athens, ties they severed in 412 b.c. Just four years later their own confederation was celebrated in the completion of the new city of Rhodes, said to have been designed by Hippodamos of Miletus; it seems more likely that it was laid out according to Hippodamean principles.
In 332 b.c. Rhodes came under the control of Alexander the Great, but following his de

years later its citizens revolted and expelled the Macedonians. Rhodes’s power and wealth reached a zenith in the second and third centuries b.c., and it became a famous cultural center. One badge of that political unity and artistic eminence was the Colossus, built to commemorate the raising of the Antigonid Macedonian Demetrios Poliorcetes’ long siege (305–304 b.c.). The metal for the statue was taken from the siege machines abandoned by the invaders when they withdrew. It is said that the dedicatory inscription read, “To you, O Sun, the people of Dorian Rhodes set up this bronze statue reaching to Olympus when they had pacified the waves of war and crowned their city with the spoils taken from the enemy. Not only over the seas but also on land did they kindle the lovely torch of freedom.”

A violent earthquake struck Rhodes about 225 b.c. The city was extensively damaged, and the Colossus, broken at the knee, crashed down. Ptolemy III of Egypt offered to meet the restoration costs, but when an oracle warned them against rebuilding, the Rhodians declined. It is ironic that the Colossus was actually lying in ruins when it was accorded a place among the wonders of the world. In a.d. 654 the Arabs invaded Rhodes, and two years later a Muslim dealer—some sources say a Syrian Jew—bought the fragments of the statue as scrap metal and carried them away to be melted down. Tradition has it that they were transported to Syria by a caravan of 900 camels.
In December 1999 the Municipal Council of Rhodes announced an international design competition for a new Colossus. As the island’s millennium project, the monument will encompass “modern artistic expression and technical construction that will surpass conventional standards [while borrowing] all the ancient symbolic values of the original.” Expected to cost U.S.$2.8 million, it is, intended to be finished in time for the Athens Olympic Games in 2004.

Further reading

Clayton, Peter, and Martin Price. 1988. The Seven Wonders of the Ancient World. London: Routledge.

Cox, Reg, and Neil Morris. 1996. The Seven Wonders of the Ancient World. Parsippany, NJ: Silver Burdett.

ath nine

Colossus Bridge, Schuylkill River Pennsylvania

The Upper Ferry bridge built at Fairmount near Philadelphia in 1812 and tragically destroyed by fire in 1838 was the longest single-trussed wooden arch in the United States, spanning over 340 feet (102 meters). It caused a sensation in its day and was inevitably labeled a new “wonder of the world,” “the Colossus at Philadelphia,” and “the Colossus at Fairmount.” This covered bridge, responding to new constraints, took timber engineering to its limits.

At the beginning of the nineteenth century, driven by the need for agricultural growth, the population of the narrow coastal plain of the northeastern United States was spreading beyond the “tidewater” region. Before then, many short streams and estuaries had adequately met communication needs, but the inland farmers demanded roads, fords, and bridges. Water mills, increasing in number as farming increased, were of necessity sited where rivers could not be forded, and they also needed transportation routes. There were good supplies of building lumber in the region and the harsh climate was better suited to wooden construction than to masonry. The earliest bridges were merely logs carried on timber stringers; their spans were limited to the available lengths. As bridge technology developed, longer spans were achieved by joining stringers and employing trusses and arches. Climate was an important factor and the covered bridge soon became not only popular but also necessary. The roof protected the structural timber from alternate wetting and drying, discouraging rot and extending the life of the bridge. There is a story, perhaps apocryphal, of a Virginia builder who observed that bridges were covered “for the same reason that our belles [wear] hoop skirts and crinolines: to protect the structural beauty that is seldom seen, but nevertheless appreciated”—a delightful analogy.
The first covered bridge in the United States replaced a pontoon across the Schuylkill River in Philadelphia and was therefore optimistically called the Permanent Bridge. A stone bridge was originally intended, but when the abutments and piers were completed in 1804, the decision was made to span the river with timber. The New England bridge architect Thomas Palmer designed a structure braced with three arches and multiple king posts, and it was constructed by Owen Biddle, a Philadelphia architect and builder. When it was opened to traffic in 1805 it had no cover, but on Palmer's advice and the prompting of Permanent Bridge Company shareholders, a roof and clapboard siding were soon added. Palmer believed the covering would extend the life of the structure from twelve years to perhaps forty; it was still sound when replaced forty-five years later.
Within five years there was a demand for another bridge across the Schuylkill, to be built at Upper Ferry and connecting the area then known as Fairmont with the western bank. The design was put in the hands of Lewis Wernwag, an immigrant carpenter from Württemburg, Germany, who had already built bridges over Neshaminy and Frankford Creeks.

