When there is one or more trailing unit and the engineer determines sand is needed, does only the lead unit apply sand, or is there a mechanism for all of the units to apply the sand? Does it make a difference that only the lead unit applies sand–i.e. is the sand from the lead unit enough for the rear units?
How about remote control for distributed power?
Gabe
While we’re on the topic of sand…If you continually dump sand in the same spot, like on a certain hill, will the sand eventually build up, and cause drainage and other problems with the track structure?
Sand usually helps with drainage. That’s why with the sandy soil around my house I don’t need a sump-pump.
Gabe -
Yes, the sand will definitely build up and cause problems with the drainage and track structure. As you know, sand is wonderful for the Operating and Mechancial Departments because it works so well at making their motive power peform better, but the track / Engineering people often think the railroad portions of their world would be better off without it.
The desirability of sand involved with drainage depends on the application. Sand is way better than clay for lawn and foundation drainage - where it’s OK if the water can drain away comparatively slowly, any imposed load is relatively light, and there are no load dynamics involved. But in the track structure sand is way worse than ballast stone, where the imposed loads are heavy and rapidly changing - it drains too slow; holds moisture that allows the subgrade to remain saturated, hence weak; separates the ballast stones and provides more places where those stones can move past each other and become less stable, and is generally undersirable for other reasons I can’t remember right now. In areas of heavy sand application - station platforms and steep grades, for example - ballast removal, cleaning, and replacement can be required because of the propensity of the ballast in those locations to become “fouled” just from the residue of the sand that is applied to the rails above. I’ve seen sections of track that looked more like a beach - with a few large stones poking out here and there - than a track. You may have seen photos of tracks on a grade where the predominately uphill track is noticeably lighter than the downhill track - that white is the sand residue. In extreme cases the sand accumulation may fill up drainage ditches and culverts, etc., but I personally have never seen it get quite that bad.
Further, sand and switch mechanisms just do not get along well together. Sand
You should see what sand-clogged ballast does to track circuits – it makes it very difficult to not have shunts anytime there’s precipitation, or dew, or frost, because all that sand makes a nice pathway for current to travel between the rails. Signal maintainer callouts and train delays caused by shunted ABS signals are in direct proportion to the presence of a lot of sand in the ballast.
RWM
…and then there is the track department playing “Lawrence of Arabia” in the major terminals and engine facilities. Silica sand and engine crater is nasty stuff. Been sorely tempted more than once to go after a hogger/ hostler who forgot about the “O-F-F” switch to the sanders with a ball pein hammer.
Have had to clean up more than one derailment in a yard where excess sand in a flopover switch was the cause. (doesn’t matter with some crews if the switch stand isn’t yellow or has a “v” on it - they still leave a trap for the next crew coming in the other direction)
WIAR: Stay out of my yard with misinformation like that!
I don’t know if this is important, or even true, but it would seem to me that sand filling the voids between much larger chunks of crushed rock acting as ballast would not only fill the voids, but increase the surface area of water retention many thousands of times due to the higher surface area of the sand. That can’t be a good thing where drainage is desired. Add mineralization, with the accompanying ionic soup in the mix, and you get the problems that RWM mentions with spurious voltage where it isn’t wanted.
-Crandell
So this one time…My sanders got stuck on for about an hour and I was sitting still.
Didn’t notice the switch being down, because I was taking a nap. [:-^]
[:D]
to which I might add that too much sand on the track itself can and has caused the opposite problem: it can make whole trains disappear, as far as the signalling is concerned! Especially light ones – RDCs were particularly prone to this problem. Can ruin your whole day…
Actually that reminds me…
There’s a few GCOR rules (I’m sure NORAC has them as well) that specifically discuss sanding over switches, grade crossing circuits, lubricators, defect detectors, and a few other locations.
They simple work together to say:
Hey Hogger! Turn those sanders off!
[edited for content by selector…sorry…]
Crandell -
All true, and important - the technical cause of what I summarized as just “poor drianage”. Mineralization is hard for me - a non-chemist - to assess accurately. Superficially, it would seem not to be a problem, because I thought the silica in the sand is pretty inert against that kind of thing with water, as would be a good grade of granite ballast. However, if either or both of those substances/ materials that would be present in large quantities are susceptible to that - or more likely, if there is any amount of another ionizing material mixed in with the ballast stone and sand, such as leaked or spilled coal, limestone, iron ore, old cinders or ash, etc. - then yes, I could see that being the mechanism and happening just as you describe.
