What is the geometry of a horizontal railroad?
Horizontal Geometry – Superelevation Highway Railroad Expressed by… “e” expressed as cross-slope in percent “E” is inches of elevation difference between “high rail” (outside) and “low rail” (inside) Function of…
How are vertical curves used in railway alignment?
Critical issues with Vertical Curves a) Overlapping vertical curves b) Avoid lowering existing tracks c) No vertical curves within turnouts d) Provide additional clearance in sag curves e) No vertical curves within horizontal spirals 16
Why are spiral transition curves used on railways?
Spiral Transition Curves TS (Tangent to Spiral) SC (Spiral to Curve) Railways use the higher length of two formulae: •To limit unbalanced lateral acceleration acting on passengers to 0.03 g per second: L = 1.63 E u
What should be the grade of a railway alignment?
Rail – rarely exceeds 1% (2-2.5% for industry lines) Highway – 4% common 6% on ramps Up to 8% on county roads LRT – maximum 4 to 6% Up to 10% for short sections REES Module #6 – Railway Alignment Design and Geometry14 Design Grade for Railways
Why do street running trains travel at reduced speed?
The rails are embedded in the roadway, and the train shares the street with pedestrians, automobile traffic, cyclist, and so on. Street running trains generally travel at reduced speed for safety reasons.
What does it mean when a train runs along a street?
On-street running or street running is the routing of a railroad track or tramway track running directly along public streets, without any grade separation. The rails are embedded in the roadway, and the train shares the street with pedestrians and automobile traffic.
What should be the cross slope of a pedestrian access route?
Where pedestrian access routes are contained within pedestrian street crossings with yield or stop control, the cross slope of the pedestrian access route must be 2 percent maximum (see R302.6). At pedestrian street crossings with yield or stop control, vehicles slow or stop before proceeding through the intersection.
How big of a gap do you need at a rail crossing?
Elongated openings in gratings shall be placed so that the long dimension is perpendicular to the dominant direction of travel. Flangeway gaps at pedestrian at-grade rail crossings shall be 64 mm (2.5 in) maximum on non-freight rail track and 75 mm (3 in) maximum on freight rail track.