The transport of rail ballast from quarry towards railway is a complex logistic process. We reached a great milestone in terms of efficiency and sustainability by bringing together several processes in one location in Amsterdam. The port area in the Western part of the city can, in the easiest way possible, directly provide all modalities and facilities for the distribution of the ballast throughout the country.
In addition to a timely delivery of the correct quantities at a good price, another requirement that has become increasingly important in railway projects is minimal environmental impact. According to Joost van der Horst, our product manager, the transport of ballast includes many different transport modalities. “The trick is to minimize the modalities used and restrict the number of trucks necessary.”
For the Dutch railway, new ballast is - among other locations - retrieved from a mountain in Norway. With the aid of dynamite, large chunks of rock are broken into pieces and dumped in a shaft.
Inside the mountain, two machines break the material into small pieces. To move the material from the mountain to the water side, it is transported on a conveyor belt of approximately 1,500 meters long. Because the belt is placed under an angle of 15 degrees, it automatically moves due to the weight of the stones. By slowing down the belt, power is generated for the quarrying activities.
After the breaking process, the semi-finished product is placed in a large self-unloading bulk carrier. This ship transports the future rail ballast to Amsterdam, where the ship unloads the ballast. Next, shovels feed the installation in which the material is further processed into even chippings that can serve as ballast. In addition, smaller fragments are made that are used for asphalt.
Subsequently, a barge brings the ballast to Amsterdam, where our SALT-wagons are waiting to be filled. This process is shown by the drone images below. There are three transport options: the easiest but also the least sustainable one, is loading the ballast on a truck that drives to the project location. Another possibility is loading the ballast onto a barge and unloading it on trucks parked as closely as possible to the project’s location for the last few kilometers. The most sustainable mode of transport is loading the material onto ballast wagons that are driven to the project’s location at the designated time the contractor needs it.
What’s great about our premises, and that of our suppliers in Amsterdam, is that we have everything within our reach. The seaport is close by, and internal vessels can dock at a long quayside where the wagons can be loaded and parked. Quite a unique setting, where you can keep your stock, park your wagons, and carry out loading activities, all at one location. On top of that, it is situated in the middle of the country and well accessible by ship. No wonder that we are very happy with this location. Previously, these activities were spread over several locations in the Netherlands.
We have about 300 wagons available to transport ballast, of which approx. 230 are SALT-wagons: wagons that allow a dust-free unloading procedure.
A fleet of this size requires a lot of space. For the SALT-wagons in particular, we need facilities to obtain water and fuel. These wagons are operated hydraulically from a distance. They have a small diesel engine that sets the hydraulics in motion, and a dust suppression system that counteracts the quartz dust that is released during unloading. Most train yards are remote areas where facilities to fuel the trains are not always present. However, in Amsterdam we do have that availability.
Our ballast trains are loaded on week days, in order to be unloaded at project locations on the weekends and during the night. This is preferably done for an entire train in one go. Loading separate wagons involves many additional tasks, because all wagons must be connected to a locomotive, moved, and disconnected again one by one.
We want to assemble the train ourselves, bring it to the loading zone, and load all the wagons. The fewer activities, the better.
By clustering activities and deploying as many ballast trains as possible, the number of transport movements required for the delivery of rail ballast is likely to decrease by 20 to 30 per cent. The largest benefit lies in saving emissions from the trucks and inland vessels. The most ideal means of transport depends on the project. What is the accessibility of the location, how much material is needed, and within which timeframe does it have to be delivered?
Working with used rail ballast is of course even more sustainable. This is also something that we are actively involved in. However, it requires a completely different logistic process.
In most cases, the contractor filters out the ballast at the project location. To this end, a large ballast sifter is installed. This machine removes all unwanted material, such as vegetation, waste, and stones that are too small. After that, the ballast is ready for use again.
Sifting as much ballast as possible at the project location will restrict the number of transport and transshipment movements to a minimum. However, no matter how sustainable and circular the deployment of used ballast, there will always be a need for new material.
In order for the ballast to function properly, the surface of these small stones must be sufficiently rough and of a particular size. The reason for this is that the ballast has to absorb the forces generated when a train moves over the tracks. A running train pushes, as it were, the tracks forward in a wave-like motion. As a result, the tracks slightly sink down at some locations. In the course of time, the ballast bed also lowers slightly, thereby touching the sleeper packing in the ground. This can partly be repaired by shaking up the ballast. However, new ballast also has to be added. This is specifically required to ensure that the material remains large and rough enough to sufficiently resist the vibrations and forces of the trains.
If you would like more information on the transport of ballast, please contact productmanager Joost van der Horst.
