SIST EN 13803:2017

SLOVENSKI STANDARD
01-julij-2017
1DGRPHãþD
SIST EN 13803-1:2010
SIST EN 13803-2:2007+A1:2010
äHOH]QLãNHQDSUDYH=JRUQMLXVWURMSURJH3DUDPHWUL]DQDþUWRYDQMHWUDVHSURJH
7LUQHãLULQHPPLQYHþ
Railway applications - Track - Track alignment design parameters - Track gauges 1435
mm and wider
Bahnanwendungen - Oberbau - Linienführung in Gleisen - Spurweiten 1 435 mm und
größer
Applications ferroviaires - Voies - Paramètres de conception du tracé de la voie -
Écartement 1435 mm et plus large
Ta slovenski standard je istoveten z: EN 13803:2017
ICS:
45.080 7UDþQLFHLQåHOH]QLãNLGHOL Rails and railway
components
93.100 Gradnja železnic Construction of railways
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13803
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2017
EUROPÄISCHE NORM
ICS 93.100 Supersedes EN 13803-1:2010, EN 13803-
2:2006+A1:2009
English Version
Railway applications - Track - Track alignment design
parameters - Track gauges 1 435 mm and wider
Applications ferroviaires - Voie - Paramètres de Bahnanwendungen - Oberbau - Trassierungsparameter
conception du tracé de la voie - Écartement 1 435 mm - Spurweiten 1 435 mm und größer
et plus large
This European Standard was approved by CEN on 21 December 2016.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13803:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Symbols and abbreviations . 10
5 General . 11
5.1 Background . 11
5.2 Alignment characteristics . 11
6 Limits for 1 435 mm gauge . 13
6.1 Radius of horizontal curve R . 13
6.2 Cant D . 13
6.3 Cant deficiency I . 14
6.4 Cant excess E . 16
6.5 Length of cant transitions L and transition curves in the horizontal plane L . 17
D K
6.5.1 General . 17
6.5.2 Lengths of linear cant transitions and clothoids . 17
6.5.3 Lengths of transition curves with non-constant gradient of curvature and cant . 18
6.6 Cant gradient dD/ds . 19
6.7 Rate of change of cant dD/dt . 19
6.8 Rate of change of cant deficiency dI/dt . 20
6.9 Length of constant cant between two linear cant transitions L . 21
i
6.10 Abrupt change of horizontal curvature . 22
6.11 Abrupt change of cant deficiency ΔI . 22
6.12 Length between two abrupt changes of horizontal curvature L . 22
c
6.13 Length between two abrupt changes of cant deficiency L . 23
s
6.14 Track gradients p . 24
6.15 Vertical radius Rv . 25
6.16 Length of vertical curves L . 25
v
6.17 Abrupt change of track gradient Δp . 26
Annex A (normative) Rules for converting parameter values for track gauges wider than
1 435 mm . 27
A.1 Scope . 27
A.2 Symbols and abbreviations . 27
A.3 Basic assumptions and equivalence rules . 29
A.3.1 General . 29
A.3.2 Basic formulae . 29
A.3.3 Basic data . 30
A.4 Detailed conversion rules . 30
A.4.1 General . 30
A.4.2 Cant D (Subclause 6.2 of the main body of the standard) . 30
A.4.3 Cant deficiency I (Subclause 6.3 of the main body of the standard) . 32
A.4.4 Cant excess E (Subclause 6.4 of the main body of the standard) . 33
A.4.5 Lengths of cant transitions L and transition curves in the horizontal plane L
D K
(Subclause 6.5 of the main body of the standard) . 33
A.4.6 Cant gradient dD /ds (Subclause 6.6 of the main body of the standard) . 34
A.4.7 Rate of change of cant dD /dt (Subclause 6.7 of the main body of the standard) . 34
A.4.8 Rate of change of cant deficiency dI /dt (Subclause 6.8 of the main body of the
standard) . 35
A.4.9 Abrupt change of curvature and abrupt change of cant deficiency ΔI
(Subclauses 6.10 and 6.11 of the main body of the standard). 36
A.4.10 Other parameters (Subclauses 6.1, 6.9, 6.12, 6.13, 6.14, 6.15, 6.16 and 6.17 of the
main body of the standard) . 36
Annex B (normative) Track alignment design parameter limits for track gauges wider than
1 435 mm . 37
B.1 Scope . 37
B.2 Requirements for a gauge of 1 520 mm and 1 524 mm . 37
B.2.1 General . 37
B.2.2 Radius of horizontal curve R . 37
B.2.3 Cant D . 37
B.2.4 Cant deficiency I . 38
B.2.5 Cant excess E . 39
B.2.6 Length of cant transitions L and transition curves in the horizontal plane L . 39
D1 K1
B.2.7 Cant gradient dD /ds . 40
B.2.8 Rate of change of cant dD /dt . 41
B.2.9 Rate of change of cant deficiency dI /dt . 41
B.2.10 Length of constant cant between two linear cant transitions L . 42
i1
B.2.11 Abrupt change of horizontal curvature . 43
B.2.12 Abrupt change of cant deficiency ΔI . 43
B.2.13 Length between two abrupt changes of horizontal curvature L . 43
C1
B.2.14 Length between two abrupt changes of cant deficiency L . 43
s1
B.2.15 Track gradients p . 44
B.2.16 Vertical radius R . 44
v1
B.2.17 Length vertical curves L . 44
v1
B.2.18 Abrupt change of track gradient Δp . 44
B.3 Requirements for a gauge of 1 668 mm . 44
B.3.1 General . 44
B.3.2 Radius of horizontal curve R . 44
