Penobscot Narrows Bridge and Observatory
The Penobscot Narrows Bridge is a 2,120-foot-long (650 m) cable-stayed bridge that carries US 1/SR 3 over the Penobscot River. It connects Verona Island to Prospect, in the U.S. state of Maine. It opened in December 2006, replacing the Waldo–Hancock Bridge, built in 1931.
The Penobscot Narrows Bridge. Observatory is at top of west tower; access is provided via elevator from west tower base.
Bridge as seen from the west in 2013
Bridge with the old Waldo-Hancock Bridge
Penobscot Bridge, August 2006
A cable-stayed bridge has one or more towers, from which cables support the bridge deck. A distinctive feature are the cables or stays, which run directly from the tower to the deck, normally forming a fan-like pattern or a series of parallel lines. This is in contrast to the modern suspension bridge, where the cables supporting the deck are suspended vertically from the main cable, anchored at both ends of the bridge and running between the towers. The cable-stayed bridge is optimal for spans longer than cantilever bridges and shorter than suspension bridges. This is the range within which cantilever bridges would rapidly grow heavier, and suspension bridge cabling would be more costly.
The Russky Bridge in Vladivostok has a central span of 1104 metres. It is the world's longest cable-stayed bridge.
Øresund Bridge from Malmö to Copenhagen in Sweden and Denmark
Chain-stayed bridge by the Renaissance polymath Fausto Veranzio, from 1595/1616. Prior to industrial manufacture of heavy wire rope (steel cable), suspended or stayed bridges were firstly constructed with linked rods (chain).
Abdoun Bridge, Amman, Jordan, example of an extradosed bridge