Sydney Harbour Bridge

The Sydney Harbour Bridge is a steel through arch bridge across Sydney Harbour that carries rail, vehicular, bicycle and pedestrian traffic between the Sydney central business district (CBD) and the North Shore. The dramatic view of the bridge, the harbour, and the nearby Sydney Opera House is an iconic image of Sydney, and Australia. The bridge is nicknamed "The Coathanger" because of its arch-based design. Furthermore, the bridge is ubiquitously known to Sydneysiders simply as "the Bridge".

Under the directions of Queenslander Dr J.J.C. Bradfield of the NSW Department of Public Works, the bridge was designed and built by British firm Dorman Long and Co Ltd of Middlesbrough and opened in 1932.The bridge's design was influenced by the Hell Gate Bridge in New York City. It is also the sixth longest spanning-arch bridge in the world, and it is the tallest steel arch bridge, measuring 134 m (440 ft) from top to water level. It was also the world's widest long-span bridge, at 48.8 m (160 ft) wide, until construction of the new Port Mann Bridge in Vancouver.
The southern (CBD) end of the bridge is located at Millers Point in The Rocks area, and the northern end at Milsons Point in the lower North Shore area. There are six original lanes of road traffic through the main roadway, plus an additional two lanes of road traffic on its eastern side, using lanes that were formally tram tracks). Adjacent to the road traffic, a path for pedestrian use runs along the eastern side of the bridge, whilst a dedicated path for bicycle use only runs along the western side. Finally, between the main roadway and the western bicycle path are two lanes used for railway tracks, servicing the T1 North Shore Line for Sydney Trains.

The main roadway across the bridge is known as the Bradfield Highway and is about 2.4 km (1.5 mi) long, making it one of the shortest highways in Australia.[citation needed]

Arch[edit]

One of the nuts that hold the bridge on its abutments; this one is at the north end.

The south-eastern pylon containing the tourist lookout, made of granite quarried at Moruya, NSW
The arch is composed of two 28-panel arch trusses; their heights vary from 18 m (59 ft) at the centre of the arch to 57 m (187 ft) at the ends next to the pylons.[citation needed]

The arch has a span of 504 m (1,654 ft) and its summit is 134 m (440 ft) above mean sea level; however, expansion of the steel structure on hot days can increase the height of the arch by as much as 18 cm (7.1 in).[9] Large steel pins (or bearings) support each end of the arch, allowing it to rotate to accommodate expansion and contraction caused by changes of temperature, and avoiding stresses that would otherwise cause damage.[citation needed]

The total weight of the steelwork of the bridge, including the arch and approach spans, is 52,800 tonnes (52,000 long tons; 58,200 short tons), with the arch itself weighing 39,000 tonnes (38,000 long tons; 43,000 short tons). About 79% of the steel was imported from England, with the rest being sourced from Newcastle.On site, the contractors (Dorman Long and Co.) set up two workshops at Milsons Point, at the site of the present day Luna Park, and fabricated the steel into the girders and other required parts.


The bridge is held together by six million Australian-made hand-driven rivets supplied by the McPherson company of Melbourne,the last being driven through the deck on 21 January 1932.] The rivets were heated red-hot and inserted into the plates; the headless end was immediately rounded over with a large pneumatic rivet gun. The largest of the rivets used weighed 3.5 kg (8 lb) and was 39.5 cm (15.6 in) long. The practice of riveting large steel structures, rather than welding, was, at the time, a proven and understood construction technique, whilst structural welding had not at that stage been adequately developed for use on the bridge.

At each end of the arch stands a pair of 89 m (292 ft) high concrete pylons, faced with granite. The pylons were designed by the Scottish architect Thomas S. Tait, a partner in the architectural firm John Burnet & Partners.

Some 250 Australian, Scottish, and Italian stonemasons and their families relocated to a temporary settlement at Moruya, NSW, 300 km (186 mi) south of Sydney, where they quarried around 18,000 m3 (635,664 cu ft) of granite for the bridge pylons.The stonemasons cut, dressed, and numbered the blocks, which were then transported to Sydney on three ships built specifically for this purpose.The concrete used was also Australian-made.[citation needed]

Abutments at the base of the pylons are essential to support the loads from the arch and hold its span firmly in place, but the pylons themselves have no structural purpose. They were included to provide a frame for the arch panels and to give better visual balance to the bridge. The pylons were not part of the original design, and were only added to allay public concern about the structural integrity of the bridge.

Although originally added to the bridge solely for their aesthetic value, all four pylons have now been put to use. The south-eastern pylon contains a museum and tourist centre, with a 360° lookout at the top providing views across the harbour and city. The south-western pylon is used by the New South Wales Roads and Traffic Authority (RTA) to support its CCTV cameras overlooking the bridge and the roads around that area. The two pylons on the north shore include venting chimneys for fumes from the Sydney Harbour Tunnel, with the base of the southern pylon containing the RMS maintenance shed for the bridge, and the base of the northern pylon containing the traffic management shed for tow trucks and safety vehicles used on the bridge.

In 1942 the pylons were modified to include parapets and anti-aircraft guns designed to assist in both Australia's defence and general war effort.The top level of stonework was never removed
There had been plans to build a bridge as early as 1815, when convict and noted architect Francis Greenway reputedly proposed to Governor Lachlan Macquarie that a bridge be built from the northern to the southern shore of the harbour. In 1825, Greenway wrote a letter to the then "The Australian" newspaper stating that such a bridge would "give an idea of strength and magnificence that would reflect credit and glory on the colony and the Mother Country".


Norman Selfe's winning design at the second competition c.1903

The Hell Gate Bridge in New York City, which inspired the design of Sydney Harbour Bridge.
Nothing came of Greenway's suggestions, but the idea remained alive, and many further suggestions were made during the nineteenth century. In 1840, naval architect Robert Brindley proposed that a floating bridge be built. Engineer Peter Henderson produced one of the earliest known drawings of a bridge across the harbour around 1857. A suggestion for a truss bridge was made in 1879, and in 1880 a high-level bridge estimated at $850,000 was proposed.


