I have an opportunity to include a reverse loop at a lower level on my roughly 18' x 8' layout plan. The 18' side runs along a wall so it would be a linear (straight line slope to the lower level as opposed to one with the additional friction of curves) and I would need about a 4 to 4.5% grade to make this work. Being a small layout, modeling a short line similar to my previous layout, I am accustomed to running short consists of 4 to 5 cars max (36 to 40") typically with GP38, GP30, SD9 and a couple of U30s as motive power. Suggestions / advice from anyone with practical experience with steep grades on their pike would be appreciated. Thanks.
how heavy are your locomotives?
greg - Philadelphia & Reading / Reading
"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."
gregc how heavy are your locomotives?
about 20.2 oz. for an SD40-2, greg
I built a mock up of the 5% grade I will have on my next layout.
An FA-1 (heavy) will only pull up 5 cars and a caboose. There are no curves on my grade, but there is a 22" radius curve at the top just beyond the end of the grade.
I suggest you build a mock-up and test as well.
-Kevin
Living the dream.
mrnimbleSuggestions / advice from anyone with practical experience with steep grades on their pike would be appreciated.
When I was testing locomotives for pulling qualities, the grade I used wasn't the steepest, at roughly 2.8%.. However, it was about 45' long, with two complete horseshoe-type curves, the first one to the right, the second to the left, then followed by several S-bends.
The train was 44 loaded hoppers, each weighing in at 8 oz., plus a 4 oz. caboose, while the two diesels (Athearn U-boats, each with two motors, weighed in at 33oz. each.
Because the track ended at the top of the grade, there was no difficulty backing it down the grade. (Later, I added a partial upper level of the layout, but by that time, had sold all three of the U-boats as I had chosen to back-date my layout to the late '30s.I have run much longer (but not as heavy) trains, using both smaller diesels, and a number of steam locos, too, sometimes 2 or 3 pulling and perhaps another two pushing. Once in a while, a mid-train loco would be used, too.
I have more hoppers nowadays, but no longer run long strings of loaded cars, as the steamers don't have the pulling capacity of those big diesels.
The steepest grade on my layout is 5.5%, but because it's only 6' long, most of my steamers can handle 20-or-so cars on it, as only a dozen cars, at most, will be on the grade at any time (not loaded hoppers, though).
Wayne
mrnimbleabout 20.2 oz. for an SD40-2
i would estimate that ~14 4 oz cars can be pulled by a 20oz loco up a 4.5% linear grade
we've measured that better quallity cars have a resistance of 2% on level track (thru some turnouts), this means the effective grade is ~6.5%. it would take ~0.26oz to pull a 4oz car up a 6.5% grade
the tractive effort of a 20 oz loco is ~5oz (25% of its weight). the loco also needs to pull itself, so subtract 1.3 oz (20 * ~6.5%). that leaves ~3.7 oz to pull ~14 cars (3.7 / 0.26).
Hey Greg - thanks for the objective insight. I think at this point I'll follow Kevin's suggestion above and set up a prototype configuration to actually validate my design which should eliminate all concerns once and for all.
I have a 14' piece of straight track and roadbed salvaged from my previous layout and have enough benchwork on the new to set up an adjustable incline. I can dig out a power supply and commnd station and kluge a hook up to run some tests as a proof of concept for sure. I have an AccuRemote angle guage as well.
May be a couple of days to get to it but I'll report my findings here which should be interesting as I'll be using actual locos and cars from my roster in the real geometry of the layout.
mrnimble Suggestions / advice from anyone with practical experience with steep grades on their pike would be appreciated. Thanks.
Suggestions / advice from anyone with practical experience with steep grades on their pike would be appreciated. Thanks.
My general advice is to avoid anything over 2%.
I have had several layouts with 5+% grades and I don't do that anymore. The old layouts featured locos with traction tires so I never had issues with pulling power.
I didn't like the look of the very steep grades near buildings or anything that can give away the angle - my eye catches it whether the brain is conscious of it or not. Of course there are other other issues with slack, runaways etc.
With the current small steam roster I am lucky to get 10 cars up a 2% grade - I shudder to think of 5%. Obviously lots of folks make it work. I think mocking it up is a good idea and if you like small trains and the look, then there shouldn't be a problem....
Of course these grades are a good excuse to add helpers
Your mileage may vary,
Guy
see stuff at: the Willoughby Line Site
Each of us has varying tolerance for unreliable running and for deviations from what is realistic in the hobby. Even so, you gotta work with whatcha got. If space is tight, you're elevations will require overpass clearances at the very least, but they'll come at the expense of both realism and real towing ability up the necessary grades.
