"Styrospline"

Allegheny Eastern February 4th, 2012

More doodling led to more ideas on what might be done. The latest update of the track plan shows that the general layout of the mainline remains the same except for the realignment between MP10 and MP25. Horseshoe Curve has been relocated about 10" "north" and the approach to The Curve straightened out to allow more room in Altoona.

The eastbound main between MP45 and MP30 has also been realigned further "south" bring the tunnel bores closer together. This leaves enough open space in Gallitzin for a Hollidaysburg staging yard on the New Portage branch. There's some reworking of the trackage for the Altoona Northern and Altoona & Logan Valley. On the A&LV I made the return loop much larger and placed the carbarn and industry tracks inside.

"Styrospline"

So much for the track plan. Incorporating these changes into the actual layout seems like a bit of work, but again the construction methods used allow for some pretty big changes. One of the techniques I'm using worked out better than I imagined. The styrofoam spline used to create the New Portage grade proved to be a huge asset. At right is a picture of the spline where each section the roadbed was essentially a 1/2" square. The four parts are glued together with tacky glue and are almost inseparable. Not only is the spline super easy to create, the only tools required are a razor blade and straightedge, it's cheap. A 4' x 8' sheet of  1/2" thick foam is less than $15...You can get a lot of spline out of that sheet.

"Old" Roadbed

One advantage I hadn't foreseen was the road bed can  be re-used. It remains flexible! I found that I could reuse the section between MP30 and MP35. In the photo on the left the roadbed is still in it's original location. The New Portage bridges have been moved to their new location towards the center of the picture and the track has been moved to approximate the new alignment. The roadbed between the bridges old location and the camera will need to be removed. I pulled it loose from the table top and realizing how flexible it was just swung it into position along the new alignment.

Flexible Spline

To my surprise it went into place creating a broad curve. If I were going to reuse it in this location all I would need to do is glue it back down and relay the track. Instead I now know it can used elsewhere on the layout, another component that's recyclable. Since I tend to use construction materials over and over this fits in well with the other design and construction methods developed so far. Kind of an "instant" 1.5% grade for two tracks. Makes me wonder if the spline could be made up ahead of time and then "flexed" into alignment. The flex of the material would create natural broad curves. I'm pretty sure the spline would have to be laid down two tracks at a time. A spline for all four tracks would be four inches across and not quite as flexible.

Revised New Portage Area

It didn't take long to layout the modifications to the Tunnel Hill / New Portage section. You can see that the New Portage bore is much closer to the Twin Tunnels and is a better representation of the area being modeled. There is now a great deal of space available for the New Portage branch to actually travel somewhere. Current plans call for a kind of "staging" yard, but other opportunities may develop. The westbound tracks will also be elevated, but only about half the height of the eastbound. The eastbound roadbed to the right of the bridge will run uphill from the 1.5" elevation at the bridge to the 3" maximum at Horseshoe. The westbound main will drop from 3" at Horseshoe to about 1" at the twin tunnels.

McGarveys

As for the other areas being revised the photo on the right shows the new alignment at McGarveys Curve at the lower right hand corner. The faint blank line running between the mainline and the Altoona and Logan Valley tracks is the edge of the old alignment. There is now almost a foot of space available. There needs to be a mountain side in this area and there is now enough room to model one. The benchwork is being extended in this corner with a "triangle" of real estate to support the relocated tracks.

Kittanning, East of Horseshoe

The situation is the same in the opposite direction toward Horseshoe Curve. This shot of the Kittanning area show that the mainline has been moved aside. The short train is on the Altoona Northern interchange track in Juniata. The two areas are now separated horizontally by about 12" and vertically by almost 3". Just like at McGarvey's Curve, there is now enough room for a mountain side. This will be the site of Baker's Run and the Kittanning Run Railroad will connect here.

Burgoon Run, West of Horseshoe

The realignment on the west side of Horseshoe looking east from McCanns. The mainline now sits about 6" further "north". The tracks of the Glenwhite Coal & Lumber Co now turn off up Burgoon Run towards Gallitzin. The elevation at the turnout will be about 2.25" descneding towards the tunnels. The large vacant area without foam will support the Gallitzin sidings and the GC&L connection to the Altoona Northern and A&LV as shown in the updated plan. This is also the location of the "access hatch" to maintain the westbound tracks in Gallitzin.


The new splines will start going in this week. I hope to show some step by step construction photos of the splines being made and installed. Once they are in place the ballast strip can be glued back down and track relaid. For the first time since it's inception years ago, the Allegeheny Eastern may even be ready for real scenery.