Technical articles

This is a collection of technical articles and other publications related to the railway industry which have been published.

Click on the title to read more.

Applied condition monitoring in railways
Evolution article 4/2011
For railway operators, increased reliability and safety are ­constant concerns alongside the desire to reduce maintenance costs. ­Condition monitoring is a mature technology that offers new capabilities in the railway industry, as it enables a proactive approach to achieve financial savings and meet safety targets.

The evolution of railway axlebox technology - Part two: present and future
Evolution article 2/2011
In the second part of the historical development of railway axlebox development, we look towards current developments that are driving the future of this key component. SKF has a long track record of axlebox developments, and trends in the industry are towards packaged solutions. These are based on wheelset axlebox assemblies, comprising the wheelset bearings or units, the axlebox housing and integrated sensors as well as condition monitoring and service packages, including service engineering, remanufacturing and training.

The evolution of railway axlebox technology
Evolution article 1/2011
In the first of a two-part article on railway axlebox design, we look at the evolution of this key railway subsystem from an historical perspective. As a company with a long tradition of developing axlebox solutions, SKF has always addressed environmental issues such as energy conservation and lubrication saving for this market.

Solutions for railway bogie condition monitoring
Evolution article 1/2010
Bogie condition monitoring offers new opportunities to increase reliability and safety and achieve lower maintenance costs. Incipient damage can be detected and mechanical failures prevented.

Covering the distance with SKF Axletronic odometers
Evolution article 4/2009
Harmonization of rail network control systems offers international interoperability as well as major savings on investment and maintenance costs and easier operation. SKF is contributing to this development with its SKF Axletronic odometers.

Sensorized traction motor bearing units
Evolution article 3/2009
Reliability combined with long maintenance intervals are essential for modern traction motors. To meet the needs of transport operators, SKF has developed specific bearing unit solutions.

Wheel flange lubrication for railway systems
Evolution article 4/2008
Willy Vogel AG, part of the SKF Group, offers wheel flange lubrication system solutions to reduce friction. Friction is a particular problem when train wheels encounter curves, as friction occurs between the wheel flanges and the inner sides of the rails.

High speed in railways
Evolution article 3/2008
Speed has been the essence of railways since the first steam locomotive made its appearance in 1804. SKF remains at the forefront of high-speed train design, providing some of the most safety-critical components of railway vehicles - the wheelset axlebox assemblies, comprising the wheelset bearings or units, the axlebox housing and integrated sensors.

More than 100 years of energy saving solutions
Evolution article 1/2008
Today energy saving is one of the main issues in terms of carbon dioxide emissions. But even a century ago energy saving was important because of limited electrical power supplied by steam engine driven generators.

SKF solution for railway articulation joints
Evolution article 1/2008
Low-floor mass transit vehicles offer easy entry for passengers. Modern articulated vehicle designs containing several body sections enable easy access inside the vehicle and contribute to passenger safety. The articulation joints of these sections contain special plain bearing solutions developed by SKF.

SKF sets new standards in China
Evolution article 1/2007
Rail transport is a high-tech growth industry in which SKF is a global leader. To become closer to the important Chinese market, SKF in 1996 established a joint venture with the Chinese Ministry of Railways. The SKF CTBU design 150 will now become a Chinese standard.

The universal polymer cage for railways
Evolution article 2/2006
Significantly improved performance can be achieved through the use of polymer cages for roller bearings
in railway journal bearing applications. The SKF Universal Polymer Cage for tapered roller bearings Class F has gained conditional approval from the Association of American Railroads to retrofit and upgrade existing bearing units manufactured by all major bearing suppliers to the North American market.

New axlebox concept for heavy loads
Evolution article 4/2005
For many years the trend in the railway industry has been to carry heavier loads at faster speeds. Today, most railway freight cars in Europe are built to run with axle loads of 25 tonnes. SKF has developed a new Y25 axlebox concept that is equipped with compact tapered roller bearing units. This design offers opportunities to achieve lower life-cycle cost through longer maintenance intervals, simplified maintenance operations and improvements in performance and safety.

New sensor solutions for railways
Evolution article 3/2005
SKF has developed new sensor solutions, which are incorporated into the bearing unit. These solutions are becoming a standard for new generations of railway vehicles.

Service engineering for Australian railways
Evolution article 4/2004
Rail companies in Australia face great technical challenges in their operations across the country. With its acquisition of Rolling Stock Supply & Service Pty Ltd, SKF plays a key role in rolling stock service engineering on this continent.