Wernwag’s new bridge, built in 1812, was an elegant single-trussed arch spanning over 340 feet (102 meters)—certainly the longest of its kind in the United States and (according to some sources) the second-longest single-span bridge in the world at the time. The totally enclosed, elegant, low-arch bridge terminated in classical loggias at each end. Ten rectangular windows on each side provided light and ventilation for travelers. Graceful as it was, its achievement does not lie in its appearance but in the genius of its timber engineering. The wooden road deck was supported on five laminated arch beams that rose a little over 3 feet (1.07 meters) at midspan. On each side of the deck the river was spanned by a bow lattice beam, shallower at midpoint than at the ends and stiffened along its length with twenty-eight sets of double diagonal bracing. Iron tension ties anchored the beams to the ground at the masonry abutments, and others complemented the bracing along their entire length.

Wernwag’s reputation was established as a builder of long-span wooden truss bridges, and he built several more, including the Hickman Covered Bridge (1838) in central Kentucky. Also known locally as the Wernwag Bridge, it was the longest cantilever wooden bridge in the country. The practice of building wooden covered bridges spread quickly throughout the United States, and literally thousands were built during the nineteenth century. The Covered Bridge Society of America identifies over 1,500 extant covered bridges throughout the world. Over two-thirds of them are in North America. Pennsylvania has 219, over half of which are still in use on public roads.

Further reading

Allen, Richard Sanders. 1983. Covered Bridges of the Northeast. New York: Viking Penguin.

McKee, Brian J. 1997. Historic American Covered Bridges. New York: Oxford University Press

Colosseum (Flavian Amphitheater) Rome

The Flavian Amphitheater, now in ruins, towers over the southeast end of the Roman Forum, between the Esquiline and Palatine Hills. Its popular name, the Colosseum, was derived from the nearby colossal (120-foot-high, or 37.2-meter) bronze statue of Nero, long since vanished. The most ambitious example of a new building type associated with urbanization, the Colosseum was an architectural feat, even by Roman standards. Its size is awesome, but the logistics of moving crowds to and from their seats was also a major achievement.

The earliest amphitheater on the site was built in timber for the pontifex maximus Gaius Scribo

Curio in 59 b.c.; that; was replaced about thirty years later by a stone-and-timber version for Augustus Octavian Caesar, the first emperor. The Colosseum was commissioned in a.d. 69 by Vespasian, whose son Titus dedicated it in a.d. 80. The highest part of that structure was also timber, and not rebuilt in stone until after a.d. 223. It seems that the first three ranges of seats were completed in Vespasian’s reign, that Titus added two more ranges, and that Domitian completed the building around 300. Although early sources claim that the Colosseum seated 87,000 spectators, modern scholarship puts the figure closer to 50,000. Other Italian amphitheaters at Capua, Verona, and Tarragona are of similar size. The vast Colosseum, elliptical in plan, measured 620 by 510 feet (189 by 156 meters), covering nearly 6 acres (about 2.4 hectares). Its general height was 160 feet (49 meters).