In 1900, the Lyne government committed to building a new Central railway station and organised a worldwide competition for the design and construction of a harbour bridge. Local engineer Norman Selfe submitted a design for a suspension bridge and won the second prize of £500. In 1902, when the outcome of the first competition became mired in controversy, Selfe won a second competition outright, with a design for a steel cantilever bridge. The selection board were unanimous, commenting that, "The structural lines are correct and in true proportion, and... the outline is graceful". However due to an economic downturn and a change of government at the 1904 NSW State election construction never began.

In 1914 J.J.C. Bradfield was appointed "Chief Engineer of Sydney Harbour Bridge and Metropolitan Railway Construction", and his work on the project over many years earned him the legacy as the "father" of the bridge. Bradfield's preference at the time was for a cantilever bridge without piers, and in 1916 the NSW Legislative Assembly passed a bill for such a construction, however it did not proceed as the Legislative Council rejected the legislation on the basis that the money would be better spent on the war effort.

Following World War I, plans to build the bridge again built momentum. Bradfield persevered with the project, fleshing out the details of the specifications and financing for his cantilever bridge proposal, and in 1921 he travelled overseas to investigate tenders. On return from his travels Bradfield decided that an arch design would also be suitable and he and officers of the NSW Department of Public Works prepared a general design for a single-arch bridge based upon New York City's Hell Gate Bridge. In 1922 the government passed the Sydney Harbour Bridge Act No. 28, specifying the construction of a high-level cantilever or arch bridge across the harbour between Dawes Point and Milsons Point, along with construction of necessary approaches and electric railway lines, and worldwide tenders were invited for the project.

As a result of the tendering process, the government received twenty proposals from six companies; on 24 March 1924 the contract was awarded to English firm Dorman Long and Co Ltd, of Middlesbrough well known as the contractors who built the similar Tyne Bridge of Newcastle Upon Tyne, for an arch bridge at a quoted price of AU£4,217,721 11s 10d. The arch design was cheaper than alternative cantilever and suspension bridge proposals, and also provided greater rigidity making it better suited for the heavy loads expected.
To offset concerns about a foreign firm participating in the project, assurances were given by Bradfield that the workforce building the bridge would all be Australians.[citation needed] Bradfield and his staff were ultimately to oversee the entire bridge design and building process, while Dorman Long and Co's Consulting Engineer, Sir Ralph Freeman of Sir Douglas Fox and Partners, and his associate Mr. G.C. Imbault, carried out the detailed design and erection process of the bridge. Architects for the contractors were from the British firm John Burnet & Partners of Glasgow, Scotland.


The building of the bridge coincided with the construction of a system of underground railways in Sydney's CBD, known today as the City Circle, and the bridge was designed with this in mind. The bridge was designed to carry six lanes of road traffic, flanked on each side by two railway tracks and a footpath. Both sets of rail tracks were linked into the underground Wynyard railway station on the south (city) side of the bridge by symmetrical ramps and tunnels. The eastern-side railway tracks were intended for use by a planned rail link to the Northern Beaches;[citation needed] in the interim they were used to carry trams from the North Shore into a terminal within Wynyard station, and when tram services were discontinued in 1958, they were converted into extra traffic lanes. The Bradfield Highway, which is the main roadway section of the bridge and its approaches, is named in honour of Bradfield's contribution to the bridge.

The building of the bridge was under the management of Bradfield. Three other people heavily involved in the bridge's design and construction were Lawrence Ennis, Edward Judge, and Sir Ralph Freeman. Ennis was the engineer-in-charge at Dorman Long and Co and the main on-site supervisor (Bradfield visited occasionally throughout the project and, in particular, at many key stages of the project, to inspect progress and make managerial decisions), Judge was chief technical engineer of Dorman Long, and Freeman was hired by the company to design the accepted model in further detail. Later a bitter disagreement broke out between Bradfield and Freeman as to who actually designed the bridge. Another name connected with the bridge's design is that of Arthur Plunkett.[citation needed]

The official ceremony to mark the "turning of the first sod" occurred on 28 July 1923, on the spot at Milsons Point on the north shore where two workshops to assist in building the bridge were to be constructed.

An estimated 469 buildings on the north shore, both private homes and commercial operations, were demolished to allow construction to proceed, with little or no compensation being paid. Work on the bridge itself commenced with the construction of approaches and approach spans, and by September 1926 concrete piers to support the approach spans were in place on each side of the harbour.

As construction of the approaches took place, work was also started on preparing the foundations required to support the enormous weight of the arch and loadings. Concrete and granite faced abutment towers were constructed, with the angled foundations built into their sides.

Once work had progressed sufficiently on the support structures, a giant "creeper crane" was erected on each side of the harbour These cranes were fitted with a cradle, and then used to hoist men and materials into position to allow for erection of the steelwork. To stabilise works while building the arches, tunnels were excavated on each shore with steel cables passed through them and then fixed to the upper sections of each half-arch to stop them collapsing as they extended outwards.

HMAS Canberra sailing under the completed arch from which the deck is being suspended in 1930

Arch construction itself began on 26 October 1928. The southern end of the bridge was worked on ahead of the northern end, to detect any errors and to help with alignment. The cranes would "creep" along the arches as they were constructed, eventually meeting up in the middle. In less than two years, on Tuesday, 19 August 1930, the two halves of the arch touched for the first time. Workers riveted both top and bottom sections of the arch together, and the arch became self-supporting, allowing the support cables to be removed. On 20 August 1930 the joining of the arches was celebrated by flying the flags of Australia and the United Kingdom (Australia being very much part of the British Commonwealth) from the jibs of the creeper cranes.

