whats the steepest incline that trains can climb? ;D
Do not make any grades in excess of 4% for a mining/logging road with shays and such, and no more than 3% for any thing else.
ok thank you very much
The 3% and 4% figures shown above are very good and conservative figures, although you will find that whaterver you have for motive power will have its pulling ability reduced dramatically.
In the real world, trains can climb steeper grades than this, but there are severe penalties in reduced tonnage rating and expensive opaeration. Cass Scenic, for instance, averages 5% on its climb up to Bald Knob, has several places with grades in the 7 to 8% range, has two stretches at 11%, and once had a stretch of 13%!
I've actually tested my Bachmann Shay with a load up an 8% test track, and it pushed up a load relatively easily. Coming down again was a different story, with slack in the gear mechanism causing a surging in speed, called "bucking." The engine would start down the grade, almost stop, then break loose and coast rapidly, then almost stall to a stop, and start the process overy again. Any ideas for cures, even if an 8% grade is rather extreme?
trainboy -
Hello, again!
Maximum grade is an interesting concept. It depends on many things: weight of the consist being lifted; locomotive wheel size, weight and power; whether the track curves; rolling characteristics of the cars being pulled; rail surface and adhesion between the drive wheels and track, among others. In the 1:1 (real) world, whether the track is dry and whether the engineer applies sand to the rails also influence the results. All of these factors work against the locomotive's progress up a hill. And the grade is the biggest factor because a locomotive's ability to pull cars up a grade drops off very fast as a grade becomes steeper. A loco which can pull 20 cars on flat track might only manage five or six on a steep grade. In the early days of railroading this often meant taking the cars up a hill a few at a time. In more recent years there have been enough locos around to double head or add locos as helpers on grades. Helpers are still used today.
In practical terms, mainline grades are kept as shallow as possible and as few as possible. That's why you'll see a pattern of fills and bridges alternating with cuts or tunnels in hilly or even mildly rolling terrain. Mainline grades over 2% are very unusual in the real world, and even spurs, sidings and branches won't go above that if a reasonable alternative is available. Old logging and mining railroads typically had much steeper grades -- even 7-8% -- but then they used exceedingly powerful, if slow, locomotives. They also tended to lack much funding so buying land and snaking their tracks all over to make a grade more gentle wasn't an option.
Taking things farther, there are so-called cog railways on which there are long, flat, stretched out gears between the rails and the motor/engine directly drives a gear so the train can climb the grade. The loco's wheels just serve to support some of the loco's weight and guide the train along the tracks. This technique was used by some railroads to get over the Appalachian mountains in the 19th century. Today you can find cog railways (or cable railways) going up Pike's Peak, climbing Mt. Washington in New England, at Angel's Flight in Los Angeles, in the city of San Francisco and, closest to home, in Dubuque, Iowa. These grades can be 45o which would otherwise be completely insurmountable by conventional railroad designs.
On a model railroad we want to learn from the originals: Keep grades as shallow as practicable. That means maybe 2%, 3% or so if you have to, for regular trackage and maybe twice that on lumber and mining lines.
-- D
on a practical level, my experience is that a typical 4 axle diesel like a gp35 or f7 will pull about 5 cars up a 4% grade. naturally you'd want to avoid 4% if possible, but sometimes space constraints force their use. my layout has a twice around, up and over mainline, the grade is 3% on one side, 4% on the other. other than limiting train lengths, the 4% grade has worked well.
OK thank you for all the help it will be a while before i can build it but it nice to know earlier and later when its to late
on a new topic
1. can bachmann easy track be cut and joined together with rail joiners if u need a certain length that the connector assortment doesn't have
2. whats the tallest height that comes in the pier sets?
TB16 ;D
1. Yes, you can cut the track to any length.
Donaldon's and J. Ward's replies tickled my brain cells a bit, and reminded me of some other factors in grades, not all of which may be applicable in our models.
One, which we can't normally use because our lines are too short, is a "momentum" grade, one that might be steeper than normal, but can be approached at speed, with the train's momentum being sufficient to take it over the top. Of course, if things go wrong and you stall, you have to call for a pusher or "double the hill" (cut the train in two and take each section up individually, then couple it back together)--a wonderful source of delay on a busy railroad. On the other hand, if traffic density isn't too great and the cargo isn't overly time sensitive, then doubling may be a routine job. The Chicago & Eastern Illinois, a midwestern road that mostly hauled coal that wasn't in a hurry and not much else, regularly tripled its worst grade day in and day out until the end of steam operations in the 1950s.
The other possiblity we can sometimes take advantage of is that trains are often longer that the grades they must surmount. If that's the case, then the locomotive or locomotives only have to pull uphill as much of the train as is on the grade. This can be useful where one track is climbing over another with relatively minimal clearance.
