Reading a Chart in Metres

[Astrid]

i believe even the kilo is based on distilled water rather than just plain fresh water

[s/v Jedi]

A kilo is slang and not normally used as unit of weight; the US congres has discontinued the use of the word in 1990. A kilo means a thousand. For weight, it's a kilogram (kg), 1,000 grams. For disance, a kilometer (km), 1,000 meters. And now one in normal use in the US for resistance: a kilo-Ohm (kOhm), 1,000 Ohms.

The kilogram is based on a prototype kilogram... Which is close but not exact to a liter of water.

cheers,
Nick.

[Astrid]

I stand corrected.

[jackdale]

Originally Posted by careka

i am metric. on all except, wind, then i use knots. and for boat speed also.

The marine world maintains the nautical miles as a measure of distance and knots (nautical miles per hour) for boat and wind speeds.

I believe aviation does the same.

[AussieGeoff]

Originally Posted by jackdale

The marine world maintains the nautical miles as a measure of distance and knots (nautical miles per hour) for boat and wind speeds.

I believe aviation does the same.

Correct. (Former pilot and Air Traffic Services officer.)

Navigational distances in aviation are measured in nautical miles and airspeed in knots in Australia anyway. ISTR some US aircraft use MPH (statute miles per hour I think) for their airspeed indicators for some unfathomable reason.

The relationship between latitude and the nautical mile is the reason for sticking to that in an otherwise metric world (standfast the USA).

In Australia, not sure about everywhere else but...:
Met mix and match a little, but only a little, they give barometric in millibars, wind speed and direction in knots and degrees, visibility in metres or kilometres, temp and dew point in degrees centigrade and altitude (clouds etc) in feet.

In Oz at least we still use feet for altimetry and not sure when (or if) that's going to change. IIRC, in the ISO standard atmosphere (1013.2mb @15c) 1mb of pressure = 32ft of altitude. Pilots have no trouble with this and it's been that way for over 30 years now.

So in an aviation met report, like this fictional one for Sydney:

METAR AYSY 0300 23010 9999 1CU050 23/06 1013

In this example, the wind is from 230 degrees magnetic at 10 knots, visibility in excess of 10km, 1 octa (eighth) cumulus cloud, base 5000 feet, the temperature is 23c and the dewpoint 6c, with a QNH (barometric pressure, that when set on the subscale of a sensitive altimeter will display the altitude of the altimeter above Mean Sea Level) of 1013 millibars.

All other measurements are in metric, runway lengths, aircraft weights etc.
For older aircraft it's often necessary to do some conversion, datum charts for older US aircraft are in inches and pounds and fluid capacities are in US gallons usually (v imperial gallons just to add to it.) Since the weight of fuel must be accounted for in weight and balance, there is some conversion required if you are using old weight and balance charts or data.

If you're a masochist, 1 nautical mile = 1852 metres, but I use nm and knots for navigation. Other weights and measures in metric.

The only real difficulty with using metric units v imperial is if you insist on converting back and forth, if you stick to one or the other its a non issue.
I know my draft in feet and in metres. I just need to know what the chargt

People that get into trouble are mostly those that try and mix and match. Ask NASA about that.


AussieGeoff

[swisscraft]

..just my five cents: use of metric in the US:

Some of U.S. military uses metric for several things:
- US Ground forces measure distances in "klicks" (yes its kilometers) - used now for 40 years I read..
- Most army firearms are measured in metric units, heavy weapon caliber is measured in millimeters
- A lot of Military vehicles are generally built to metric standards
- Timing in the US Army is not AM and PM its Zulu which is GMT 2200 for example (which comes from 22:00 as used in the rest of the world) - OK not metric issue but the better system won
I agree, Navy is still on imperial and knots and nm
The federal law against drugs defines the penalties in metric masses (why that - because the stuff is coming mostly out of metric countrys??)
Science and Medicine is General metric

To my knowledge just three countries are not using metric today: USA, Liberia and Myanmar/Burma

So don't tell me its easier or better to keep none metric, when you already use it to that extend....I guess Imperial had a chance, but at the point when a pound or a pint was not the same in the US and the UK imperial lost.

