# Handbook for track geometry design

## Raidegeometrian suunnittelu

This handbook discusses the general principles of track geometry and its role and meaning in the track design process. The goal is to supplement and explain the national regulations and guidelines relating set by the Finnish Transport Agency (later FTA). These guidelines are regularly updated according to effective EU legislation and the Finnish Transport Safety Agency's regulations. The text is written based on the effective regulations and guidelines. The main source has been the updated guideline for track geometry design, which was published 8.4.2010 (Guidelines of the Finnish Transport Agency 3/2010). The regulations and guidelines normally present only the essential aspects and the respective limiting values of subjects that the designer needs to take into account. Since these publications lend limitedly for example to educational purposes there has been a call for a supplementing publication. This handbook is meant to elucidate these areas of track geometry design. At first the basic principles of track geometry design and related subjects are discussed. These include for example the track centre line; track height line and track tilt in curves. Also the use of geodetic co-ordinates are explained. In the second part the elements of horizontal and vertical track geometry are presented. The horizontal elements include straight line, curve, different transition curves and points. The vertical elements include gradients and vertical curves. Also the equations used for the dimensioning of the above elements are respectively presented and explained. In the third part the dimensioning of track geometry is discussed. This starts with the dimensioning of track curves, where the centrifigural forces between the train and the track are decisive. The equations used for the calculation of centrifigural acceleration, twist, cant deficiency and the changing speed of cant deficiency are presented and explained. According to effective guidelines the dimensioning of horizontal track geometry is based either on cant deficiency or centrifigural acceleration -methods. Later in detail all the limiting values of different track geometry elements are discussed. In addition to track geometry, also dimensioning of track length in operational railway locations and distance between track centre lines are explained. From vertical track geometry the principles of dimensioning of the longitudinal gradients and vertical curves are explained. In the last part the relation of track geometry design with other areas are shortly discussed. These include for example the design of speed areas and limitations of different structures etc. regarding to allowed speeds. Also the drainage of track system is discussed. Later the different documents that guide the design process are explained. Also a short description of design programs used in track design and the printouts of a track design project are discussed. This report may be found at http://alk.tiehallinto.fi/julkaisut/pdf3/lts_2011-22_raidegeometrian_suunnittelu_web.pdf

• Finnish

## Filing Info

• Accession Number: 01343131
• Record Type: Publication
• Source Agency: Finnish Transport Agency
• ISBN: 978-952-255-665-3
• Files: ITRD
• Created Date: Jun 28 2011 10:12AM