Underground Yard

[Kris Everett]

nope look at pic

[Doneldon]

Kriss-

Yes, you can use EZ Track for your helix but it will cost a bundle. I suggest flex track instead. You buy it in three-foot sections and curve it to whatever you need. You don't need roadbed for concealed track so the track alone will be just fine.

Remember that curved grades are harder for your locos to go up than straight grades so don't go for the tightest radius and most severe grade you can. Open up the radius and you'll have better operations.
                                                                                                             -- D

[Kris Everett]

i have about a 3 or 4% grade slope that's open and it works great no probs for any of my engines w/ or w/o loads, however that is 26"rad curve also.

[jward]

i have a 4% grade with 18" curves on it. i have no trouble pulling at least 6 cars with most of my engines. i have a couple of walthers trainline engines that will pull over 10 cars apiece. if one won't pull the train you can always add another, after all diesels usually run in multiple......

from my experience, sharper curves help increase the pulling power of the locomotives while they are on the curve. it's when they hit the straight track that they usually stall, with the rest of the train in the curve. things are much better now than they used to be, with free rolling metal wheels standard on most cars, and a truck tuner tool readily available to help the rest of the cars roll smoother.

basically, if you want to do the helix and you only have room for 22" curves, don't ket that stop you.

kris, you'd asked about using ez track in the helix. you could do that but you may not be able to maintain full clearance between levels. this is one area where i will deviate from the nmra standard. as long as your tallest car will run through the helix i wouldn't worry too much. best thing to do is get yourrself one of those 40 foot hi cube boxcars, or a 50 foot flat with trailers on it, and run that to checque clearances.

i grew up and still live in the east where low clearances were common. to get the effect of this, i often trim my tunnel portals down so my tall cars just fit through the portal. the effect is great, i really like the way they look. you can go as low as 2 1/2" and still run the boxcars. since the ez track is about 1/4" tall, you should have enough room. just don't try to run double stacked container cars and you'll be fine.

[Kris Everett]

http://i956.photobucket.com/albums/ae45/trainboy16/brainspirt1withmarkups001.jpg

hope you can see this well  enough if not let me know and ill make a better one

i need to know where the other iso track need to go to avoid making a short.

which one would be better this idea or the helix?

if you could help me out it would help a bunch
    thank you
KRIS


HAPPY NEW YEARS EVE

[Doneldon]

jward-

There's something to what you say about locos and curves. I think what happens is that the locos bind a little in the curves and thus have better adhesion to the rails which means they can pull a little more. Once they leave the curve they no longer have this advantage but the cars still have greater friction due to the curve and it makes it seem the loco has gotten weaker.

Real railroads have the same issues. They have tables which tell them how much curvature they can have on a given grade and conversely. Sometimes they even grease the insides of the railheads to make it easier for trains to pass. For the 1:1 boys it's all about getting the most freight through in the shortest time without breaking anything. That doesn't just mean the contents of the rolling stock; it includes the rolling stock itself, the locos, the rail and the value of the railroad's stock on Wall Street.

                                                                                                                                             -- D

[jward]

i worked in the railroad industry for several years, and had access to the "track charts" for the territory i covered. these are the "blureprints" pf a particular section of road......

it is common when climbing a grade to lessen the steepness while in a curve to compensate for the increased resistance of the curve. a locomotive pulling a train uphill thus sees no increased resistance because of the curve. the problem comes for trains descending the mountain. horseshoe curve near altoona, pa ( part of my territory) is a very good example. when a train is coming down the mountain, they will lower the brake pressure by 5 or 10 lbs to slightly apply the airbrakes on the entire train. fine control is done through the locomotive's dynamic brake. when they hit the flatter plspots on the mountain such as horseshoe curve, the engineer will back off on the dynamic and let the increased resistance of the curve hold the train back.

standing in the park at the curve, you can hear the dynamic brakes howling as the train enters the curve. then the engineer backs off the dynamic and they quiet down. if they've set too much air, they sometimes actually have to apply power and pull the train through the curve. once the train starts to roll freely again, they will come back out on the dynamics to keep the speed at a safe level.

one wonders how they maintained speed with steam locomotives that didn't have dynamic brakes. if your train bogs down and you release the air brakes, by the time the pressure builds back up to the point where you can apply them again, you may have lost control of the train.

[Doneldon]

jward-

Yes, I've experienced the same phenomenon on the west side of Cajon. Only in a diesel, though, so I don't know what the steamies did. My dad worked for the ATSF. He had enough clout to get me into the cab of a diesel but not enough to get me in the way inside a steam loco. (Not there, anyway. I did ride a 4-8-4 to San Diego once when the trip was set up before they had to put the steamer into service due to a problem with the F-units.) Sometimes we'd drive up to Cajon at night and watch the locos' lights reflect every which way off of the canyon's walls. What a sight! And the sounds. That was busy track even in the 50s so there were always lots of trains, many behind steam. Whistles, horns, brake squeals and all modes of screeches were constant.

                                                                                                                                     -- D

[jward]

i'm not old enough to remember steam, but we had the next best thing. we had alcos everywhere around here in the 1970s. the century series alcos had their dynamic brake grids behind screened openings over the prime mover, and when the grids got hot  it looked like the whole interior of the locomotive would glow red. add to that, the red hot wheel rims from the brake shoes, and a heavy coal train descending the mountain was a sight to behold......to-day, the dynamics are much stronger and they don't have to use as much air. in fact, the sd80macs i worked around weren't allowed to use full dynamic brake as they could roll rails over from the force. we had one instance where we had 2 macs pushing on a back on a coal train on the shawmut line. they rolled the rail over and by the time the train stopped it had rolled out from under 2 locomotives and 23 cars. after that, we had to double that hill even though we had enough power to make it in one shot we had to leave half the train at the bottom and take it up in two cuts, then put everything back together at the top.


railroading..... i miss it.

[trainman1248]

OK i just read this post and I'm interested in some of the things in here. I'm new to this forum so forgive me if i seem a little out of place. whats this thing called a reversing loop modual that Kris talks about and how dose it work i want to do some along the same lines as Kris but I'm in the same predicament as he is as where to put the isolated gap tracks? could you help us both out please?

trainman

[jward]

your reversing loop track should have one or more switches through which trains enter the reversing section. these switches at the entrance are where you should gap your track. gap both rails of the reversing section, at the frog end of the switches. you MUST have both rails gapped at both ends of the reversing loop.  the reversing loop module is connected to the rails of the reversing section anywhere between the gaps, and the other end is connected to the power bus wires that power the rest of the layout. reverse loop modules will only work on dcc, but you can do something similar with dc or analog layouts using a bridge rectifier in place of the module.

the following link explains reversing loops.
http://www.wiringfordcc.com/intro2dcc.htm#a26
on the right side of the page, scroll down and click on "reversing basics"