Track Realignment by the “Hallade” Method

Course Aims

This course is intended to provide a delegate with an in-depth knowledge in the surveying, calculation and design of track re-alignment schemes when using the “Hallade” method.

Learning Objectives

At the end of this course the delegates will: –

  • Have a clear understanding of track geometry and track parameters, speed, curve, gradient etc.
  • Be able to demonstrate a clear understanding of the principles of the “Hallade” survey, including the use of relevant surveying equipment
  • Have an understanding of the theory of overlapping chords
  • Be able to demonstrate an understanding of design requirements and the relevant tolerances
  • Understand the quarter chord theory
  • Understand the transition theory – cubic parabola
  • Have an understanding of the tangential changes of radius relating to the curvature of the track
  • Be able to demonstrate a clear understanding of the method of employing couples
  • Understand the relationship between a theodolite straight and Hallade curve
  • Be aware of the requirements for making the track for on-track machines
  • Be aware of Railway Group Standards, Network Rail Company Standards and D.O.T. requirements relating to track re-alignment schemes

Course Duration

Ten days, consisting of two continuous five day modules, Monday – Friday.


There are no particular educational or competence pre-requisites for the course. However, the following factors will benefit the delegates:-

  • Prior technical experience of working on the maintenance/ renewal of the track
  • Good numeric skills
  • Prior basic skills in surveying and use of equipment

Personal Protective Equipment

This course requires the delegate to be on or near the running line and therefore, he/she MUST be in possession of:-

  • Valid P. T. S. Card
  • Protective “all orange” High Visibility Clothing to BS EN 471:2003
  • Safety Footwear to BS EN ISO 20345:2004
  • Safety Helmet (white/blue) to BS EN 397:1995
  • General Purpose Gloves to BS EN388:2121
  • Safety Glasses to BS EN 166 and of Optical Class 1 with Impact Resistance F

To assist the delegate in the high level of design calculations required on the course it is recommended that each attending delegate be in possession of a laptop computer.


The delegate is required to complete an examination to demonstrate his/her ability to complete a survey and design scheme using the “Hallade” Method.
Re-certification is not required.