¿Did you know why is the speed of ships measure in knots?

The fact that there is a unit of measurement called nautical knots is not just a coincidence, it has a whole history behind it. In this post you will find out why the speed of ships is measured in knots as well as the equivalences with the other units of measurement and how many knots some of the most famous ships in history can go at so that you can get an idea of how fast they can go. Are you ready to be surprised?

History

This was no more and no less than the 12th century before the creation of the compass. At that time, sailors were still afraid of falling off the edges of the Earth and therefore used to sail close to the coast. However, some brave men put this fear aside and decided to set sail on the high seas in complete ignorance of such things as speed and course.

As for the course, once the voyage was underway, their best allies were the sun and the stars when the days were clear. Another option was to be guided by the ocean waves, noting their alignment with respect to the rising sun, the setting sun and the stars. All these methods were imprecise and depended on many factors.

Calculating speed was even more complicated. It was in the 16th century, 400 years after the creation of the compass, that two methods of estimating the speed of a ship were tested. The first was to measure the time it took for a ship to pass an object thrown from the bow. Later, a more accurate system was devised in which a piece of wood was thrown overboard, tied to a rope with a knot every few yards. As the ship moved forward, the driftwood would pull on the line. When a certain time limit was reached, it was picked up and the knots were counted, which is why the speed was calculated using this unit of measurement, which is still in use today. The device used was called a "slider" or "nacelle slider" and the calculation of the speed was completed by measuring the elapsed time with an hourglass.

Once the speed was known, the navigator determined the distance covered in a day and reflected the progress made towards the destination point by drawing a line on a sea map. Ocean currents and side winds could throw the ship off course, so the steering modifications required to maintain the course had to be calculated and noted periodically. Thanks to the estimation procedure, Columbus managed to sail to and from Spain to America more than five hundred years ago, and his detailed charts allow today's sailors to reproduce his extraordinary voyage.

Today, instruments for measuring speed have evolved enormously. From the original wooden ones, to mechanical and electro-mechanical slides, to today's increasingly modern electronic systems, which integrate with other elements of the ship such as satellite and radar.

Now you know why boat speed is measured in knots, but it is also important to know the equivalence.

How much is one knot?

To get a clearer idea of speed in other measurements that we are more familiar with, we can use the following conversion formulas:

- One knot would equal 101.268591 feet per minute.

- One knot equals 1.687810 feet per second.

- One knot equals 0.514444 metres per second (m/sg).

- One knot equals 1.150779 statute mile per hour (mp/h).

- One knot equals 1.852 kilometres per hour (km/h).

How fast can the world's famous ships go?

What better example to put this curious unit of measurement into "practice" than to know how many km/h the most famous ships in the world from our previous post can reach ;).

- RMS Titanic: This movie ship had a design speed of 21 knots (39 km/h) and a top speed of 23 knots (43 km/h).

- La Niña, La Pinta and Santa María. It is not entirely clear at what speed these three caravels that allowed Christopher Columbus to discover America could reach, but La Pinta, whose main characteristic was its speed, in its logbook, it was mentioned that in one night it had sailed at 15 miles per hour (24 km/h), so its speed would be about 11 knots, the same as an average cargo ship of today.

- Battleship Bismark: Its powerful turbines allowed the ship to reach a speed of 30.8 knots (57 km/h), making it the fastest battleship in the world when it was built; it had a range of 8,525 nautical miles at 19 knots and 4,500 nautical miles at 28 knots.

- The aircraft carrier Enterprise: This US Navy Yorktown-class carrier was the only surviving carrier of its class in World War II. It weighed 21,000 tons and travelled at a maximum speed of 32.5 knots (60.7 km/h).

- The Victory: This ship, which is still in service today, can reach a speed of 8 or 9 knots (16 km/h).

- The Flying Dutchman: It is quite a mystery, one of its many legends of terror says that it was capable of making the crossing between Amsterdam and Indonesia in only three months, it had such an amazing speed that its captain had sold his soul to the devil.

- The Nao Victoria: Taking 164 days to make what would be the first round-the-world voyage by boat, unfurling all sails to the winds that propelled her to her destination, the Nao Victoria could reach an average speed of 3.5 knots (6.4 km/h).

In this post we have managed to solve the question of why the speed of ships is measured in knots, and not only that but we have also seen their equivalents and discovered how fast the most emblematic ships in history were going. 

We are sure that after reading this post you have learnt a little more about the nautical world. Don't forget to follow us on social media to keep up to date with all the curiosities and interesting facts about the sea. Will you be able to stay afloat with everything that's coming up?