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Requirements for the European education of railway track welders in aluminothermic welding (June 2006)

   
Tim Jessop, TWI and Hans van den Brug, RI

EUROJOIN 6, Santiago de Compostela, Spain, 28 - 30 June 2006

Summary

On 1 October 2004 the European project RAILSAFE started. The aim of the project is to harmonise the education, training, qualification and certification of railway track welders in aluminothermic welding in Europe.

In 5 countries workshops have been held to formulate the requirements for aluminothermic welders and for the harmonised education and training.

This paper reports how the existing national and international differences can be addressed.

Introduction

What is aluminothermic welding?

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In the aluminothermic welding process, molten steel is poured into a mould surrounding the gap between the rail ends to be joined. The rail ends are connected by the liquid metal. The principle of aluminothermic welding is based on an exothermic chemical reaction of aluminium powder and iron oxide, producing sufficient heat to cause melting.

Before melting can start, the ends of the rails are cut to create a specified gap and the rails are aligned. Then a refractory mould is fastened around the gap by means of steel mould shoes. Leaks in the moulds are prevented by special luting material. After pre-heating both rail ends the exothermic reaction of the aluminium powder and iron oxide is started in a re-usable or a 'one-shot' crucible and the liquid metal flows into the mould. The metal fills the mould and the slag is discharged into slag bowls. After a cooling period the excess metal at the head of the rail is removed and grinding of the rail can commence.

As the welding quite often takes place in tracks which are in use, the speed of the welding operation and the safety of the welders are important aspects of welding on railway tracks.

Why RAILSAFE?

Safety of rail traffic depends highly on the quality of the tracks, on the welds in the tracks and thus on the skills of the welder. Throughout Europe there is a lack of uniformity of training and testing of aluminothermic welders,lack of common syllabuses and lack of mobility of skilled welders. This is not only true between countries but also within some countries. To set welders to work for other companies or in other countries is often hindered by different procedures and different qualification of welders.

The policy of the European Commission is to promote interoperability between the separate national railway systems and to improve safety. (See EC White paper: European Transport Policy for 2010: Time to decide, 2001).

Another policy of the European Commission is to stimulate, through the 'Leonardo da Vinci Community Vocational Training Action Programme', education and training in a life-long learning process to improve employability and to make work across national boundaries possible: free movement of people in the European Union.

The European standardisation organisation, CEN, and in particular TC256/SC1/WG4, has been developing standards on railway track welding procedures and on training of welders for aluminothermic welding, prEN 14730. These standards are for comments and are not in force yet.

On 1 October 2004 a 3 year European project has been started: 'Development of a Harmonised System for Education, Qualification and Certification of Railway Track Welders', RAILSAFE. The project is partly financed by the EU 'Leonardoda Vinci Community Vocational Training Action Programme'.

The aim of the RAILSAFE project is the development of a harmonised system for education, qualification and certification of railway track welders.

Harmonised education, training and qualification makes exchange of welders possible, nationally and in Europe. Certification assures continuing vocational education for life-long competences. Qualification and certification also provides visible verification of a welder's competence in accordance with harmonised European guidelines, which is recognised and accepted by relevant employers and authorities throughout Europe. In this way multiple- or re-testing of welders can be avoided.

The results of the project contribute also to the improvement of the 'interoperability' between national railway systems, more effective maintenance, reduction of track possession time and improvement of workforce safety and to free movement of welders in the EU.

The emerging standards prEN 14730 prove to be a basis for the RAILSAFE activities, especially the standard on procedures. The draft standards however do not specify in detail the level of training or competence of welders. The outcomes of RAILSAFE will include these details.

The expected results of the project are:

  • Industry requirements with regard to performance objectives for aluminothermic welders and for the harmonised education and training.
  • A guideline for the education, training, qualification and certification of railway track welders
  • A database of qualified and certified welders
  • Pilot courses with examination and qualification
  • A plan for an organisation to operate the system
  • Dissemination of the project results in Europe

The project is carried out by 9 partners from 7 different countries: a contractor building railways, a consultant on quality and harmonisation in welding, a European organisation representing welding institutes and welding institutes themselves with expertise in education, training, qualification and certification of welders.

During workshops in 5 European countries, railway track experts have determined the industry requirements with regard to education and training of welders.

Requirements for education and training

Workshops

Some 50 rail welding experts have participated in workshops in Copenhagen, Cambridge, Genoa, Hannover and Bratislava. The participants were representatives of railway authorities, contractors, process suppliers, research andconsultancy organisations, training establishments and welding institutes.

The experts have discussed draft proposals on performance objectives, on welding specification procedures, on a database for certified welders and on a structure for operating the harmonised system.

From the - sometimes contradictory - comments the following results were obtained, which is again subject for discussion among the workshop participants.

Structure of education, training, qualification and certification

The harmonised system provides for theoretical education and practical training of aluminothermic welders, their examination, issue of a Diploma, valid for the life of the holder, and Certificates with limited time validity.

