Knots versus mph/kph

[Hugz]

I was about to suggest on the moderators meeting thread that we should keep to maritime parlance. It has irked me for a while to see frothblowers describing their boat speed in mph or kph. I just now discovered that English waterway's speed markers are in mph. When did this moral travesty take place? A knot is a nautical mile travelled in an hour. A nautical mile is a minute of latitude. The knot has a rich and centuries old tradition. In 1593 Queen Elizabeth 1 decreed that a nautical mile was 5280 feet. I'm not suggesting that we tie knots in a rope and measure its passing with a sandglass, though....

I note in Australia, NZ and Bermuda (am l correct?) still use the knot. What about Canada? I would be disappointed if they too have dispenced with the knot.

This is more upsetting than when l discoverd that fish and chips in Cornwall were no longer wrapped in newspaper.

Thank God and the Queen that Kiwis won the Americas Cup in knots.

I'm a traditionlist.

[Keith.P]

I think that its a matter of Knots at sea, maritime law and all that.
Inland waterways use MPH/KPH, it's just the sign of the times Hugo, plus I don't think the common satnav's works in knots.

[Hugz]

Our inland waters are in knots... others?

Annoys me that my vernier caliper measures in inches to a decimal point. Where did that come from?

and

gps knots.png (152.46 KiB) Viewed 5679 times

[Keith.P]

That's no going to work on a seagull.

[Charles uk]

The vernier is OK on a Seagull as everything pre the 170 is Imperial, just to vex the Aussies!

[Hugz]

I'm going to sound stupid here but if I buy a ruler in England will it have inches broken into 10 intervals ie .1 of an inch or will it have 1/16", 1/8", 1/4" etc?

Downunder currency went to decimal in 1966 and measurement to decimal in 1970 ish. ie metres.

I still think of a perfect Shiela as 36/24/36 though. Have they been re-calibrated as well?

[Keith.P]

Charles was telling me about the pre-decimal money 1971, not that I know much about it, I was only seven, It's quite interesting, he seemed to be very knowledgable, definitely a age thing.
I have got a half descent silver coin collection, going back to Elizabeth I, I still don't get it with the old money.

[Hugz]

You don't have silver thruppences in your xmas pudding anymore? Probably a tradition instigated by dentists....

Ok, I've figured out why my digital vernier calipers are doing my head in. I bought from Aldi but it is made in China. Indeed my imperial inch digitally reads in 1000 segments whereas I need a caliper that reads to 1280 segments per inch which with a quick mental calculation will give 1/16", 1/8" etc. As they say "you get what you pay for".

[Nudge]

Annoys me that my vernier caliper measures in inches to a decimal point.

Well put it into metric then! I not old enough to get into the inch / metric thing.

I still think of a perfect Shiela as 36/24/36 though. Have they been re-calibrated as well?

So I guess you loke them small then? My 14 yr daughter is bigget than that (and she is not big)

Oh, and yes we use Knots here..... I have the GPS set in KPH because it reads to a smaller anount, other than that Im with you on the Kt / KPH thing.

[Hugz]

Annoys me that my vernier caliper measures in inches to a decimal point.

Well put it into metric then! I not old enough to get into the inch / metric thing.

Seeing gulls are imperial (apart from 18mm spark plugs and modern ones) I wish to measure in imperial.

Jacob, read no further.

and https://www.youtube.com/watch?v=Y8LSJjWvsP4 I'm happy with that calibration

[Nudge]

I understand now

[Liam2k3]

All the verniers i have come across measure in decimal inch. Especially the digital ones.
But heres an odd one. 1/50 of mm

Plus some ref tables for decimal inch to metric and fractions

[Charles uk]

All my non digital Mitutoyos have the vernier scale set in 0.02 mm.

1/50 of a mm is less than 1 thou Imperial.

[Liam2k3]

Yeah but we dont write down

245 23/50 mm
It
245.46mm

[Sandro_Picchio]

In this Country Nautical Miles and Knots are used for any and every distance and/or speed at sea, and to me this is correct for the reasons said by Hugh.
On inland waterways instead Kilometers are used.

About mechanical measures, metrical system is unbeatable for the simplicity of reckoning. I am amazed when I think how imperial engineers could do, often mentally, all the adding and subtracting of dimensions needed for designing and making any machine part.
By the way, my caliper's (non digital, born in 1955) inches scale is divided in 1/2s, 1/4s and so on.
The fractional division is more convenient for measuring imperial parts.
Sometimes you can tell if an unknown part is imperial or metric by seeing that a dimension is a round figure on one scale or the other.
I think that the decimal division of inches is mainly used in the US. American members could confirm or not.