So at one point the US may have to adapt as well, probably as earlier as better - because you use it already that much. This is just creating addional cost and a handicap for the future which is maybe not the best thing in todays world. Or the US may of course found a "back to imperial unit" together with Liberia and Burma to change the world

[hoppy]

Originally Posted by swisscraft

.
To my knowledge just three countries are not using metric today: USA, Liberia and Myanmar/Burma

The UK is struggling to move to metric. The speed and distances on the road network are still in miles.

According to what I read in the media at the time, when they tried to convert weights and measures for food and beverage to metric some people thought it was the end of the world that they could no longer get a pint of milk LOL

When I was living in Dublin in the late 90's they still used miles, except on the EU funded motorway to the airport. The distances were in KM although I cannot remember if the speed limit was in KMH. I see that Ireland now has fully converted

[Wotname]

Originally Posted by s/v Jedi

A kilo is slang and not normally used as unit of weight; the US congres has discontinued the use of the word in 1990. A kilo means a thousand. For weight, it's a kilogram (kg), 1,000 grams. For disance, a kilometer (km), 1,000 meters. And now one in normal use in the US for resistance: a kilo-Ohm (kOhm), 1,000 Ohms.

The kilogram is based on a prototype kilogram... Which is close but not exact to a liter of water.

cheers,
Nick.

Technically the kilogram is a unit of mass not weight!

[Benz]

A few observations after reading down the list of postings.
1. Lord Nelson kicked butt
2. The Space thingy failed because some metric-loving fathead failed to read directions. If he had read the nomenclature properly, he would have assembled correctly.
3. All central american countries use some imperial in the midst of some metric. I bought gas by the gallon, measured my boat officially in feet, purchased groceries by the pound--they are not exclusively Metrical as some would claim.
4. The US military has failed to win any really decisive victories since they began their dalliance with Metric. But most of WWII was fought in Sensible. What was Japan using? Or Germany?
5. The Soviets were using the Metric system, and we still beat them to the moon. And where are the Soviets now?
6. The Metric system cannot properly express a concept as simple as one-third. Always chasing after that infinite repeating decimal.
I will not say that imperial is perfect (I think we should go exclusively duodecimal for everything--Time's already there, and money would be fine that way also), but Metric is not all it's hopped up to be.

[s/v Jedi]

Originally Posted by Benz

A few observations after reading down the list of postings.

5. The Soviets were using the Metric system, and we still beat them to the moon. And where are the Soviets now?.

How about the only nation left capable of launching humans to outer space?! The rest is either on the knees in pending bankruptcy or not capable yet...

cheers,
Nick.

[goboatingnow]

Originally Posted by hoppy

The UK is struggling to move to metric. The speed and distances on the road network are still in miles.

According to what I read in the media at the time, when they tried to convert weights and measures for food and beverage to metric some people thought it was the end of the world that they could no longer get a pint of milk LOL

When I was living in Dublin in the late 90's they still used miles, except on the EU funded motorway to the airport. The distances were in KM although I cannot remember if the speed limit was in KMH. I see that Ireland now has fully converted

The uk is not struggling to move to metric. It still had remnants of imperial measures especially as a generation schooled in imperial is still alive. But in practice while people use imperial measures from time to time it's a metric country.

Dave

[David_Old_Jersey]

Originally Posted by Benz

I will not say that imperial is perfect (I think we should go exclusively duodecimal for everything--Time's already there, and money would be fine that way also), but Metric is not all it's hopped up to be.

Or we could go back to Roman Numerals ....the current financial crisis would not be so big...........as no 0 (Zero)! Albeit may well be that for many of us the taste of seafaring life would involve being chained to an oar .

Whilst we are thread drifting a tad, the concept (and use of in the modern way) of zero is a fairly late development - hard to imagine something so obvious took so long to create.........and without a 0 could not have decimal.

0 (number) - Wikipedia, the free encyclopedia