Bogies and wheelset maintenance

Type of bogie depends on the rolling stock unit

Rolling stock sit on bogies which runs on tracks. The structure of a car bogie is comprised of the bogie frame, wheelsets, brake system, primary suspension, secondary suspension (including any tilting systems), pneumatic system and electric cables and equipment. The bogie frame is usually comprised of two longitudinal beams, two cross beams and a support beam to which the brake units and equipment are mounted. The steel beams are fastened to each other by welding. The bogies are approximately 4.5–5 metres long, 2.5–3 metres wide and 0.9–1.2 metres high. The maintenance of massive bogies requires overhead and boom cranes, transporters and bogie turning equipment to turn the bogie around at the workstation. VR FleetCare refurbishes both trailer and motor bogies.

Trailer bogies, found in both passenger and freight cars, do not include a traction motor or drive wheelset. Trailer bogies weight approximately 5–8 tonnes. Motor bogies have either an electric motor or a drive wheelset. The electric motor transmits force from operation equipment on the wheelset axle to the wheel and hence to the rail. The axle-drive device in the centre of the drive wheelset axle is driven by the train engine, for example via a cardan. The drive wheelsets of electric trains weigh approximately 9–13 tonnes and those of locomotives approximately 15–18 tonnes.

Bogie maintenance is divided into operational regular maintenance, overhauls and repairs due to faults/damage. Regular maintenance at depots, carried out between overhauls, is performed without removing the bogie from the train or locomotive. Daily maintenance ranges from visual inspections to minor maintenance measures. VR FleetCare services approximately 2,300 bogies per year. Also foreign bogies with different track gauges can be serviced without problem. Overhauls are carried out based on mileage or service life. Bogies can also come in for inspection or repair following error reports. When the service life or kilometre limit is reached, a system indicates the need for maintenance. Usually, overhauls take place every 6–12 years or after about one to three million kilometres of running. At this time, the bogies are disassembled and refurbished according to the manufacturer’s instructions so that they are safe and in operational condition ready for the next overhaul interval. When arriving at the depot or service workshop, the car receives a refurbished bogie and the old bogie enters a maintenance cycle. The bogie is cleaned and disassembled. Removed components and parts are inspected and serviced. Rubber bearings and other wearing parts are replaced or refurbished. During a major maintenance, the bogie is sandblasted, checked for cracks and completely repainted.

Our component production is equipped with a comprehensive range of required tools and machines for the maintenance of bogies. Various hand tools, such as wrenches, electric and pneumatic wrenches, measuring instruments, torque wrenches, scrapers and threaded pins, are also widely used in overhauls. Also in-house washing machines are used for washing components and bogies.

Wheelset maintenance

VR FleetCare continuously employs 60 people for the maintenance and servicing of wheelsets. Massive wheelsets are subject to wear and tear in operation, and service needs are also affected by operating conditions, such as seasonal variations. Wheelsets come in for service according to pre-defined service intervals, based on either the kilometres run or the maintenance interval. Certain limits have also been set for the components which must be met, so that wheelsets can be authorised for traffic use. Each year, VR FleetCare services and maintains approximately eleven thousand wheelsets, ensuring the safety of rail traffic and the utilisation of the entire lifecycle of the wheelsets.

A single bogie attached to the car has two wheelsets. A wheelset comprises two wheels and their connecting axle, and may also include brake discs and actuator. Different rolling stock units are equipped with wheelsets according to the needs. The weight of a wheelset varies from about one to four tonnes.

VR FleetCare services the wheelsets of freight wagons, passenger cars, locomotives, high-speed trains and track-work machines. The wheelsets of locomotives include an actuator through which the power from the electric motor is transmitted via the shaft to the wheels. Generally only passenger, high-speed train and commuter traffic cars are equipped with brake discs.

Upon arrival for service, the condition of the wheelsets is inspected and the necessary maintenance measures are defined. The wheelset passes through maintenance, and the measures may include lathing the wheels and brake disc, refurbishment of the actuators or inspection of axles, and a final full inspection. The maintenance is carried out according to standards and the manufacturer’s instructions. VR FleetCare also assembles new trailer wheelsets. Both machines suitable for demanding maintenance and professional employees ensure a high-quality end result. The special expertise required for maintenance is ensured by training of the operating equipment.