> Superelevation is introduced into curved track a the spiral. > At what is called the TS (Tangent to Spiral) the elevation > and curvature are zero. They are both introduced at a > constant rate until the SC (Spiral to Curve) point at which > both the elevation and curvature are at their maximums for > that curve. This is also called the "Full Body". The inside > or low rail is often called the grade rail. The elevation is > introduced by jacking up the outer rail, and then tamping the > track. Lowering the inner rail would require the track to be > undercut, and no one is going to do that. To get EL content > the EL General Track Work Standards states, "The > super-elevation at any point on a spiral shall be sufficient > to conform to the super-elevation tables for the ordinate at > that point." So if you have a 4 degree curve with 4" of > superelevation (which according to the EL book is good for 45 > MPH); the halfway point of the spiral should?be a 2 degree > curve with 2" of elevation. In the table tha! > t combination is good for 50?MPH;?so we meet EL standards. > > In the picture both tracks are elevated, and are set as > presented, i.e. in one plane. Another catch to curved > turnouts is that the lead distance must be modified when they > are placed in curves - one is shortened and one lengthened.. So basically my original thought was probably correct? I was going to handlay the curved crossover on a single piece of Homasote, and then bank the entire piece to the 2" elevation (not that much in HO scale) - and bank the tracks coming into/out of the crossover accordingly? - Paul The Erie Lackawanna Mailing List http://EL-List.railfan.net/ To Unsubscribe: http://Lists.Railfan.net/erielackunsub.html ------------------------------
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