B.3.3 Cant D . 44
B.3.4 Cant deficiency I . 45
B.3.5 Cant excess E1 . 46
and transition curves in the horizontal plane L . 46
B.3.6 Length of cant transitions LD1 K1
B.3.7 Cant gradient dD /ds . 47
B.3.8 Rate of change of cant dD /dt . 48
B.3.9 Rate of change of cant deficiency dI /dt . 49
B.3.10 Length of constant cant between two linear cant transitions L . 50
i1
B.3.11 Abrupt change of horizontal curvature . 50
B.3.12 Abrupt change of cant deficiency ΔI . 50
B.3.13 Length between two abrupt changes of horizontal curvature L . 51
C1
B.3.14 Length between two abrupt changes of cant deficiency L . 51
s1
B.3.15 Track gradients p1 . 51
B.3.16 Vertical radius R . 51
v1
B.3.17 Length vertical curves L . 52
v1
B.3.18 Abrupt change of track gradient Δp . 52
Annex C (informative) Supplementary information about shape and length of transition
curves . 53
C.1 General . 53
C.2 Definitions and properties of different transition curves and cant transitions. 53
C.2.1 Definitions . 53
C.2.2 Properties . 54
C.3 Further aspects that may be considered for a progressive track alignment design . 59
C.3.1 Background . 59
C.3.2 Progressive track alignment design . 59
Annex D (informative) Constraints and risks associated with the use of exceptional limits . 62
Annex E (informative) Evaluation of conditions at the toe of a switch . 63
E.1 General . 63
E.2 Method based on effective radius . 63
Annex F (informative) Design considerations for switch and crossing units . 65
F.1 Examples of common switch and crossing units . 65
F.2 Use of diamond crossings, diamond crossings with slips and tandem turnouts . 67
F.3 Switch and crossing units on, or near, under-bridges . 67
F.4 Abutting switch and crossing units. 67
F.5 Switch and crossing units on horizontal curves. 67
F.6 Switch and crossing units on canted track . 68
F.7 Vertical alignments and switch and crossing units . 68
Annex G (informative) Examples of applications . 71
G.1 General . 71
G.2 Example of crossover on horizontal curve. 71
G.3 Example of bi-linear cant transition . 72
G.4 Example where a cant transition is designed without a coinciding transition curve . 73
G.5 Example of substandard transition curve . 74
G.6 Example where several alignment elements forms an intermediate length. 75
Annex H (informative) Examples of local limits for cant deficiency . 76
Annex I (informative) Considerations regarding cant deficiency and cant excess . 77
I.1 Introduction . 77
I.2 Cant deficiency . 77
I.3 Cant excess . 77
I.4 Wheel climb criterion . 77
I.5 Vehicle overturning . 78
I.6 The lateral strength of a track under loading (Prud'homme limit) . 78
I.7 Cant deficiency at switch and crossing layouts on curves . 78
Annex J (informative) Passenger comfort on curves . 79
J.1 General . 79
J.2 Lateral acceleration . 79
J.3 Lateral jerk . 79
J.3.1 Lateral jerk as a function of rate of change of cant deficiency . 79
J.3.2 Lateral jerk as a function of an abrupt change of cant deficiency . 80
J.4 Roll motions . 80
Annex K (normative) Sign rules for calculation of ΔD, ΔI and Δp . 81
K.1 General regarding the sign rules . 81
K.2 Sign rules for calculation of ΔD . 81
K.3 Sign rules for calculation of ΔI . 81
K.4 Sign rules for calculation of Δp . 82
Annex L (informative) Length of constant cant between two linear cant transitions L . 84
i
Annex M (informative) The principle of virtual transition . 85
M.1 Virtual transition at an abrupt change of cant deficiency . 85
M.2 Virtual transition at a short intermediate length between two abrupt changes of cant
deficiency . 86
M.3 Limits based on the principle of the virtual transition . 87
M.3.1 General . 87
M.3.2 Characteristic vehicle with a distance of 20 m between bogie centres . 87
M.3.3 Characteristic vehicle with a distance of 12,2 m and 10,06 m between bogie centres . 87
Annex N (normative) Lengths of intermediate elements L to prevent buffer locking . 89
c
N.1 General . 89
N.2 Basic vehicles and running conditions . 89
N.3 Lengths Lc of an intermediate straight track between two long circular curves in the
opposite directions . 89
N.4 General cases for end throw differences . 90
Annex O (informative) Considerations for track gradients . 93
O.1 Uphill gradients . 93
O.2 Downhill gradients . 93
O.3 Gradients for stabling tracks and at platforms . 93
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2008/57/EC . 94
Bibliography . 97

European foreword
This document (EN 13803:2017) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2017, and conflicting national standards shall
be withdrawn at the latest by October 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13803-1:2010 and EN 13803-2:2006+A1:2009.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive 2008/57/EC.
