Thousands of years ago, people mainly used to explore the waters by boats. Even though they could easily trace their way back to the land during the daytime, it was somehow difficult to find their way home during the night. This escalated the need to design a tall structure that would help guide them to the desired landing location. This is how lighthouses came into being.
It is imperative to note that the first lighthouses were actually offered to us by nature. If you didn’t know, the ancient sailors mostly used natural landmarks such as glowing volcanoes for guidance. However, these structures could not provide adequate protection against the potentially dangerous forces of nature such as high winds, storms, waves which could easily push them against the rocks thus resulting in severe injuries or even fatalities. And so, the need for lighthouses as towers for protection arose.
Although most individuals usually think of a lighthouse as just a tall and white conical tower, we have many variations regarding the design of lighthouses. Depending on the location, a lighthouse can assume many shapes. If there is a flat area of land, the lighthouse can be very tall. On the other hand, where the ground is rocky and has high cliffs the lighthouse can be short and squat. Also, it could be octagonal, square, cylindrical or conical.
Initially, lighthouses were constructed using whatever materials which were readily available. Again, they were built to fit the climatic as well as the geographic conditions of a particular location. However, some of the current ones are typically designed from stones, concrete, cast iron, steel, and wood. Some are even constructed using tabby, which is a mixture of lime, water and shells thus are relatively more stable and durable.
So how does a lighthouse survives high winds and storms?
This is a very critical question. For us to find an answer to it, we must first understand the role of the modern construction of lighthouses. Thanks to technological advancements, especially in the world of structural engineering; modern, efficient lighting equipment allowed for the construction of bigger and more durable towers including those exposed to the sea. As you might assume, the primary purpose of lighthouses shifted toward the provision of adequate protection against inclement weather conditions such as reefs, rocks and most importantly, storms. Most of the latest lighthouses are constructed using hydraulic lime, which is a form of concrete. The lighthouse was also secured to the granite rocks with the help of dovetail joints and marble dowels. As a result, the dovetailing characteristic served to enhance the structural stability, especially against strong winds, waves, and storms.
To increase the stability of a lighthouse even further, the thickness of the tower had to be shifted towards the top while also ensuring that they are somehow curved inwards on a gentle gradient. This structural shape had the added advantage of enabling most of the energy of the storm to dissipate substantially, on impact with the walls of the tower. As technological continued to advance, the use of prefabricated skeletal steel or iron structures tended to be employed in the overall construction of lighthouses. This enhanced the stability as well as the durability of these historic structures.
There are instances where a lighthouse needs to be constructed of the water itself. Wave-washed towers are typical masonry structures designed to withstand the impact of water as well as a storm. A classic example is the Eddystone Lighthouse in Britain. Apparently, it is the design, as well as the types of the materials, used that play a significant role in ensuring that a lighthouse can withstand the wrath of storms.
There are at least twenty masonry lighthouses around the UK which are exposed to storm and wave action. Even though Mariners currently rely heavily on the use of satellite-based navigation systems, there is still the need to preserve and retain rock lighthouses as a natural aid for navigation. But, lots of questions remain unanswered regarding how well lighthouses would withstand the intense wave loading often associated with increased storminess.
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