Spline roadbed Part II …

Hi all,

Today saw the installation of the first section of spline. YAY!

I went to the hardware store to get some 6mm masonite to use for the spacer blocks, but could not find any.  So I ended up getting a sheet of 1200 x 600 x 6mm exterior 5-ply.  When I did the drawings for the spline last night, I was envisaging using 50mm long spacers.  So I cut the ply into 50mm wide strips, and then docked these off to 25mm wide, same as the spline height.

After docking about half a dozen ply strips, I then realised that 50mm would probably be too long for around the curves, so I test fitted a piece against my 40 inch radius template and found this to be correct.  So I then proceeded to cut a quantity of the spacers in half which will work better on the curves.  I’ll still be able to use the 50mm ones on straight sections and gentler curves.

I then spent a few hours trying to get the first curve from the storage yard correct.  In the original plan, I wasn’t going to model the bridge over Chilcott’s Creek, which is at the start of the 1 in 40 climb to Ardglen.  After taking some pictures of it last week on the way back from a few days at Dubbo, I am now going to model this bridge.

chilcotts ck bridge

After looking at Google Maps, I calculated that the bridge is 150 feet long with 5 spans each of 30 feet.  Micro Engineering make a 30 foot long plate girder bridge so I am looking at using this.  More on this bridge later.

Anyway, back to the spline.  After some tweaking of the track plan to allow for the bridge and moving it slightly more towards the front of the layout, I came up with a slightly revised track layout for this section along the wall to Kankool.  It’s not that much different from the diagram I have posted previously, but that is the beauty of using spline, in that it can be adjusted as you go.

After making some centreline marks on the benchwork, I then devised a method to hold the spline underneath the storage yard ply just until the spline is complete, and then it will be raised to the correct elevation.

temporary spline anchor point

I cut a short piece of L-girder that I had made previously.  This was clamped basically in line with the easement on top of the ply, then the first piece of spline was clamped here.

At the marks on the joists made previously, I drilled a small hole to allow for a nail to be inserted on the outside of the spline to hold its position.

locating nail

Once this first piece was in position, another piece of strip was cut a bit shorter so the joins are staggered, and was glued and clamped to the first piece.

first piece in place             second piece glued and clamped in position

This first pair of strips forms the centre of the spline.  This will be left to set overnight, and tomorrow I’ll add the spacer blocks and more strips and see how it looks.  The short joist at an angle is the start of a tangent section of track where the bridge will be located.

Cheers for now.


Posted on October 12, 2011, in Benchwork and tagged , . Bookmark the permalink. 2 Comments.

  1. Ian,
    hope you got a good deal on those 28 clamps in the last shot

    • Hi Bob,

      Yeah, I got them from Go-Lo (I think) some years ago. That size was $1 each from memory. I have quite a few more of different sizes. Perfect for spline construction!


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