Deutsche Bahn

The Death of VAB - What Now!

Rob Dale: "... what has replaced the old VAB system so well known by our industry?"

Rob Dale, Certification Manager at Railway Approvals Limited (RAL) discusses: "GM/RT2000 and the use of Vehicle Acceptance Bodies (VAB) ceased in June 2016.  What has replaced the old VAB system so well known by our industry?"

The RSSB has issued RIS-2700-RST, which provides guidance on how to obtain suitable verification for a project.  This is a voluntary standard, but, as with all RIS, in order to do something different you need to demonstrate that the alternative is as good as RIS-2700. 

RIS-2700 introduces attestation statements to replace certificates, indicates where responsibility now lies and advises when independent verification is needed.


How does RIS-2700 compare to the VAB system?


Main differences between VAB and RIS-2700

  1. Responsibilities
  2. Body performing verification
  3. Scope of certification
  4. Selection of standards
  5. Certificates Issued
  6. Notification to RSL
  7. .Certificate History
  8. Limitations

1. Responsibilities

Under the VAB system, either the train operating company (TOC) or rolling stock leasing company (RoSCo) was responsible for ensuring modifications to vehicles were safe.  This was achieved by complying with Railway Group Standards (RGS) and obtaining Engineering Acceptance to prove it. Responsibility was normally discharged through contracts with suppliers who were required to appoint a VAB, although an operator could perform Engineering Acceptance themselves.  Towards the end of VAB more emphasis was placed on minor modification certificates and most maintenance changes were passed off in-house.

Under RIS-2700, the TOC/RoSCo remains responsible for ensuring modifications to vehicles are safe.  They need to demonstrate compliance to standards and for that they need independent verification. Again responsibilities are discharged commercially to suppliers such as ESG Rail, who are required to become the applicant requesting certification. Suppliers need to ensure that they understand what is required by the TOC/RoSCo to feed into their Engineering Change process and obtain suitable verification.


2. Body performing verification

The TOC/RoSCo can choose who will provide verification. For very simple changes, they can use internal peer review to verify compliance to standards, but as the complexity of engineering change increases, more independence to the verification process is required. For slightly more complex changes, they may choose a separate department of the company to complete the verification, or pass it on to an external consultant.

For complex projects, they should seek accredited third party verification (which is equivalent to using a VAB).  The United Kingdom Accredited Service (UKAS) have accredited a number of ex-VAB, including Railway Approvals Ltd., to be RIS-2700-RST verification bodies. The RIS-2700 accredited bodies give the highest degree of confidence in impartiality and competence of staff, which means their attestation is recognised by TOCs/RoSCos and is accepted throughout the industry.

3. Scope of certification

The VAB considered, not only the change, but the impact on the whole vehicle. This is no longer the case. The verification body now only considers the scope of engineering change specified by the applicant.  The applicant should be aware of interfaces to other vehicle systems, or the impact on the vehicle as a whole and include them within the scope.

The applicant does not need to have all the areas of certification considered by a single verification body.  It is common for the RIS-2700 accredited verification body to only assess the design and build, with the operator taking responsibility for changes to the maintenance regime.


It is also possible for the TOC/RoSCo to identify that design compliance is the complex area of a project; the actual installation maybe a routine matter.  It can then ask an accredited verification body to verify the design, but accept construction through their supplier accreditation process. A minor modification is often requested for this type of project.

If a build attestation is required, the scope needs to be defined. The first vehicle could be passed off by inspection, with the TOC/RoSCo responsible for subsequent builds; a full QMS of the arrangements and implementation of the modification could be carried out; a partial QMS assessment (similar to VAB); inspection of each vehicle; or a desktop review of the installation procedure.  The choice should be agreed with the TOC/RoSCo before engaging a verification body.

4. Selection of Standards

The TOC/RoSCo now has the choice as to which standards should be applied. They can ask for the attestation to cover TSI, EN standards or even an in-house specification. The content of RGS has changed and now reflects only those requirements necessary to act as National Notified Technical Rules for Interoperability.  RGS are being pared down and many existing requirements are moved to a RIS instead.  Further legislation outside of RGS may need independent verification.

While a competent Verification Body like Railway Approvals Ltd. can offer advice on the applicable standards, it is the responsibility of the applicant to define the standards to be assessed. The designer needs to be aware of which standards must be complied with before starting the design to minimise risk of non-compliance, which could result in potential problems at the end of the project.


5. Certificates – Attestation Statements

Under the VAB there were design, build and maintenance certificates with an Engineering Acceptance (EA) certificate over- arching them.  There were also some simplified processes for like-for-like replacements, minor mods and fleet mod certs.
Under RIS-2700 the verification body does not issue an equivalent to the EA certificate and the maintenance is normally only considered at design level (although attestations can be issued). There is still scope to issue like for like certificates, minor mods etc. Instead of Engineering Acceptance there is a new certificate called a Declaration of Configuration (but the content is different, see below).

6. Notification to RSL

One of the requirements for an EA certificate was to report details of vehicle changes to the Rolling Stock Library (RSL). The changes could include technical data such as weights, speed, design codes etc. Additional data such as braking curve and gauge was also included on the certificate for use in the route acceptance process. The EA also included any expiry dates imposed by the VAB, so that vehicles will deregister without further certification. Now it is the responsibility of the TOC/RoSCo to update R2 and RSL.  The Verification Body only checks RSL data if GM/RT2453 is one of the applicable standards.

To advise RSL of changes, the TOC/RoSCo can update R2 directly.  Verification Bodies do not have the necessary access rights. GM/RT2453 has introduced a Declaration of Configuration (DoC) to allow the TOC/RoSCo to submit to RSL changes to vehicle data.

The RSL4 (and RSLEA4) are still recognised, but they are on behalf of the TOC/RoSCo rather than the VAB.  This enables the TOC/RoSCo to issue a single DoC (clearly stating that it is a fleet modification) and then reporting individual vehicles directly from the manufacturer using RSL4 forms. If there are no changes to RSL data there is no need to issue a DoC.

7. Certificate History
The VAB process required the EA certificate to list previous EA and design certificates that applied to each individual vehicle. This is no longer part of the attestation certificates.   It is now the responsibility of the TOC/RoSCo to maintain the vehicle configuration records.


8. Limitations

 When the VAB found a non-compliance, it could issue a certificate with a limitation (and expiry date if required).  The limitation stated why the limitation was in place and what action was required to remove it. The EA certificate also carried forward all existing limitations and expiry dates for each vehicle.

Now the verification body identifies non-compliance or the conditions of use to maintain compliance. It is the responsibility of the TOC/RoSCo to control the non-compliances and ensure the vehicle remains compliant and safe to operate. The Verification Body does have a professional duty to advise the applicant of risks, or restrictions in the verification, the attestation may therefore include reservations; these can range from a handshake for important issues to be considered at design/build, to identification of areas not assessed, and a warning on risks identified.

The attestation certificates do not carry forward limitations or expiry dates from other certificates (unless superseding a previous attestation).

It is the responsibility of the TOC/RoSCo to keep track of all the non-compliances and risks, and to manage them.


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