What often amazes me is the various colours sand, gravel and soil can come in. For example, I have seen ballast on the real railway which in the area where I came from was light grey, but when it was re-ballasted with pink ballast and a modeller went to a level crossing, took a few pieces of the new pink ballast, took it home and crushed it up for his railway (As he modelled an up-to-date railway scene), only to find that when he applied this new ballast, it was sticking to the underside of his locos as he found it was magnetic!
But yes. Ballast in all its colours is interesting. It basically is small stones so I guess it will vary a lot compared to where they quarried it. In the early years I when building the railways, in coastal areas, if they had pebble beaches, I would imagine they would have started off using them if they were a suitable size?
Have a mix of sand and small pebbles on the beach where I live now. Is a lovely beach and as not many people know about it, and we happen to live next to the footpath that goes down to it, so there are only room to park about two or three cars near the path opposite, so we find that the other beaches are crowded (Tourist area) and we get our beach to ourselves as a river is inbetween our nice long beach and their beaches! If we pass or see six people we think it is busy down there!
The first time we went down there, Mum and I saw two seals which popped their heads out of the sea to look at us as if to say "Look. Two humans!"
But ballast is interesting. When I see modellers use brown ballast, I think "That does not look right?" BUT, if I travel to the areas where they live, I find it looks perfect! Is really surprizing how much variation of colour one can find on the railway network, and that is JUST one railway network. Think about all the others round the World, let alone the other railways in the UK which are not part of the railway network.
Some areas of the railway (Or railways) never were ballasted as it all depended on the need and the ground one used and even the sleepers. The basic idea is that the stones provide drainage, a stable solid ground for the track to sit on, and a means to prevent (Or minimize) track movement if used on higher speed railways. But for some lightweight railways (with a few not-so-lightweight, they never had ballast! Surprizing that the odd parts of the railway network I know where the track goes through a muddy marsh and one would sink if one tries to walk it, there is no ballast! The track there floats on top of mud! (Such as around Beavers Hill on the Pembroke Dock branch which is inbetween Tenby and Pembroke Dock. Trains pass through a jungle of growth to get past that short area of the railway and from older photographs I have seen taken around 40 years ago, they always have!
To add to this, one long stretch of line which was built around the 1840's to 1850's they had to cross a large marsh. They employed hundreds of locql women to sew together a large membrane of rabbit skins which was tarred and laid down on the marsh and the track ballast and the track went on top, and it still survives to this day as the main line passes over a couple of miles of marsh on the main line between Carmarthen and Whitland in Wales.
