# Track Needed for an Elevated Figure 8?



## MackDaddy (Jul 26, 2017)

Hi, I'm getting back into the hobby and am in the process of designing my first outdoor layout. I'm having a hard time figuring out how much space is needed for a figure 8 layout which crosses over itself and uses 4' curves. I'm running small kitbashed stuff like HLW Macks and the LGB Steinz. 

Thanks!


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## Mike Flea (Apr 8, 2014)

It'll take 6 LGB R1's (4 ft Diam) to make a half circle. Figure 1 more on each side of the half, to get the track aimed at the cross, so you're up to 8 curved tracks (each side), then just add how may straight pieces you'll need for the length of your available space.


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## Semper Vaporo (Jan 2, 2008)

I don't know how accurate this is, but I decided to use SketchUp to draw the track layouts possible using whole curved sections, assuming each section accounts for 30 degrees of a circle (12 sections per circle). I figure cutting the curved pieces is a bit more tedious than cutting a straight section.










the bottom one is just 2 circles overlapping (this would require the crossover being over/under grade separated) 24 curved pieces/no straights. 8-ft by 16-ft area (add the width of the track and the maximum overhang you will have with your cars and room to walk around the layout, etc.) That is a 25.13-ft circumference (301.6-inches) to one circle and for an over/under crossover with a grade separation of, say, 10 inches that is a grade of 3.3%... kind of steep!

The middle one is using 20 curved pieces and two straight sections of 4-ft 7&7/16 inches long. Fits in an area 8-ft by 17-ft 2&7/8-inches (plus the width of the track, etc. as above). The grade is about 3.2 percent... didn't gain much.

The top one is using 16 curved pieces and two straight sections of 13-ft 10&1/4-inches. Fits in an area 8-ft by 24-ft (plus as above). The grade is about 2.7 percent.


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## MackDaddy (Jul 26, 2017)

Semper Vaporo said:


> I don't know how accurate this is, but I decided to use SketchUp to draw the track layouts possible using whole curved sections, assuming each section accounts for 30 degrees of a circle (12 sections per circle). I figure cutting the curved pieces is a bit more tedious than cutting a straight section.
> 
> 
> 
> ...


This is awesome, thank you! It was impossible to visualize these grades without actually building it , I'm not super familiar with sketch-up but it looks like it works way better than my software (SCARM)


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## ThinkerT (Jan 2, 2008)

4' diameter curves for a figure 8 over and under...that's a 4% grade - or steeper.

I'd strongly suggest 5 foot diameter curves, and squeeze in as many straights as you possibly can.

Tried building a helix with a 4% grade years ago, ran several loco's up it as tests. Most could not manage more than 2-3 cars. One of those was a Hartland Mac - it managed three cars - barely. The Annie was able to tow four - best of the bunch.


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## Dan Pierce (Jan 2, 2008)

One could always use the LGB rack loco and go up to 25% grade if needed!!!!!!
Of course this would be a ack and forth run as the Rack loco is always at the bottom of the train for safety/no run away cars.


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## Greg Elmassian (Jan 3, 2008)

Don't start with a layout with these grades, just too much trouble with locos and cars. Make an oval all on the same level and add a passing siding so you can change things up... more interest.

Greg 887


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## Semper Vaporo (Jan 2, 2008)

I think I would stay away from an over/under, also.

The crossover angle in both the top and middle drawings I made are 120/60 degree. I suppose there is some logical reason why they both came out to the same angle, but I think it is interesting that they are the same angles (though one is rotated 90deg to the other).

Of course the at-grade crossover limits the length of a train on the loop to just 1/2 of the total track, but can make for some excitement if you like to play "dodge'm trains" with two trains on the single track!


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## ThinkerT (Jan 2, 2008)

For a single grade layout that's something more than an oval, you could go with this:

http://forums.mylargescale.com/13-indoor-railways/23015-pizza-pile-up-paging-vic.html

With R1 curves, it fits into a 9x9 foot space. 

The inner loop of my current layout is a variant of this, using 90 degree crossovers and a fair bit of straight track. With R1 curves...call it 8 x 11 (my version uses R2 curves.)


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## Randy Stone (Jan 2, 2008)

When I first got into G, I inherited a box of 4 ft diameter curves and thought I'd only buy small locos and frt cars. But even the LGB Moguls which LGB said would run on 4 ft diameter curves, didn't like them. So I bought two boxes of 8 ft diameter curves still thinking I would stay with small locos. But as most things go, bigger always seems better and I found my self buying F units then RS1s and finally a Dash 9. So, my suggestion is, buy and install the largest curves you have room for. Small locos will look and run fine on large diameter curves while large locos will look bad or worse not work at all on tight radius curves.


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## Greg Elmassian (Jan 3, 2008)

Randy, you got "bit" by FotoFuggit.... you may want to update your signature picture.

Greg 884


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