A track ballast maintenance and inspection model for a rail network

Abstract

The geometry of railway track governs the quality of the ride for passengers and, should it deteriorate to an extreme state, can become a safety concern with potential derailment. The geometry is dependent upon a number of different factors, among which is the condition of the ballast. Several options exist to control the condition of the ballast, including manual intervention, tamping and stoneblowing. Ballast condition is monitored implicitly by measuring the geometry of the railway lines using a specially equipped measurement train. By analysing the data collected by this train, the deterioration process of the railway geometry can be understood. Using this understanding, mathematical models can then be constructed, which take account of the possible maintenance and renewal options to predict the track state. This model enables decisions to be made on the best or optimal strategy for maintenance and renewal of the ballast. This article describes a model of the track maintenance process for a railway network. Owing to their flexibility, the model is formulated using a Petri net and combines the deterioration, maintenance and inspection processes for a railway network containing a number of regions. There are a limited number of maintenance machines in the network and the maintenance in each region is organised independently. The model also takes account of the fact that the maintenance of track sections with severe levels of ballast deterioration must take priority over all other maintenance in the network and allows for opportunistic maintenance to be analysed.

Petri net modelling of bridge asset management using maintenance-related state conditions

“…A reset transition (Andrews, 2013;Prescott DR, 2012), when it fires, resets the marking of specified places in the PN to the desired number of tokens. This transition has an associated list of places and number of tokens that they will contain after reset.…”

“…A place conditional transition (Andrews, 2013;Prescott DR, 2012) is a transition in which the delay time is sampled from different distributions depending on the number of tokens residing in a specific place in the network to which they are linked by a dashed arc. Note that, the dashed arc only indicates the link between the conditional places to the place conditional transition.…”

Modelling wind turbine degradation and maintenance

“…This feature is useful for when maintenance action has happened and component condition is restored. A place conditional transition [35] is a transition in which the delay time is sampled from different distributions depending on the number of tokens residing in a specific place in the network to which they are linked by a dashed arc. This transition allows easy modelling of dependent deterioration processes.…”

Generalized Stochastic Petri-Net Algorithm with Fuzzy Parameters to Evaluate Infrastructure Asset Management Policy

“…Petri-net has been widely used in modelling business processes [3][4] [5] [6] [7] and engineering processes specifically in manufacturing and control engineering [8][9] [10] [11] [12]. In past few years, its application in asset management has received a great deal of attention to model degradation process and maintenance & renewal process of assets in wind turbine [13] [14], railway [15] [16] [17] [18] and bridges [19] [20]. The main characteristic of SPN is its ability to support structural organization and visualization of knowledge or information related to asset degradation and its maintenance policy in different situations.…”