Most hands say a MRR grade shouldn't pass more than 2%. I can do this, but I think I want to stay out in the Mountains. So is this still true, or what might be a more dynamic Moutain grade? The line will cross over itself twice at different points, I know I have enough room to do that at a 2.5% grade, And then I need to haul downgrade to get lined up. I can go a gentle 1% drop, or a more treacherous grade with some ups and downs at yor reccomendations in about a 50ft run. To me though, a long, slow crawl doesn;'t seem right to me Any more questions, ask.
-Morgan
Main line at more than 2% is difficult with long trains and Passanger trains. However I have a switrchback on the logging mountain with 5%. It is limited to Shay or Climax and a couple logging cars.
If you want opperations, then stay with 2% or less. If scenery is the real issue, as it is with me, 2 1/2 is not all that bad. You need more than 50 feet to have everything. Choose what you want most and adjust to the rest. That's what I did.
I have read about some of the other problems that go with the grades. Your loco of course has to be "up" (pun intended) to the task, or you may have to shorten the train . When you start going downhill the cars will start smacking together , pushing the loco if there is any length to the decline. I guess the effect would all depend upon the final track elevations as to whether it makes the loco "jerky" or not. I'm thinking it was the Allegheny Midland that had these problems. The layout looked awesome, but was troublesome.
As with the real world engines, they have to work harder, and working harder means a shorter life cycle before second and third line maintenance. It is one thing to keep in mind...you'll have to repair or replace engines that are asked to work harder than others. The other thing to remember is that you needn't make a grade do all of the "lifting". You can have a grade up crossing over a grade down, and between the two get a nice and natural separation if you scenic it properly.
It might pay to think like the prototype.
The 2 percent idea is fine, but if your trains will operate in both directions, then making a 1 percent grade on the opposite side serves no purpose, since half of your trains will go down the other side at 2 percent.
Trains going uphill must have sufficient coupler strength and rigging strength to handle the additional forces placed on the pulling face, shank, box and box lid. Descending grades place compression or buff forces on the couplers, and if your cars are weighted to NMRA RP's, then the force exerted could cause trobule for truck mounted couplers.
I am not real clear about your comment "I want to stay out in the Mountains" I assume you meant you want to stay out of the mountains? If so, reduce your grade to the minimum required to do the job.
Most prototype railroads minimize their grades to the extent possible, so a long slow crawl as you put it, is VERY prototypical.
A 50 foot run is actually a 25 foot run on each side of the summit, assuming no level track at the top. At that, it is a 300 inch run, and a 1 percent grade would give you less than 4 inches of vertical clearance, less the roadbed and track. A 2 percent would provide around 6 inches inches of clearance less R&T. A 1.75 to 2.00 percent grade is not unreasonable, it seems to me, and it would permit a little greater speed both ascending and descending.
Two different thoughts -
You can make your grade look like it's doing more by setting up your scenery so it declines as the track climbs. If you have to get over another track, let that track go down as much as the other goes up, and you only need half the grade. My own main line is completely flat, but it goes through gorges and over trestles, because the scenery around it climbs and dips, rather than the tracks.
For operational interest, steep grades require the addition of helpers. What's more fun, watching the train climb up the hill, roll over the crest and brake a bit on the descent, or having a helper come along, hook up with the train, climb to the top, disconnect and then watch them go their separate ways? Managing that sort of peak will give you and your operators a lot of satisfaction.
It takes an iron man to play with a toy iron horse.
4merroad4man It might pay to think like the prototype. The 2 percent idea is fine, but if your trains will operate in both directions, then making a 1 percent grade on the opposite side serves no purpose, since half of your trains will go down the other side at 2 percent. Trains going uphill must have sufficient coupler strength and rigging strength to handle the additional forces placed on the pulling face, shank, box and box lid. Descending grades place compression or buff forces on the couplers, and if your cars are weighted to NMRA RP's, then the force exerted could cause trobule for truck mounted couplers. I am not real clear about your comment "I want to stay out in the Mountains" I assume you meant you want to stay out of the mountains? If so, reduce your grade to the minimum required to do the job. Most prototype railroads minimize their grades to the extent possible, so a long slow crawl as you put it, is VERY prototypical. A 50 foot run is actually a 25 foot run on each side of the summit, assuming no level track at the top. At that, it is a 300 inch run, and a 1 percent grade would give you less than 4 inches of vertical clearance, less the roadbed and track. A 2 percent would provide around 6 inches inches of clearance less R&T. A 1.75 to 2.00 percent grade is not unreasonable, it seems to me, and it would permit a little greater speed both ascending and descending.