Qualification, resulting in the issue of a Diploma, requires theoretical education, practical training and theoretical and practical examination.

Certification requires qualification as above plus satisfactory track welding experience.

The theoretical education and examination for a Diploma is generic and the practical training and examination for a Diploma is process specific. After passing the examinations the welder will receive a generic Diploma valid his/herwhole life.

 

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Diploma holders are required to demonstrate a one year period of supervised, documented and satisfactory experience to receive a Certificate, which is process specific. This applies to the Certificate of the process in which the welder has been trained for the Diploma as well as to additional Certificates in other processes. To get a Certificate in other processes, the welder must also undergo practical training in that process.

Certificates are valid for two years. In order to renew a Certificate for another two-year period, holders are required to demonstrate supervised, documented and satisfactory experience in the process for which the certificate was awarded during the period of validity of the certificate.

Overall structure

A European Rail Welding Organisation (to be assigned or established by the European rail welding community) produces special rules for Authorised National Bodies (ANBs) in each country that wish to implement the rail welder training, qualification and certification scheme. These rules would require the ANB to establish a National Rail Welding Specialist Committee for this activity with representatives of the national rail industry sector. There presentation on this committee would include:

  • rail authorities
  • rail welding contractors
  • the rail welding process suppliers that are active in the country concerned
  • rail welder training organisations.

This rail welding National Rail Welding Specialist Committee would be responsible for the implementation of the scheme at the national level on behalf of the governing board of the ANB.

ANBs assess and approve Approved Training Bodies (ATBs) and the ANB's Authorised Examiners (AE).

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A Rail Welding Specialist Group is established on a European level to maintain the harmonised guidelines and rules. The representation on this group would include rail authorities, contractors, process suppliers, training organisation and ANBs.

Performance objectives

The workshop participants have defined performance objectives for the aluminothermic welder. Performance objectives are statements which identify the specific knowledge and skills the person should gain and display as a result of his/her education and training. They are described in terms of 'expected results'. The performance objectives will form the basis of a Guideline 'Minimum Requirements for the Education, Training, Qualification and Certification' of a'European Aluminothermic Welder'.

In the next table the structure has been presented in which the performance objectives are defined.

An indication of the number of teaching hours is also included.

ModuleSub ModuleRecommended teaching hours
I. Theoretical education
  1. Materials and their behaviour during welding
  2. Welding Processes and Equipment
  3. Fabrication, Applications Engineering
8
24
8
Total Module I 40
II. Practical training
  1. Aluminothermic welding
  2. Ancillary activities
64
16
Total Module II 80
Total course 120

Two examples are given of performance objectives in terms of expected results in the following tables, one in the module 'Theoretical education', sub module 'Materials and their behaviour during welding' and one in the module'Practical training', sub module 'Aluminothermic welding'.

Module I - Theoretical education 40
I.1 Materials and their behaviour during welding  
I.1.1 Basics of metallurgy 4
Expected results  
  1. Describe properties of steel
  2. Evaluate the effects of cooling rate
  3. Interpret mechanical properties
 


Module II - Practical education 80
II.1.1 Aluminothermic welding 64
Expected results  
  1. Competent and full execution of an aluminothermic rail weld; including:
    - Prepare and dry the crucible
    - Select the correct portion
    - Ensure correct rail end preparation and condition, and align the rails
    - Understand alignment requirements
    - Etc.
 

Welding procedures

In view of the emerging CEN standard prEN 14730-1, many workshop participants thought that a welding procedure document would not be required.

A Practical Test Specification form has been introduced to specify the training and the examination of the practical part of the qualification (Diploma).

Database

The database is still a point of debate. Most contracting companies and railway authorities have data bases for qualified and certified welders. An international data base is seen by many workshop participants as a much needed instantaneous European-wide check on welder's qualification/certification. Others think however that such a data base is not needed.

As the database is a deliverable of the project, RAILSAFE will develop a data base, which will be web-based. Data will be supplied by ATBs and inserted by ANBs.

Data is based on one life-long Diploma and one or more Certificates with limited time validity issued to the welder and the welder/employer has to agree (or not) to data kept in database.

Continuation

With all the industry requirements in mind, the project will continue with making a Guideline for education, qualification and certification of welders, a Practical Test Specification, a data base of qualified and certified welders,pilot courses with qualification and certification and further dissemination of the system in Europe.

The partners in the project will organise a European wide seminar later in 2006 to discuss the project results with railway welding experts from all European countries.

Observations

From the workshop discussions it can be concluded RAILSAFE will have benefits for mobility and recognition, and will bring national and European harmonisation to existing welder competence.

RAILSAFE will add detail to the CEN standards: unified performance objectives for welders and a guideline on education, training, qualification and certification, to underpin the standards and it will provide reliable instantaneous European-wide check on welder's qualification/certification by database.

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