Symbols and their meaning for railway construction


Meaning of the symbolUnit
aVertex distance with vertical curvem
AAStart of vertical curve 
AEEnd of vertical curvem/s²
arRadial accelerationm/s²
apTransverse acceleration 
BAStart of curve 
BEEnd of curve 
BMCentre of curve 
BWChange of radius 
eDistance between centres of linesm
fDisplacement of the track curve compared with the tangent with a transition curvemm
Δ hHeight differencem
lLongitudinal gradient
kCurvature of the track curve 
aLength of the connecting curve with peaks and troughsm
bLength of the circular curve (length of curve)m
gLength of an intermediate piece of trackm
nUsable track length (also known as the UL)m
RLength of the superelevation rampm
RBLength of the superelevation ramp according to Blossm
RSLength of the S-shaped superelevation rampm
tTangent lengthm
taTangent length of the vertical curvem
ULength of transition curve, straight curvature linem
UBLength of transition curve according to Blossm
USLength of transition curve, S shaped curve m
wLength of turnoutm
ldSchLast long sleeperm
maxAttachment for highest value 
minAttachment for lowest value 
1 : mInclination of the superelevation ramp 
1 : nInclination of the turnout tangent 
HüNNHeight above normal zero 
NWChange in gradientm
oAWithout details of the vertical gradient radius 
rCurve radiusm
oRadius of the branch-track of the turnout shapem
aVertical gradient radius of the change in gradientm
sRadius of the main line of a curved turnoutm
zRadius of the branch-track of a curved turnoutm
regAttachment for basic value 
RAStart of ramp 
regEnd of ramp 
RMCentre of ramp 
sDistance of the centres of the rail heads or linemm; m
SLine gradient as specified by DIN
TSTangent intersection point 
uSuperelevation of the outer railmm
oEqualising superelevationmm
fCant deficiencymm
uSuperelevation excessmm
UAStart of transition curve 
UEEnd of transition curve 
UMCentre of transition curve 
eDesign speedkm/h
WAStart of turnout 
WEEnd of turnout 
WTSPoint of intersection of the turnout tangents 
zulAttachment for permissible value