graeme templer - atrs - a look at special cases of turnouts
DESCRIPTION
Graeme Templer delivered the presentation at 2014 RISSB National Rail Turnouts Workshop. The RISSB National Rail Turnouts Workshop gives all those involved an in-depth forum for discussion and the sharing of expertise. A key element of this workshop is participation and knowledge sharing from audience as well as the workshop leaders. It is a chance for you to bring your experience and to take away new approaches for best practice. For more information about the event, please visit: http://www.informa.com.au/railturnoutsworkshop14TRANSCRIPT
A look at special cases of turnouts
Graeme Templer
Senior Associate,
Australasian Transport Risk Solutions (ATRS)
May 2013
Newcastle
• Grinding turnouts, when is it necessary?
• Effect of wheel profile
• Effect of hollow wheels
• Rail head shape when not ground
• Impacts and discontinuities
• Contact band and ARTC grinding standard
• Axle load distribution, histogram
• Fatigue failure of rail
• Effect of lubrication in turnouts
• Rail Seat Tolerances, re inventing the wheel
Questioning the Absolute Truths
Grinding turnouts when is it necessary
• Impacts
• Frederick’s 1968/74 at a bad fishplated joint, 10 x axle load at
rail surface
• Australian National Railways 1984/89 3x axle load at dipped
peaked or stepped weld
• Core 2002 5x axle loads in turnouts
• CRC AT9 2010 confirmed the above impacts in turnouts
IMPACTS
• The following contact stresses calculated from a computer
model
• Both wheel and rail profile
• Model Moves wheel from side to side to obtain maximum
contact stress
• Maximum allowable for Pt Kembla rail is 1035 Mpa otherwise
corrugations will develop
• 985 Mpa to less than 1035 mpa corrugations may develop
• Below 985 Mpa corrugations will not develop
• (BHP Melbourne research laboratories early 1980’s)
Rail stresses static condition no dynamics
New ANZR1 wheel on
R3 rail profile
Contact stress is
1231 MPa
(NCOP profile)
Average
worn ANZR
on R3 profile
contact
stress is
1154 MPa
Slightly worn
WPR2000 on R3
profile
Contact stress
2000 MPa
Average worn
WPR2000 on R3
profile
Contact stress
1328 MPa
Add Impact factor five times axle load
Contact stresses
• New ANZR1 on R3 contact stress is 6255 MPa
• Average worn ANZR1 on R3 contact stress is 5770 MPa
• Slightly worn WPR2000 on R3 profile is 10,000 MPa
• Average worn WPR2000 on R3 profile is 6640 MPa
• Contact stress for LWC to develop in 47kg,53kg rail ex Pt
Kembla is 1035 MPa
Current grinding profile for turnouts
50
40
30
20
10
0 -40 -30 -20 -10 0 10 20 30 40
45
Gauge Corner
C/L
~ 30-40 mm
Gauge Corner
Region
Field Side
Region Running Surface Region
Joints in T/O’s have not been straightened
• Narrow contact band, stresses well above 1035 Mpa
• A good strategy to trash the 47kg and 53 kg turnouts is to
grind a narrow profile on the rail where weld geometry in
turnouts has not been rectified.
• Do not grind without rectifying weld geometry
Why does the 47 kg Pt Kembla rail corrugate into 0.5
to 2m wavelength long wave corrugations? • Rail is a poorly designed section for bending
• Pt Kembla Rail has a low 0.2% FATIGUE failure yield stress
231 MPa
• Fracture mechanics by (BHP) MRL determined that at a
contact stress above 1035 MPa corrugations will develop
• Speeds and axle loads increased beyond 19 t at 90 KPH
• Currently 23 t at 80kph, 21 t at 115kph, locos 23t at 115kph
• It is the unsprung mass of the locos that cause the damage
• Rail fails in full section bending some plastic flow of the rail
surface
Curve 51kms North of Adelaide 19 November, 2009
CAT Trolley
1m to 1.5m corrugations in rail
Derrinallum, Western Line Victoria, 47 kg on Concrete, instantaneous values
greater than 0.3mm
Rail GTKs have an influence on residual life of 47kg
53kg rail• Western Victoria 300 MGT
• Vic Border to Adelaide 500 MGT
• Some sections of TAR 500 MGT
• Some sections of the TAR 200 MGT
• Coonamia to Broken Hill 150 MGT
• Melbourne to Albury 300 MGT
• Tottenham to Newport 500 MGT
• Victorian NE West track 50 MGT
• Southern NSW 53 kg rail 200 to 300 MGT
• Northern NSW 200 MGT maximum
Why grind the East West Nth Sth rail?
