Healthy tracks mean healthy operations
Posted: 1 August 2013 | | No comments yet
Railway diagnostics – in other words a set of activities used to detect the ‘health conditions’ of rail infrastructure – is today an irreplaceable tool to optimise the maintenance of railway networks. It is a crucial area for railway network providers because it guarantees operating safety, prevents failures and directs both human and technological maintenance resources where necessary in an efficient way.
For a few decades now, all major worldwide railway companies have been operating mobile diagnostics tools – from small maintenance trolleys to trains – which monitor the line in typical operating conditions and are equipped with the latest technological systems to detect, process and analyse data on the infrastructure.
By incrementing the development of diagnostics, Rete Ferroviaria Italiana (RFI) – a company of Gruppo FS Italiane, the Italian network manager – has optimised costs and minimised resource waste by programming maintenance actions. As a matter of fact, the field of ‘on-condition’ maintenance has been enlarged, reducing cyclic maintenance to the minimum.
In addition to saving on maintenance costs, mobile diagnostics has contributed additional benefits to the Italian rail network – among them a higher availability of infrastructures (lower number of interruptions) and a higher operating reliability (reduction of possible failures).
Sensors and defect detection algorithms require state-of-the-art technologies and a diffuse use of expert systems. Such circumstances are impaired by a common drawback of high-tech systems, i.e. a rather short life-cycle (from two to four years). Therefore all organisations operating in the diagnostics field must foresee a continuous use of resources for ‘development’, often providing useful elements for the evolution and experimentation of new rail technologies. This makes it possible to offer tools and incentives to rail infrastructure providers – from control to development and from certification to support for innovative maintenance policies.
RFI has its own fleet of diagnostics trains – the Dia.Man.Te. and Archimede vehicles are equipped with very high technological instruments, equivalent, if not better, to the famous ‘Doctor Yellow’ vehicle – the diagnostic train for the Japanese high-speed network.
Fixed and mobile diagnostics
Every year, RFI invests €10 million for the technological development of fixed and mobile diagnostic systems. Fixed diagnostics is made with measurement devices installed permanently in specific infrastructure bodies for continuous detection of operating parameters. Mobile diagnostics is made with dedicated trains owned by RFI and equipped with highly technological measuring systems, which travel on high-speed and traditional lines to detect parameters on the infrastructure status and operation.
Several parameters are measured during test running cycles, among them height, slope, stagger, contact wire thickness, and voltage of the contact line. Moreover, diagnostic trains are equipped with video-inspection systems for the power area contact line. For track inspection, they analyse parameters such as rail profile and wear, track geometry, compliance with distance and level difference between two rails. When the parameter values exceed the reference threshold, a defect is recorded and suitable maintenance actions must be implemented.
For this reason, the measures detected by diagnostic trains and the data processing system are going to dramatically change the way in which maintenance actions on infrastructure are planned and made.
Diagnostic trains permit what is technically defined as ‘predictive diagnostics’ – being the result of mathematical models that interpret the data measured by the diagnostic trains and simulate the cause/effect ratio upon occurrence of a failure. They are basically used to ‘predict’ when the failure is going to occur in order to prevent it.
Thanks to IT systems with small dimensions, low cost and low impact on the engineering of installations and equipment, modern technologies play a crucial role in managing large amounts of data (saving, processing and displaying) of complex diagnostics and auto-diagnostics systems of the installations.
In the last decades special rolling stock has been developed for mobile diagnostics – from traditional IT trolleys to the first measuring cars that can detect values at high speed in composition with ordinary trains or individual locomotives. Back in the 1950s the rail infrastructure provider (Azienda Autonoma delle Ferrovie dello Stato) was equipped with diagnostic machines with more and more sophisticated tools, progressively enlarging the systems detected in its installations and the types of diagnosed failures.
Dia.Man.Te. – an acronym of Diagnostica e Manutenzione Tecnologica – is RFI’s latest and most technologically-advanced diagnostic train. It is dedicated to high-speed lines and is the first rail vehicle in the world capable of measuring the status of rail infrastructure at 300km/h. It controls over 200 parameters on fitting-out (track and ballast), energy (contact line), signalling (ERTMS) and telecommunications (GSM-R radio system).
The diagnostic systems on-board Dia.Man.Te. are the result of a 100% Italian innovation. The train is a bi-voltage 3 kVcc and 25kVca ETR500 composed of two locomotives in double symmetrical traction and eight cars.
Data, measurements and defect lists are concentrated in the on-board database. At the end of each day, they are transferred by means of a mass memory unit or over a wireless or intranet RFI connection, in order to be additionally processed and loaded into the RFI Maintenance Information System and made available to all operators. Relevant defects, considered as abnormalities in progress under all aspects, are identified in real-time, validated by the operator and informed to the Infrastructure Operation Centres – infrastructure check points – so that the technical staff can take immediate action.
Each car of the Dia.Man.Te. vehicle has its own function: data on electrical voltage is collected in the first car, data on telecommunication (and on GSM-R network) is collected in the second car; and the next car operates as workshop/warehouse for tools, instruments and spare parts. Some generators are installed in the fourth car in case of emergency energy; the fifth car is used for logistics; the sixth car has two meeting rooms (one with 22 and one with eight seats) used for work meetings and data sharing; the seventh car analyses operating dynamics (for example, wheel/track interaction) and finally data on fitting-out is collected in the eighth car.
Other RFI diagnostics vehicles
Introduced in 2003, Archimede is an extraordinary innovative concentration of technology. It can measure 119 different parameters per minute at 200km/h that are integrated to control the rail infrastructure status in real-time. Archimede is mainly dedicated to analysis and tests on traditional lines.
Introduced in 1997, Galileo is a measuring train that carries out rail ultrasound checks and digital video-inspections.
Used to detect rail geometry, accelerations and wear, Talete measures all rail alignment and level values by means of optical triangulation laser and gyroscopes.
Caronte is the motor train unit dedicated to diagnostics of lines equipped with Train Running Control Systems (SCMT) and Driving Support System (SSC). Moreover, it is the first rail vehicle in the world to certify signalling in accordance with European standards.
The mobile diagnostics of electrical installations is entrusted to Aldebaran – a special car that was the first to use laser technology to measure all parameters of a contact line and the interaction between pantograph and wires.
The fleet is completed by 15 railcars spread out on the territory and fitted with special equipment used to detect the rail geometry and a series of portable trolleys used to check the switch geometrical parameters.
In September 2006, Michele Mario Elia was appointed CEO of RFI – part of the Ferrovie dello Stato (FS) Italiane Group. He began his career at FS in 1975 as an Electrical Systems and Plant Inspector, and from there worked doing surveys of operations and maintenance of signalling, electrical traction, lighting and electromotive systems and plants in the Bari Infrastructure Regional Offices.