Once the arch was completed, the creeper cranes were then worked back down the arches, allowing the roadway and other parts of the bridge to be constructed from the centre out. The vertical hangers were attached to the arch, and these were then joined with horizontal crossbeams. The deck for the roadway and railway were built on top of the crossbeams, with the deck itself being completed by June 1931, and the creeper cranes were dismantled. Rails for trains and trams were laid, and road was surfaced using concrete topped with asphalt.Power and telephone lines, and water, gas, and drainage pipes were also all added to the bridge in 1931.

The pylons were built atop the abutment towers, with construction advancing rapidly from July 1931. Carpenters built wooden scaffolding, with concreters and masons then setting the masonry and pouring the concrete behind it. Gangers built the steelwork in the towers, while day labourers manually cleaned the granite with wire brushes. The last stone of the north-west pylon was set in place on 15 January 1932, and the timber towers used to support the cranes were removed

On 19 January 1932, the first test train, a steam locomotive, safely crossed the bridge.[citation needed] Load testing of the bridge took place in February 1932, with the four rail tracks being loaded with as many as 96 steam locomotives positioned end-to-end. The bridge underwent testing for three weeks, after which it was declared safe and ready to be opened.The construction worksheds were demolished after the bridge was completed, and the land that they were on is now occupied by Luna 

The standards of industrial safety during construction were poor by today's standards. Sixteen workers died during construction,[27] but surprisingly only two from falling off the bridge. Several more were injured from unsafe working practices undertaken whilst heating and inserting its rivets, and the deafness experienced by many of the workers in later years was blamed on the project. Henri Mallard between 1930 and 1932 produced hundreds of still and film footag]which reveal at close quarters the bravery of the workers in tough Depression-era conditions

The total financial cost of the bridge was AU£6.25 million, which was not paid off in full until 1988.

Mackinac Bridge

The Mackinac Bridge   is a suspension bridge spanning the Straits of Mackinac to connect the Upper and Lower peninsulas of the U.S. state of Michigan. Opened in 1957, the 8,614-foot (2,626 m) bridge (familiarly known as "Big Mac" and "Mighty Mac") is the world's 16th-longest in total suspension and the longest suspension bridge between anchorages in the Western hemisphere. The Mackinac Bridge carries Interstate 75 and the Lakes Michigan and Huron components of the Great Lakes Circle Tours across the straits and connects the city of St. Ignace on the north end with the village of Mackinaw City on the south.

Envisioned since the 1880s, the bridge was designed by the engineer David B. Steinman and completed in 1957 only after many decades of struggles to begin construction.

The bridge opened on November 1, 1957,[4] connecting two peninsulas linked for decades by ferries. A year later, the bridge was formally dedicated as the "world's longest suspension bridge between anchorages", allowing a superlative comparison to the Golden Gate Bridge, which had a longer center span between towers, and the San Francisco–Oakland Bay Bridge, which had an anchorage in the middle.

It remains the longest suspension bridge with two towers between anchorages in the Western Hemisphere.[3] Much longer anchorage-to-anchorage spans have been built in the Eastern Hemisphere, including the Akashi Kaikyō Bridge in Japan (12,826 ft or 3,909 m). But the long leadups to the anchorages on the Mackinac make its total shoreline-to-shoreline length of 5 miles (8 km) longer than the Akashi-Kaikyo (2.4 mi or 3.9 km).

The length of the bridge's main span is 3,800 feet (1,158 m), which makes it the third-longest suspension span in the United States and 16th longest suspension span worldwide. (See also List of longest bridges in the world.)

History[edit]

Vacationland, the largest and last MSHD automobile ferry put in service prior to the completion of the Mackinac Bridge
The Algonquian peoples who lived in the straits area prior to the arrival of Europeans in the 17th century called this region Michilimackinac, which is widely understood to mean the Great Turtle. This is thought to refer to the shape of what is now called Mackinac Island. This interpretation of the word is debated by scholars. Trading posts at the Straits of Mackinac attracted peak populations during the summer trading season; they also developed as inter-tribal meeting places.[5]

As exploitation of the state's mineral and timber resources increased during the 19th century, the area became an important transport hub. In 1881 the three railroads that reached the Straits, the Michigan Central, Grand Rapids & Indiana, and the Detroit, Mackinac & Marquette, jointly established the Mackinac Transportation Company to operate a railroad car ferry service across the straits and connect the two peninsulas.[6]

Improved highways along the eastern shores of the Lower Peninsula brought increased automobile traffic to the Straits region starting in the 1910s. The state of Michigan initiated an automobile ferry service between Mackinaw City and St. Ignace in 1923; it eventually operated nine ferry boats that would carry as many as 9,000 vehicles per day. Traffic backups could stretch as long as 16 miles (26 km).[7]

After the opening of the Brooklyn Bridge in 1883, local residents began to imagine that such a structure could span the straits. In 1884, a store owner in St. Ignace published a newspaper advertisement that included a reprint of an artist's conception of the Brooklyn Bridge with the caption "Proposed bridge across the Straits of Mackinac".
The idea of the bridge was discussed in the Michigan Legislature as early as the 1880s. At the time, the Straits of Mackinac area was becoming a popular tourist destination, especially following the creation of Mackinac National Park on Mackinac Island in 1875.

At a July 1888 meeting of the board of directors of the Grand Hotel on Mackinac Island, Cornelius Vanderbilt II proposed that a bridge be built across the straits, of a design similar to the one then under construction across the Firth of Forth in Scotland. This would advance commerce in the region and help lengthen the resort season of the hotel.

Decades went by with no formal action. In 1920, the Michigan state highway commissioner advocated construction of a floating tunnel across the Straits. At the invitation of the state legislature, C. E. Fowler of New York City put forth a plan for a long series of causeways and bridges across the straits from Cheboygan, 17 miles (27 km) southeast of Mackinaw City, to St. Ignace, using Bois Blanc, Round, and Mackinac islands as intermediate steps.