Compact taper roller bearing lives up to its name
Evolution article 3/2004
SKF has developed a new bearing generation for railway applications that offers lower life-cycle costs and longer maintenance intervals. Laboratory and field-test results confirm the performance expectations.

Axlebridge designs for low-floor tramways
Evolution article 1/2004
Low-floor tramcars and light rail vehicles offer easy entry for passengers into the vehicle. The Combino® modular tramcar made by Siemens is equipped with an advanced axlebridge developed by SKF.

Hybrid traction motor bearing units for mass-transit vehicles
Evolution article 4/2003
Traction motor bearing units are increasingly used to lower life-cycle cost and improve performance in railway applications. Škoda Trakcní Motory is using these bearing units in its traction motors for mass-transit vehicles.

Sensors for railway bearing units
Evolution article 3/2002
Wheel slide and skidding on railway vehicles can be avoided by using systems similar to antilock braking systems for cars and trucks. SKF has developed this technology to better meet the needs of railway applications.

Chinese railways right on track
Evolution article 3/2002
China's rail system is undergoing a massive overhaul - with ambitious new rail lines and new and upgraded technology to lower costs and improve safety.

The compact TBU, a new concept in axlebox bearing units
Evolution article 1/2002
Design is the key to lower life-cycle cost. SKF engineers have taken this maxim to heart in developing the Compact Tapered Bearing Unit (Compact TBU) for use in railway applications.

High pressure and slow movement ideal for plain bearings
Evolution article 4/2001
AMPEP self-lubricating plain bearings are ideal for applications where bearing pressures are high, movement is slow and maintenance is difficult or impossible.

Hybrid bearings for electrical machinery
Evolution article 3/2001
Hybrid bearings can prolong the service life of electrical motors, machine tools, fluid machinery, etc., where the operating conditions may include electrical-current passage, high speed, contamination or poor lubrication.

Prevention of electric erosion in bearings
Evolution article 2/2001
SKF has developed electrically insulated bearings, called INSOCOAT, to protect against damage caused by electric current.

New drive systems for mass transit
Evolution article 2/2001
Mass transit is becoming more important in cities and suburban areas worldwide. New generations of vehicles equipped with newly designed drive systems have entered service in recent years.

Added safety for today's railway industry
Evolution article 1/2001
A new bogie monitoring system helps increase railway reliability and safety and at the same time lowers life cycle costs.

Railway bearings pass new test
Evolution article 4/2000
SKF's railway axlebox with cylindrical roller bearings was the first to pass the 25-tonne test under the new standard EN 12082 (European Norm). 

Lubrication of bearings at low temperatures
Evolution article 4/2000
In low-temperature conditions, lubrication media must be carefully selected, taking into account the whole range of temperatures over which machinery has to function.

A nation built by railways
Evolution article 2/2000
It's no accident that Italy came together as a nation around the same time that railways first linked the extremities of Europe's longest peninsula. The spread of the railways helped to forge a national consciousness.

Optimised bearings for locomotive transmissions
Evolution article 2/1999
Modular design makes the new Adtranz Octeon locomotives flexible. SKF optimised the bearings for the integrated drive system.

Polymers enhance railway axlebox bearings
Evolution article 4/1998
Significantly improved performance can be achieved through the use of polymer cages for roller bearings in railway axlebox applications.

Testing standards set for railway bearings
Evolution article 3/1997
Reliability is a key word in railways operation. One way of ensuring the long-term reliability of Europe''s network is through rigorous testing procedures. New standards are being negotiated to achieve this end.

Testing times for greases
Evolution article 4/1996
Grease plays a crucial part in the lubrication of railway axleboxes and bearings. SKF has evaluated its test procedures for measuring grease performance. The SKF V2F method has been confirmed as the proper test to use in this application.

Electrically-insulated bearings
Evolution article 3/1996
Reliability is an essential requirement for modern bearings with longer intervals between maintenance. For example, they must be robust enough to operate in electrical equipment with modern AC technology.

Development of traction motor bearings
Evolution article 2/1996
New generations of traction motor bearing units have evolved to meet more exacting customer requirements.

High-speed operations
Evolution article 4/1995
Railway companies today demand modern equipment that is compact, easy to handle and contributes to a reduction in total life cycle cost.

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