The structural skeleton of the Colosseum was made of travertine limestone, quarried at Tivoli in the hills near Rome and transported to the site along a specially built road. Travertine blocks, some of them 5 feet high and 10 feet long (1.5 by 3 meters), were fixed together with metal cramps to form concentric elliptical walls. These were linked with radiating tufa walls carrying complex rising vaults of brick-faced concrete, in which volcanic stone such as pumice was used to reduce the weight. The vaults carried the tiers of seats. The Colosseum was built to house extravagant spectacles that took place in an arena measuring 280 by 175 feet (86 by 54 meters). Apart from a number of minor entrances to the arena, there were four principal gates at the ends of the axes, directly joined by passages to the exterior. A 15-foot-high (4.5-meter) walls probably faced with marble, defined the arena and provided a measure of protection for the spectators. The floor of the arena was made of heavy planks, strewn with sand for the purpose of soaking up the blood of gladiators, prisoners of war, and wild animals that died in their thousands. Such emperors as Caligula and Nero even ordered cinnabar and borax to replace the sand. A labyrinth of chambers beneath the floor possibly housed the participants in the games, and there were complicated machines and hoists to lift men, beasts, and theatrical sets into the arena, adding to the spectacle. Sometimes the entire floor was removed and the arena flooded by a system of pipes so that galleys could be pitted against each other in mock naval battles.
The terrace on top of the surrounding wall was wide enough to contain two or three rows of movable seats. Undoubtedly the best in the house, they were reserved for senators, magistrates, the vestal virgins, and other important people. The emperor and his immediate retinue occupied an elevated cubiculum. Upon entering the Colosseum through numbered arches corresponding to their ticket numbers, other visitors climbed sloping ramps to the gradus (bleachers), which were divided into stories and allocated according to gender and social class. The first fourteen rows of marble seats were covered with cushions and set aside for the equestrian order. Above them a horizontal space defined the second range, where a third class of spectators, the populus, was seated. Still further up were the wooden benches for the common people. The open gallery at the very top was the only part of the amphitheaters from which women were permitted to watch. There were exceptions, of course. When the games were over, the crowd could quickly disperse through no fewer than sixty-four strategically placed exits, aptly known as vomitoria.
The external wall of the Colosseum was divided into four stories, reflecting the circulation corridors within. Its eighty arches, most of which provided access to the interior, were framed by superimposed orders of pilasters (nonstructural columns): Tuscan on the ground floor, Ionic above them, and Corinthian at the top. The fourth story, also embellished with Corinthian pilasters, had stone brackets for the wooden masts from which an awning (velarium) was suspended across the interior to shield spectators from the sun while they watched the slaughter below. Many of the visible parts of the building were enriched with moldings, ornament, facings of marble or polished stone, and statuary. Fountains of scented water were provided for refreshment.
The Flavian Amphitheater was damaged several times by lightning strikes and repaired as often, so that games continued spasmodically until the sixth century, despite the opposition of the church and some Christian emperors. The last recorded slaughter of wild beasts was in the reign of Theodoric (a.d. 454–526), since when it has been used sometimes as a fortress and (to its detriment) as a quarry. Renaissance palaces in Rome, such as the Cancellaria and the Farnese, and churches including Saint Peter’s Basilica, were built with columns plundered from the ancient monument. Various popes made efforts to preserve it, and in 1750 Pope Benedict XIV consecrated it to the martyrs who died there. Surprisingly, and despite popular belief, it was not the main venue for the execution of Christians. In 1996 a U.S.$25 million restoration of the Colosseum was launched. After the cellars were drained, fallen masonry replaced, bushes and weeds cleared from the arena, and the structure repaired and cleaned, the greatest amphitheater was reopened in July 2000 with a season of Greek plays.

See also

Circus Maximus

Further reading

Luciani, Roberto. 1990. The Colosseum: Architecture, History, and Entertainment in the Flavian Amphitheatre. Novara, Italy: Istituto Geografico De Agostini.

Nardo, Don. 1998. The Roman Colosseum. San Diego: Lucent Books.

Pearson, John. 1973. Arena: The Story of the Colosseum. London: Thames and Hudson.

nius

CN (Canadian National) Tower Toronto, Canada

The CN Tower, next to the city hall on Front Street, Toronto, stands on the shore of Lake Ontario. It transmits television and FM radio for more than twenty broadcasters, as well as serving various other communications purposes. Including the masts, it is the tallest freestanding structure in the world; the top of the transmission antenna is over 1,815 feet (553 meters) high. But at the beginning of the twenty-first century, as technically demanding as it is, height alone does not constitute an architectural feat. The twin Petronas Towers in Kuala Lumpur, Malaysia, currently rank as the world’s tallest buildings, at 1,483 feet (454 meters). Others are proposed that will exceed that, including the 1,660-foot (508-meter) Taipei Financial Center on Taiwan, to be completed in August 2002, and the 2,100-foot (642-meter) Russia Tower in Moscow; at 2,755 feet (843 meters), the Millennium Tower in Tokyo will dwarf them all. The CN Tower is remarkable architecture because of its construction technique. For about a year, concrete, mixed and tested on-site to ensure consistent quality, was poured around the clock into a “slip form” that gradually decreased in diameter, to create the elegantly tapered contour of the post tensioned hollow structure.