In 1923, the state legislature ordered the State Highway Department to establish ferry service across the strait. More and more people used ferries to cross the straits each year, and as they did, the movement to build a bridge increased. Chase Osborn, a former governor, wrote,

"Michigan is unifying itself, and a magnificent new route through Michigan to Lake Superior and the Northwest United States is developing, via the Straits of Mackinac. It cannot continue to grow as it ought with clumsy and inadequate ferries for any portion of the year."

By 1928, the ferry service had become so popular and so expensive to operate that Michigan Governor Fred W. Green ordered the department to study the feasibility of building a bridge across the strait. The department deemed the idea feasible, estimating the cost at $30 million.

In 1934, the Michigan Legislature created the Mackinac Straits Bridge Authority to explore possible methods of constructing and funding the proposed bridge. The Legislature authorized the Authority to seek financing for the project. In the mid-1930s, during the Great Depression, when numerous infrastructure projects received federal aid, the Authority twice attempted to obtain federal funds for the project but was unsuccessful. The United States Army Corps of Engineers and President Franklin D. Roosevelt endorsed the project but Congress never appropriated funds. Between 1936 and 1940, the Authority selected a route for the bridge based on preliminary studies. Borings were made for a detailed geological study of the route.

Besides the length of the span, a unique engineering challenge is created by the tremendous forces that operate against the base of the bridge. During winter, the lakes freeze and enormous stress is placed on the bridge structure by large icebergs.

The preliminary plans for the bridge featured a 3-lane roadway, a railroad crossing on the underdeck of the span, and a center-anchorage double-suspension bridge configuration similar to the design of the San Francisco – Oakland Bay Bridge. Because this would have required sinking an anchorage pier in the deepest area of the Straits, the practicality of this design may have been questionableA concrete causeway, approximately 4,000 feet (1,219 m), extending from the northern shore, was constructed in shallow water from 1939 to 1941.

At that time, with funding for the project still uncertain, further work was put on hold because of the outbreak of World War II. The Mackinac Straits Bridge Authority was abolished by the state legislature in 1947, but the same body created a new Mackinac Bridge Authority three years later in 1950. In June 1950, engineers were retained for the project.

By the 1950s, it was reported that cars queuing for the ferry at Mackinaw City did not reach St. Ignace until five hours later, and the typical capacity of 460 vehicles per hour could not match the estimated 1600 for a bridge.

After a report by the engineers in January 1951, the state legislature authorized the sale of $85 million in bonds for bridge construction on April 30, 1952. However, a weak bond market in 1953 forced a delay of more than a year before the bonds could be issued.


G. Mennen Williams was governor during the construction of the Mackinac Bridge. He began the tradition of the governor leading the Mackinac Bridge Walk across it every Labor Day.U.S. Senator Prentiss M. Brown has been called the "father of the Mackinac Bridge," and was honored with a special memorial bridge token created by the Mackinac Bridge Authority.

Sunshine Skyway Bridge

The Bob Graham Sunshine Skyway Bridge is a bridge spanning Tampa Bay, Florida, with a cable-stayed main span, and a total length of 21,877 feet (4.1 miles or approximately 6.67 km).[5] It is part of I-275 (SR 93) and US 19 (SR 55), connecting St. Petersburg in Pinellas County and Terra Ceia in Manatee County, Florida, passing through Hillsborough County waters. Construction of the current bridge began in 1982, and the completed bridge was dedicated on February 7, 1987. The new bridge cost $244 million to build, and was opened to traffic on April 20, 1987. It replaced an older bridge constructed in 1954 and partly destroyed in a collision in 1980.

It is constructed of steel and concrete. Steel cables clad in 84 9-inch (229 mm) steel tubes (42 per pylon) along the center line of the bridge support the main span. It was designed by the Figg & Muller Engineering Group (who also designed the popular Seven Mile Bridge), and built by the American Bridge Company.

In 2005, an act of Florida Legislature officially named the current bridge the Bob Graham Sunshine Skyway Bridge, after the Governor of Florida and then U.S. Senator who presided over its design and most of its construction. According to sources, he was inspired to suggest the current design by a visit to France, where he saw a similar cable-stayed bridge, the Brotonne Bridge. The original bridge was dedicated to state engineer William E. Dean, as noted on a plaque displayed at the rest area at the south end of the bridge.

The Travel Channel rated the Sunshine Skyway #3 in its special on the "Top 10 Bridges" in the World. The bridge is considered the "flag bridge" of Florida.

Because of its height above the emerald-green Gulf waters, length of continuous travel, location in a warm-weather state, and modern architectural design, it is a popular spot for filming automobile commercials.

One of the major problems with the Sunshine Skyway Bridge is corrosion of the steel in the precast concrete segmental columns on the high level approaches. Because the segments are hollow, workers were able to enter the bridge superstructure in 2003 and 2004 to reinforce the corroded sections of the bridge, ensuring its future safety.Another problem arose around 2005–2006 when several news bureaus reported paint discolorations on the bridge's cables. These paint splotches and patches were a result of touch-ups that were performed over the years but began to show through over recent years. In 2008, FDOT began an overhaul including repainting the cables in their entirety (instead of touching up) and rehabilitating the lighting system at the summit of the bridge.
The present bridge replaces a steel cantilever bridge of the same name. The original two-lane bridge built by the Virginia Bridge Company was opened to traffic on September 6, 1954,with a similar structure built parallel and to the west of it in 1969 to make it a four-lane bridge and bring it to Interstate standards. Opening of the newer span was delayed until 1971 for reinforcing of the south main pier, which had cracked due to insufficient supporting pile depth. The second span was used for all southbound traffic, while the original span was converted to carry northbound traffic.

The old bridge replaced a ferry from Point Pinellas to Piney Point. US 19 was extended from St. Petersburg to its current end north The original Sunshine Skyway Bridge is featured in the old-time radio series "Yours Truly, Johnny Dollar" in the episode "The Fancy Bridgework Matter" (11/22/1959) and in the original opening credits to the 1988 Superboy TV series which showed the hero flying over the damaged original span and then turning to view the new bridge under construction.

