I sure don’t know much about the use of sand by locomotives. I know that sand is used to provide traction on rails, and I know the local BNSF yard has a sand tower. That’s about it. So, some questions:
Is sand used on hills, or on slippery tracks, or both?
Is the sand automatically put down by a wheel slip sensor, or does the engineer turn the sander dispenser on and off?
If sand is used a lot in a place, does the ballast in that place eventually fill up with sand and cause problems?
Does the sand fall because of gravity or is is pushed out with air?
Are there certain kinds of sand used for the purpose, like silica sand because it’s so round and flows easily?
Are there rail lines that never need sand, like flat as a pancake through a treeless desert, for example?
How much sand does a locomotive carry? Who checks the level on the sand dipstick?
How did I get this far in life knowing so little about locomotive wheel sanding?
Both. Newer engines are more restrictive with when sand can be laid down. Older engines, you just flip the switch anytime. Also used when starting out a lot, and used for braking as well.
Both
Yeah, it can also mess up switches (gets in the grease)
Air
It’s a fine sand, but I’m no sand expert. You don’t want non-sand things in the sand - it will clog up the sanders.
Sure.
Don’t know. Part of a daily inspectioni s to make sure the sanders are, in fact, laying down sand (used for emergency stopping). You can look in the sand hatches to see how much is in there, too.
Hey, I’ve been thinking about sand lately, too. Murphy asked and Zug answered some of them. Thanks. A couple more:
Are there sand boxes in both ends of the locomotive? As I recall, diagrams I’ve seen only show one.
Steam engines had their sand boxes on top of the boiler where I think the heat would keep it dry. Is there any provision for keeping the sand dry with heat or anything else? Or is damp sand not a problem? I would think it would tend to clump up.
Murphy asked about sand on flat terrain. I remember years ago I was watching the wheels on the Genesis locomotives on City Of N.O. when it started moving in Hammond, La. (perfectly flat land), and it spit some sand out when it started. I assumed it was set up to automatically do this on every start. Of course I realize Amtrak procedures could very well be different from those on freight trains.
The best locomotive sand has lots of angular faces for better grip between rail and wheel and to avoid the higher loss from top of the rail associated with round grains. No beach sand!
To the best of my knowledge, railroad sand is quarried. You might ask your local ballast train supplier if they recover their fines for sale as sand. IIRC they are mining quartzite which should make nice traction sand for both railroad and highway use.
The streetcars of Toronto carry sand in hoppers under the frontmost seats. At some of the turn-around stations like Dundas West or Broadview, there are big plastic boxes full of sand on the platform and the driver fills the hopper with a shovel.
MOW people hate sand, for the reasons Murphy asked and zug answered - it fouls/ clogs the ballast in areas of heavy use (grades), and gums up the switch slide plates (and anything else similar, such as at a movable point frog) as well as filling the spaces around the operating and connecting rods, which means they need to be cleaned and lubed fairly often. I understand the C&S people also hate sand because of the deleterious effect it has on their gizmos, but since I don’t belong to that tribe, I’ll let someone else speak to that. Often there are general rules discouraging the use of sand in such places, but the need to keep a train moving on a heavy grade without slipping and stalling usually supersedes that. Also I understand that traction motors don’t like it, but again will defer to someone else.
Interesting article (mainly Euro-centric), including some of the downsides - especially interfering with good electrical contact for the signals:
The prime consideration about use of sand on the railroad - IT MUST BE DRY.
The fuel service trucks that CSX normally contracts refueling with also top off the sand boxes on the locomotives they service, in addition to pumping the chemical toilets - at least they are supposed to, if they do in fact may be open to question.
Ah yes- they use a lot of crushed quartzite on icy roads here. It looks a lot like mini arrowheads and if you pick some up it feels really rough grit sandpaper.
Back in the day it was common to go into high short hood and bang on sand tank w Yellow Hose Wrench when it started to slip on a bad, cold, dark night, the summit miles away.
This practice would leave dents in tank and knock the paint off.
On the other hand, when descending on GP9s etc. the Mechanical Speedometer would drop to ZERO when in heavy Dynamic on poor rail.
If not corrected, a Thump Thump Thump would soon appear once wheels rotated again.
Back in Steam days some coaling stations had a conical coal fired heater at ground level over which sand was shoveled. Once dry, the Sand was blown by compressed air up into sand tower, then dispensed by gravity into Sand Domes on locomotives.