For relationship with EU Directive 2008/57/EC, see informative Annex ZA, which is an integral part of
this document.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
1 Scope
The purpose of this European Standard is to specify rules and limits for track alignment design
parameters, including alignments within switches and crossings. Several of these limits are functions of
speed. Alternatively, for a given track alignment, it specifies rules and limits that determine permissible
speed.
This European Standard applies to nominal track gauges 1 435 mm and wider with speeds up to
360 km/h. Normative Annex A describes the conversion rules which shall be applied for tracks with
nominal gauges wider than 1 435 mm. Normative Annex B is applied for nominal track gauges
1 520 mm, 1 524 mm and 1 668 mm.
This European Standard is also applicable where track alignment takes into account vehicles that have
been approved for high cant deficiencies (including tilting trains).
More restrictive requirements of Technical specifications for interoperability relating to the
‘infrastructure’ subsystem of the rail system in the European Union (TSI INF) and other (national,
company, etc.) rules will apply.
This European Standard need not be applicable to lines, or dedicated parts of railway infrastructure
that are not interoperable with railway vehicles tested and approved according to EN 14363.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 13848-5, Railway applications — Track — Track geometry quality — Part 5: Geometric quality
levels — Plain line
EN 14363, Railway applications - Testing and Simulation for the acceptance of running characteristics of
railway vehicles - Running Behaviour and stationary tests
EN 15273-1, Railway applications — Gauges — Part 1: General — Common rules for infrastructure and
rolling stock
EN 15273-2, Railway applications — Gauges — Part 2: Rolling stock gauge
EN ISO 80000-3, Quantities and units - Part 3: Space and time (ISO 80000-3)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
track gauge
distance between the corresponding running edges of the two rails
3.2
nominal track gauge
single value which identifies the track gauge but may differ from the design track gauge, e.g. the most
widely used track gauge in Europe that has a nominal value of 1 435 mm although this is not the design
track gauge normally specified
3.3
limit
design value not to be exceeded
Note 1 to entry: These values ensure maintenance costs of the track are kept at a reasonable level, except where
particular conditions of poor track stability can occur, without compromising passenger comfort. However, the
actual design values for new lines should normally have substantial margins to the limits.
Note 2 to entry: For certain parameters, this European Standard specifies both a normal limit and an
exceptional limit. The exceptional limits represent the least restrictive limits applied by any European railway,
and are intended for use only under special circumstances and can require an associated maintenance regime.
3.4
alignment element
segment of the track with either vertical direction, horizontal direction or cant obeying a unique
mathematical description as a function of chainage
Note 1 to entry: Unless otherwise stated, the appertaining track alignment design parameters are defined for
the track centre line and the longitudinal distance for the track centre line is defined in a projection in a horizontal
plane.
3.5
chainage
longitudinal distance along the horizontal projection of the track centre line
3.6
curvature
derivative of the horizontal direction of the track centre line with respect to chainage
Note 1 to entry: In the direction of the chainage, curvature is positive in a right-hand curve and negative on a
left-hand curve. The magnitude of the curvature corresponds to the inverse of the horizontal radius.
