Development of integrated wear-fatigue-lubrication model for

assessment of rail-wheel degradation & operational risks

Dr. Gopi Chattopadhyay, QUTA/P Doug Hargreaves QUT

Mr. John Powell, QR

Industry Challenges• Extend the life of rail and wheels• Minimise derailments and maximise track

access • Make informed, defensible decisions in an

environment with many interdependencies• Make wheel/rail interaction more understandable

to the general railway practitioner• Promote a risk based approach to engineering

decision making in a commercial environment • Integrate asset management systems

Background of the problem• Increasing

– axle loads – Speed– Tonnage– Longer trains

• Wheel/rail – profile– material– hardness

• Lubrication• Inspection• Grinding Material

HardnessGeometry

Friction

Increase of traffic & freight

Lack of inspection, preventative maintenance

Weather, Environment conditions

Human factors

RCF defects alone cost European Union railways around € 300 million per year and as these defects probably account for 15% of the total, the emerging cost of all defects is about 2 billion Euros per year.

Industry Challenge

Minimising or eliminating derailments is a target for all railways

Head Check (HC) cracking at gauge corner (top view of railhead)

Transverse rail fracture from a Head Check

Rail gauge corner spalling which is the result of rolling contact fatigue that has not been well managed. If not ground regularly the defect becomes impractical to remove with rail grinding.

Consequence: Hatfield, London 4 Killed, 34 Injured, £730 Million Cost: How to Prevent?

How to prevent degradation/failures

Lubrication• Effective inspection• Effective Lubrication• Preventive grinding • Effective maintenance

activities • Eliminating segments

with defects and • Rail replacements

Rail GrinderRail Grinding

10 20 30 Million ton

0.21 grinding

2 grinding

3 grinding

Initial cracks

Accelerating cracks

Optimum wear rate

Rail Grinding Cycles

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Crack depth (mm)

Source: Kalousek, J., Magel, E. “Achieving a balance: The “magic” wear rate”, Railway Track&Structures, March 1997, pp. 50-52, (1997)

Rail Grinding Logistics

Grinding machines are large, costly and may consume available train paths

The timing for grinding is important if it is to be successful at removing defects

Condition Monitoring

Track Recording is an important process for condition monitoring the track geometry and rail profile

Ultrasonic rail flaw detection is an important process for locating defects within the rail

Wear rate [mm2/MGT]

Radii [m]300 600 900 1 200

Bad lubrication, un-lubricated

Good lubrication, lubricated

Increased rail life – saving costs

Investment in lubrication

Lubrication

New Lubricators

QR is investing in electric lubricator technology. Reliability and controllability is superior to older mechanical lubricators. We now need to improve the science of lubricator placement and optimisation.

Integrated approach for Rail and Wheel Maintenance

Reliability, Maintainability, risk assessment and optimisation for safety

Rail trackWheel

Rail and

wheel grinding

Increase of Traffic axle loads & longer trains

Research &

Experience

Lubrication strategies

Integrated Approach

• Curvature• Steel grade• Lubrication

• Wheel profile• Wheel

material• Wheel

hardness• Train/Track

interaction• Modelling• Inspection• Mathematics• Mechanics• R&D Findings

• Rail profile• Rail material• Rail hardness• Axle load• No of

passages

PROJECT OBJECTIVES• Development of a decision support system to

estimate the probability of hazards under operating, curve and environmental condition associated with rail/ wheel defects, rail/wheel breaks and derailments.

• This will be useful for informed strategic decisions in inspection, rail/ wheel grinding, lubrication and rail/ wheel replacements.

PARTICIPANTS Dr. Gopi Chattopadhyay, QUT

Mr. John Powell, QR

Mr. Nick Wheatley, QR

Mr Neil Keynes, QR

Mr Don Skerman, QR

Mr Graham Creese, QR

Dr. P-O Larsson, SRRC

A/Prof. Doug Hargreaves, QUT

A/Prof. Kunle Oloyede, QUT

Dr. Martin Murray, QUT

Prof. Luis Ferreira, QUT

Dr. Colin Cole, CQU

A/Prof. Manicka Dhanasekar, CQU

Prof. Uday Kumar, LTU

QR, Swedish Rail, QUT, CQU, LTU

• QR• SWEDISH RAIL • QUT• CQU• LTU