Some modern steam engines had a Sand Bin on OUTSIDE Rear Cab Wall ( Which had no doors as Oil Burner ) this sand accessed by Fireman with scoop and poured thru opening in Fire Door to
We once had someone get some play sand for use in the locomotives. It had small pebbles in it. Took ages to work all of that through and out of the system.
In steam days, I understand that some railroads had steam jets behind the drivers on passenger locomotives to blow the sand off the rails. The idea was to reduce rolling resistance.
I can’t find any figures for capacities of modern wide-nosed locomotives, but second-generation EMD locomotives could hold anywhere from 56 to 75 cubic feet of sand. Switchers held a lot less, sometimes as little as 17 cubic feet.
As Zug said newer engines won’t allow manual sand above certain speed ranges when in power throttle. They all will allow manual sanding in dynamic braking. All modern (at least the last 20 or so years) EMD engines are so equipped. I’ve noticed some of the newest GE engines also have this affliction. When above the speeds, and it varys between models but generally about 15mph, the computer can put down sand. I’ve noticed that usually it takes a lot of slipping before the computer decides it needs sand. On our worst hill, I hate to have an EMD lead when there is slick rain conditions with a close to full tonnage train. By the time the computer decides to lay sand it’s usually too little, too late. You’ve lost speed too early on the hill to not stall.
As i said manual sand is always available in dynamics and I use it. Might even use it on that “flat as a pancake, treeless desert” that really doesn’t exist (The flat as a pancake part) under the right conditions. I’ve noticed with sand you may not have to go as deeply into dynos as without it. The help sand gives may not be much, but sometimes it’s enough.
One place sand is not supposed to be used is over the moveable parts of an interlocking or other controlled point. It’s because sand is an insulator and enough could negate track detection of equipment or maybe when points have locked up. Either way, it’s fun to shut off the manual sand coming up to such a place and then have the computer turn them back on through the restricted area.
Most units have two sander switches, “manual sand” which will operate all the sanders in the consist, and “lead axle sand”.
GE Dash-8’s do not allow manual sanding above 7 mph. You can use lead axle sand at any speed on those, but it doesn’t do a whole lot.
This may vary from railroad to railroad, but most if not all modern units have spring loaded sander control switches, so you cannot leave them on constantly (I tie my keychain lanyard from the manual sand switch to something else to hold it on, the rear headlight switch on our GEVO’s is in just the right place!). For units with push button sanders, a bent up torpedo clip works pretty well to hold the button in, or the red flag from the flagging kit.
Older units like SD40-2’s have a simple on/off switch that will stay in either position, so you can leave it on and then in theory forget about it and waste all the sand (not that anyone has ever done that, especially not when leaving units on the shop track).
I agree with Jeff that the computers on both GE and EMD units do not sand early or often enough.
Units from both builders have “sand anti-clog” features that periodically blow a shot of air through the sander valves and hoses, even if they are not in use.
MOW people hate sand, for the reasons Murphy asked and zug answered - it fouls/ clogs the ballast in areas of heavy use (grades), and gums up the switch slide plates (and anything else similar, such as at a movable point frog) as well as filling the spaces around the operating and connecting rods, which means they need to be cleaned and lubed fairly often. I understand the C&S people also hate sand because of the deleterious effect it has on their gizmos, but since I don’t belong to that tribe, I’ll let someone else speak to that. Often there are general rules discouraging the use of sand in such places, but the need to keep a train moving on a heavy grade without slipping and stalling usually supersedes that. Also I understand that traction motors don’t like it, but again will defer to someone else.
Interesting article (mainly Euro-centric), including some of the downsides - especially interfering with good electrical contact for the signals:
The PA Turnpike used to cross the then double track B&O P&W Sub between Pittsburgh and New Castle - it crossed over the tracks on the Bakerstown Hill grade. When glancing down at the track structure it was easy to tell the normal up hill track from the down hill track (Current of Traffic signalling) - the Up hill track had a continuous white cast to it - down hill was just the norm black/brown track structure.
In the middle 70’s, the P&W was single tracked by Chessie System. In the early 2000’s leased the P&W to both the Allegheny Valley RR and the Buffalo & Pittsburgh. The AVL & BP perform all Dispatching and maintenance on the line.