Suspension Bridge

How Suspension Bridge is made

How Suspension Bridge is Made: In a Suspension Bridge, the Traffic carrying Deck is supported by a series of Wire Ropes that Hang from Massive Cables Draped between Tall Towers.

Raw Materials: Many of the Components of a Suspension Bridge are made of Steel. The Girders used to make the Deck Rigid are one example. Steel is also used for the Saddles, or open Channels, on which the Cables Rest atop a Suspension Bridge Towers.
Steel is Drawn into Wires its Strength Increases: Relatively Flexible Bundle of Steel Wires is Stronger than a Solid Steel Bar of the Same Diameter. This is the reason Steel Cable is used to Support Suspension Bridges. Some Suspension Bridges, the Steel Wires Forming the Cables have been Galvanized. The Towers of most Suspension Bridges are made of Steel, Although a few have been built of Steel Reinforced Concrete.

Design: The Geology of the site provides a Foundation for the Towers and Cable Anchorages, and may be Susceptible to Earthquakes. The Depth and Nature of the Water being Bridged, Fresh or Salt Water, and Strength of Currents may affect both the Physical Design and the choice of Materials like Protective Coatings for the Steel.
In navigable waters: It may be Necessary to Protect a Tower from Possible Ship Collisions by Building up an Artificial Island at its base. New Bridge Designs have been Tested by Placing Scale Models in Wind Tunnels. For Long Bridges, it may be Necessary to Take the Earth Curvature into account when Designing the Towers.

The Manufacturing Process: Construction of a Suspension Bridge Involves Sequential Construction of the three: Tower Constructions that will Stand in Water begin with Caissons that are Lowered to the ground Beneath the Water, Emptied of Water, and Filled with Concrete in Preparation for the Actual Towers.
Tower constructions: That will Stand in Water begin with Caissons that are Lowered to the ground beneath the Water, Emptied of Water, and Filled with Concrete in Preparation for the actual Towers.
Major components: Towers and Cable Anchorages, the Support Cable itself, and the deck Structure.

Tower Foundations:
Prepared by Digging Down to a Sufficiently Firm Rock Formation. Some Bridges are Designed so that their Towers are Built on Dry Land, which makes Construction easier. If a Tower will stand in Water, its Construction Begins with Lowering a Caisson to the ground Beneath the Water; removing the Water from the Caisson Interior allows Workers to Excavate a Foundation without actually Working in Water.
Anchorages Structures that support the Bridge Cables: are Massive Concrete blocks securely attached to strong rock formations. When the Towers and Anchorages have been completed, a Pilot Line must be strung along the Cable Eventual Path, from one Anchorage across the Towers to the other Anchorage. each of these Blocks, in Turn, Consists of three Horizontal Sections. After Completing a block on each Column, the "bootstrapping" Crane was Jacked up to the next level, where it lifted the sections of the next Layer into Place.

Anchorage Construction: Anchorages are the Structures to which the ends of the Bridge Cables are secured. They are Massive Concrete Blocks Securely attached to strong Rock Formations. During Construction of the Anchorages, strong Eyebars are Embedded in the Concrete. Mounted in Front of the Anchorage is a Spray Saddle, which will Support the Cable at the Point where its individual Wire Bundles fan out each Wire bundle will be secured to one of the Anchorage eyebars.
Cable construction: When the Towers and Anchorages have been completed, a pilot line must be strung along the Cable Eventual Path, from one Anchorage across the Towers to the other Anchorage. Various methods can been used to Position the Pilot line.

To begin Spinning the Cable: a Large Spool of Wire is Positioned at the Anchorage. The free end of the Wire is Looped around a strand Shoe. Between the Spool and the Strand Shoe, the Wire is looped around a Spinning wheel that is mounted on the Pilot line. This Wheel Carries the Wire across the Bridge Path, and the Wire is Looped around a strand Shoe at the other Anchorage; the Wheel then Returns to the first Anchorage, Laying another Strand in Place.
Until a Bundle of the Desired number of Wire Strands is Formed: During the Spinning, Workers Standing on the Catwalk make sure the Wire Unwinds Smoothly, freeing any Kinks. As Spools are Exhausted, the end of the Wire is Spliced to the Wire from a new Spool, forming a continuous Strand. When the bundle is thick enough, Tape or Wire straps are applied at intervals Once the Vertical Cables are attached to the main support Cable, the Deck structure must be Built in both directions from the support Towers at the Correct rate in order to keep the Forces on the Towers balanced at all times.

Vertical Cables are Attached to the Main Support Cable: The Deck Structure must be Built in both directions from the support Towers at the correct rate in order to keep the forces on the Towers balanced at all times. A moving Crane lifts Deck sections into Place, where workers attach them to previously placed sections and to the Vertical Cables that hang from the main Suspension Cables. To keep the Wires together. The Wire coming off the Spool is cut and secured to the Anchorage. Then the process begins again for the Next Bundle.
Number of Bundles Needed for a Complete Cable Varies: On the Golden Gate Bridge it is 61. When the proper number have been Spun, a special arrangement of radially positioned jacks is used to compress the Bundles into a compact Cable, and Steel Wire is Wrapped around it. Steel Clamps are mounted around the Cable at Predetermined intervals to serve as Anchoring Points for the Vertical Cables that will connect the Decking to the support Cable.

Deck construction: After vertical cables are attached to the main support cable, the deck structure can be started. The structure must be built in both directions from the support Towers at the correct rate in order to keep the forces on the Towers balanced at all times. A moving Crane that rolls atop the main Suspension cable lifts deck sections into place, where workers attach them to previously placed sections and to the vertical cables that hang from the main Suspension cables, extending the completed length.
Finishing: When the Deck Structure is complete, it is Covered with a base Layer and Paved over. Painting the Steel Surfaces and installing Electric Lines for lighting are examples of other Finishing Steps. Ongoing maintenance Procedures begin.


Wishing you all the best,
http://www.seeyourneeds.in