Crushed flint as trackway ballast

[richwrig]

In his book The Railways: British Track Since 1804 Andrew Dow writes that flint is one of the materials that was crushed and used as ballast.

Does anybody know of surviving examples of crushed flint ballast, or know of any photos of flint ballast?

 

[krus_aragon]

I can't name any railways that used flint as ballast, but I can tell you that those building railways would use whatever (suitable) local stone was available: if they had to make a cutting throught stone, they'd typically use that stone as ballast elsewhere on the line.

Later, larger concerns would probably enter into contracts with a quarry for stone to reballast, which could travel a long distance. (In modern times, Penmaenmawr stone has been used on many areas of the national network.) So I suspect your best chance is to search for an independent or industrial line in a flint-based area.

I suggest using a geological map (like this one) to help narrow your search

 

[richwrig]

Hi krus_aragon

Thanks for your comments, and I should have said I am in Australia. A question has been raised as to whether some flint, of River Thames origin, was crushed for use as ballast.

 

[krus_aragon]

Flint exported from the river Thames to Australia for ballast? I can't imagine there would be much money in exporting stone half way around the world for building/maintaining a railway: surely there'd be a cheaper source nearer to home.

One possibility does spring to mind, however: I know that there are some artificial islands in the Porthmadog estuary as a result of the slate export industry. Ships would sail out laden with slate, but would need some ballast load to sail back with. If they didn't have trade goods to ship back to Wales, they'd just load up with local rubble to keep the ship balanced and in trim for the return journey; this rubble would be dumped before mooring up at Porthmadog for a fresh load of slate.

On that basis, it could be the case that some ships were exporting some Australian goods to London, but had nothing to convey on the return journey, and balalsted up with local stone instead. (Though surely they could find *something* profitable to ship?) When this rubble was discharged at the Australian end, it could be used by an enterprising individual as a ready-quarried source of railway ballast.

 

[edwin_m]

I saw a story (BBC website I think) a few days back of Aborigines using flint for tool-making, that had been brought in as ballast on ships. Never heard of it being used as ballast on a railway.

 

[Flamingo]

http://www.bbc.co.uk/news/world-australia-43551015

Snap!

 

[richwrig]

http://www.bbc.co.uk/news/world-australia-43551015

Snap!

Flint exported from the river Thames to Australia for ballast? I can't imagine there would be much money in exporting stone half way around the world for building/maintaining a railway: surely there'd be a cheaper source nearer to home.

One possibility does spring to mind, however: I know that there are some artificial islands in the Porthmadog estuary as a result of the slate export industry. Ships would sail out laden with slate, but would need some ballast load to sail back with. If they didn't have trade goods to ship back to Wales, they'd just load up with local rubble to keep the ship balanced and in trim for the return journey; this rubble would be dumped before mooring up at Porthmadog for a fresh load of slate.

On that basis, it could be the case that some ships were exporting some Australian goods to London, but had nothing to convey on the return journey, and balalsted up with local stone instead. (Though surely they could find *something* profitable to ship?) When this rubble was discharged at the Australian end, it could be used by an enterprising individual as a ready-quarried source of railway ballast.

You comment is spot on. My request relates to the reports on Australia that the other posters refer to. Those reports are simplifying a complex question and not everybody accepts that the flints were flaked by Aborigines. Some have suggested that they are crushed.

Nevertheless, there seems to be no question that the flints are from southern England - a test has shown that they are chemically the same as flints from Thames valley gravels. Nor is there any doubt that ships came into Sydney harbour carrying flint pebbles as ships' ballast.

What has interested me is a newspaper report from 1920 about a tram collision along a track in Sydney. The report states that passengers were injured by the "flinty ballast" as they fell onto the tracks.

Unfortunately these tramways were long ago ripped up and in the main built over with sealed roads.

To cut a long story short, it would interest me to have evidence of what the crushed flints referred to by Andrew Dow looked like.

By the way, there are many historical reports, from around the world, of harbour masters forbidding the discharge of ships' ballast into unregulated areas. Discharged ballast was interfering with waterways. Sometimes it was put to good use. Hundreds of thousands of tonnes of WW2 bombed ruins of Bristol were shipped back to New York and used as landfill. Each Liberty ship discharged its goods at Avonmouth, and had to take on 1,500 tonnes of rubble ballast for its return to USA. Mats Burstrom's book Ballast Laden with History gives a fascinating account.

 

[krus_aragon]

Thank you for the added information about the use of rubble as ships' ballast.

Looking at the quote you have, I suspect that the journalist may be describing the shape rather than the material of the railway ballast, but I agree that it's a possibility worth investigating.

I've had a brief look into the flint mines of southern England, looking for likely sources of the exported Thames flint. My working theory was to find a source of flint worked (relatively)recently, and then look for small or industrial railways in the immediate vicinity. Unfortunately most of the information readily available online concentrates on the prehistoric mining of flint, not its use in the industrial era.

