Living in New York City I took the train over the Manhattan Bridge from Brooklyn to Manhattan. Looking out the front of the first car I found myself interested in the trackwork spanning the bridge. Just past the main span I noticed that the tracks seemed to be spliced at one point. Meaning that the rails on both sides could move past each other accounting for expansion and contraction of the rails. At least this is my best explanation for this area of track. I would imagine that the bridge itself is designed to move slightly do possible to heat or cold, traffic weight, and wind speed. Has anyone ever noticed this track splicing configuration.
Are their any implications for model railroading in dealing with expansion and contraction.
Or am I just reading this trackwork incorrectly. I respectfully await your input.
If you mean to deal with the model rails expanding/contracting from temperature, most modelers will leave a little gap between the rail ends at some rail joiners to let the rails expand/contract without buckling. I’m not swearing that I’m right though.
Yep. Models have that problem too.
With models, the expansion/contraction is caused more by the wood and cork roadbed than the track itself. Cutting expansion gaps in your rails helps. A proper climate controlled room is really the answer.
loathar is right on the money. Expansion and contraction is mostly caused by humidity making the wood and other materials move. If possible try to control both the temperature and the humidity in the trainroom. I keep the temperature between 55°F and 75°F (oddly enough it is 75° down there right now because of the dehumidifier…). I also keep the humidity around 50% on average year round. I no longer have trouble with track buckling.
I believe the original question involves modeling the specialwork the prototype uses to deal with rail movement, where the rails can slide past each other while maintaining a smooth, in-gauge surface for the wheels to roll on.
In building the Shinkansen, the JNR installed what looked like paired switch points - except that both were closed and solidly anchored to prevent sideways shifting. The rails that would have been stock rails of a turnout were spring-loaded against the ‘points’ and the whole business was always installed trailing point on one-way track. I never saw anything equivalent on any other JNR line, and I have covered thousands of kilometers watching out the front ends of EMU and, especially, DMU.
Since it has been 50+ years since I last crossed the Manhattan Bridge, my memories of the track configuration are, to put it mildly, hazy - but I do vaguely recall some kind of sliding joints at both ends of the span.
The Shinkansen type would be easy to model. Exactly what modeling the New York City version would involve I can’t even guess without a clear, close-up photo.
