Aerial Bridge History

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CHAPTER 1: INTRODUCTION (1.1) VERTICAL LIFT MECHANISM The bridge has a unique feature that it based on the “Vertical Lift Mechanism”, its middle (movable) part lifts to give way to the ship passing by thus maintaining waterways transport. Till now no bridge such has been built in India. (1.2) HISTORY OF VERTICAL LIFT MECHANISM (BRIDGE) The Aerial Lift Bridge (earlier known as the Aerial Bridge or Aerial Ferry Bridge) is a major landmark in the port city of Duluth, Minnesota. The span is a vertical lift bridge, which is rather uncommon, but it began life as an extremely rare transporter bridge—the first of just two such bridges ever constructed in the United States. Originally built in 1905, the bridge was upgraded in 1929–30 to the current…show more content…
The history of engineering is as old as mankind itself, and it is without doubt that technical progress and the rise of human society are deeply interwoven. Bridges have often played an essential role in technical advancement within Civil Engineering. The development of important types of bridges and the changing use of materials and techniques of construction throughout history will be dealt with in the first part of this chapter. Notably, manifold legends and anecdotes are connected with the bridges of former eras. Studying the history of a bridge from its construction throughout its life will always also reveal a fascinating picture of the particular historical and cultural background. The second part of this chapter introduces the main challenges that the current generation of Bridge engineers and following generations will face. Three important areas of interest are identified. These are improvements in design, construction, maintenance, and rehabilitation of abridge, application of high-performance materials, and creative structural concepts. As Technology advances, many new ways of innovation thus open for the bridge…show more content…
The vertical lift offers several benefits over other movable bridges such as the bascule and swing-span bridge. Generally speaking they cost less to build for longer moveable spans. 2. As a result, heavier materials can be used in the deck, and so this type of bridge is especially suited for heavy railroad use. 3. Although most vertical-lift bridges use towers, each equipped with counterweights, some use hydraulic jacks located below the deck. 4. The counterweights in a vertical lift are only required to be equal to the weight of the deck, whereas bascule bridge counterweights must weigh several times as much as the span being lifted. (1.6) ADVANTAGES & LIMITATION OF VERTICAL LIFT MECHANISM ADVANTAGES: 1. An advantage of making bridges moveable is the lower cost, due to the absence of high piers and long approaches. 2. For seldom-used railroad bridges over busy channels, the bridge may be left open and then closed for train passages. 3. While moveable bridges in their entirety may be quite long, the length of the moveable portion is restricted by engineering and cost considerations to a few hundred feet.

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