I saw something at a rural BNSF crossing that caught my eye. Some work had been done at a culvert near a crossing that included some track work. What I noticed was that the gravel and ballast seemed to come from 4 distinctively different sources.
Most of the ballast was pink Sioux Quartzite. It's available 15 miles up the road at a quarry in Sioux Falls, SD. Some of the ballast and some of the finer gravel was dark red Sioux Quartzite available from the quarries in Dell Rapids, SD about 30 miles up the line. There was also granite ballast which would be available about 100 up the line from quarries near Granite Falls MN. There is also some finer granite type gravel of an entirely different color and texture.
The curious mind wonders. Why wouldn't gravel and ballast be sourced from the nearest quarry that does business with the railroad? Are there differing sizes of ballast for different applications? Is there a certain hardness needed for ballast? Around here we have Sioux Quartzite which is really hard. North of Omaha, the gravel there looks like the byproduct of the chalkboard industry. Does that difference in hardness matter?
Thanks to Chris / CopCarSS for my avatar.
Gravel in the ballast is a capital bozo no-no. (Crushed hard rock ballast only)
ROUND ROCK is like building track on ball bearings, the rock won't lock up. And it goes to dust faster than limestone usually. (ie gravel is a dirty word around trackmen )
On the Class ones, if your local ballast supply and fleet is maxed-out, then they will send a cut of cars (fully loaded) from somewhere else and run those cars to the nearest pit, staying with that loading circuit until the crisis is over, especially out on the plains.
The harder the rock the better, the more fractured sides the better. Gravel is the crap the highway bubbas use.
Murphy Siding The curious mind wonders. Why wouldn't gravel and ballast be sourced from the nearest quarry that does business with the railroad? Are there differing sizes of ballast for different applications? Is there a certain hardness needed for ballast?
The curious mind wonders. Why wouldn't gravel and ballast be sourced from the nearest quarry that does business with the railroad? Are there differing sizes of ballast for different applications? Is there a certain hardness needed for ballast?
Class 1 railroads usually do have two classes of track ballast. Class 1 ballast is for mainline track, class 2 ballast for all other tracks. The class requirements differ in gradation and abration resistance of the stones. Here is a specification from CN:http://www.winnipeg.ca/finance/findata/matmgt/documents//2013/539-2013//539-2013_Appendix_D-CN_Ballast_Specification.pdf Regards, Volker (Germany)
In addition to the pretty complete answers above, refer to the first several paragraphs and Table 6-8 per AREMA gradations on the page at this link, which should also address most of your questions:
http://armytransportation.tpub.com/TI-850-02/Table-6-8-Recommended-Ballast-Gradations-64.htm
The quantity needed for such a project is so small that it wouldn't justify even running ballast train past it, unless it was going there anyway. It's more than likely that the MOW guys used what they had laying around in a stockpile for such little projects, perhaps supplemented by a carload or two also sitting around or diverted from another project, or maybe it was ordered just for this one.
Yes, there are different sizes for different applications - see (c)(1) and Table 6-8. The 4A is for mainline, the 4 for sidings and secondary tracks, and the 5 for walkways. The gravel would make good bedding and backfill for the culvert, since it will easily run down into the space around the pipe and compact easily. For that, it's better than any of the ballasts which are too pointy for the pipe to lay on, and too angular to flow down into the space properly - they'd likely 'hang up' there. For your comparatively lightly trafficked line, any mixing of the ballasts would be OK - not worth a huge amount of trouble to keep them separated, as long as the gravel is kept out; any of that in the ballaset section might be accidental spillage. Back in the day, here on the East Coast (coal country) cinders from steam engines and furnaces/ boilers were also used for low volume and light-weight traffic lines - worked better than you might think, and made it real easy to change ties and tamp the track, esp. with hand tools.
Yes, a certain hardness is needed, and it does matter - a lot. It's tested by what used to be known as the "Los Angeles Rattler Test". Most quarries can't meet mainline specifications, which essentially require granite, quartzite, etc. Limestone is a second choice, but only for lightly used non-critical tracks and where the better ballast is unavailable or uneconomic. Refer also the Sec. 7.02 Ballast of these 2011 Norfolk Southern specifications:
http://www.nscorp.com/content/dam/nscorp/industrial-development/track-design-information/07_Materials.pdf
- PDN.
If you used crushed and graded Peridotite, very similiar to granite, it will slowly but surely absorb CO2 from the atmosphere and in the process convert the peridotie to limestone. This is how many of the great thick limestone deposits around the world have came about. Nature's own check and balance. The CO2 is entombed in the Limestone and removed from the atmosphere.
If this was enacted all across North America you could remove atmospheric CO2 Pretty evenly all across the continent. The process starts right away so we do not have to wait in Geological Time. Results can be measured and seen in 3 years if we do it right.
Just a thought for all the greenies.
Maybe the Railroads could claim carbon credits. Why not?
They'll just drive their unmaintained Subarus with the bald tires that are badly in need of a tune-up even more.
Miningman If you used crushed and graded Peridotite, very similiar to granite, it will slowly but surely absorb CO2 from the atmosphere and in the process convert the peridotie to limestone. This is how many of the great thick limestone deposits around the world have came about. Nature's own check and balance. The CO2 is entombed in the Limestone and removed from the atmosphere. If this was enacted all across North America you could remove atmospheric CO2 Pretty evenly all across the continent. The process starts right away so we do not have to wait in Geological Time. Results can be measured and seen in 3 years if we do it right. Just a thought for all the greenies. Maybe the Railroads could claim carbon credits. Why not?
mudchicken They'll just drive their unmaintained Subarus with the bald tires that are badly in need of a tune-up even more.
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Murphy Siding: Yes, absolutely .. not a pipe dream or fantasy.
Good suggestion on your part. Good but small deposits of Peridotite along the coast in Oregon and Washington, plenty up here in the Canadian Shield.
Peridotite is, without getting into all the mineralogy and geological jargon, is basically the original surface rock on the earth. There are a few exposed deposits/ outcrops still on surface, mostly where glaciers have bulldozed away multiple layers of covering rock.
limestone is formed by the interaction of the original earth composite rock "peridodite" ..the Calcium in it reacts with oxygen to form calcium oxide which interacts with very high CO2 levels in the atmosphere and forms Calcium Carbonate CaCO3 ...this is a self regulating mechanism which emtombs the much higher CO2 levels in past geological eras and forms Limestone CaCO3 ...and now we lay our roadbeds and build our buildings out of it...so take that Al Gore...a little bit of science goes a long way explaining things...Miningman
edblysardAnd Volvos, they all have a secret Volvo hidden somewhere…the Diesel Wagon one.
It's behind the AMC Eagle.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
zugmann edblysard It's behind the AMC Eagle.
edblysard
Eagles as I recall were full time 4WD
Never too old to have a happy childhood!
edblysard Wow, my best friend’s Mom had an Eagle back in the day…they lived in a very rural area near Dibol, Texas…..that thing earned it’s keep and then some. Ugly as all get out, but tough and did just what they advertised it could.
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