How Archimedes “built” the world’s largest tanker carrying cruise ships

It is shocking what Engineering can achieve today if properly taught by the theories of of great ancient Greek mathematicians. Take for example modern cruise ships. “But what happens when these giants of the seas need help mooring? “Even the largest semi-submersible heavy transport vessels, such as the Boka Vanguard, are recruited there.” notes CNN in an extensive article.

Made the 2012, the Boka Vanguard, 275 meters long is the largest ship of its kind that serves a specific purpose.

The colossal ship was built to carry oil and gas platforms, but is sometimes used to transport other ships – such as the Carnival Vista, the Carnival’s second largest cruise ship fleet of 133,500 tonnes and 325 meters which, in July 2019, after a problem had to be transferred.

The miracle of modern Engineering

The huge boat with the strange, seemingly, appearance has a central, open, completely empty deck while five huge vertical columns are located at the ends of its steel frame.

So what is the “miracle” of engineering in this case? The ship can and does sink so that only these five steel beams are visible and with surgical precision its potential cargo – whether it is an oil rig or a cruise ship – is transported to the right position, so that when it emerges it “sits” accurately on its deck.

The bridge and crew facilities are located at the largest and highest of these columns. “It simply came to our notice then Archimedes “(which means that every body that sinks in a fluid receives a buoyancy equal to the weight of the fluid it displaces) to lift some huge loads,” he explains. Mitchell Sei, General Manager of Engineering at Boskalis, of the Dutch company that built the Boka Banguard.

However, according to a CNN report, in addition to the Boka Vanguard, there are smaller semi-submersible heavy-duty vessels – such as the Transshelf and Treasure, which in 2017 had to carry USS Fitzgerald and USS John S. McCain who suffered damage after colliding with merchant ships, in two separate incidents, in Asian waters.

I found: the Principle of Archimedes

Archimedes’s Principle refers to the method he invented for determining the volume of an object with an irregular shape. According to the historian Vitruvius, King Jerome II had ordered a votive crown made of pure gold. Because he did not trust the goldsmith, he asked Archimedes to examine whether the gold had been counterfeited with silver.

Because the Archimedes had to solve the problem without destroying the crown, could not melt it in order to calculate its density and its origin. As he was bathing, he noticed that the water level in the bathtub had risen when he entered, and he realized that this effect could be used to determine the volume of the crown.

Assuming that the water is practically incompressible, the result of the immersion would be for the crown to displace an amount of water equal to its own volume. Dividing the mass of the crown by the volume of water displaced results in the density of the crown. This density would be lower than that of gold if some cheaper and less dense metals were added. Archimedes was so excited by his discovery that he went out into the street naked shouting “I found it! I found it!” Eureka!». Examination of the crown later proved that it had indeed been adulterated with an iron.

Nevertheless, the story of the golden crown does not appear in the well-known works of Archimedes. In addition, the practicality of the method he describes has been questioned, due to the high accuracy one needs to measure water displacement. Instead, Archimedes sought a solution of hydrostatics known as “Principle of Archimedes”, which he describes in his book “On floating bodies”. This principle states that a body immersed in a fluid receives a buoyancy force equal to the weight of the liquid it displaces.

Using this principle, it would be possible to compare the density of the golden crown with that of solid gold with the balancing of the crown on a balance with a gold reference sample, and then immerse the device in water. The difference in density between the two samples could cause the scale to be inverted accordingly.

Galileo considered that “it is probable that this method is the same as that of Archimedes, since, in addition to being very accurate, it is based on demonstrations presented by Archimedes himself.” In a text of the 12th century AD. entitled “Mappae clavicula” there are instructions on how to perform the weighings in the water in order to calculate the percentage of silver used, and therefore the solution of the problem. However, the Latin poem “Carmen de ponderibus et mensuris” of the 4th or 5th century AD. describes the use of hydraulic balance to solve the crown problem, and attributes the method to Archimedes.