Long ton (weight ton or Imperial ton) is the name for the unit called the "ton" in the avoirdupois or Imperial system of measurements that was used in the United Kingdom and several other Commonwealth countries before metrication.
One long ton is equal to 2,240 pounds (1,016 kg), 12% larger than a short ton and 1.6% larger than the 1,000-
The Imperial ton was explicitly excluded from use for trade in the United Kingdom by the Weights and Measures Act 1985.
A long ton is defined as exactly 2,240 pounds (a little over 1.016 tonnes, see below).
A pound is defined as exactly 453.59237 grams.
A long ton then is exactly 1,016,046.9088 grams, which is approximately 1,016 kg – conveniently close to a (metric) tonne.
The long ton arises from the traditional British measurement system.
A long ton is 20 hundredweight.
Each hundredweight is 8 stone.
One stone is defined as 14 pounds.
Thus a long ton is 20 × 8 × 14 lb = 2,240 lb.
View a Plan, drawing/diagram from any archive source in the UK and all dimensions will be in Imperial Measurements. It was only after metrification was introduced that dimensions were placed in metric dimensions. However a few from as early as the 1960’s may be in metric units.
UK Modellers had a great advantage when metrification was introduced as they were already used to converting Feet and Inches to Millimetres. And most model engineers were familiar with the majority of Metric systems. But to most modellers it was hardly noticed. Mainly Many think is because the Public houses still served Ale in Pints not litres.
Metrication in the United Kingdom is the process of introducing the metric system of measurement in place of imperial units in the United Kingdom.
Metrication in the United Kingdom remains partial. Most of government, industry and commerce use metric units, but imperial units are officially used to specify journey distances, vehicle speeds and the sizes of returnable milk containers, beer and cider glasses. Imperial units are also often used informally to describe body measurements and vehicle fuel economy. At school, the use of metric units is the norm.
The use of "supplementary indications" or alternative units (generally the traditional imperial units formerly used) was originally to have been permitted for only a limited period. However, that period had to be extended a number of times due to public resistance, until in 2009 the requirement to ultimately cease use of traditional units alongside metric units was finally removed
UK Lengths before metrification
One inch is divided into the following parts.
One thousands of one inch. 1/1000” Used in engineering practices and modelling.
64ths of one inch 1/64”
32nds of one inch 1/32”
16ths of one inch 1/16”
Eighths of one inch 1/8”
One quarter of one inch 1/4”
One third of one inch 1/3”
One half of one inch 1/2”
Also was divided into 10ths of one inch 1/10”
Inch, in, or 1" and 12 inches = 1 foot. Foot, ft. or 1'
3 foot (pronounced) 3 feet = 1 yard, or yd., and 1760 yards = 5280 feet = 1 statute mile
The term chain or chains is also used in UK Railway practice especially in curves and locomotive minimum radius that can be safely negotiated.
In modelling railways this is one point were the art of compromise is used especially when limited space is available. This can also determine which scale or gauge is used.
3 foot = 1 yard:
22 yards = 1 chain
100 links = 1 chain,
10 chains = 1 furlong
8 furlongs = 1 statute mile