The remaining approaches to the old cantilever bridge remain in use as Skyway Fishing Pier State Park.

The original Sunshine Skyway Bridge was the site of a number of tragic events, including the collision of the US Coast Guard Cutter Blackthorn and inbound freighter Capricorn in 1980 which claimed 23 Coast Guardsmen's lives, and a structural collapse caused by a collision with the bridge support by the inbound freighter Summit Venture in 1980 which killed 35 people and ultimately ended the bridge spans' useful life.

On January 28, 1980, the 180 ft Iris class buoy tender USCGC Blackthorn was outbound from Tampa Bay, having just completed a total refit, as the 605 ft tanker Capricorn  was inbound. Having just been overtaken by a brightly lit cruise ship, the Blackthorn had maneuvered into the center of the channel to allow the passenger ship to pass. As a consequence of the cruise ship's lights, the Blackthorn was unable to see the approaching Capricorn in the night's darkness. As the two ships approached, the Capricorn gave two short whistles to signal its intention to pass to starboard as the Blackthorn crowded the center of the channel.[disputed – discuss][citation needed] At some point, the Blackthorn, helmed by a junior officer, initiated evasive action but it was already too late. The two ships collided nearly head-on, with the anchor of the tanker imbedding itself in the hull plates of the cutter. At least 6 crewmen of the Blackthorn were trapped by the mangled metal skin of the ship. As the ships' momentum carried each other along, the anchor line of the tanker grew taut and pulled the Blackthorn over, capsizing the smaller ship and resulting in the drowning deaths of 23 crew trapped on board and below decks, approximately 3/4 of a mile from the Sunshine Skyway Bridge.

Following the accident, the Blackthorn was recovered and taken to drydock for postmortem analysis. Because it had been involved in a fatal accident, it was decided not to repair the vessel.[citation needed] She was stripped of her gear and had her mast and superstructure reduced. The hull was then towed offshore and intentionally sunk as an artificial reef.


The southbound span (opened in 1971) of the original bridge was destroyed at 7:33 a.m. on May 9, 1980, when the freighter MV Summit Venture collided with a pier (support column) during a blinding thunderstorm, sending over 1200 feet (366m) of the bridge plummeting into Tampa Bay. The collision caused six cars, a truck, and a Greyhound bus to fall 150 feet (46 m) into the water, killing 35 people.

One man, Wesley MacIntire, survived the fall when his pickup truck landed on the deck of the Summit Venture before falling into the bay. He sued the company that owned the ship, and settled for $175,000 in 1984.

The pilot of the ship, John Lerro, was cleared of wrongdoing by both a state grand jury and a Coast Guard investigation
The south main pier (the one that required reinforcement before completion) withstood the ship strike without significant damage. It was the second pier to the south of it that was destroyed, a secondary pier that was not designed to withstand a large ship strike.[10]

After the Summit Venture disaster, the northbound span carried one lane in either direction until the current bridge opened. Before the old bridge was demolished and hauled away in barges, MacIntire (the only survivor in the collapse) was the last person to drive over it. He was accompanied by his wife, and when they reached the top of the bridge, they dropped 35 white carnations into the water, one for each person who died in the disaster.[17] The main span of the northbound bridge was demolished in 1993 and the approaches for both old spans were made into the Skyway Fishing Pier State Park. These approaches sit 1/2 mile (0.8 km) to the south and west of the current bridge.

Gov. Graham's idea for the design of the current bridge won out over other proposals, including a tunnel (deemed impractical due to Florida's high water table) and a simple reconstruction of the broken section of the old bridge that would not have improved shipping conditions. The new bridge's main span is 50% wider than the old bridge. The piers of the main span and the approaches for 1/4 mile (0.4 km) in either direction are surrounded by large concrete barriers called "dolphins" that can protect the bridge piers from collisions with ships larger than the Summit Venture like tankers, container ships, and cruise ships.


In 1990 the Florida Department of Transportation awarded the winning bid to the Hardaway Company to demolish all steel and concrete sections of the Sunshine Skyway Bridge. The scope of the project required that all underwater piles and piers, and surface roadway, girders, and beams be dismantled. Special care had to be taken in removing underwater bridge elements near the shipping channel. Additionally, the concrete material, deck sections, pilings and steel girders were to be collected in order to be placed offshore and along the remaining bridge approaches to become artificial reefs for the new planned state fishing park. The main bridge span had to be removed in one piece in order not to block the main shipping canal leading to the port of Tampa.

During the disassembly work of the bridges’ structural steel members, several difficult engineering challenges had to be resolved: the order of disassembly, a safe method for detonating charges on concrete and steel members in a publicly open and difficult to control area such as the Tampa Bay, and the development of a safe methodology for the removal in one piece of the bridge’s main span and concrete piers.

After extensive research, the engineering team developed a 4 × 1: 16 ratio pulley system where each of the 4 corners of the span was connected to two 25 ton winches (bolted to the pavement of the deck). These winches controlled the descent of the main 360-foot (110 m), 608 ton span to a barge anchored 150 feet (46 m) below. As part of the project design, the engineering team developed a real time computerized, synchronized descent calculator and control program to help each of the two winch management teams ensure that all winches were synchronized at the same 30 feet (9.1 m) per minute descent rate. The operation was executed successfully in 21⁄2 hours despite adverse weather conditions.
Bridge suicides[edit]
According to compilations from various media reports as of 2009, at least 207 people have committed suicide by jumping from the center span into the waters of Tampa Bay since the opening of the new bridge in 1987, and an estimated 34 others have tried, but survived. A Rottweiler named Shasta survived after either following or being carried over the edge by its owner, who died. Another 51 people ended their lives from the old Sunshine Skyway from 1954 to 1987. One man (23 year old Michael "Luciano" Plezia of Clevelandwas forced to jump at gunpoint in 1981, after having been kidnapped, beaten, tortured, and stabbed.; another, a 24 year old Sarasota carpenter, hanged himself from the bridge on Saturday morning, 4 July 1992. Several other missing persons are suspected of having jumped from the bridge, but their deaths could not be confirmed as no bodies were recovered.