Murph,
You hijacked my thread!
Lost in your interesting observation was my initial question.
Gabe.
Gabe -
Nah, Murphy didn’t hijack it - it’s just that we don’t know either.
We’d rather answer Murphy’s question instead, which we do know the answer to ! [swg]
-Paul North.
Under normal circumstances, Gabe, if the engineer applies the sander, all units in the consist will drop the grit. There is a control option that will allow only the leading unit to apply sand, but I’ll have to let an engineer explain more about when this is desirable (maybe the second-worst option in hour-long naps).
My apologies - sorry for the misinformation. [X-)] However, I still like the sand in my soil at home (and so do the damned moles).
Ya gotta love the railroad humor! [tup]
Gulp! [:I] Um…Sorry.
I just figured the two sand questions would be somewhat related, and since the sand guys were going to be on your question anyway, why start a different post.
Whell when the engineer pulls back the throttle the rest of the engines do it too. I don’t see why the other unit’s wouldn’t put down sand too. Won’t too much sand disrupt the track circuits for the signals on ABS track?
Ok Each unit can sand independant of the lead unit. and ill exsplain that in a minute. If im climing a hill and need extra traction, ill reach over and grab some sand, Now all dash 8 and newer engines will not manual sand ( all wheels) past 12 mph but i can throw the lead axel switch and just throw sand under the lead axel. and this does it on all engines. its not alot of sand as our thinking its just light not shovel fulls. and also if sanding it can have the opposit affect and slow you down. to get the beach affect your hearing these guys talk about its sitting still or going slow dumping the 35 cubic feet out at one time. Ok if i get lead axel sand it will throw light sand under the lead wheels on all engines. on line or not. this will be worn off by the time the last cars go over this spot. Now lets say im going 8 mph and pulling hard but slipping the engine will automatic sand all wheels . Now engines can sand independant from others lets say i have a 4 engine consist and engine 3 decides one of its axels is slipping it will automatic sand by its self sometimes it will send a light telling me its sanding but most generally ill get a light and bell telling me that a unit has wheel slip and as long as its not constant wheel slip i stay in 8 applying sand and keep heading home. It takes several years to build up that much sand to cause the problems these guys are talking about. the only exception i can think of is line of road where guys forget to turn sanders off amd dump lots of sand, but ive got a hard grade to pull and they decided to put a greaser on the grade, i just turn the sanders on til im past the grease. tonnage trains need tracktion.
so after this long winded line of stuff your answer is each unit operates its sand from wheel slippage locally or i can turn them on from the lead unit in unison but not seperate. if someone is riding in the other units they can turn the sanders on the units also.
There are two sanding buttons/switches. One is Lead Truck Sand and the other is Manual Sand. The exact wording may vary a bit depending on model and maker. Lead truck only turns on the sander for the lead truck. Manual Sand turns on all sanders thru the consist. On some engines, the Lead Truck must be on for Manual sand to work. Many lead truck switches are on until you turn them off. Some of the switches on newer engines are spring loaded so you have to always hold them on. Many manual sand buttons or switches are spring loaded and have to be held on.
The computer control on modern engines can also put down sand if it determines a need.
For DPU, there is a button/soft key to turn on the sanders in the DPU consist. The DPU consist will put down sand and then automatically turn off after a preset time limit. (Some locomotives that have the sand buttons on the computer screen also work this way.)
GE engines usually allow the engineer to use sand in power or dynamic braking at any speed. EMD (newer ones) usually allow the engineer to use sand in dynamic braking at any speed but when in power the engineer can use Lead Truck up to about 15mph and manual sand up to about 12mph. Over those speeds the computer can put down sand if it determines the need. (Many times in dynamics I’ll turn off the sanders coming up to the switches at a control point, only to have the computer turn them back on.)
My favorite sanding story was back when I was a conductor. We had an engine where the Crew Alerter had been added by the railroad. It wasn’t original equipment. Every time the engineer acknowledged the alerter, the sanders came on.
Jeff