Managing track through wheel

maintenance

Dr Martin Murray

20 May 2014

Brisbane

Who am I? • Director of KCPM Consulting (track consulting business)

• BE (Civil) 1973, PhD (Melb) 1978

• 25 years of R&D projects and consulting work for railway

industry

• Published >60 international papers on rail track

• Created railway infrastructure MEng @ QUT

• University academic for 35 years

• Grandfather, pastor, grey & bald, & >50!

• Presentation drawn from CORE2012 conference paper..

What’s the problem?

But aren’t track forces well understood?

Accepted wisdom for safe operation of trains & track and to

ensure long life in train & track components:

• Maximum impact force for wagons: ~230kN

• Maximum impact force for locos: ~300kN

• Where these forces are exceeded due to wheel-tread defects,

the wheels should be removed and machined..

A rich source of data from real trains & track

Typical maximum

permitted impact

force Weibull

distribution

What are the real forces? - 1

What are the real forces? - 2

What’s a Weibull distribution?

I = magnitude of impact force (kN)

f = frequency of occurrence of force

(the rest are constants defining the shape of the curve)…

Typical maximum

permitted impact

force

What are the real forces? - 3

1.5% of all axles

> 1 million axles /annum each site

=1 axle/year

What are the real forces? - 4 Four WID sites

Three Aust. states

Three track owners

Coal & ore trains

All >100MGT/a

60-68kg/m rail

Heavy conc sleepers

≥ 250mm ballast

25-35TAL

70-80km/h

Many Gb of data

2005 to 2011

What are the real forces? - 5

What are the real forces? - 5

What are the real forces? - 5

What are the real forces? - 5

What are the real forces? - 6

A1

A2 B

What are the real forces? - 7

What are the real forces? - 7

What’s going on here? • Large impact forces at WID sites are from

defected wheels, eg wheel flats

• So, smaller impact forces must mean less

severe wheel defects in the fleet (esp for large

axle loads)

• Less severe fleet defects are related to

operator issues:

• Harder steel chosen for wheel treads, and/or

• “Gentler” driver behaviour through training &

supervision, & better braking systems, and/or

• Better policy & practice with defect detection,

removal, rectification…

www.sodahead.com

www.trainboard.com

And the consequences are? The policies and practices of the operator

can dramatically affect maximum track

forces, which means for the track owner:

• better operator policies & practices can

mean cheaper track;

• with this sort of WID data analysis, the track

owner can:

• reward a diligent operator and/or penalise

lower quality operator;

• make informed decisions about future

growth in traffic volumes, speeds and axle

loadings…

www.kenyan-post.com

Managing the track asset through

wheel maintenance

Dr Martin Murray

20 May 2014

Brisbane

Thank you