Long and slow, but also usually steeper. Also, the fifty feet is only the way down from the summit and roughly the other half of the layout. The Hylixes consist of 5 34" radius turns of 86.26 sections and the straits to line and change direction.
Most of my cars are not/not yet weighted down, and eventually will get body mounted.
Nope, I meant Stay out there in them thar mountains
MisterBeasley Two different thoughts - You can make your grade look like it's doing more by setting up your scenery so it declines as the track climbs. If you have to get over another track, let that track go down as much as the other goes up, and you only need half the grade. My own main line is completely flat, but it goes through gorges and over trestles, because the scenery around it climbs and dips, rather than the tracks. For operational interest, steep grades require the addition of helpers. What's more fun, watching the train climb up the hill, roll over the crest and brake a bit on the descent, or having a helper come along, hook up with the train, climb to the top, disconnect and then watch them go their separate ways? Managing that sort of peak will give you and your operators a lot of satisfaction.
The hill trick is a good idea. ANd helpers is one of the reasons I want to do this, Helpers and Cab Forwards...
tinman1: I have read about some of the other problems that go with the grades. Your loco of course has to be "up" (pun intended) to the task, or you may have to shorten the train . When you start going downhill the cars will start smacking together , pushing the loco if there is any length to the decline. I guess the effect would all depend upon the final track elevations as to whether it makes the loco "jerky" or not. I'm thinking it was the Allegheny Midland that had these problems. The layout looked awesome, but was troublesome.
Helpers and large locos were planned, But especially that last line is why I asked
selector As with the real world engines, they have to work harder, and working harder means a shorter life cycle before second and third line maintenance. It is one thing to keep in mind...you'll have to repair or replace engines that are asked to work harder than others. The other thing to remember is that you needn't make a grade do all of the "lifting". You can have a grade up crossing over a grade down, and between the two get a nice and natural separation if you scenic it properly.
Sounds like a good idea, but I;m not picturing it right. Also, where it crosses, it needs t start climbing to get over itself. I;m not sure I'd start our too low to get up high enough
Thanks guys!
Out here in California, a prototypical 2.2-2.4% grade is fairly common, especially in the Sierra, the Tehachapi and Cascade ranges--also the 2.2% over Cuesta Summit on the Coast Line. The old SP Donner Pass line had a mean average grade of 2.2% with a couple of 2.4 and 2.5% sections. On my own MR, the grade averages between 2.0 and 2.2 with a very short section of 2.4%, but the grades are not constant and I have large (34-36") radii, so a lot of time, my 'helper' locos are more for show than anything else. I usually run freights of between 20-30 cars and passenger trains of up to 10 cars without much trouble at all.
Also, remember that in a great many cases, actual railroads built through the mountains by following rivers close to the BOTTOM of watersheds--the 1% ex-WP Feather River Route and Rio Grande's 1.4% Arkansas River grade between Pueblo and Tennessee Pass line are good examples of this. That way you can make your mountains as big as you want, and still have the railroad climbing at a reasonable grade (well, except for the short, nasty 3.0% on the west side of Tennessee Pass, anyway, LOL!).
I have read somewhere that a maximum mainline grade of 2.2% was set by American railroads because that was the ruling grade of the Baltimore and Ohio over the Appalachians in the early 19th Century. I have no idea if this is true or not, but it might be a fair guide for laying grades in your mountains.
Tom
Tom View my layout photos! http://s299.photobucket.com/albums/mm310/TWhite-014/Rio%20Grande%20Yuba%20River%20Sub One can NEVER have too many Articulateds!
Morgan, in a confined space, as we face typicially, it can be odd-looking, and give our tiny engines fits, when we force them to climb a steep grade. But, rather than give up on the idea of tracks crossing over themselves at some point on the layout, and that only possible by grades somewhere, we can split the difference so that you can still get your clearance between the rail tops and what is above them. Some of us do this by not making a track crossing over another do all the rising. You can construct your track plan so that as your overpass is met by the climbing grade, what trackage will be crossed descends at the same time...to the overpass. Now, instead of being confined to a 6' grade that has to rise @ 5% in order to get your minimum clearance, you can have the rising grade at 2.5% and the tracks being passed over descending at 2.5%. Imagine a figure 8 track plan. You want one part of the crossing to rise up and then dip again so that it can pass overhead. That's a tall order. But if the nether track also dips, now you have reduced the work that either train must do at that point. Do you follow?