One likely candidate I found is the Chislehurst Caves. These were apparently worked up until the 1830s. This would easily be late enough for flint rubble to be shipped out to the new(ish)colony of Australia, but predates the advent of the railways. There could have been tramroads used in Chislehurst before then, but I can't find any evidence of them. (Furthermore, I've no idea off-hand what sort of substrate early tramroads' tracks were laid upon.)

Without finding a source of British flint that was still being worked in the Victorian era, I doubt we could find an example of a British railway using flint as ballast. But given the desirability of ballast made of irregular, angular stones, and the fact that local stone would be used wherever possible*, I have no doubt that flint ballast could have been used in Australia.

*A little closer to me, the use of waste slate chippings for ballast is common on (industrial) lines throughout the slate-quarrying areas of North Wales.

 

[edwin_m]

As far as I recall flint is only found distributed in chalk, and after the Stone Age wasn't of any particular value. So it's unlikely it would have been mined specifically for use as ballast, but it may have been an unwanted by-product of chalk mining.

 

[30907]

As far as I recall flint is only found distributed in chalk, and after the Stone Age wasn't of any particular value. So it's unlikely it would have been mined specifically for use as ballast, but it may have been an unwanted by-product of chalk mining.

Flint as a (decorative and upmarket) building material is very common in Norfolk and of course Kent, including most of the pre-Victorian churches near Chislehurst.

 

[Adlington]

deleted

 

[edwin_m]

Flint as a (decorative and upmarket) building material is very common in Norfolk and of course Kent, including most of the pre-Victorian churches near Chislehurst.

Indeed. I'm not sure whether it was mined specifically for that purpose or people used it for that because it was lying around as a by-product of something else, but either way it doesn't suggest flint was mined for the purpose of being use as ballast (on either ships or track).

 

[randyrippley]

Hi krus_aragon

Thanks for your comments, and I should have said I am in Australia. A question has been raised as to whether some flint, of River Thames origin, was crushed for use as ballast.

Its possible - the keels of wooden ships were often filled with inert material to act as permanent ballast. Sand, gravel, crushed stone, I've even heard (somewhere) of crushed shellfish. Once in the ship it often stayed there either until scrapping, or until it needed digging out to enable the fitting of replacement timbers.
Note this was often permanent weight to hold the ship upright - not always ballast in lieu of cargo

Its also worth remembering that in some parts of the UK crushed flint was used in the 1800's through to the early 1900's to metal roads. Sometimes on its own, sometimes with tar sprayed on top. Flint locks together when used as a road topping, and the steel wheels of early road vehicles helped bed it in.

As for the material source, you can get alluvial deposits of flint pebbles including in the Thames: the chalk powders and gets washed away, leaving the flints. I suspect those used for ballast were dredged from the river.

There's a photo of a crusher at http://www.etruriamuseum.org.uk/history/jesse-shirleys-bone-and-flint-mill/
Crushed flint was used there in pottery manufacture

 

[richwrig]

As far as I recall flint is only found distributed in chalk, and after the Stone Age wasn't of any particular value. So it's unlikely it would have been mined specifically for use as ballast, but it may have been an unwanted by-product of chalk mining.

I doubt that in situ flint was ever mined to get ships' ballast. All the gravel pits along the Thames produced flint pebbles, produced over aeons by the river cutting through chalk. There was a major Victorian industry around the lower Thames to produce ships' ballast. See for example https://www.cambridge.org/core/jour...-new-yorkdiv/E07FC1C585E625E0F41804F74F8BFEF2

If crushed flint was used as trackway ballast then I imagine it would be produced by crushing flint pebbles.

There is another possible explanation for crushed flint, that has nothing to do with trackway ballast - that it was crushed, roasted, and ground into a paste to improve the quality of ceramic clay. https://en.wikipedia.org/wiki/Staffordshire_Potteries

Anyway, thank you all for your comments. That's about it for now I think. I'll let you know if we find material evidence of crushed flint being used as trackway ballast. Likewise, please reciprocate.

 

[randyrippley]

FWIW, here's a flint mine near Thetford that provided stone for railway use

http://www.breakingnewground.org.uk/earthheritagetrail/brandon-flint-mine-pits/

 

[randyrippley]

Almost identical situation in the USA
https://forums.arrowheads.com/forum...thic-material-types-gc24/131859-flint-ballast

 

[richwrig]

Almost identical situation in the USA
https://forums.arrowheads.com/forum...thic-material-types-gc24/131859-flint-ballast

Brilliant. And just as I was signing off. I shall follow that up.

 

[richwrig]

FWIW, here's a flint mine near Thetford that provided stone for railway use

http://www.breakingnewground.org.uk/earthheritagetrail/brandon-flint-mine-pits/

My previous reply should have reference this post. Sorry.

 

[randyrippley]

this link may be an indication that caution is required: records of flint tools that were assumed to be locally made, but were probably actually carried in ballast
https://books.google.co.uk/books?id...ChDoAQglMAA#v=onepage&q=flint ballast&f=false