Modyfing The General train set for figure eight over and under

[billyb]

What additional pieces do I need to buy to convert "The General" train set to a figure eight over and under set up?

[bbmiroku]

So you have the train, transformer, and an oval of track (12 curved pieces and 2 straight pieces) correct?
I'm going to assume you are in HO Scale.

20 curved pieces (18" radius [standard EZ Track])
4 straight pieces (9")
14 piece graduated pier set
Is what track you'll need from scratch, also is what is included in the Bachmann EZ Track Over-Under Figure 8 kit ($89, #44475).  Just to make sure you have the room, this will be 78"x36".

So what you need to get are 8 curves, 2 straights, and the piers.

[jward]

Before you buy anything, remember this:

The General is a small locomotive that doesn't have a lot of pulling power. Upgrades severely reduce that pulling power. With the steep incline of the pier set, you may find that your locomotive will only pull itself, or at most one or two cars up the grade. You'd be better off using this one on level track.

If you do want an over and under configuration, the best thing you can do is lengthen the length of the upgrade, thus reducing its steepness. I would suggest that, instead of using a pier set that you look into the incline sets from Woodland Scenics. They come in 2%, 3% and 4% inclines, and I would suggest using the 2% set if you can. The lower the grade the more cars you'll be able to pull.

[bbmiroku]

Woodland Scenics inclines are great.  I've used some myself.  But they take away from the ability to under-track scenic with bushes, trees, buildings, roads, etc.
What I like to do is make sure of which way my train will run, then make the upgrade section longer and the downgrade section shorter.  So the upgrade may start before the crossover.  But since the General is a short locomotive, and the piers are 3" at the tallest pair, that leaves a lot of wiggle room in grade placement.  You could have as little as 1.5% upgrade.  In fact, you don't even have to use all of the piers.  Make the top level shorter, stretch the piers out to less than 1 per track section, and you could go to less than 1% grade.

[jward]

Are you sure you know how grade percentages are calculated? 1% is 1 inch rise per 100 inches of track. You can NOT get a 1% grade using a pier set. 1% would require at least 300" of run. That's 25 feet, or about 34 track sections. The track rise per section would be about 3/32". Using 7 piers over 25 feet would leave then over 3 feet apart, providing NO support for the track. Added to that, the room required for such a gentle grade would make it impractical to use in most situations.

[Len]

The grade can be lowered by using 2 pier sets. Glue shim strips whose thickness is equal to half the height difference between adjacent piers. You can use styrene, basswood, or whatever for the shims. Start with a regular pier, then alternate with shimmed piers.

This will bring the grade down to somewhere around 1.5%. But like jward says, the distance it will take to get to the top will greatly increase.

Len

[jward]

Using the 14 piece pier set, each pier under a track joint for optimal support, gives a grade of just under 5%. Even a heavy diesel would have trouble pulling more than 3 or 4 cars up that. I have a stretch of 4@ on my own layout, and those numbers are based on my experience. Figures listed in an old Atlas layout plan book indicate that pulling power is reduced to 1/6 on a 4% grade, compared to what it will pull on level track.

Using two pier sets, with shims as Len suggested, will still yield a grade of about 2.5%. That is much better, but will still significantly reduce your locomotive's ability to pull a train up the grade. Ironically, the track configuration you are considering, using the pieces described by bbmiroku, would give a grade of about 3% if the rise and fall were evenly distributed around the track.

To use the two pier sets as described by Len requires a 4 additional straight pieces, two on each side of the figure 8. The two straight pieces can be located anywhere on the curve, but must be directly across from each other. If you experiment with their location, you should be able to fit the enlarges figure 8 on a 4x8 sheet of plywood.