Thousand Islands Bridge

44.347419 - 75.9835Koordinaten: 44 ° 20 ' 50.7 "N, 75 ° 59' 0.6 " W

F1

Interstate 81, Highway 137

St. Lawrence River

Thousand Islands Bridge is the collective term for a total of 13 km long series of bridges and roads that connect the United States and Canada through the archipelago Thousand Islands and the St. Lawrence River across. It is the first bridge link across the St. Lawrence River below the Lake Ontario, the next bridge is around 60 km further downstream Ogdensburg -Prescott International Bridge.

Location

On the U.S. side of the starting point is the intersection of Interstate 81 with the New York State Route 12 in the town of Collins Landing, on the Canadian side of the intersection between the Ontario Highway 137 and the Thousand Islands Parkway or the Ontario Highway 401

General

All the bridges except the two short border bridges are two-lane steel bridge on concrete foundations, which were designed by Robinson & Steinman and built in 1937 /38. The steel parts are decorated in the typical, by David B. Steinman preferred green, which contrasts with the yellowish brown concrete of the foundation piers. The bridges have demarcated by barriers, narrow sidewalks, but they are only open during the summer months.

Initially drove 150,000 vehicles per year over the toll Thousand Islands Bridge, today there are about 2,000,000 vehicles.

In August 2013 large celebrations for the 75th anniversary of the Thousand Islands Bridge are planned.

The Thousand Islands Bridge and its surroundings is uniformly operated due to a Canada-US Agreement of the Thousand Islands Bridge Authority, serviced and maintained.

Wellesley Iceland Suspension Bridge

The Wellesley Iceland Suspension Bridge begins immediately after the toll plaza on the U.S. side and leads to Interstate 81 on the American arm of the current at Wellesley Iceland. She is a total of 1 372 m long suspension bridge with 76 m high pylons, a main span of 244 m ( 800 ft), the two 564 m long ramps and a clear height of 45.72 m (150 ft). There are striking addition to the vertical hangers attached stay cables in the longitudinal direction between the support cables and the bridge deck and suspended between the support cables framework of narrow steel beams that were stiffened by diagonal cables. Unusual is also the anchorage of the suspension cable, which fan out shortly before the armature blocks in their individual strands 37 and each strand is fixed individually by an adjustable sleeve in the anchor block.

Wellesley and Hill Islands Bridge ( border bridges )

The Wellesley and Hill Islands Bridge crosses the narrow, International Rift mentioned branch of the river, which forms the state border. It is only 27 m long segmental arch bridge made ​​of concrete, which is clad in masonry. Because of lack of space in front of the border station an equal, three-lane bridge was built next to her in 1959. From the border of the now called Highway 137 road passes through the Hill Iceland.

Hill and Constance Islands Bridge

The Hill and Constance Islands Bridge is a 183 m long Warren through truss bridge that leads from the Hill to Constance Iceland Iceland and is supported in the center with a Pfahljoch of reinforced concrete on a tiny rocky island.

Constance and Georgina Islands Bridge

The Constance and Georgina Islands Bridge is a steel arch bridge a few meters after the truss bridge. It has a span of 106 m (348 ft).

Georgina Iceland Bridge

The Georgina Iceland Bridge is a suspension bridge over the northern arm of the St. Lawrence River, the Pfahljoch a reinforced concrete shared with the steel arch bridge, at its base, the anchor blocks of the supporting cables are. It has 62 m high pylons and is a total of 404 m long, has a main span of 229 m (750 ft) and a clear height of 37 m (120 ft). As well as the Wellesley Iceland suspension bridge there is here an additional diagonal ropes and cables between the support frame and the same anchoring the support cable to the fanning out of the strands 37.

History

The two suspension bridges provide a striking point in the development of this design dar. Leon S. Moisseiff had going back to Joseph Melan Deflektionstheorie developed and first time at the Manhattan Bridge opened in 1909 applied. This new static analysis method allowed much easier and hence cheaper and faster -to-build suspension bridges than before. In the following years the Deflektionstheorie by numerous engineers, including David B. Steinman, was further developed. One of the most developed of her views was that flat bridge decks were more suitable than the previously usual high truss structures because they offer less resistance to the wind. The Deflektionstheorie and the interim improvements to the steel qualities now made ​​flat bridge decks from plate supporting structures possible for high above the water running bridges.

The construction of a bridge over the St. Lawrence River had been discussed since 1920, but failed again and again to financing problems. 1932 Robinson & Steinman was commissioned by private initiatives with a design in the following year, the Thousand Islands Bridge Authority was established. David B. Steinman presented in 1934 a draft, which corresponded to the tight financial framework as far as possible and providing for extremely lightly built suspension bridges with flat plate carrier decks. On April 30, 1937 was finally held the groundbreaking ceremony. The entire project was completed in just 16 months - 10 weeks before the agreed completion date. On August 18, 1938, the opening ceremony with President Franklin D. Roosevelt and Prime Minister Mackenzie King took place.

By the end of the construction period had noticed vibrations of the bridge decks that were up to 61 cm high with a corresponding wind direction. As a temporary measure Steinman was installing diagonal stay cables, although dampened the vibrations, but the shorter wavelengths. Finally, a system of stay cables and stiffeners was installed, with which the problems are eliminated. This experience, he experienced even with the similar problems at its only briefly finished Deer Isle Bridge, brought him to the realization that the well- recognized Deflektionstheorie in its then form the aerodynamic effects of the wind not taken into account - which by shortly after the collapse of the planned Moisseiff Tacoma Narrows Bridge was proved on 7 November 1940. David B. Steinman responded by he knew the built from 1954 to 1957 and as his life's work respected Mackinac Bridge with extremely deep and stiff -makers from wind-permeable truss structures.