In response to the high number of suicide attempts from the bridge, the state of Florida installed six crisis hotline phones along the center span in 1999, and began 24-hour patrols. As of 2003, the call center received 18 calls from potential jumpers, all of whom survived, according to a St. Petersburg Times report.However, the total number of jumpers has not significantly declined since the introduction of these safeguards.

On April 27, 1997, a group of amateur daredevils, led by a bartender from Ft. Lauderdale and composed of a mix of male and female participants, performed an unannounced guerrilla "pendulum swing" bungee jump off the bridge, wherein they planned to swing back and forth on a home-made bungee cord made of steel cable attached to the cast-off point. Arriving by stretch limousine, the group unexpectedly pulled over at the apex of the bridge, quickly rigged up their cable, tethered themselves to it with harnesses, and jumped over the edge. This stunt failed when the plastic sheathing on the steel cable, unable to handle the increase in gravitational forces exerted on it by the initial pendulum swing, sheared off and allowed the connecting clamps to slide freely off the cable, plunging the jumpers 60 feet (18 m) into the water, leading to broken bones and neck injuries. The entire accident was caught on multiple video cameras that had been set up to record the feat.

When later interviewed for a television video program, the group's leader stated that all of the components were rated to handle the combined weight of the participants, and, at the time, he thought the assembly was safe. Later studies showed that his design had failed to take into account the increased g-load caused by the pendulum action of the jump itself, exceeding the ratings on the components and leading to catastrophic failure of the structural integrity of the bungee cable. Since the accident, no other groups have attempted to perform a stunt jump from the bridge. This incident aired on Destroyed In Seconds on March 2, 2009.

In 2006, a feature film entitled Loren Cass was released, which depicted a suicide jump off the Sunshine Skyway.[29] Two years later, a second filmmaker, Sean Michael Davis of Rhino Productions, was inspired by his haunting experience witnessing a woman jump off the bridge so quickly that no one could intervene, to create a non-for-profit film titled Skyway Down. His objectives: to deter other potential jumpers by " 'punch[ing] them in the face' with interviews with survivors and family members",[30] to give them "hope and to try to de-glorify the romanticism of the bridge",in part by informing those who have "mulled a leap to know about the bloody, battered aftermath."

Corporal Gary Schluter of the Florida State Highway Patrol - who has "seen the number of suicides, and attempts, climb steadily over the last few years" at the Sunshine Skyway Bridge, as well as persuaded multiple would-be suicides at that site to live - advises: "People look at that water and think it's very serene, an easy way to die." But "it's more like hitting concrete." As he and other troopers explained to The New York Times reporter Rick Bragg, "Jumpers tend to die ugly. The fall, less than four seconds, ends in a bone-snapping, organ-rupturing trauma, but some jumpers do not lose consciousness, and drown in agony." Schluter elaborated: "We retrieve the bodies. They are distorted, mangled."
On October 12, 2009, a body was found in the trunk of a burning car on the Sunshine Skyway bridge. Witnesses saw a man carrying a gas can near the car. A Florida Highway Patrol trooper later saw the man jump from the bridge, to his death.[33] After an investigation, authorities deemed the deaths a murder-suicide. The jumper, Robert Cecil Laird, shot his ex-wife, Sheryl Laird (39), multiple times at her home in Lakeland before depositing her body in the vehicle's trunk and driving approximately 60 miles (97 km) to the bridge, where he set the car afire and jumped to his death.


Stopping on the bridge for any non-emergency (including sightseeing) is prohibited. As part of a controlled-access highway, pedestrians and bicycles are also prohibited. Traffic on the bridge is remotely monitored by the Florida Highway Patrol, and a stopped or illegal vehicle or a pedestrian will elicit a police dispatch.

Pont du Gard

The Pont du Gard is an ancient Roman aqueduct bridge that crosses the Gardon River, from which it takes its name. It is located in Vers-Pont-du-Gard near Remoulins, in the Gard département of southern France. The bridge is part of the Nîmes aqueduct, a 50 km-long (31 mi) structure built by the Romans to carry water from a spring at Uzès to the Roman colony of Nemausus . Because the terrain between the two points is hilly, the aqueduct – built mostly underground – took a long, winding route that crossed the gorge of the Gardon, requiring the construction of an aqueduct bridge. Built in the 1st century AD, the Pont du Gard is the highest of all Roman aqueduct bridges and is, with the Aqueduct of Segovia, one of the best preserved. It was added to UNESCO's list of World Heritage Sites in 1985 because of its historical importance.

The bridge has three tiers of arches, standing 48.8 m (160 ft) high. The whole aqueduct descends in height by only 17 m (56 ft) over its entire length, while the bridge descends by a mere 2.5 cm (0.98 in) – a gradient of only 1 in 3,000 – which is indicative of the great precision that Roman engineers were able to achieve using only simple technology. The aqueduct formerly carried an estimated 200,000 m3 (44,000,000 imp gal) of water a day to the fountains, baths and homes of the citizens of Nîmes. It continued to be used possibly until the 6th century, with some parts used for significantly longer, but lack of maintenance after the 4th century meant that it became increasingly clogged by mineral deposits and debris that eventually choked off the flow of water.

After the collapse of the Roman Empire and the aqueduct's fall into disuse, the Pont du Gard remained largely intact due to the importance of its secondary function as a toll bridge. For centuries the local lords and bishops were responsible for its upkeep in exchange for the right to levy tolls on travellers using it to cross the river, although some of its stones were looted and serious damage was inflicted on it in the 17th century. It attracted increasing attention starting in the 18th century and became an important tourist destination. It underwent a series of renovations between the 18th and 21st centuries, commissioned by the local authorities and the French state, that culminated in 2000 with the opening of a new visitor centre and the removal of traffic and buildings from the bridge and the area immediately around it. Today it is one of France's most popular tourist attractions and has attracted the attention of a succession of literary and artistic visitors.

