1 knot: how many nautical miles per hour and kilometres per hour?

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Imagine finding yourself at the sea, off shore, far from any landmarks with no electronic devices to guide you or to help you measure the distance you’ve covered. Top this up with the limited food and water supplies and the threat of scurvy. That was exactly the situation the sailors centuries ago had to face on everyday basis.

As we know, necessity is the mother of invention, so they came up with a device, which gave rise to a unit later known as ‘the knot’.

The said invention was a chip log a.k.a. Dutchman’s log. It was a floating wooden panel with a long line spooled around it. The line had knots tied on it 14.4018 metres apart from each other. A chip log was cast over the stern of a ship and a sailor let the unrolling line slide through his fingers, and measured the time which passed from touching one knot to another with a 30-second sand-glass.

That was the origin of a unit called ‘knot’, also known as the nautical mile per hour (nautical mile = 1852 m), whose modern value is only 0.02% different from the original measure. It has been agreed in the 20th century that the knot is equal to:

1 knot =
1 nautical mph
1.852 km/h
1.150 779 mph
1.687 810 ft/s

At present, the knot is used in maritime as well as air navigation.

Did you know?

A nautical mile is different from the land mile. The land mile originated from the measure of 1,000 paces of the Roman soldiers. In 1593, Queen Elisabeth I established its length as 5,280 feet.





Top Discussions

~ School kid 2020-08-29 15:01:41

Note: if you included the whole of the UK Highland/s would have appeared by now

~ Paul 2020-08-28 00:24:09

They meant Lancashire, not Lincolnshire - a sloppy editorial error. Came about when part of the Furness area (especially...

~ Abba 2020-08-20 11:15:55

This is England, not uk