The steel wheel and rail are both fairly smooth. Quartz sand particles, even after they are crushed, are much larger than the surface irregularities on the wheel and rail and with quartz being harder than steel, they sink into the steel providing vertical surfaces for pushing against.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Norm48327 Larry, Sounds like you have a good recollection of the Oakland County county road commission.They love to use salt, and my truck shows the effects of that.. I'd rather deal with the sand..
Larry,
Sounds like you have a good recollection of the Oakland County county road commission.They love to use salt, and my truck shows the effects of that.. I'd rather deal with the sand..
Since I left MI when I was 17 (USAF), my recollections with regard to driving in MI in winter are limited. I lived in the village of Milford - but I don't recall just how heavily they were into salt vs sand.
Here in NY, when they were getting ready for the 1980 Olympics at Lake Placid, DOT decreed a "bare roads" policy that pretty much is still the rule today. And that means they use a lot of salt.
The crushed limestone the city used (uses) had a tendency to fuse together, too, requiring scraping with a loader in some cases to clean it up in the spring.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
As Larry supposed, there are different sands. Way back, wanting to build an outdoor fire place, I took a brick laying class. For mortar, you must use sharp sand, not river or beach sand (both round and smooth), so that the mortar will do it's 'thing'.
And during my teen age years, I often wondered why mortar was used with brick, not portland cement. The instructor on brick laying cleared that up; bricks fail - and to replace the bad brick, the mortar can be removed and the brick easily replaced. If portland cement is used, getting out the brick becomes a wall breaking task!
Art
t
Norm
tree68 It probably does matter, though, what kind of sand you're using. I'm no expert on sand, but just like with ballast, I'm certain that certain sands have more "grip" than others. Rather like why you'd never use pea gravel as ballast... A city near here used to use crushed limestone instead of sand. I'm sure it was much "sharper" than grains of sand, thus worked that much better.
It probably does matter, though, what kind of sand you're using. I'm no expert on sand, but just like with ballast, I'm certain that certain sands have more "grip" than others. Rather like why you'd never use pea gravel as ballast...
A city near here used to use crushed limestone instead of sand. I'm sure it was much "sharper" than grains of sand, thus worked that much better.
Tree: Here in Georgia many locations are using granite sand. It is very sharp and works it way into snow and ice. The granite sand is from fines of the rock crushing process. makes a very good motar that is almost impossible to break apart later.
Too much sand on a sidewalk or road can decrease traction, that's true. But the right amount of sand between your tires (or shoes) and ice will give you traction.
Traction isn't the only reason for putting sand down on a road. The sand will also work down into, and break up, hard packed snow, and possibly even ice, making it easier for the plows to clear. Many places now use so much salt that bare roads are commonplace, but I can remember many road reports in the past including "hard packed snow and ice" as the condition of the highways.
gabe I know someone is going to roll their eyes and say that I obviously do not have an engineering degree, but I never completely understood how sand improved traction. Typically, if there is sand on the road way or side walk, it reduces rather than increases my traction. Is the extreme weight of the locomotive what prvevents the slike that would be experienced by an automobile on sand? Gabe
I know someone is going to roll their eyes and say that I obviously do not have an engineering degree, but I never completely understood how sand improved traction.
Typically, if there is sand on the road way or side walk, it reduces rather than increases my traction.
Is the extreme weight of the locomotive what prvevents the slike that would be experienced by an automobile on sand?
Gabe
Gabe,
The sand when sandwiched between the wheel and rail creates smaller surface area of contact between the rail and wheel. This gives less space to carry the same amount of weight than one large spot does without the sand. This exerts more pressure in the smaller spots than the larger helping grip the track better. This is the same reason if you have tires with smaller knobs on your vehicle, It will get better traction than a smoother tire.
RJ
"Something hidden, Go and find it. Go and look behind the ranges, Something lost behind the ranges. Lost and waiting for you. Go." The Explorers - Rudyard Kipling
http://sweetwater-photography.com/
Gabe, 'Think of ballast rocks...they hold the track structure in place because they have sharp edges and corners that lock together under compression.
Now, imagine thousands of tiny tiny rocks wedged in between the rail and the wheel tread, each edge and sharp points cutting into the surface of both...it removes/replaces the smooth surface of both for a few minutes, just enough to allow the now "rough" surfaces to increase friction between each other...the small roughness goes away quite quickly as each trailing wheel of the consist crushes the sand, it ends up as fine a flour, but for the few moments ts is in use, it works wonders.
23 17 46 11
Traction is relative between the surfaces you talk of.
Between rubber and asphalt, traction is reduced. But between steel and steel, it's an increaser. Why do you think some states sand roads in the winter when there is snow and ice between your wheel and asphalt (with or without salt for the thawing action)?
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
zugmann A good conductor carries a 50# bag of sand in his grip for traction emergencies. Or at least it feels like that sometimes.
A good conductor carries a 50# bag of sand in his grip for traction emergencies.
Or at least it feels like that sometimes.
Also an extra knuckle pin. A good engineer will sometimes help out a good condr who's forgotten his extra pin by putting it in his grip for him. Or so I've heard.
Jeff (No, I haven't done that, nor had it done to me.)
Thanks for the great information. Now I know how to better position my locomotive to receive sand by my sand tower.
Tom
oltmannd The sand is stored in sandboxes in the nose are rear end of the carbody. Each has about 60 cu ft capacity. On locomotives with wide cabs, the front sandbox is split left and right. The fillers are round tubes about 4" in diameter with hinged flip caps on them. Older EMDs and GEs had the rear sand fill on the top of the long hood, but this was relocated to a notch in the rear hood end for safety's sake so the employee doesn't have to climb the ladder on the hood to fill the sandbox.
The sand is stored in sandboxes in the nose are rear end of the carbody. Each has about 60 cu ft capacity. On locomotives with wide cabs, the front sandbox is split left and right. The fillers are round tubes about 4" in diameter with hinged flip caps on them. Older EMDs and GEs had the rear sand fill on the top of the long hood, but this was relocated to a notch in the rear hood end for safety's sake so the employee doesn't have to climb the ladder on the hood to fill the sandbox.
To add a little to what Don (oltmand) has said:
There was a recent posting on these Forums by moelarrycurly4 Posted: 08-24-2011 10:51 PM: reference was to an SP RR facility in Houston,Tx.
linked here: http://cs.trains.com/TRCCS/forums/t/195908.aspx
"SP's Houston Hardy Street Engine Facility"
The first couple and the last two photos in the posting show the Diesel fuel and sanding facility. The large round tanks on top of the facility are sand tanks that feed the sand down to the locomotive sand bins/on board sand storage on the locomotives. The sand used in the locomotives is a very fine grit, dried sand, not what one would expect to find in a river (large stones and grit). it is processed to flow within the locomotives distribution lines to the wheels and rails; this helps to prevent clumping and blocking the sand tubes,
Hope this will help you see and understand what these facilities look like,
Just wondering where the sand is stored in Diesel locomotive and where it is added?
Thanks for the help. Tom
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