Unique in every respect: maintenance of the Uithof line

It is a unique situation. We are maintaining a line, only half of which has been handed over to the customer by the construction company. But we are going full tilt just the same. We are also maintaining the other tram line in Utrecht, between Central Station and Nieuwegein/IJsselstein. But still, the Uithof line is very different, if only because in the near future there will be a tram every six minutes, in both directions.

99% availability

This high number of trams is needed due to the high number of passengers. Each morning, large throngs of people are waiting at Utrecht CS to catch the bus – for the time being – to Utrecht Science Park. You can imagine that with these crowds, malfunctions of the Uithof line will be out of the question in the future. The contract with the Province of Utrecht, our customer, therefore stipulates that the line is to be available 99% of the time. The number of allowable malfunctions of critical objects (switches, tracks, overhead line) is minimal. If, unexpectedly, something were to happen anyway, we are required to be on-site within half an hour. That includes on a rainy Tuesday morning in November, when traffic in the city is completely jammed.

Custom maintenance

As far as we were concerned, all of these requirements meant only one approach would do: smart maintenance. Where in the past we maintained a switch on the basis of a fixed schedule – because that’s simply how we did things – today we analyse the data associated with the switch. This data tells us how the switch is behaving and when the boundary conditions are coming into view. We then do the maintenance prior to this, so as to prevent malfunctions. This way each switch – and every component of the tracks and overhead line – is maintained on a customised basis. When maintenance is not required, we don’t do it. This saves time and money, and increases the track’s availability. The trick is to find the right balance between reliability and availability. Thanks to smart maintenance we are able to determine this balance. 

A great deal of knowledge

We collect the data with the help of a KRAB measuring trolley: a small unit drives over the track and maps everything: level, position, cant and more. We also measure the overhead line. What is the position of the wires above the track, horizontally as well as vertically? How much contact line wear is there? 
We compare this data with the standard, so that we can intervene where necessary. In addition, we superimpose all measurement data. This creates a graph that enables us to read and predict the quality of the track and the overhead line. We enrich our knowledge with every measurement. Furthermore, we have of course built up a tremendous amount of knowledge thanks to our other light rail projects within the Netherlands and abroad. Thanks to algorithms, we can use this knowledge to optimise the maintenance of the Uithof line.

Smart struggle against ice formation

As far as I am concerned, smart maintenance also equates to smart thinking. That’s what we do in countering ice formation on the overhead line, for example. Each year this is a tricky area. Due to the ice formation, the tram’s pantograph may not be able to make sufficient contact with the overhead line. As a result, the tram is unable to drive. In the past we solved this problem by having trams drive throughout the night, thus making it impossible for ice to accumulate. One of the disadvantages of this approach is that it is then impossible to carry out any maintenance, because the tracks are occupied. This is why we are going to use IceGuard, an automated and patented system that applies a fluid to the overhead line to prevent white frost and ice formation. This substance continues to do its work for a period of six weeks. This reduces the number of malfunctions and allows us to adhere to our maintenance schedule. 

The customer and passengers benefit

While this in itself is a major benefit, we are under the impression that IceGuard can produce even greater benefits. We believe that the fluid reduces the wear on the overhead line and the pantograph, since the fluid – a type of oily substance – reduces the ‘harshness’ of the contact. If so, this would mean that we could counter wear formation by permanently applying IceGuard. We are currently researching this possibility.
In short, smart means continuously giving thought to how we can do our work better, so that the customer and passengers benefit from a safe, available and reliable Uithof line.