18-20 inch gauge railways has been used extensively in both estate, mining, industry and military light railways. We are interested in all these areas there this gauge has been used. Only exception is for pure park/tourist lines, which is more like a very big garden railway.
For the ones interested, there is a rather distinct difference between 15in, 18in and two foot gauge railways. In a 15in gauge coach you can´t even stand up straight. In a two foot gauge coach, it looks more like the bigger railways, even if a lot narrower.. In an 18in gauge coach it is just right! You need to lower the coach rather much to be able to stand up in it. You can´t have normal height on vans because of the risk of getting top-heavy. All this, along with the rather special designs which has been developed, makes this type of railway stand out rather much compared to others.
In United Kingdom there was several 18inch gauge lines.
USA mostly had 18inch lines in or at mines.
Sweden did not have any 18inch lines as far as I know, but I am not giving up the research ..There should at least by some mine railways, but sofar no details found. Only found a few 500mm gauge peat lines.
For Denmark I included an article about there 700mm gauge beet railways instead.