Suspension Bridges: How are They Constructed

Poyab Bridge under construction, Freiburg, Switzerland
Poyab Bridge under construction, Fribourg, Switzerland. Photo: iStock

Suspension bridges are among the most impressive engineering feats, with their long spans and elegant designs. These bridges rely on the strength of cables and towers to support the cables which provide safe passage over rivers, gorges, and other obstacles.

In this article, we will explore how suspension bridges are constructed.

Bridge Suspension Cables

Cables on Royal George Bridge - Colorado
Suspension Cable on Royal George Bridge – Colorado. Each cable is made up of 2100 galvanized steel wires. Photo: ©SMS

Once the towers are in place, the cables can be installed. The cables are assembled on the ground and then lifted into place using cranes or other heavy machinery. The cables are anchored to the towers using large steel plates, which are bolted to the tower and embedded in the concrete foundation. The cables are also anchored to the ground using massive concrete blocks, which are buried deep below the surface of the earth to provide a secure anchor point.

Suspension cables are an essential part of the suspension bridge design, which hold up the load (bridge deck or road) and are braced by towers on each side of the bridge. Anchoring the cables to the towers, or sometimes to the ground on both sides, enables the load to stretch across the entire span of the bridge without any further bracing required (e.g. truss or arches holding it up).

The cables are typically made of high-strength steel wires woven together that act as one unit. These cables can weigh thousands of tons and must be anchored securely to the towers and the ground.

The tension in the main cables is transferred to the suspension cables, which then transfer the weight of the bridge deck to the towers and anchorages at the ends of the bridge.

The towers provide additional support to the bridge and help to distribute the weight of the bridge evenly.

In the photo above of the Royal Gorge Bridge in the Rocky Mountains, Colorado, each of the cables consists of 2100 galvanized steel wires.

Bridge Deck

With the cables in place, the next step is to construct the bridge deck. The deck is typically made of steel or reinforced concrete and is suspended from the cables using hangers. The hangers are attached to the cables using large steel pins and are spaced at regular intervals to provide support for the deck. The deck is often assembled on the ground and then lifted into place using cranes or other heavy machinery.

Once the deck is in place, the final touches can be added. This includes the installation of guardrails, lighting, and other safety features, as well as the application of the final coat of paint. The bridge is then inspected to ensure that it meets all safety standards and is ready for use.

Summary

In conclusion, suspension bridges are an incredible feat of engineering, requiring meticulous planning, precision construction, and rigorous safety testing. The construction process involves the careful placement of towers, the installation of massive cables, and the suspension of the bridge deck. Despite the challenges involved, suspension bridges have become an iconic symbol of human ingenuity and technological advancement, connecting people and places all over the world.

The Impact of Climate Change and What We Can Do About It

Illustration of the effects of climate change, showing grass and then barren ground
Photo: iStock

Climate Change Overview

Climate change is one of the most pressing issues facing our planet today, and its significance cannot be overstated. It is a global problem that affects every aspect of our lives, from the environment to the economy, and if left unchecked, it has the potential to cause devastating consequences

In this essay, we will explore why climate change is so important and why urgent action is necessary to mitigate its effects.

The Environment

Oil Rig
Photo: Wikipedia CC

First and foremost, climate change also referred to as ‘global warming’, poses a major threat to our ecosystem. The Earth’s climate is a complex entity, and any changes to it can have far-reaching consequences.

The continuous rise in greenhouse emissions such as pollutants from cars, planes and industrial complexes is what is causing temperatures to rise. 

For example, these rising temperatures and changing rainfall patterns can lead to more frequent natural disasters such as hurricanes, floods, and droughts. These weather events can destroy homes and infrastructure.

The temperature has risen about 1.8 degrees F (1 C) over the last century, but most of this rise has occurred within the last four decades.

If this small rise in temperature doesn’t sound significant, it is and has already caused numerous issues across the globe. 

The natural disasters that are occurring because of this can also lead to a significant economic burden, as governments and individuals would be forced to spend billions of dollars to rebuild damaged infrastructure and homes, as discussed later in this article.

Upsetting the Balance of Nature

Koi fish
Photo: Pexels

Wildlife will not be immune to this changing environment. As temperatures rise, it is becoming increasingly difficult for some animals to adapt.

Some species could become endangered or even go extinct, and even now, polar bears are struggling to find food as the Arctic ice melts, and coral reefs are dying due to rising ocean temperatures. 

The potential results can have problematic effects on our crops and argriculture. Crop failures will lead to increased food prices and potential famine in certain parts of the world. Disruption in supply chains can lead to food and water shortages.

A negative change in the climate will also cause sea levels to rise, which can lead to flooding and erosion of coastlines, further exacerbating the damage caused by natural disasters. 

The Human Effect

Amazed Woman
Photo by Sincerely Media on Unsplash

Climate change can have a significant impact on our health. As temperatures rise, so does the risk of heat-related illnesses such as heat stroke and dehydration.

Increased air pollution due to industrialization and deforestation can result in respiratory problems, heart disease, and even cancer. It can also lead to the spread of diseases such as malaria and dengue fever, as warmer temperatures create more favorable conditions for disease-carrying insects to proprogate and spread to new regions.

Poor air quality resulting from increased pollution can exacerbate the situation as well. Respiratory problems such as asthma may be more commonplace and can also increase the risk of heart disease and stroke.

These health issues will disproportionately affect vulnerable populations, such as children, the elderly, and people with a pre-existing medical conditions. In populated communities, such as large cities, they can increase exponentially.

The Economy

As extreme weather events become more frequent, there is an increasing risk of damage to infrastructure, such as buildings, roads, and bridges. In addition, its impact on prices for food will be detrimental across the world.  Building sea walls and other protective infrastructure, is likely to be more common and subsequently very costly.

Is There Light At the End of the Climate Tunnel?

Offshore Wind Turbines
Digital Illustration of an offshore Wind Turbine

The transition to a low-carbon economy can create economic opportunities, such as the development of renewable energy sources and the creation of green jobs. ant economic issue. The effects of climate change can disrupt agriculture, leading to lower crop yields and higher food prices. This can have a disproportionate impact on low-income countries, where agriculture is a significant part of the economy. 

Given the significant impacts of climate change on the environment, human health, and the economy, we must take action to address this problem. The good news is that there are many things that individuals, governments, and businesses can do to mitigate the effects of climate change.