3.7
circular curve
curved alignment element of constant curvature
3.8
transition curve
alignment element where curvature changes with respect to chainage
Note 1 to entry: The clothoid (sometimes approximated as a 3rd degree polynomial, “cubic parabola”) is
normally used for transition curves, giving a linear variation of curvature. In some cases, curvature is smoothed at
the ends of the transition.
Note 2 to entry: It is possible to use other forms of transition curve, which show a nonlinear variation of
curvature. Informative Annex C gives a detailed account of certain alternative types of transitions that may be
used in track alignment design.
Note 3 to entry: Normally, a transition curve is not used for the vertical alignment.
3.9
compound curve
sequence of curved alignment elements, including two or more circular curves in the same direction
Note 1 to entry: The compound curve can include transition curves between the circular curves and/or the
circular curves and the straight tracks.
3.10
reverse curve
sequence of curved alignment elements, containing alignment elements which curve in the opposite
directions
Note 1 to entry: A sequence of curved alignment elements can be both a compound curve and a reverse curve.
3.11
cant
amount by which one running rail is raised above the other running rail, in a track cross section
3.12
equilibrium cant
cant at a particular speed at which the vehicle will have a resultant force perpendicular to the running
plane
3.13
cant deficiency
difference between applied cant and a higher equilibrium cant
Note 1 to entry: When there is cant deficiency, there will be an unbalanced lateral force in the running plane.
The resultant force will move towards the outer rail of the curve.
3.14
cant excess
difference between applied cant and a lower equilibrium cant
Note 1 to entry: When there is cant excess, there will be an unbalanced lateral force in the running plane. The
resultant force will move towards the inner rail of the curve.
Note 2 to entry: Cant on a straight track results in cant excess, generating a lateral force towards the low rail.
3.15
cant transition
alignment element where cant changes with respect to chainage
Note 1 to entry: Normally, a cant transition coincides with a transition curve.
Note 2 to entry: Cant transitions giving a linear variation of cant are usually used. In some cases, cant is
smoothed at the ends of the transition.
Note 3 to entry: It is possible to use other forms of cant transition, which show a nonlinear variation of cant.
Informative Annex C gives a detailed account of certain alternative types of transitions that may be used in track
alignment design.
3.16
cant gradient
absolute value of the derivative (with respect to chainage) of cant
3.17
rate of change of cant
absolute value of the time derivative of cant
3.18
rate of change of cant deficiency
absolute value of the time derivative of cant deficiency (and/or cant excess)
3.19
track distance
lateral distance between two tracks, measured at the horizontal projection of the track centre lines
Note 1 to entry: Other standards can define track distance as the sloping length parallel to a canted track plane.
4 Symbols and abbreviations
No. Symbol Designation Unit
1 dD/ds cant gradient mm/m
2 dD/dt rate of change of cant mm/s
3 dI/dt rate of change of cant deficiency (and/or cant excess) mm/s
4 D cant mm
5 D equilibrium cant mm
EQ
6 E cant excess mm
7 g acceleration due to gravity according to EN ISO 80000-3 m/s
8 I cant deficiency mm
9 Lc length between two abrupt changes of curvature m
10 L length of cant transition m
D
11 L length of constant gradient m
g
12 LK length of transition curve m
13 Li length of alignment elements between two linear cant transitions m
14 Ls length between two abrupt changes of cant deficiency m
15 L length of vertical radius m
v
16 p gradient -
17 qE factor for calculation of equilibrium cant: 11,8 mm∙m∙(h/km)
18 qN factor for calculation of length of cant transition or transition curve with -
non-constant gradient of cant and curvature, respectively
2 2
19 qR factor for calculation of vertical radius m∙h /km
20 q factor for calculation of lengths between abrupt changes of cant deficiency -
s
21 q factor for conversion of the units for vehicle speed: 3,6 (km/h)/(m/s)
V
22 R radius of horizontal curve m
23 Rv radius of vertical curve m
24 s longitudinal distance m
25 t time s
26 V speed km/h
27 CE, lim limit applicable at fixed crossings and expansion devices (index) -
28 lim general limit (index) -
29 limit applicable at small radius curves (index) -
R, lim
30 upper limit for a parameter which also have a lower limit (index) -
u, lim
5 General
5.1 Background
This European Standard specifies rules and limits for track alignment design. These limits assume that
standards for acceptance of vehicle, track construction and maintenance are fulfilled (construction and
in-service tolerances are not specified in this standard). Engineering requirements specific to the
mechanical behaviour of switch and crossing components and subsystems are to be found in the
relevant standards. Certain design considerations for switches and crossings layouts are presented in
informative annexes.
This European Standard is not a design manual. The limits are not intended to be imposed as usual
design values. However, design values shall be within the limits stated in this European Standard.