Slip forming is a rapid construction technique based on extrusion. It employs a self-raising formwork that continually moves upward as the concrete is being placed, at a rate that gives the concrete time to set before being exposed as the formwork rises on a ring of hydraulic jacks, developing enough strength to support the work above. Continuous slip forming obviously speeds up the construction process while enabling excellent quality control, optimizing labor, and reducing the cost of building plant and scaffolding. It also results in monolithic, seamless structures. Developed in North America in the 1920s—The Granary at Logan Square in Philadelphia (1925) was one of the first examples in the United States—it has been widely used to build grain silos, building service cores, and (normally) any tall structures with a consistent cross section.
Early in the 1970s the number of multistory office blocks in downtown Toronto increased significantly, with a consequent interference with television and radio reception in large parts of the city. Toronto needed an antenna taller than any existing office block, indeed, of any that was anticipated, and the CN Tower was proposed to meet that need. The project was initiated in 1972 by the Canadian National Railway, which commissioned John Andrews Architects, working in collaboration with Webb Zerafa Menkes Housden Architects of Toronto. The structural engineering consultant was Roger R. Nicolet of Montreal; the mechanical and electrical engineers were Ellard-Wilson Associates Ltd. of Toronto; and the manager-contractor was Foundation Building Construction.
The original design proposed three concrete towers linked by structural bridges, but that was developed into a single tower with three hollow “legs.” As well as serving as electrical and mechanical service ducts, the hollow columns provided the necessary degree of flexibility for such a tall structure. Construction started in February 1973, and in four months a Y-shaped, 22-foot-thick (6.7-meter) reinforced concrete base was founded on the bedrock 50 feet (15 meters) beneath the city. The continuous slip-form process then began. When the tower reached 1,100 feet (336 meters), a seven-story “SkyPod,” fabricated on the ground, was raised into position

and anchored by twelve steel-and-timber brackets that were slowly pushed up the tower by forty-five hydraulic jacks. The concrete-walled SkyPod, reached by four high-speed, glass-fronted elevators, houses a 400-seat revolving restaurant, a nightclub, and indoor and outdoor observation decks. Later, a 2.5-inch-thick (6.4-centimeter) glass floor was installed. Beneath the SkyPod, delicate microwave dishes and other broadcasting equipment are protected by an annular radome. The concrete tower continues to the Space Deck at 1,465 feet (447 meters)—an observation gallery that on a clear day provides a view with 100-mile (160-kilometer) visibility. A Sikorsky Skycrane helicopter lifted the tower’s 335-foot (100-meter) communications mast in forty sections, each of about 7 tons (6.4 tonnes), and they were bolted together in place. The mast, erected in three weeks, was covered by fiberglass-reinforced sheathing. The maximum sway experienced at the very top in 120-mph (190-kph) winds with 200-mph (320-kph) gusts is 3.5 feet (1.07 meters).

The CN Tower was completed in June 1975 and officially opened on 1 October. It cost Can$57 million and took about 1,550 workers forty months to construct. It is nearly twice the height of the Eiffel Tower and more than three times as tall as the Washington Monument. Soaring above Toronto, it is struck by lightning about seventy-five times every year.
In 1995 Canada National passed ownership to a public company, the Canada Lands Company. In June 1998, the CN Tower officially opened a 75,000-square-foot (7,100-square-meter) expansion including an entertainment center, shopping facilities, and restaurants.

Further reading

Campi, Mario. 2000. Skyscrapers: An Architectural Type of Modern Urbansm, Boston: Birkhäuser.

McDermott, Barb, and Gail McKeown. 1999. The CN Tower. Edmonton, Canada: Reidmore Books.

