US Measurement system
My biggest fear coming out here on attachment was the measurement system, besides people with guns and the MVA. It is essentially an archaic foreign language with little real utility in the modern metric world; a little like Gaelic. The best way to deal with issues like this is obviously to avoid them that is a little difficult here so I’ve had to just roll with it and enjoy the chaos.
This blog is not meant to be a definitive list of all forms of measurement, for that there is Wikipedia, rather a quick run down of the ones I’ve come across to help anyone coming out here on attachment in the future and also anyone that finds themselves in the economic shadow of the USA. Places, as Nick West has found out, like Montserrat use the US measurement system because the US is their chief supplier.
A few things to note are: firstly, the US measurement system is that it is not the same as British Imperial measurement. It’s mainly the same but not always, so beware! Secondly, the descriptions of how they came about are entirely logical as a unit of measure from when they were thought up. They just don’t really combine together quite as well as metric when combined and some funky factors start coming out. The big danger in trying to convert backwards and forwards is that calculator errors start to add up and cause issues with suppliers trying to over charge you for ‘non standard’ items.
The simple ones:
Feet (ft or ‘) and inches (in or “): Simple stuff, 12 inches to a foot, 3 feet to a yard. When you start to go smaller than an inch fractions are often used. On drawings the rough rules are: less than 2’ all measurements will be in inches only, after that feet and inches are mixed.
Pounds (lbs): 0.454kg. Straightforward, there is no use of the stone, but the hundredweight is used which is, as one might imagine, 100lb or 45.4kg.
Liquid Measure: Mainly for cooking and fuel to be honest but kids are taught: ‘two cups to the pint, two pints to the quart, four quarts to the gallon.’ Key points to remember here are that both the pint and gallon are smaller in the US than in the UK. That means that the people are less accomplished drinkers and that cars seem less efficient (not the only reason they seem less efficient!). A US gallon is 3.79l and a pint is 473ml.
Fahrenheit (F): The weather is as much a topic of idle conversation as it is in the UK. The difference being that out here it swings wildly across the seasons but the conversion is pretty straightforward. Fahrenheit = 1.8xCelsius + 32.
Where it starts getting interesting:
CFM because it takes too long to say cubic feet per minute is used for airflow in ventilation systems. 1m3s-1 is 2119fcm; which is close enough to 2000 for mental arithmetic.
PSI is pounds per square inch, which we are used to for car tyres etc. When speaking about gauge pressure it must be remembered to add 14.6 psi for atmospheric pressure to get the absolute pressure.
And onto my favourites:
BTU stands for British Thermal Unit, which I have personally taken the blame for on a number of occasions already. For dinner parties it is the energy required to heat one pound of water by one Fahrenheit. It is equivalent to 1055 Joules, fortunately close to 1kJoule!
Ton. Also called a ‘ton of refrigeration’ this is the heat absorbed by melting a short ton of pure ice at 32F in 24 hours. Out here it seems to be exclusively used for large chillers in HVAC units but is equivalent to 3.5kW.
Footcandle (fc). This is a measure of illuminance and is simply the light given out by a candle at a foot. This shows the weakness of the customary units as illuminance should be measured as luminous intensity per unit area. Fortunately its difficult to measure this with any more than10% accuracy and 1 fc is 10.7lux so close enough to 10 for measurement.
So that’s ‘how for now’. I assume some imperial units are still used by the old and bold out on site in the UK as that’s how people learnt their trades. What is it like in Australia? I’m sure Howard and Brad will have seen some pretty funky civil units! Please feel free to add any more in the comments section that people have seen. I will try to keep this up to date more as I go through the attachment.
Holdfast Training Services Trial Blog 
Of course very good Englishman knows that there’s actually 8 Stone to a hundred weight which is 112 pounds – We use it all the time to weigh church bells… not also that the US have the dry gallon and the wet gallon which are both different to one another and to the UK gallon.
112 pounds to a ‘long’ or ‘Imperial’ hundredweight Richard; we use the ‘short’ version out here, where to their credit, the maths is easier. I’ve not come across the dry gallon yet, and long may that stay the same!
I have just come across the ‘mil’ in terms of waterproof membrane thickness. It means ‘a thousandth of an inch’ in the UK we would call it a ‘thou’ to avoid confusion with a millimetre. A combination of a ruler and logic, supported by wikipedia were used to remove confusion out here.