{"id":167,"date":"2017-03-02T16:11:03","date_gmt":"2017-03-02T16:11:03","guid":{"rendered":"http:\/\/www.harlemrivercrossways.com\/blog\/?p=167"},"modified":"2023-05-18T11:21:47","modified_gmt":"2023-05-18T11:21:47","slug":"building-the-outer-circular-track","status":"publish","type":"post","link":"https:\/\/www.harlemrivercrossways.com\/blog\/building-the-outer-circular-track\/","title":{"rendered":"Building the Outer Circular Track"},"content":{"rendered":"\n

There’s little doubt that the outer circular track with its 14 team tracks fanning out is the most challenging part of the CNJ Bronx Terminal. In order to succeed I’d also have to adapt my approach for building the track work. I mentioned earlier that for the more complicated turnouts I produced a design beforehand using a drawing program<\/a> on my computer. This was now an absolute necessity for the turnouts on the south-eastern side of the freight house as all of them are three-way turnouts.<\/p>\n\n\n\n

Design Challenges<\/h3>\n\n\n\n

Three-way turnouts have three frogs. One of the design constraints was to avoid a geometry where the left and right frog would be juxtaposed such that there would be no guard rail for locos or cars running on the middle track. It later turned out that this could not always be completely avoided. The three-way turnout to tracks 7 and 8 is an example of this kind. In any case, a properly designed geometry on paper will avoid serious issues during operation later.<\/p>\n\n\n\n

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3-way Turnout to Tracks 13 and 14<\/figcaption><\/figure>\n\n\n\n
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Turnouts to Tracks 7 to 12<\/figcaption><\/figure>\n\n\n\n
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3-way Turnouts to Tracks 1 to 4<\/figcaption><\/figure>\n
Increasing complexity of turnout construction<\/figcaption><\/figure>\n\n\n\n

Another challenge is the available space for the turnouts, specifically for the first four 3-way turnouts for tracks 1 to 6 and 9 and 10. Those four turnouts and their eight throw bars need to be placed in short sequence (a bit more than 12″) over the first 90 degrees of the outer circular track. <\/p>\n\n\n\n

Hinged Points<\/h3>\n\n\n\n

While building the turnouts I got better over time, and so was able to reduce the minimum distance between the two throw-bars from 30 to 17 millimeters. The only way I was able to achieve this short distance was by using hinged points for the short point rails. It took me some time to figure which design would give me the least amount of stress to the joints with the most robust design. In most cases it was sufficient to use one hinged point with a joiner soldered the closure rail while the other point rail stayed solid (I’m totally aware that I’ll be doomed for the rest of my life to re-soldering loose closure points to their throw-bar…).<\/p>\n\n\n\n

Materials Used<\/h3>\n\n\n\n

Here are some details about the material I used for building the tracks:<\/p>\n\n\n\n