Limits in this European Standard are based on practical experience of European railways. Limits are
applied where it is necessary to compromise between train performance, comfort levels, maintenance
of the vehicle and track, and construction costs.
Unnecessary use of design values close to limits should be avoided, substantial margins to them should
be provided. There are often conflicts between the desire for margins to one parameter and another,
these should be distributed over all design parameters, possibly by applying a margin with respect to
speed.
For certain parameters, this European Standard also specifies exceptional limits less restrictive than
normal limits, which represent the least restrictive limits applied by any European railway. Such limits
are intended for use only under special circumstances and can require an associated maintenance
regime. In particular, use of exceptional limits (instead of normal limits) for several parameters at the
same location shall be avoided. Informative Annex D describes the constraints and risks associated with
the use of design values in the range between a limit and corresponding exceptional limit.
Operational limits for speed and cant deficiency shall be applied to specific vehicles according to their
approval parameters.
Due to lack of experience among the European railways, no limits are specified for higher speeds than
360 km/h.
The limits are defined for normal service operations. If and when running trials are conducted, for
example to ascertain the vehicle dynamic behaviour (by continually monitoring of the vehicle
responses), exceeding the limits (particularly in terms of cant deficiency) should be permitted and it is
up to the infrastructure manager to decide any appropriate arrangement. In this context, safety margins
are generally reinforced by taking additional steps such as ballast consolidation, monitoring of track
geometric quality, etc.
5.2 Alignment characteristics
The alignment defines the geometrical position of the track. It is divided into horizontal alignment and
vertical alignment.
The horizontal alignment is the projection of the track centre line on a horizontal plane. The horizontal
alignment consists of a sequence of alignment elements, each obeying a unique mathematical
description as a function of longitudinal distance along the horizontal projection (chainage). The
elements for horizontal alignment are connected at tangent points, where two connected elements have
the same coordinates and the same directions. Elements for horizontal alignment are specified in
Table 1.
Table 1 — Elements for horizontal alignment
Alignment element Characteristics
Straight line No horizontal curvature
Circular curve Constant horizontal curvature
Transition curve, Clothoid type Horizontal curvature varies linearly with chainage
a
Transition curves, other types Horizontal curvature varies nonlinearly with chainage
a
Informative Annex C gives a detailed account of certain alternative types of transition curves that
may be used in track alignment design
Most modern switches have a tangential geometry, where the diverging track starts with an alignment
that is tangential with the through track. However, switch designs may start with an abrupt change of
horizontal direction at the beginning of the switch. Possible design criteria for the alignment before the
switch, taking the entry angle in account, are described in informative Annex E.
When a turnout is placed on a track gradient other than zero, a vertical curve and/or cant, the
horizontal geometry of the diverging track will deviate slightly from the element types in Table 1.
The vertical alignment defines the level of the track as a function of chainage (the longitudinal position
along the horizontal projection of the track centre line). The elements for vertical alignment are
connected at tangent points, where two connected elements have the same level and the same track
gradient p (with certain exceptions). Elements for vertical alignment are specified in Table 2.
Table 2 — Elements for vertical alignment
Alignment element Characteristics
Constant gradient No vertical curvature
Vertical curve, parabola Derivative of gradient with respect to chainage is constant
Vertical curve, circular Derivative of vertical angle with respect to sloping length along the track
is constant
NOTE A vertical curve in track that starts or ends in canted switches and crossings can be of a higher order
polynomial than a parabola.
The applied cant D in the track is the difference in level of two running rails. Cant can be applied by
raising one rail above the level of the vertical profile and keeping the other rail on the same level as the
vertical profile, or by a pre-defined relationship raising one rail and lowering the other rail. The cant
can be considered as a sequence of elements connected at tangent points where two elements have the
same magnitude of applied cant. (At a tangent point with cant, the same rail is the high rail before and
after the tangent point.) Elements for cant are specified in Table 3.
Table 3 — Elements for cant
Alignment element Characteristics
Constant cant Cant is constant along the entire element
Cant transition, linear Cant varies linearly with chainage
a
Cant transition, nonlinear Cant varies nonlinearly with chainage
a
Informative Annex C gives a detailed account of certain alternative types of cant
transitions that may be used in track alignment design.
Cant transitions should normally coincide with transition curves, but exceptions are possible.
The geometrical consequences of placing a turnout on track gradients, vertical curves and/or applying
cant in a turnout are described in informative Annex F.
The alignment of a ballasted track is normally maintained by Track Construction and Maintenance
Machines. The maintenance with such machines is simplified if there is no more than one tangent point
wit
...