Sustainable superstructure renewal of industrial estate and yard tracks

06/24/2021 Track construction and maintenance

For Charlotte Pars of ProRail, it is clear: as a contracting authority, you must use the influence you have to contribute to a more sustainable world. She shows that this can be done with little effort. For procuring entities which have perfected the basics, like ProRail, there are chances that require courage to take, but which also have the potential to achieve more results. In concrete terms, ProRail allows contractors to contribute to the design of projects and even to the standards that must be met. ‘By using the contractor's expertise, we can make more sustainable choices.’

Why should you, as a procurer, use the CO2 Performance Ladder in your tenders?

Charlotte: 'The CO2 Performance Ladder is one of the few award criteria that has been properly and thoroughly developed. It requires relatively little work on your part as a client.’ And indeed, a contracting authority which grants an award advantage to organisations with a Ladder certificate in the call for tenders does not have to reduce CO2 itself, but it does ensure that its tenderers do so on a structural basis – ‘a simple way to make a big impact in terms of CO2 reduction.' ProRail established the Ladder in 2009 and transferred the instrument to SKAO in 2011. The organisation itself has been certified since 2015 and has been using the Ladder as an awarding instrument in tenders since 1 December 2010. And not just occasionally: in 2020, the Ladder was included in no less than 84% of all ProRail’s contracts in the 'works' category and in 83% of all its engineering contracts. Charlotte: 'We always use the Ladder, unless we estimate that the contractor would produce little CO2 or can only reduce their emissions a little. For example, the ladder wasn’t included in an assignment to improve the intelligibility of speech over public address systems.’

‘The CO2 Performance Ladder is one of the few award criteria that has been properly and thoroughly developed.’ - Charlotte Pars (ProRail)

What does 'tendering with the Ladder' usually look like at ProRail?

Charlotte: 'We start all our tenders with a contracting plan. This states which award criteria we want to use: the CO2 Performance Ladder is one of them. Then we come to the tender instructions, in which we elaborate the award criteria. The CO2 Performance Ladder is worked out as an award criterion in accordance with SKAO's Procurement Guide. This way, companies know how to apply. Most contractors working for ProRail - certainly the rail contractors - are certified at level 5 of the CO2 Performance Ladder and therefore receive the same fictitious 10% discount on the tender price. If an organisation does not maintain this highest level, it immediately falls behind the other tenderers.’ If the organisation awarded the contract fails to meet the award criteria in practice, it must pay a penalty of one and a half times the discount granted.

‘If an organisation does not maintain the highest level of the CO2 Performance Ladder, it immediately falls behind the other tenderers.’ - Charlotte Pars (ProRail)

How does ProRail challenge itself to achieve even more CO2 reduction in projects?

Charlotte: 'By inviting the contractor to think with us about the assignment itself.’ She explains: 'We recently put the superstructure renovation of industrial estate and yard tracks in Zeeland and Brabant out to tender. Superstructure includes ballast, sleepers, rails and points. We want to make the renovation as sustainable as possible, and as the client, we naturally thought about the best way to achieve this. However, we also know that we are failing to make use of much of what the contractor offers: in this way, the contractor is limited to thinking about how the project can be executed sustainably, while they may also have some very good ideas for the approach.’

Charlotte continues: ‘On top of that, we also challenged the contractors to think about ProRail's own product specifications. Do they consider them realistic? After all, whether the trains speed along the rails at 140 km/h or are powered by steam, ProRail has the same specifications for all tracks. Is that necessary, or could you differentiate? Perhaps rails from the main track, for instance, are no longer good enough to be driven over at 140 km/h but they are still good enough for the railway yard.’

A bold step to involve the contractor in the assignment in this way. Does the tendering process look different than usual?

Charlotte: 'Yes, unlike most of our tenders, this one consists of two phases: engineering and realisation. For the first phase, we asked the tenderers to write an action plan in which they had to demonstrate that they could think along with us about the most sustainable renovation of the superstructure. What is their vision, how do they want to cooperate, and of course: what measures do they want to take? We also asked them to provide two emissions inventories: one showing the CO2 emissions of the project if all the measures were applied, and one showing the CO2 emissions without applying all the measures.’ We gave 'sustainability' and 'cooperation' high priority in the tender, explains Charlotte. ‘So we set our sights very high on a party that can think in sustainable terms.’

With VolkerRail as the winning party, ProRail sat down at the table to go through all their proposed plans. ‘Which of the proposed measures are we going to apply, and which not? At the end of the first phase of this two-phase contract, we will have the measures in focus and then the phase ends with setting up a contract that states what has to be done. In phase 2 the contract is then executed.’

What special measure did VolkerRail initiate for this project?

Charlotte: 'Until now, materials at ProRail have only been incidentally reused, because our organisation and regulations are not yet sufficiently geared towards this. VolkerRail is now contributing to our thinking about how to determine whether a used material can be reused: what kind of instruments do you need for this? What information do you need to be able to determine whether a component is still good enough to be stored elsewhere? And where do you differentiate: in speed, track position, etc.? If this project shows that you can differentiate, we will also apply it in other projects. That will boost our circularity and reduce our CO2 emissions.’

In addition to thinking about the standards for reuse at ProRail, VolkerRail also made a concrete proposal for applying those standards. Maarten Smolders, tender manager at VolkerRail: 'The best innovation that we mentioned in our plan of action is the reuse of materials that have a major impact on the environment and that occur in large numbers. So rails, switches and sleepers. These materials can be by-products in other projects. They may not be suitable there, but they are, for example, at sidings. We regard these locations as 'harvesting locations,' which is why we have coined the term 'infra-mining.' The materials are collected at a central location in the region. There, the residual value of the products is examined and, where necessary, the raw materials are separated. This information is recorded digitally, making them traceable and providing insight into their potential applications.’


Project details


± €3.000.000,-


Zeeland and Brabant, the Netherlands

Project duration

 two years

Ambition level winning party/parties

level 5

Award advantage given

10% of the tender price

Focus CO2 reduction on project

 Infra-mining (large-scale collection, management and revaluation of residual materials for reuse)