MK Tom
Established Member
Simple question here - why do Scottish railways used this red/pink ballast rather than the grey ballast used everywhere else?
It's due to our natural socialist tendencies.Simple question here - why do Scottish railways used this red/pink ballast rather than the grey ballast used everywhere else?
Wait till the Ministry pull you over for a check for the Red stuff.Red ballast has reduced tax paid at the refinery, so it's not for general consumer use.![]()
Mineralogically it is higher iron oxide content that causes the redness.
I don't think iron has anything to do with it. It's felsite, a fine-grained intrusive volcanic rock that happens to be red because of the mineralogy, but not necessarily iron compounds..
It is caused by the recrystallisation of Irn Bru that has passed through non-retention tank train toilets.
I imagine it's coincidence that roads in Lanarkshire, where that quarry is, used to have red surfaces, from the use of red colliery waste material in the surfacing.
It is caused by the recrystallisation of Irn Bru that has passed through non-retention tank train toilets.
Well if we're listing places where red road surfacing was used, it was once common in Manchester. When there was a 2+3-lane tidal flow system in Upper Brook Street, the central reversible lane was surfaced in black and the other four lanes in red.Not just Lanarkshire. 35y ago the A9 on a Auchterarder to Perth section looked very rosy. Likewise the A85 Perth to Dundee.
Wait till the Ministry pull you over for a check for the Red stuff.
Well if we're listing places where red road surfacing was used, it was once common in Manchester. When there was a 2+3-lane tidal flow system in Upper Brook Street, the central reversible lane was surfaced in black and the other four lanes in red.
Meanwhile - back at ballast...
Everywhere else is absolutely not all grey. There's at least six different main colours in the Independent Lines around the back of Crewe station - including pink and green.
Meanwhile - back at ballast...
Everywhere else is absolutely not all grey. There's at least six different main colours in the Independent Lines around the back of Crewe station - including pink and green. (And there's no re-crystallisation of Irn Bru going on there).
Wherever you go in the country the ballast colour is always simply a consequence of what material is used and where it is sourced - plus degradation and whatever lands on it.
Technically - and others will know far more about this than I do - different grades of route (according to weight and speed of traffic for a start) get different grades of ballast material. Naturally the heaviest routes get the hardest stone that wears best. More lightly used lines get less expensive less strong material. All this is adjusted according to local conditions - especially drainage.
Given the weight of ballast it is also natural that the nearest local sources of the correct material are used with the result that there are often large "patches" over which one colour will tend to predominate. then again, when a line has a change of route grading or a quarry runs out a new colour or colours may be introduced - leading to a mix for some time.
Just to add colour stone not used in one job may be run out to top up other areas rather than be taken back as part loads to the quarry - or a different quarry.
That's the simple version.![]()
In the northwest there are three main ballast colours, one each for Penmaenmawr, Shap and Mountsorrel
Felsite ... granite.
Which my limited understanding of mineralogy and geology translates as "Same thing, only different." Would that be a fair summary?A distinction without a difference, given that one is a felsic intrusive igneous rock and the other is a fine-grained matrix of felsic materials, typically of extrusive origin.
andDiorite (pronunciation: /ˈdaɪərˌaɪt/[1][2]) is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and/or pyroxene. The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite. Diorite is usually grey to dark-grey in colour, but it can also be black or bluish-grey, and frequently has a greenish cast.
--- old post above --- --- new post below ---Microdiorite is a medium-grained intrusive igneous rock. It contains crystals that are smaller than grains of rice, which are interlocking and randomly oriented. It is dark grey or greenish brown.
Like diorite, microdiorite forms from magmas that do not contain much quartz (silica) or the light coloured minerals that make up granite. The crystals are smaller than those in Diorite, indicating that the magma cooled more quickly.
They originally did in Lancashire (and sometimes elsewhere in NW England) and in central Scotland, and possibly some other places. When the M6 was extended north from Lancaster, the hard shoulders were red in Lancashire, then yellowish in Westmorland, then red again in Cumberland.Didn't motorway hard shoulders used to be pink too, or was that paint?
They originally did in Lancashire (and sometimes elsewhere in NW England) and in central Scotland, and possibly some other places. When the M6 was extended north from Lancaster, the hard shoulders were red in Lancashire, then yellowish in Westmorland, then red again in Cumberland.
Sir James Drake, then county surveyor of Lancashire, says in his book Motorways, page 101,
"The hard shoulders ... are paved, and the surface sealed. The practice in Lancashire is to use a bituminous sealing material called 'Schlamme' with an added red pigment to provide additional contrast with the carriageway."
More details of hard shoulder construction and surfacing are given on page 161.