The article presents the state of knowledge and research in the field of surface cracks occurring in disc braking systems of rail and car vehicles. The craze formed during the operation of vehicles is particularly dangerous and leads to breaking the disc into several pieces. It may lead to a loss of braking force and damage to the entire disc brake caliper. The main aim of the research is to identify surface cracks in brake discs made of cast iron and use experimental methods to estimate their depth. Research were conducted on the disc braking system developed by the authors. In examining the location and depth of cracks, the penetration method, ultrasound, as well as a special probe were used. This device measures the crack depth based on the electrical resistance between two points on the surface of the metallic object. The tests showed that the first microcracks on the brake discs appeared after 309 braking tests on the test stand. In addition, it was observed that the surface cracks length of the disc increased linearly to depth until they reached about 11.5–12 mm with corresponded to crack lengths in the range of 65–70 mm. However, determination of the regression functions presented in the article allows to estimate the depth of surface cracks up to 70 mm long on cast iron brake discs by measuring their length.

The aim of the article is to present the results of research and modelling of wheel set wear on the rolling diameter of the drive and rolling wheels of a multi-unit traction unit. The object of the research was the PESA ELF I electric multiple unit constructed as a five-unit unit based on two end drive bogies and three central rolling bogies. The article presents the results of research on the change in wheel diameter recorded every two months during a periodic inspection over a period of five years of vehicle operation until revision repair. Based on the results of wheel diameter tests, wear was determined, on the basis of which the change in wheel diameter and wear as a function of time and vehicle mileage was modelled. Based on the models, mileages expressed in kilometres were determined for each wheel set with longer vehicle operation. The reason for implementing the subject is the uneven wear of individual wheels in the wheel set of drive and rolling bogies in multi-unit traction units. The vehicle maintenance system documentation requires that after a specified period of time, e.g. 5 years, the vehicle is sent for a revision repair, even if none of the wheel sets has reached the wear limit.

The decarbonization of regional passenger rail transport is one of the key challenges for the sustainable transformation of the transport sector in Poland. While railway transportation remains one of the least carbon-intensive modes of transport, significant emission disparities persist between electrified and non-electrified lines, where diesel traction is still prevalent. This article presents a comparative analysis of various propulsion technologies—diesel, hybrid, battery-electric and hydrogen fuel-cell—taking into account both local (TTW) and total (WTW) greenhouse gas emissions. The study incorporates Poland’s current energy mix and proposes a methodological framework to assess emissions at the line level. It highlights the risks of focusing exclusively on in situ zero-emission technologies and calls for a more flexible, efficiency-based approach to fleet modernization. The analysis demonstrates that hybrid and optimized combustion-based systems can provide substantial emission reductions in the short term, especially in rural and transitional regions. The paper also critically discusses transport funding policies, pointing to discrepancies between incentives for private electric mobility and the lack of support for public transport solutions that could effectively counter mobility exclusion. The presented methodology and conclusions provide a basis for further research on transport decarbonization strategies tailored to national and regional contexts.

The article aims to present the testing of hydraulic oil testing in accordance with the requirements of ISO and NAS standards and the results of oil testing from two selected construction machines, i.e. Liebher 566 first class wheel loaders. The article also takes into account the influence of...

The aim of the article is to present a computational model to determine the losses generated by the brake discs of rail vehicles. The energy consumption of the disc (energy losses) is divided into inertia losses and fan losses. The article is preceded by a review of the design solutions of brake discs of rail vehicles in terms of their ventilation and cooling after braking. Particular attention was paid to three types of brake disc designs with ventilation blades, bars and other shapes of ventilation bridges, and how the ventilation of these discs affects energy losses. On the one hand, forced ventilation of brake discs shortens the cooling time after intensive braking, on the other hand, it causes energy losses due to forced ventilation when the brakes are not used. The article presents the state of knowledge regarding the cooling efficiency of brake discs as a result of forced ventilation and presents a method for calculating the energy consumption generated by the brake disc in relation to the rotational speed. The energy losses were divided in the article into inertia losses due to the rotating mass and losses on the fan, in which the energy necessary for the rotation of the brake disc was determined from the method of calculating centrifugal fans with known geometric dimensions.

The transition from Time-Based Maintenance (TBM) to Condition-Based Maintenance (CBM) remains a challenge for the railway sector due to stringent safety regulations. This paper addresses this gap by presenting a framework for diagnostic monitoring of traction motor cooling fans in Electric Multiple Units. Using vibration analysis and adaptive statistical thresholds, the study demonstrates increased sensitivity compared to ISO 10816-3 limits. Research on 42 fans revealed that the proposed method achieved a 92.9% agreement with normative classifications while identifying early-stage degradations. A crucial part of the study is the formal analysis of change significance in accordance with the 402/2013 (CSM RA) regulation, providing a systematic approach to managing safety risks during technology implementation. The article provides a practical roadmap for integrating this 19-minute procedure into routine light maintenance, offering a scalable solution to overcome formal and technical barriers in adopting predictive maintenance for safety-critical systems.