# Height difference question



## Steve Rothstein (Jan 1, 2021)

I hope this doesn't sound as dumb as I think it might be, but I have a design question for a layout. My son and I are going to move our first layout from his garage into his shed. I am about 90% sure it will actually be torn apart and a whole new one started. The current layout is a 4x8 table style and the shed is 8x16 so I don't think just expanding this will work (not enough room on the sides as it is). We are probably going to use a U shaped layout around the perimeter of the shed, though even that will be a tight fit. Thirty inch sides will leave three feet in the center. I think that will work while one person is there but two might be bumping each other fairly often.

Anyway, one of the things my son wants to do is have the rails cross over each other on one of the legs. He was thinking town and factories on one side and scenery, including mountains on the other. I don't want to get too steep a grade and want it kept around 1.5% at the most. That would not give me clearance normally for the cross over in that distance. Has anyone ever tried to have the one leg dropping while the other leg climbs, so the clearance as they cross is around three inches? I can't see why it would not work, but I might be missing something.


----------



## Magic (Jan 28, 2014)

That's the way I did it. 
I have a set of crossovers at 1 1/2 inches above the base level.
Upper track rises 1 1/2" and the lower drops the same.
Worked great for me. 
Still takes the same amount of track but looks better IMO.

My grades are at 2% and are no problem but I use 2 or 3 locos on my long trains.
Small layout like yours with short trains one good loco shouldn't be a problem.

Magic


----------



## Lehigh74 (Sep 25, 2015)

I have a U shaped 20 X 20 O gauge layout. The third loop goes from 0” level to 3”. The fourth loop goes from 3” to 6” and crosses over the other three loops. Max grade is 2.5%.

Since the legs of your U are 16’ and you need to go up 1.5” and down 1.5”, I suspect you could do it with 1.5% grades.


----------



## CTValleyRR (Jul 26, 2014)

Steve Rothstein said:


> I hope this doesn't sound as dumb as I think it might be, but I have a design question for a layout. My son and I are going to move our first layout from his garage into his shed. I am about 90% sure it will actually be torn apart and a whole new one started. The current layout is a 4x8 table style and the shed is 8x16 so I don't think just expanding this will work (not enough room on the sides as it is). We are probably going to use a U shaped layout around the perimeter of the shed, though even that will be a tight fit. Thirty inch sides will leave three feet in the center. I think that will work while one person is there but two might be bumping each other fairly often.
> 
> Anyway, one of the things my son wants to do is have the rails cross over each other on one of the legs. He was thinking town and factories on one side and scenery, including mountains on the other. I don't want to get too steep a grade and want it kept around 1.5% at the most. That would not give me clearance normally for the cross over in that distance. Has anyone ever tried to have the one leg dropping while the other leg climbs, so the clearance as they cross is around three inches? I can't see why it would not work, but I might be missing something.


Yes, that's a fairly standard practice. What matters is vertical clearance at the crossing point.


----------



## Steve Rothstein (Jan 1, 2021)

Thank you all for the answers. I thought it would work, but had some doubt because I use SCARM to make the layout. It will not let you indicate a decline from the base height. I had figured if I make the first piece of track elevated then it should allow me to show both the increase and decrease from there.

I am glad to here I am not as far out of line as I thought it sounded.


----------



## JeffHurl (Apr 22, 2021)

You can do it if you make your base level the lowest point in the plan. Then just have your true "ground level" be elevated at a consistent height


----------



## cv_acr (Oct 28, 2011)

Steve Rothstein said:


> I don't want to get too steep a grade and want it kept around 1.5% at the most. That would not give me clearance normally for the cross over in that distance. Has anyone ever tried to have the one leg dropping while the other leg climbs, so the clearance as they cross is around three inches? I can't see why it would not work, but I might be missing something.


Yes, BUT...

If you already have a consistent grade from 0 to the highest point, with no flat track anywhere on that run, it won't change anything.

Grade is simply the total rise in height of the track over the length of track it takes to make that rise - it has nothing to do with the height of the table. If the grade starts rising immediately from the low point under the bridge and rises continuously to the high point over the bridge, there's no difference between going from 0" to 3" or -1.5" to 1.5".


----------



## Steve Rothstein (Jan 1, 2021)

cv_acr said:


> Yes, BUT...
> 
> If you already have a consistent grade from 0 to the highest point, with no flat track anywhere on that run, it won't change anything.
> 
> Grade is simply the total rise in height of the track over the length of track it takes to make that rise - it has nothing to do with the height of the table. If the grade starts rising immediately from the low point under the bridge and rises continuously to the high point over the bridge, there's no difference between going from 0" to 3" or -1.5" to 1.5".


I am planning a new layout. So far it is flat but I want to put the cross over on the one leg. A 1% grade means a change of 1 inch in height for a 100 inch run. To do a cross over like that I need them to have about 3 inches of clearance, so I would need 300 inches to raise it to the cross point and then 300 inches to bring it down again. I don't have that much room.

But if I raise the elevation of my start point to 2 inches, I can go down 1.5 inches on one side and up on the other. This cuts the distance needed from the flat to the cross point to 150 inches. That I have and can plan for.


----------

