‘Every railway manager balances between maintenance and uninterrupted train traffic’
Carrying out preventive maintenance on time or disrupt train traffic as little as possible? “Should you ensure that train traffic can continue now or should you stop it now so that it can continue in the long term? When is the right moment?” It is the daily struggle of every rail manager, which Marco Gallini of Italian railway manager RFI talked about at the Rail Safety Days in Porto.
The solutions sound very straightforward, Marco Gallini believes, but he too realises that the reality is more intractable. “We simply have to ensure that as little maintenance as possible is required. In addition, we must minimise the length of maintenance periods and optimise maintenance once planned.” The head of diagnostics and maintenance vehicles department at Rete Ferroviaria Italiana (RFI) was one of the speakers at the three-day European Rail Safety Days of the European Union Agency for Railways (ERA).
Replacing on time
“If you want to minimise the amount of maintenance, you have to replace in time, because most failures occur towards the end of the service life. It is also important to use high-quality innovative materials that are reliable and long-lasting”, says Gallini. “And not just replace, but upgrade immediately. Replace the wooden sleepers with concrete ones and install under sleeper pads, cables with reinforcement in the sheathing, and contact wires that last longer, for example.”
In addition to reducing the duration of closures, these must also be used as efficiently as possible. “A lot of time is currently lost on procedures. Sometimes half an hour or more is spent on paper forms that have to be exchanged to gain access to the tracks. That’s very precious time for an outage of a few hours. In Italy, we will be starting a pilot next year in which this process will run digitally with the aid of a 4G/LTE/5G connection, with track workers communicating via a tablet. This will reduce the process to a few minutes and make it safer too.”
Fast yellow fleet
RFI is also investing in replacing its ‘yellow fleet’ with faster and more multifunctional work equipment. Some machines can travel from one project to another at speeds of 140 kilometres per hour. “And that’s fast for work equipment.” RFI has also invested in tamping machines which, in addition to correcting track layout, also take measurements. Furthermore, they only stop the track where it is really necessary, instead of generically completing an entire section.
“In recent decades, the railways have evolved from corrective maintenance to a cyclical variant, and within RFI and the rest of the railway world, the transition is now underway from condition-based to predictive maintenance.” The latter requires permanent diagnosis, both from the track and from the vehicles that drive over it. “The vulnerability of the current system lies in the frequency of monitoring. If the system makes one mistake or a measurement vehicle is defective, preventing a measurement from being taken, you run the risk of missing an incipient failure.”
More measuring trains
RFI’s approach is to expand its fleet of measuring vehicles. In recent years, this has grown from 23 to 30 measuring trains, but it will soon be 40. The frequency is also being increased and double systems are being installed on board so that an error in one system is compensated for by the other. RFI makes no distinction between passenger trains with measuring equipment and pure measuring trains. “We still work a lot with human visual inspections and manual checks with measuring tools and trolleys, but we want to get rid of that. The frequency must be increased and the accuracy improved. We are working on having this done entirely by vehicles. Infrabel in Belgium has already achieved this. We hope to be able to do the same in Italy soon.”
“We are looking for a more objective way to monitor infrastructure, from human visual inspection to automatically using machine learning technology. In doing so, we are working towards becoming certified ourselves as a research laboratory according to the Euro 17025 and the ISO standard.” RFI plans to be the first to use this technology to detect track geometry and rail wear.
As part of this project, the Italian rail operator is converting its own San Donato test track in Bologna into a six-kilometre Freely Adjustable Test Track (FATT). Various defects can be introduced on this track in order to improve the measuring systems, to let them learn, but also to calibrate the own measuring equipment. “The next step is to convert the data into information that is of real use to the people working on the track. The human factor is indispensable for this. Even if it’s only as a backstop to check the work of the system. It is therefore invaluable to retain the knowledge that is currently available among the staff. No matter how smart the technology gets.”