Timeline of three longest spans

This is the timeline of the 3 longest man-made spans in the world, all categories, that at least have the strength to carry some persons. It can be the span of any type of bridge, aerial tramway, powerline, structural ceiling or dome etc.

Overview

In this timeline, only spans that were still standing a particular year are considered for that year. This is perhaps more fair than a timeline of the records of all time, because the old figures might be incorrect. At the points when the old spans falls, new spans with more certain figures are allowed to appear in the timeline. This is a top 3 list of existing longest spans per day.

When several structures of the same length exists, the oldest is counted as the longest.

Some more rules for this timeline follows as: Only the length of the horizontal projection of the span, that is the distance that can be measured on a map, counts. When the two supports have different height above the sea level the distance between them is longer than the horizontal projection of the distance, but this longer distance doesn't count. This is because it is more difficult to build a 100m horizontal span than a 100m span that is tilted let's say 45 degrees, as if it was the support for an escalator. The stress in the material is higher for the horizontal span, creating higher engineering difficulty, so only the length of the span perpendicular to the force of gravity counts. For many structures in the timeline it is unfortunately not known if the stated length is the desired horizontal projected length, or the direct "laser beam" length.

Spanning structures in water counts only if they would still be standing if the water was removed.

The longest 5376 m Ameralik Span and others have pylons that are not completely man-made. The lines are attached to small man-made pylons that in turn stand on the mountain, which forms the rest of the height of the pylons required for a span of this huge length. If the present man-made pylons were placed in a flat area there would be no span, because the lines would touch the ground. It could be argued that this span should not appear in the timeline because the pylons are not completely man-made. However, as the focus of the engineering design task here is not to make something that is tall, but to make something that is long, it is concluded that this type of span is enough man-made to be in this timeline.

The spans of ancient structures are short. It would have been easy for somebody to tie a long rope between two poles and this way create a very long ancient span. However, the ancient people had no reason to do this, and if they did it's not documented and therefore not in this timeline. Only with the discovery of electricity and radio communication people had a reason for tying a wire between two poles, thus creating the simplest form of long spans.

The span of Pantheon, Rome is not 43.3 m because there is a hole at the top of 9.1 m, so the span have been reduced with the size of the hole to 34.2 m. The span of any structure is measured the following way: Place the largest possible imaginary horizontal circular disk under or inside the structure, barely touching any load-bearing pillars or walls, or parts used to stabilize the structure like wires. The disk must also not encircle any objects of this kind. At least one diameter of the disk have to be completely covered, that is rain-sheltered, by the structure. The span of the structure is diameter of the disk. Now, if the structure contains a hole at the center of the disk, as in the case of Pantheon, the span is measured by using a second largest possible imaginary horizontal circular disk that is smaller than the first disk and completely encirceled by it. At least one diameter of the second disk have to be completely covered by the structure. The span of the structure is diameter of the second disk. Applying this method of measurement to Pantheon gives the previously stated result 34.2 m. The method works for many types of structures.

Note: almost all information in this timeline have uncertainty.

Longest Spans 1813–present

• 5376m Ameralik powerline, Greenland
• 3646m Messina powerline, Italy
• 1280m Golden Gate Bridge
• 1067m George Washington Bridge, New York
• 2580m Herzogstand Radio Antenna, Germany
• 549m Quebec Cantilever Bridge, Canada
• 521m Forth Cantilever Bridge, Scotland
• 486m Brooklyn Bridge, New York
• 387m Niagara Clifton Bridge, USA–Canada
• 322m Roebling Suspension Bridge, USA
• 317m Lewiston-Queenston Ruin, USA–Canada
• 317m Lewiston-Queenston Bridge, USA–Canada
• 308m Wheeling Suspension Bridge, West Virginia
• 271m Zaehringen Bridge, Switzerland
• 176m Menai Suspension Bridge, UK
• 137m Iron Bridge, Tibet
• 4850m Sognefjord powerline 1, Norway
• 3500m Omega antenna, Norway
• 2831m Blanche Tramway, France
• 3248m Kootenay powerline, Canada
• 1782m Bosporus powerline, Turkey
• 570m Rhine River powerline, Germany
• 521m Forth Cantilever Bridge, second span
• 387m Second Falls View Bridge, USA–Canada
• 234m Niagara Falls Bridge, USA–Canada
• 206m Hungerford Bridge, UK
• 200m Port-Sainte-Marie Bridge, France]]
• 137m Union Bridge, UK
• 120m Philadelphia Footbridge, Pennsylvania
• 104m Luding Bridge, China
• 3019m Peak 2 Peak Gondola, Canada
• 2353m Sandia Peak Tramway, USA
• 564m Ambassador Bridge, USA–Canada
• 488m Williamsburg Bridge, New York
• 198m La Roche-Bernard Bridge, France
• 190m Pont Charles-Albert, France
• 103m Colossus Bridge, Pennsylvania

Longest Spans 62 BC–1813

• 137m Iron Bridge, Tibet
• 48m Castelvecchio Bridge, Italy
• 72m Trezzo sull'Adda Bridge, Italy
• 45m Pont du Diable, France
• 43m Pantheon, Rome
• 63m Maya Bridge at Yaxchilan, Mexico
• 52m Trajan's Bridge, Romania–Serbia
• 32m Ponte di Augusto, Italy
• 24m Pons Fabricius, Italy
• 104m Luding Suspension Bridge, China
• 100m Tashigang Chain Bridge, Bhutan
• 45m Apurimac bridge, Peru
• 38m Malabadi Bridge, Turkey
• 38m Temple of Apollo, Italy
• 52m Trajan's Bridge, other span
• 31m Ponte Saint-Martin, Italy
• 24m Pons Fabricius, second span
• 76m Phuntsholing Chain Bridge, Tibet
• 37m Zhaozhou Bridge, China
• 37m Puente del Diablo, Spain
• 35m Ponte do Porto, Portugal
• 34m Severan Bridge, Turkey
• Ponte di Pietra, Italy

Known incorrect construction years

In the timeline above, some completion years are given which are known to be incorrect. The following guesses were used to generate the graphic, but should not be taken as definitive.

See also

• List of spans
• List of longest suspension bridge spans
• List of longest cantilever bridges
• Arch bridge

External links

• http://www.bridgemeister.com/index.htm
• http://en.structurae.de/index.cfm
• Port-Sainte-Marie Bridge http://www.bridgemeister.com/bridge.php?bid=1765
• Philadelphia Footbridge http://www.bridgemeister.com/bridge.php?bid=20
• http://www.bhutanstudies.org.bt/admin/pubFiles/Chakzampa.pdf Chakzam/Iron Bridge p78, Tashigang Bridge p94, Phuntsholing Bridge p69
• :pt:Ponte do Porto, http://en.structurae.de/structures/data/index.cfm?id=s0020363