The location of Nemausus (Nîmes) was somewhat inconvenient when it came to providing a water supply. Plains lie to the city's south and east, where any sources of water would be at too low an altitude to be able to flow to the city, while the hills to the west made a water supply route too difficult from an engineering point of view. The only real alternative was to look to the north and in particular to the area around Ucetia (Uzès), where there are natural springs.

The Nîmes aqueduct was built to channel water from the springs of the Fontaine d'Eure near Uzès to the castellum divisorum (repartition basin) in Nemausus. From there, it was distributed to fountains, baths and private homes around the city. The straight-line distance between the two is only about 20 km (12 mi) but the aqueduct takes a winding route measuring around 50 km (31 mi).[6] This was necessary to circumvent the southernmost foothills of the Massif Central, known as the Garrigues de Nîmes. They are difficult to cross, as they are covered in dense vegetation and garrigue and indented by deep valleys.[7] It was impractical for the Romans to attempt to tunnel through the hills, as it would have required a tunnel of between 8 and 10 kilometres (5 and 6 mi), depending on the starting point. A roughly V-shaped course around the eastern end of the Garrigues de Nîmes was therefore the only practical way of transporting the water from the spring to the city.

The Fontaine d'Eure, at 76 m (249 ft) above sea level, is only 17 m (56 ft) higher than the repartition basin in Nîmes, but this provided a sufficient gradient to sustain a steady flow of water to the 50,000 inhabitants of the Roman city. The aqueduct's average gradient is only 1 in 3,000. It varies widely along its course, but is as little as 1 in 20,000 in some sections. The Pont du Gard itself descends 2.5 cm (0.98 in) in 456 m (1,496 ft), a gradient of 1 in 18,241.[8] The average gradient between the start and end of the aqueduct is far shallower than was usual for Roman aqueducts – only about a tenth of the average gradient of some of the aqueducts in Rome.

The reason for the disparity in gradients along the aqueduct's route is that a uniform gradient would have meant that the Pont du Gard would have been infeasibly high, given the limitations of the technology of the time. By varying the gradient along the route, the aqueduct's engineers were able to lower the height of the bridge by 6 metres (20 ft) to 48.77 metres (160.0 ft) above the river – still exceptionally high by Roman standards, but within acceptable limits. This height limit governed the profile and gradients of the entire aqueduct, but it came at the price of creating a "sag" in the middle of the aqueduct. The gradient profile before the Pont du Gard is relatively steep, descending at 0.67 metres (2 ft 2 in) per kilometre, but thereafter it descends by only 6 metres (20 ft) over the remaining 25 kilometres (16 mi). In one section, the winding route between the Pont du Gard and St Bonnet required an extraordinary degree of accuracy from the Roman engineers, who had to allow for a fall of only 7 millimetres (0.28 in) per 100 metres (330 ft) of the conduit.

It is estimated that the aqueduct supplied the city with around 200,000 cubic metres (44,000,000 imp gal) of water a day[11] that took nearly 27 hours to flow from the source to the city.The water arrived in the castellum divisorum at Nîmes – an open, shallow, circular basin 5.5 m in diameter by 1 m deep. It would have been surrounded by a balustrade within some sort of enclosure, probably under some kind of small but elaborate pavilion. When it was excavated, traces of a tiled roof, Corinthian columns and a fresco decorated with fish and dolphins were discovered in a fragmentary condition.The aqueduct water entered through an opening 1.2 metres (3 ft 11 in) wide, and ten large holes in the facing wall, each 40 centimetres (16 in) wide, directed the water into the city's main water pipes. Three large drains were also located in the floor, possibly to enable the nearby amphitheatre to be flooded rapidly to enable naumachia (mock naval battles) to be held.

The water tank or castellum divisorum at Nîmes, into which the aqueduct emptied. The round holes were where the city's water supply pipes connected to the tank.

The spring still exists and is now the site of a small modern pumping station. Its water is pure but high in dissolved calcium carbonate leached out of the surrounding limestone. This presented the Romans with significant problems in maintaining the aqueduct, as the carbonates precipitated out of the water during its journey through the conduit. This caused the flow of the aqueduct to become progressively reduced by deposits of calcareous sinter. Another threat was posed by vegetation penetrating the stone lid of the channel. As well as obstructing the flow of the water, dangling roots introduced algae and bacteria that decomposed in a process called biolithogenesis, producing concretions within the conduit. It required constant maintenance by circitores, workers responsible for the aqueduct's upkeep, who crawled along the conduit scrubbing the walls clean and removing any vegetation.

Much of the Nîmes aqueduct was built underground, as was typical of Roman aqueducts. It was constructed by digging a trench in which a stone channel was built and enclosed by an arched roof of stone slabs, which was then covered with earth. Some sections of the channel are tunnelled through solid rock. In all, 35 km (22 mi) of the aqueduct was constructed below the ground. The remainder had to be carried on the surface through conduits set on a wall or on arched bridges. Some substantial remains of the above-ground works can still be seen today, such as the so-called "Pont Rue" that stretches for hundreds of metres around Vers and still stands up to 7.5 m (25 ft) high.[Other surviving parts include the Pont de Bornègre, three arches carrying the aqueduct 17 m (56 ft) across a stream; the Pont de Sartanette, near the Pont du Gard, which covers 32 m (105 ft) across a small valley; and three sections of aqueduct tunnel near Sernhac, measuring up to 66 m (217 ft) long.However, the Pont du Gard is by far the best preserved section of the entire aqueduct.

