Clearance question

depends on the height of your audience

Random thots:

When ever working with various  levels for over / under operation I usually seek to achieve as much separation as practically possible.  The more separation the better the view IMO.  Your taste may vary.  You may not have the space to do that. 

For out of view minimum you may be able to get most equipment through 4 1/2".  7" is a for sure.  Get and use an NMRA gauge, that is a good middle of the road standard.

I like 10" of vertical railhead difference if the tracks are viewed close.  If the right of ways are far apart you can close that up.  Again, opinion.

Thanks for Advice 

audience for now is me average height 5 ‘8

no grandkids at moment 

While the trains all by themselves only need about 4 1/2" of clearance (assuming it's just passenger cars) the real answer to your question depends on a lot of decisions you first have to make; the kind of lumber you're going to use, the height of the track plus any roadbed on the lower level, how you're going to support the upper level, the thickness of the sub-roadbed on the upper level,  and where those supports are going to be located relative to the track on both levels.  7" sounds about right but depending on the factors above it could vary +- an inch. You didn't mention the size of the layout you're considering but to raise/lower the track 7" and be less than a 4% grade, which is kind of steep to begin with, you can do the math and see that you're going to need some room.

Subways don't need as much vertical clearance as regular trains. I use 8" from rail top to rail top for regular trains which includes 3/4" plywood and 3/4" for horizontal support. Just remember whatever you decide to go with you will need to be able to reach into and possibly rerail the cars, so leave room for your hand.

As for the grade issue, again you have an advantage with subways, since trains are short. With regular trains 2% is a good rule of thumb, but subways should easily handle double that. You might want to put some straight track on a board, and keep trying the train at steeper grades to find the max limit. Then lower that a bit to arrive at a final answer.

I use 6 inches. Also another 6 inches for elevated although my ramp will go from a 6 inch deep subway to roughly 4.5 inches above ground as it will initially connect to a complex set of elevated before it ascends a further 1.5 inches. Grade is between 3.5 and 3.8 percent for nearly 23 feet of ramp.

Thanks . Don’t have 23 feet to play with. May have to forget this idea. 

What is the size of your space.  My ramp has 2 curves.

Planning on 8 x 18

If possible use a car garage technique.  Build your subway oval below and your elevated oval above.  Branch off the subway with a ramp connecting to the elevated.  You have the space to do so.

You need slightly less than 15 linear feet of track to descend/ascend 7" assuming a 4% grade. That shouldn't be too much of a problem with an 8x18.

If clearance is tight, consider supporting the upper level with supports from the side of the tracks, that will lower your required height to provide clearance on the lower deck.

Thanks for advice 

Replying to xrayvizen

if there is el on main level about 7 inches high above main level going to down to a second level  which is 7 inches below wouldn’t  train being descending a total of  14 inches.

yanksali posted:

Replying to xrayvizen

if there is el on main level about 7 inches high above main level going to down to a second level  which is 7 inches below wouldn’t  train being descending a total of  14 inches.

Yeah, I misread your original post. I read where you wrote it was two levels but realize, in re-reading, that it's actually three; The elevated section is going to be a real "El", I guess. Cool. Lots of opportunity for some city-scaping scenery. So yes, you will need about 15 feet of track to get from the "El" to street level, then another 15' down to the subway. Still doable for your planned 8x18. Just more track will be needed.

You need 30 feet of span?  Could be done with 8 x 18 layout?  What grade would that be? 

Pretty easy. Attached is a SCARM diagram showing 8x18 table with a 7" elevation change in 220-some inches...a 3% grade. (If you zoom in you can see the elevation notations marked on the track sections.)

I would suggest you make a diagram of your room and table, maybe sketch out some of your own ideas for a track plan and post in the Track Plans and Layout Design forum. There are lots of folks there who can help you design and fine tune your layout.

Isolated elevated, isolated subway, no grade.

To  xrayvizehn 

thank you - very  nice of you to take the time

much appreciated 

is scarm  a free or bought software. Where do I get it? Easy to use? 

on your diagram not clear which  is the elevated portion 

looks like a portion is like a yard that ends rather than connect to a portion of the loop 

To Tom Tee

definitiey  the easier way  for a newbie.  Having an el line descend to a lower board for underground subway and then come back up as do some NYC lines do would be more interesting but much more difficult. 

yanksali posted:

To  xrayvizehn 

thank you - very  nice of you to take the time

much appreciated 

is scarm  a free or bought software. Where do I get it? Easy to use? 

on your diagram not clear which  is the elevated portion 

looks like a portion is like a yard that ends rather than connect to a portion of the loop 

 

SCARM is free to download and use up to a point (the number of track pieces.) Beyond that (I'm not sure what the number is, but it's a lot) there's a license fee. It's pretty easy/intuitive. Website. Also, on the track planning forum there's an ongoing thread all about SCARM.

To your second question, it doesn't matter. I was just demonstrating that you can get the clear elevation needed in a half a turn around an 8x18 layout. I could have continued the track on around clockwise and by the time the original  start point was reached (the switch) it could have been close to the 14" needed to get from subway to the main, and then main to the El. (or visa versa.)

Good luck.

Thank you again for all of your time and good advice. Very much apprecoated 

Another point is to use MTH PS 2 or 3 and run point to point upper to lower, no loops at all,  with station platforms along and behind the fascia of the platform for the lower level.

Nice photos thanks