About Cant Variables and Formulas

Use the following set of variables to calculate transition distances.

{e} The equilibrium cant for the curve. This value is determined from the Equilibrium Cant formula that is specified in the Calculate Cant Wizard - Attainment Method Page.
{a} The applied cant for the curve.
{u} The cant deficiency for the curve.
{t} The transition length value that is read from the transition length table, based on the design speed and the curve radius.
{l} The length of the spiral, if a spiral is involved in the transition. This is the actual length of the spiral element in the curve group.
{s} The track width value that is defined on the Rail Parameters tab of the Alignment Properties dialog box.
{g} The gravitational acceleration.
{r} The radius of the curve. This is the actual radius of the curve element.
{v} The design speed at the alignment station.
{p} The fractional part of the transition length achieved before the BC point. This value is specified as either % On Tangent for Tangent-Curve or % On Spiral for Spiral-Curve in the Calculate Cant Wizard - Attainment Method Page.
{d} Maximum applied cant on tangent for tangent-curve. This value is specified in the Calculate Cant Wizard - Attainment Method Page.
{m} Maximum allowable cant deficiency. This value is determined from the Maximum Allowable Cant Deficiency formula that is specified in the Calculate Cant Wizard - Attainment Method Page.

The variables in the previous table are used to calculate the following:

XML Code Description
LR Level Rail
FC Full Cant
BC Begin Curve
EC End Curve

The following table describes the formulas:

XML Code Description
LRtoFC The distance from the Level Rail Station to the Full Cant station is the value {t}, which is read from the selected transition length table. The formula assumes that the transition length table defines the transition length.
LRtoBC The distance from the Level Rail station to the Beginning of Curve station is a percentage of the transition length {t} based on the variable {p}.