Cluny Abbey Church III France

The town of Cluny in eastern France’s Burgundy region was important because of the Benedictine abbey jointly founded in 910 by Abbot St. Berno of Burgundy and William the Pious, Duke of Aquitaine. The third convent on the site, the great Basilica of St. Peter and St. Paul known as Cluny III (mainly 1088–1130), was the largest church, monastic or otherwise, in the world until St. Peter’s, Rome, was completed in the seventeenth century. Cluny III was the high point of Romanesque architecture in France, and, heralding the Gothic, it emphasized the continuity of architecture. Its form and detail repudiate the idea of a succession of discrete styles, each somehow frozen in time.

The reformist Benedictine community that originally occupied a Gallo-Roman villa in Cluny eventually developed an innovative system of centralized ecclesiastical government: by the fourteenth century the abbey controlled over 1,450 Cluniac foundations or priories from England to Poland to Palestine, which together could boast a complement of over 10,000 monks. After the pope himself, Cluny’s abbots were the most powerful clerics in the Roman Catholic Church and were at the epicenter of religious influence in Europe.
Two earlier abbey churches—the first, dedicated in 927, was succeeded by a larger building in 955–981—were replaced at the end of the eleventh century by Cluny III, which commenced soon after the other monastery buildings had been rebuilt (1077– 1085). The new church was over 440 feet (136 meters) long; the narthex and towers added in the late twelfth and thirteenth centuries brought the total length to 600 feet (180 meters). The barrel-vaulted ceiling, especially acoustically suited to the Cluniac uninterrupted sung liturgy, soared 98 feet (30 meters) above the floor. There were double transepts and double aisles to both the nave and choir; the chevet end had five chapels. The ceiling of the crossing under a central tower was 119 feet (36 meters) high. Yet Cluny III was remarkable not just for its size.
Its form, emerging over more than a century, demonstrated the perpetual development of Western

religious architecture. Since about 1000, the itinerant mason-architects of Europe had addressed their ecclesiastical clients’ demands for stone-ceiling churches (perhaps prompted by fear of fire), dealing with the major structural problems that entailed. The need to manage the huge loads and thrusts involved had led (although not all at once) to a number of architectural and engineering innovations. Cluny III, a mature expression of the new form, incorporated them all, masterfully blending liturgical and structural necessities—the two towers at the west end to provide longitudinal stiffening; vaulted aisles to brace the walls of the nave against the thrust of the stone vaults; massive side walls reinforced with even thicker buttresses, employed for a similar reason; small windows, creating the appearance of what someone called “the fortresses of God”; and a complex east end, where apsidal chapels with hemidomes completed the lucidly articulated building, which showed exactly how the vast weight of the superstructure was gently coaxed down to the supporting earth.

At the same time, Cluny III had many features that foreshadowed what would be commonplace just a few decades later: piers disguised as clusters of narrow columns, elegantly tall proportions, pointed arches (a lesson from Islam), and sophisticated vault construction. It also had beautifully carved decorations, giving a glimpse of the reemergence of naturalism. Some sources claim that here were to be found some of the first medieval sculptural allegories (dating from 1095) and the prototype for many carved and painted west portals (dating from 1109 to 1115).
Cluny III influenced a few great buildings (for example, Paray-le-Monial, La Charité-sur-Loire, and Autun Cathedral). But clergymen are notoriously conservative, and the impact of its avant-garde architecture was therefore limited. Indeed, the design was attacked in a Cistercian polemic even before the work was completed. Pope Urban II, who had been a novice and later prior at Cluny, consecrated the high altar of the unfinished church on 25 October 1095.

He announced that its community had reached “so high a stage of honor and religion that without doubt Cluny surpassed all other monasteries, even the most ancient.”

The abbey and the town both suffered in the religious wars of the sixteenth century. Early in the French Revolution the abbey was suppressed and then closed in 1790. Most of the basilica was demolished a few years later, and only ruins of the main southern transept and bell tower hint at what was once the greatest church in Christendom.

Further reading

Aubert, Marcel, and Simone Goubet. 1966. Romanesque Cathedrals and Abbeys of France. London: Vane.

Conant, Kenneth John. 1959. Carolingian and Romanesque Architecture. Harmondsworth, UK: Penguin