Bogie & undercarriage maintenance
Bogie maintenance comprises the scheduled disassembly, inspection, repair, and reassembly of the complete bogie structure, including the frame, suspension elements, wheelsets, axleboxes, bearings, and brake equipment.
A bogie overhaul begins with lifting the vehicle body to allow bogie removal. The bogie is transported to the workshop, where it is cleaned and stripped.
Frame inspection uses visual examination supplemented by magnetic particle testing or dye penetrant testing of welds and high-stress zones, and ultrasonic testing of the frame structure where internal defects are possible.
Cracks exceeding permitted limits require repair welding qualified to DIN EN 15085, which governs welding of railway vehicles and components.
Suspension elements — primary and secondary springs, dampers, anti-roll bar assemblies — are inspected and replaced against defined criteria. Axlebox bearings are removed, the axlebox housings inspected, and new bearings fitted.
Wheelsets are typically sent separately for reprofiling or replacement. After reassembly, the bogie passes through a bogie press or test stand that simulates the vehicle’s static load, settling the suspension to verify ride height and check for any geometry deviations before the bogie is returned to service.
Lifting and handling equipment
Vehicle body lifting for bogie removal uses sets of synchronised electric jacks deployed along the vehicle underframe. Modern synchronised jack systems use digital control to maintain level lift across all columns simultaneously, with electronic interlocks preventing uneven loads that could damage the vehicle structure.
Configurations range from four-column sets for single vehicles to 128-column installations for simultaneous lifting of complete trainsets.
Bogie drop tables — self-propelled, battery-powered platforms that run on workshop tracks — collect the bogie once lowered and transport it to the maintenance area, keeping the lifting bays clear for the next vehicle.
Structural and fatigue requirements
EN 13749:2021 specifies the method for defining structural requirements of bogie frames, covering design procedures, fatigue assessment, and manufacturing quality.
The standard forms part of a package with EN 12080 (axlebox bearings), EN 12081 (bearing grease), and EN 12082 (bearing performance testing). Bogie frame structural calculations use the load cases defined in EN 13749 to verify that repaired or modified frames remain within fatigue limits.