Tuesday, July 7, 2015

Ever Wonder About Nautical Knots...?

Have you ever thought about how a ships speed was measured? Not exactly something most land lubbers would think about, for sure.

Actually the history behind measuring the speed of a ship is very interesting. I never knew about why or how the speed was measured myself until I read this article at History.com.

Why is a ship’s speed measured in knots?

Ancient mariners used to gauge how fast their ship was moving by throwing a piece of wood or other floatable object over the vessel’s bow then counting the amount of time that elapsed before its stern passed the object. This method was known as a Dutchman’s log. By the late 16th century, sailors had begun using a chip log to measure speed. In this method, knots were tied at uniform intervals in a length of rope and then one end of the rope, with a pie-slice-shape piece of wood (or “chip”) attached to it, was tossed behind the ship. As the vessel moved forward, the line of rope was allowed to roll out freely for a specific amount of time, which was typically tabulated with an hourglass. Afterward, the number of knots that had gone over the ship’s stern was counted and used in calculating the vessel’s rate of speed. A knot came to mean one nautical mile per hour. Therefore, a ship traveling at 15 knots could go 15 nautical miles per hour.

For a number of years, there was disagreement among various nations about the exact measurement of a nautical mile, which is based on the Earth’s circumference. In 1929, the international nautical mile was standardized at 6,076 feet; it was adopted by the United States in 1954. A nautical mile is different from a mile on land, which is based on walking distance. The Romans first defined a land mile as 1,000 paces or pairs of steps; it was set at its current measurement of 5,280 feet by Queen Elizabeth I in 1593.

Well, now we all know how fast our ship is going in knots. Might come in handy someday...you never can tell!

Coffee out on the patio again today.

7 comments:

Chickenmom said...

Learned something new again today, Mr. Hermit - thanks! I'll bring a fresh fruit salad for all!

linda m said...

Boy, I never knew that; learned something new today. Thanks for sharing this with us. Chickenmom, I would love some fresh fruit salad.

JO said...

Yep another lesson learned here Thank You!
Coffee on the patio sounds like a good way to start the day

HermitJim said...

Hey Phyllis...
I do love fruit salad, especially in the summer!
Thanks for stopping by today!


Hey Linda...
Always glad to share some new (to me) knowledge. I really like finding out this stuff.
Many thanks for dropping by today!


Hey Jo...
Sharing stories with friends over coffee is a greeat way to start any day!
Thanks, sweetie, for coming over today!

Dizzy-Dick said...

You managed to do it again; come up with something I didn't know. Thanks and keep up the great work.

Mamahen said...

I'm with the rest....learned something new and love me some fruit salad :))

Sixbears said...

Just to make things even more confusing for the nautical traveller: Most marine distances are measured in knots. However, the ICW (Intra Coastal Waterway) is marked out in land miles. Makes a big difference on a long day's sail.