I have almost always exceeded the 'standard' maximum of 2.2%, but the closer I get to it, the better things work and the more realistic they look. From my experience, decent sized locomotives, no matter if diesel or steam, can run 20 cars up a 2.8-ish% rise. Once you crest 3%, there are diminishing returns. Those grades will need to be 'uncompensated' and short, about five feet or less, as Wayne describes his situation. But for me, with my go-to folded loops, it's the overhead clearance, including bridge deck, that determines what the grade will have to be. From there, double up power or run reduced consists.
Does anything over 2.2% incline look realistic on a small layout? Besides that, I worry about fewer cars getting hauled.
Woodland Scenics makes foam subterrain incline sets in 2, 3 and 4% grades. Might not hurt to get the 4% grade set and do a 'real world' test with your equipment and see how it works.
https://woodlandscenics.woodlandscenics.com/show/item/INCLDECLSET
You can get it direct from WS, from Walthers or other online dealers, or at a local hobby shop.
after over 50 years in the hobby the railroad being built will have all track on the same level. Iam fortunate to have a basement consisting of two sections. one is 14'x20' attached to a section 12'x30'. i have come to the conclusion that the prototype made every effort to keep the tracks level as much as possible. instead i will vary the topography around the railroad. i know some people do not have that space but nothing is worse then a railroad that is overbuit trackwise for the space available in my opinion and double decking a small space is a disaster waiting to happen in most cases.
ndbprr after over 50 years in the hobby the railroad being built will have all track on the same level. Iam fortunate to have a basement consisting of two sections. one is 14'x20' attached to a section 12'x30'. i have come to the conclusion that the prototype made every effort to keep the tracks level as much as possible.
after over 50 years in the hobby the railroad being built will have all track on the same level. Iam fortunate to have a basement consisting of two sections. one is 14'x20' attached to a section 12'x30'. i have come to the conclusion that the prototype made every effort to keep the tracks level as much as possible.
Rich
Alton Junction
As a follow up to my 8/27 reply I have found that necessity, indeed, can be the mother of creativity. After I cobbled together an adjustable incline I set about running a number of consists (4, 6, and 8 cars) with a variety of both 4 and 6 axle locos (GP20, RS-2, SD9, SD45, etc) at some key grades (1, 2, 3, 4 and 5%) making and noting observations of performance to best judge reliability.
Keeping in mind, as I stated in my original post, that I'm running a short, branch line layout with other than an RDC car and an FP40 powered 4 car passenger service all locals are 4 and 5 car consists. Absent a lot of boring numbers I can pretty much report the following: basically all equipment performed as expected in a variety of train configuration through a 3% grade. At 4% things began to get a little squirrely and I had to pay attention as to combinations of motive power and train length which would seriously affect future dispatching. Some consists of 4 cars and prime movers were completely reliable where others at 6 cars just plain ran too slow or experienced traction problems at 8 cars. Generally, at 5%, things didn't go well at all. A 4 axle GP38-2 would outperform a 6 axle SD9 . . . go figure! My SD45 at a whopping 34 oz. and 8 40' box cars didn't skip a beat. Also noted, as I checked the climbing speed of each configuration at the same throttle setting over a 36" section of track, was the slowdown. Averaging 3 runs of each train the pattern seemed to be an increase of about .6 seconds for each degree of increase in grade, or until there was a total loss of traction.
Given the above I went back to the drawing board (AnyRail) and, along with the progress I had made so far on the benchwork to date, I was able to make some adjustment to my track plan as well as elevations to arrive at more reasonable, practical and reliable maximum of 3.2 and 3.6% on my two main grades. I did this by relocating a couple of structures and scenic features picking up about 68" of run and reducing the elevation of the lower level by 1 inch of rise.
And that's my story and I'm sticking to it. At least until the next obstacle comes up. Meanwhile, I'll update this post in the future as to how it all worked out. Thanks for eveyone's consideration and comment.
Re the "slow down" going uphill - if you're running DCC, most all decoders now have Back EMF, which compensates by applying more power to the motor when it senses the train slowing down due to a grade. You can adjust the Back EMF as far as how much it compensates.
Hey wj - probably shouldn't have mentioned "slow down" as its probably not relavent to the issue at hand. As an FYI: my exercise wasn't a precision experiment by any means but just a test I cobbled together to assure my self that my overall layout plan was workable in the room I have to work with. A proof of concept if you will. Secondly, BEMF is in fact set for all locos tested, but to work on my previous layout on which they regularly ran up and down my 6 turn 2.7% helix and worked wonderfully! I suspect I'll have to revisit the appropriate CVs once I have the new layout up and running. Another thought is wheel slippage. I had no way to evaluate that but it became immediately pretty obvious above 3.9% - both visually and audibly.