The construction of the aqueduct has long been credited to Augustus' son-in-law and aide, Marcus Vipsanius Agrippa, around the year 19 BC. At the time, he was serving as aedile, the senior magistrate responsible for managing the water supply of Rome and its colonies. Espérandieu, writing in 1926, linked the construction of the aqueduct with Agrippa's visit to Narbonensis in that year.[7] Newer excavations suggest the construction may have taken place between 40 and 60 AD. Tunnels dating from the time of Augustus had to be bypassed by the builders of the Nîmes aqueduct, and coins discovered in the outflow in Nîmes are no older than the reign of the emperor Claudius (41–54 AD). On this basis, a team led by Guilhem Fabre has argued that the aqueduct must have been completed around the middle of the 1st century AD. It is believed to have taken about fifteen years to build, employing between 800 and 1,000 workers.

From the 4th century onwards, the aqueduct's maintenance was neglected as successive waves of invaders disrupted the region.[33] It became clogged with debris, encrustations and plant roots, greatly reducing the flow of the water. The resulting deposits in the conduit, consisting of layers of dirt and organic material, are up to 50 cm (20 in) thick on each wall.An analysis of the deposits originally suggested that it had continued to supply water to Nîmes until as late as the 9th century, but more recent investigations suggest that it had gone out of use by about the sixth century, though parts of it may have continued to be used for significantly longer.

West end of the Pont du Gard in 1891, showing the stairs installed by Charles Laisné to enable visitors to enter the conduit

Although some of its stones were plundered for use elsewhere, the Pont du Gard remained largely intact. Its survival was due to its use as a toll bridge across the valley. In the 13th century the French king granted the seigneurs of Uzès the right to levy tolls on those using the bridge. The right later passed to the Bishops of Uzès. In return, they were responsible for maintaining the bridge in good repair.[39] However, it suffered serious damage during the 1620s when Henri, Duke of Rohan made use of the bridge to transport his artillery during the wars between the French royalists and the Huguenots, whom he led. To make space for his artillery to cross the bridge, the duke had one side of the second row of arches cut away to a depth of about one-third of their original thickness. This left a gap on the lowest deck wide enough to accommodate carts and cannons, but severely weakened the bridge in the process.

In 1703 the local authorities renovated the Pont du Gard to repair cracks, fill in ruts and replace the stones lost in the previous century. A new bridge was built by the engineer Henri Pitot in 1743–47 next to the arches of the lower level, so that the road traffic could cross on a purpose-built bridge.[11][41] The novelist Alexandre Dumas was strongly critical of the construction of the new bridge, commenting that "it was reserved for the eighteenth century to dishonour a monument which the barbarians of the fifth had not dared to destroyThe Pont du Gard continued to deteriorate and by the time Prosper Mérimée saw it in 1835 it was at serious risk of collapse from erosion and the loss of stonework.

Napoleon III, who had a great admiration for all things Roman, visited the Pont du Gard in 1850 and took a close interest in it. He approved plans by the architect Charles Laisné to repair the bridge in a project which was carried out between 1855–58, with funding provided by the Ministry of State. The work involved substantial renovations that included replacing the eroded stone, infilling some of the piers with concrete to aid stability and improving drainage by separating the bridge from the aqueduct. Stairs were installed at one end and the conduit walls were repaired, allowing visitors to walk along the conduit itself in reasonable safety.

There have been a number of subsequent projects to consolidate the piers and arches of the Pont du Gard. It has survived three serious floods over the last century; in 1958 the whole of the lower tier was submerged by a giant flood that washed away other bridges, and in 1998 another major flood affected the area. A further flood struck in 2002, badly damaging nearby installations.

The Pont du Gard was added to UNESCO's list of World Heritage Sites in 1985 on the criteria of "Human creative genius; testimony to cultural tradition; significance to human history".The description on the list states: "The hydraulic engineers and ... architects who conceived this bridge created a technical as well as artistic masterpiece.

The Pont du Gard has been a tourist attraction for centuries. The outstanding quality of the bridge's masonry led to it becoming an obligatory stop for French journeymen masons on their traditional tour around the country (see Compagnons du Tour de France), many of whom have left their names on the stonework. From the 18th century onwards, particularly after the construction of the new road bridge, it became a famous staging-post for travellers on the Grand Tour and became increasingly renowned as an object of historical importance and French national pride.

The bridge has had a long association with French monarchs seeking to associate themselves with a symbol of Roman imperial power. King Charles IX of France visited in 1564 during his Grand Tour of France and was greeted with a grand entertainment laid on by the Duc d'Uzès. Twelve young girls dressed as nymphs came out of a cave by the riverside near the aqueduct and presented the king with pastry and preserved fruits. A century later, Louis XIV and his court visited the Pont du Gard during a visit to Nîmes in January 1660 shortly after the signature of the Treaty of the Pyrenees.In 1786 his great-great-great-grandson Louis XVI commissioned the artist Hubert Robert to produce a set of paintings of Roman ruins of southern France to hang in the king's new dining room at the Palace of Fontainebleau, including a picture depicting the Pont du Gard in an idealised landscape. The commission was meant to reassert the ties between the French monarchy and the imperial past Napoleon III, in the mid-19th century, consciously identified with the Roman emperor Augustus and accorded great respect to Roman antiquities; his patronage of the bridge's restoration in the 1850s was essential to its survival.

By the 1990s the Pont du Gard had become a hugely popular tourist attraction but was congested with traffic – vehicles were still allowed to drive over the 1743 road bridge – and was cluttered with illegally built structures and tourist shops lining the river banks. As the architect Jean-Paul Viguier put it, the "appetite for gain" had transformed the Pont du Gard into "a fairground attraction".[49] In 1996 the General Council of the Gard département began a major four-year project to improve the area, sponsored by the French government, in conjunction with local sources, UNESCO and the EU. The entire area around the bridge was pedestrianised and a new visitor centre was built on the north bank to a design by Jean-Paul Viguier. The redevelopment has ensured that the area around the Pont du Gard is now much quieter due to the removal of vehicle traffic, and the new museum provides a much improved historical context for visitors.[50] The Pont du Gard is today one of France's top five tourist attractions, with 1.4 million visitors reported in 2001.