I would say stick to 2-2.5% or less unless the point is to have the grade be a main feature of the layout - i.e. trains stopping at the base of the grade to add pusher engines, or trains stopping at the top of a down grade to set retainers/brakes for the trip down.
wjstix I would say stick to 2-2.5% or less unless the point is to have the grade be a main feature of the layout - i.e. trains stopping at the base of the grade to add pusher engines, or trains stopping at the top of a down grade to set retainers/brakes for the trip down.
Right, but on the other side of the hylix, I end up with a run of flat track, unless I could safely tease (vary the desent grade or stop and have to climb up a little bit before dropping again because the Mountain decided that was an excellent spot for a a large hunk of rock that was easier just to go over) up and down a little bit along the way. Unless this would create a nightmare of derailments and uncouplings. And I want the grade to at least be prominent. In the setting of things, there should already be Helpers tacked on further back, Though additionals or fresh would be on hand in the area.
If my MSTS still worked, I've actually wanted to wrok the Donner Pass add on, as Norden would make a decent study point, And my V scale version is a lot closer than the more accurate 1:1 scale
I'm trying to get Photobucket to load my trackplan. We'll see if it'll take this time.
selector Now, instead of being confined to a 6' grade that has to rise @ 5% in order to get your minimum clearance, you can have the rising grade at 2.5% and the tracks being passed over descending at 2.5%. Imagine a figure 8 track plan. You want one part of the crossing to rise up and then dip again so that it can pass overhead. That's a tall order. But if the nether track also dips, now you have reduced the work that either train must do at that point. Do you follow?
EDIT: WHy did I just get a notification of my own posting???
Morgan--
I don't know whether or not this will help in determining your grade, but here is the cross-over at San Juan Ridge on my Yuba River Sub. The lower track is the eastbound, the upper track on the truss bridge is the westbound. What I did was level the 2% of the eastbound to 0% for about two feet of running, and keep the westbound at a 2% downgrade. Right after the crossing, the westbound increases to a 2.4% downgrade, while the eastbound again increases to a 2% up-grade. It's a fairly tight fit, but it clears my tallest cars by about 3/4 of an actual inch.
As I said, I don't know whether or not this will help you on your crossovers, but it works for me.
Howdy, Morgan,
The 2.2% grade mentioned earlier was the grade the B&O used crossing the Appalachians. Congress wrote it into the bill that authorized subsidizing the transcontinental railroad builders. The rest is history.
OTOH, different roads in different places built to different grades - and sometimes found out that they had miscalculated. The Rio Grande approached Cumbres Pass from the east on fairly easy grades for a mountain railroad, then plunged down to Chama on a 4% grade. They never anticipated that the newly-opened territory would become a major shipper of livestock and agricultural products. Their planning had included moving machinery and supplies to the mines, and shipments of boullion out...
My Class 1 prototype operated over 2.5% grades in the area that I model, so that's the grade I use on the equivalent visible track. Grades in the netherworld are held to 2% upgrade, but may go to 2.5% downgrade. (I do have hidden tracks that only handle traffic in a single direction) The coal-hauling shortline is being built with 4% grades, part of a deliberate effort to justify big power on short trains. (REALLY short trains - a half-dozen four wheeled wagons.)
If you are following a prototype, research that prototype's practices and standards. It simplifies life.
Chuck (modeling Central Japan in September, 1964)
Grades do not exist!; this was proven to my satisfaction about two weeks ago when we last had this discussion.
From the far, far reaches of the wild, wild west I am: rtpoteet
Morgan, about our figure 8....it must be either a level crossing, or it must have a full separation to allow the train to pass under what is above it....correct? No in-between. So, if you intend to have a graded separation (an overpass), your higher track must rise to the overpass, and then fall again, and those two grades can be exactly the same grade....say 3%.
You decide it is too slight a grade to derive the vertical separation you'd need to pass one train under another at that overpass. But, you have no more room to allow the grade to work for you longer to get you more vertical separation.
What I am suggesting is, if you actually needed 4.5% in the space you can allow to get the required separation, your engines will face a daunting job on one side of the rise to the overpass...whichever direction it approaches the overpass will be 4.5%, and very tough. What I am saying is, depress both tracks so that the high track on the overpass only rises at 2.4%, and and the newly depressed nether track only has to descend the same 2.4%, thus maintaining your vertical separation, but halving the difficulty imposed by the grade. Does that work?