Spline roadbed and vertical curves

[gshin]

Good Morning,

 I'm sure someone's covered this, but after 1/2 hour of searching this forum I've given up and I'll ask the question: How does one deal with vertical curves with spline roadbed?

I'm planning to use 1" thick masonite strips.  I can't imaging trying to bend these things vertically for a grade.  Any thoughts?

Thanks,

Greg 

[NeO6874]

I think 1"wide strips are just a bit too big.  I could be wrong though.  Generally you'd need to make 2-3 splines follow the grade (glue them together, then screw & glue to the riser), and then after the glue has dried overnight, glue the remaining splines in place & clamp overnight again.   You can then remove the screws from the risers after the splines have dried.

 

Joe Fugate has a pretty good tutorial/overview of laying spline roadbed on his website. Click Here to go directly to the tutorial/overview.

 

If that doesn't help, I know electrolove & joe had a pretty in-depth discussion on spline roadbed and vertical curves on these forums a while back... 

  

[Geohan]

Two additional ways to form vertical curves in a spline roadbed.

1  Kerf the splines (cut a series of cuts about 3/4 of the way across the spline on the inside of the vertical curve with the cuts spaced about 1-inch apart) Full strength will be restored after the glue has set.

2  Transition to wood splines and soak/steam in hot water to make pliable.

Geohan

[selector]

First, anchor two or three of the splines (mine were 1/4" MDF in strips 15/16" wide) laminated together at the lower end of the grade.  Fix the first few inches level on a riser.  Support the rest of the lengths.  If you are handy, you can merely clamp the glued level beginning and continue to rest the other parts of the three splines on riser that force the easement.  Clamp after gluing, an check again after a few minutes to make sure nothing has slipped.

The key is to start with one or two strips and don't have an abrupt transition or easement.  They'll bend.  Once that first set is dry, clamp another two or three beside them, and let them dry.  Presto, your transition.

[Texas Zepher]

I think 1"wide strips are just a bit too big.

What are you trying to support?  I think our spline is 3/4" stripped pine and has proven to be very sturdy.

[gshin]

Thanks everyone - lots of good ideas and links to good ideas here.  Now, I've got to go try some of them!

 Regards,

Greg 

[jfugate]

Greg:

I use 7/8" wide masonite spline and vertical curves work just about perfect -- way better than 1/2" plywood. The trouble is half-inch plywood lets you put in vertical curves that are much too sharp for proper tracking. Spline roadbed, however, forces you to not get too aggressive with your vertical curves. For example, it should take about 4 car lengths to go from level to a 4% grade.

The beauty of solid masonite spline roadbed is it forms natural easements on curves, and on grades the vertical curves are also excellent. It's hard to beat the stuff as great roadbed and it's very economical on materials, too.

I'm completely sold on masonite spline as the near-ideal roadbed material. As long as you use latex caulk to fasten down the track, it's excellent (you can't spike into masonite spline, it's too hard). And the spline is dense, giving it very good sound absorption, too. Masonite spline roadbed is way quieter than flex track laid on foam.