Search results
Results From The WOW.Com Content Network
In some countries, momentum gradient which is a steeper but shorter gradient may be allowed. This is usually when a track gradient connects to a leveled tangent track long enough and with no signal between them such that a train can build momentum to push through a steeper grade than it can without the momentum gained on the leveled tangent track.
The grade (US) or gradient (UK) (also called stepth, slope, incline, mainfall, pitch or rise) of a physical feature, landform or constructed line is either the elevation angle of that surface to the horizontal or its tangent. It is a special case of the slope, where zero indicates horizontality. A larger number indicates higher or steeper ...
Too tight a 'crest' curve could result in the train leaving the track as it drops away beneath it; too tight a 'trough' and the train will plough downwards into the rails and damage them. More precisely, the support force R exerted by the track on a train as a function of the curve radius r, the train mass m, and the speed v, is given by
This segment of track has always been worked by adhesion. This line is owned by Great Smoky Mountains Railroad and in 2019 is out of service. 1 in 14.2 (7.0%) Bernina Railway, Switzerland: MAX Light Rail system, Portland, Oregon, United States System's ruling gradient of 7.0% is located on the viaduct connecting the Steel Bridge with Southwest ...
To compensate for this, the gradient should be a little less steep the sharper the curve is; the necessary grade reduction is assumed to be given by a simple formula such as 0.04 per cent per "degree of curve", the latter being a measure of curve sharpness used in the United States. On a 10-degree curve (radius 573.7 feet) the grade would thus ...
A transition curve can connect a track segment of constant non-zero curvature to another segment with constant curvature that is zero or non-zero of either sign. Successive curves in the same direction are sometimes called progressive curves and successive curves in opposite directions are called reverse curves.
The American gauges converged, as the advantages of equipment interchange became increasingly apparent. Notably, all the 5 ft (1,524 mm) broad gauge track in the South was converted to "almost standard" gauge 4 ft 9 in (1,448 mm) over the course of two days beginning on 31 May 1886. [21] See Track gauge in the United States.
Ideally, the track should have sleepers (railroad ties) at a closer spacing and a greater depth of ballast to accommodate the increased forces exerted in the curve. At the ends of a curve, where the rails straighten out, the amount of cant cannot change from zero to its maximum immediately. It must change gradually in a track transition curve ...