Another thing to remember, if dealing with two tracks crossing each other, is that one track can slope down while the other slopes up. This gives the advantage of say, a 2% grade in the length of a 4% grade, which can be an important consideration in cramped track plans. The prototypes often do the same thing too, for just that reason.
If you get the chance, I very highly recommend reading the book "Track Planning for Realistic Operation," by the late John Armstrong. He has many comments about track standards and other things you'll find useful. My personal favorite section is an elongated caption to a map of the operation of the Lehigh Valley Railroad in Pennsylvania, describing the track arrangements used and why they were what they were. In my mind, I could picture the Wooten-fireboxed Pacifics, double-headed Mikados, and sleek 4-8-4s storming the grades and racing where they could along a curving river, fighting time and gravity in the competition for business against the Lackawanna, the Erie, and the NYC.
Hollywood's missing out on something here. . .
thx ABC and J3a-614 everything i get from here on out is going to help me even further of understanding grade and the mechanics of these trains
:o ::) ;D
TB16
PHOTO
http://s956.photobucket.com/albums/ae45/trainboy16/
PHOTOS
http://s956.photobucket.com/albums/ae45/trainboy16/
Just a few added tidbits. The steepest grade on a class one railroad main line was Saluda grade on the Southern Railway, which topped out at just about 5%. Somewhere in the upper midwest, early in the 20th Century, there was a logging railroad that was located in a deep valley. The interchange connection was over the hill. In order to get trains out, they built very steep grades up both sides of the valley. The trains would head up one side until they stalled, then rolled back down and up the other end. Heading back down, they gained speed and got further up the first side, then repeated again (and maybe again!) until they were able to crest the hill and head on out.
very cool
As I recall I rode a subway called the Carmelit in Haifa Israel that was specifically designed to go up and down a mountain. The cars are not level rather they are designed in a staircase fashion. I do not remember how it was powered IE whether it was pulled up or not. I just remember it was pretty steep.
SWEET ;D
TB16
Here's an interesting configuration from Cincinnati, Ohio, circa 1905. Conventional street cars and other vehicles are transported up and down a tall hill and then continue on their way.
Be sure to click on View full size under each photo to see a hi res image, and make sure to read the comments underneath
http://www.shorpy.com/node/8235
I love the title The Underwear Railroad ;D referring to the clotheslines it passes
http://www.shorpy.com/node/7783
TB 16 -
Nice pix. Thanx for sharin' 'em.
Joe -
Interurbans and trolleys with lines so steep that the cars had to be leveled like in your pic are usually cog railroads or, much less often, cable lines. I don't know for certain but I suppose it's possible that streetcars could have had a helper mechanism on very steep grades and such a thing would most likely be cable. Of course, there would have been no effort to level the cars themselves on such trackage. One sure sign of cabling is double track, or at least a passing section, so one car can counterweight the other, allowing a much smaller electric motor to move the cars.
Many cities also built short tunnels under cross streets to lengthen a grade so street cars could climb the hill unassisted. I don't know of any of these operating today but I do know that some such tunnels have been turned into streets for regular vehicle traffic. In the Twin Cities we have one which has single-lane up and down hill streets with the old streetcar grade between, and one uphill and one downhill lane there. For those of you who care, you can see this on Robert Street, just south of Downtown St. Paul.
-- D
cool
TB16
Quote from: J3a-614 on June 21, 2010, 01:13:50 AM
The 3% and 4% figures shown above are very good and conservative figures, although you will find that whaterver you have for motive power will have its pulling ability reduced dramatically.
In the real world, trains can climb steeper grades than this, but there are severe penalties in reduced tonnage rating and expensive opaeration. Cass Scenic, for instance, averages 5% on its climb up to Bald Knob, has several places with grades in the 7 to 8% range, has two stretches at 11%, and once had a stretch of 13%!
I've actually tested my Bachmann Shay with a load up an 8% test track, and it pushed up a load relatively easily. Coming down again was a different story, with slack in the gear mechanism causing a surging in speed, called "bucking." The engine would start down the grade, almost stop, then break loose and coast rapidly, then almost stall to a stop, and start the process overy again. Any ideas for cures, even if an 8% grade is rather extreme?
i just reread this
i might have a solution
add more weight to the engine?
ounce by ounce
J3a -
I'm not so sure more weight will help. In fact, it just might make things worse. But I may have an idea.
Put the Shay in reverse on the downslope but don't give it enough juice to push the train up the hill. Let the train push the Shay down the hill. If you install a regenerative braking system you might even be able to send some power back to the grid and save a few bucks on your utility bill. Hey. It could work.
-- D
good point i just figured adding a little more weight will apply more griping force but not enough to stop or hurt the motor :'(