• To prevent corrugations forming
• Weld geometry in T/O’s has never been rectified
• Axle loads are such that normal surface defects shelling,
flaking spalling RCF does not develop.
• Grinding does not improve dipped weld geometry
• Grinding a narrow contact band increases contact stresses
with impact which ensures the corrugations will develop
faster
• Why grind?
The P1 gauge
MP12 grinders incapable of producing 0mm peak over 1m
Intermodal axle loads
From wayside Approximately 12 %
of axles are above
19 t those that do the damage to
the rail
Final Grinding: A reciprocating grinder. GOOD FINISH, REGULAR LATERAL PROFILE AND NO DIPS
Another type linear grinder
Good lateral profile as a bi-product
Weld shape effect• Effect of shape of weld
profile
• Next lot of slides
Dipped weld profile not improved by grinding
Weld pulls down with incorrect grinding technique
TR Weld 0010G018
217.5 km - Mar 2001
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
-500 -400 -300 -200 -100 0 100 200 300 400 500
Distance from Weld C/L (mm)
He
igh
t (m
m)
Coota to Parkes Weld profile after straightening
Coota to Parkes after straightening
Fatigue curves Stress versus cycles
Bending Stress Pt Kembla rail
Summary• If average axle loads are below 20 t. Ask the question why
are we grinding the turnouts
• If you decide to grind because it is nice to have then rectify
the welds first
• Grind off welds with a reciprocating linear grinder
• Throw out the P1 gauges
• Note turnout grinders do not grind pout long wave
corrugations in turnouts
• Long wave corrugations 0.5m to 2.0m primarily 0.7m
Wheel profile the WPR2000 wheel• Effect of introduction of the WPR2000 wheels to the
Interstate Network
The WPR2000, I in 10 conicity with a worn profile in the corner
The high conicity is designed to pull the high outer
wheel from the high rail and reduce wear of
both wheel and rail
The thickening of 7mm total in the gauge corner
gives the wheel more metal to wear
The 1 in 10 conicity allows this profile to go around
tighter curves than the ANZR1 profile without
wheel creep
Stability for wheels that end up with a lot of running on tangent tracks
Conicity of the WPR2000 Profile
0 20 40 60 80 100 120 140
-30
-20
-10
0
10
20
30
40
50
60
70
WPR2000 wheel profile
Millimetres
Mill
imetr
es o
r conic
ity 1
:n
WPR2000 shape
Conicity, 1:n
WRP2000 on un canted rail as per all of ARTC unground T/Os
except new Vossloh T/O
Contact Band through Points and unground crossings
Note at bottom and top through VEE
At sides on running rail WRP2000 on Gauge
Vee crossing up end Leeor Loop
Ararat mixed gauge diamond K crossing
Westmere Down End Vee crossing
Tattyoon up end vee crossing
Lubeck up end Vee crossing
Murtoa up end vee crossing
Murtoa down end vee crossing
Jung siding
Pimpinio vee crossing down end
Gerang Gerung down end vee crossing
New vee crossing at Stawell in service for two weeks
New vee crossing at Stawell
New vee crossings at Stawell
Vee crossings at Stawell
T/O at Musswellbrook
Note how wheels with high conicity cause abnormal wear
Recent order for turnouts had the same problem
• For a third time a new supplier delivered turnouts
not designed for the WPR2000 wheel still used in
the Hunter Valley
• Change of people and drawings not altered
• Wheel profiles must be given to supplier
Solution
Hollow wheels
• When the WPR2000
profile was introduced
no wheel condemning
gauge was introduced
to measure hollowing
• Wheel became more
hollowed that prior to
the WPR2000
introduction
• Effect of hollow wheelsEffect of wheel defects
Plastic failure in the gauge
corner creating untestable rail
Corrugations, Shelling,
Flaking, Squats, RCF
Hollow wheels Solution is to grind a
champher in the gauge corner
What is actually happening
• Grinding off the corner
creates high contact
stresses at the interface
pf corner grinding
• this leads to
accelerated RCF
• This generates more
grinding to remove the
RCF
• Solution new wheel
gauge developed and
hollowing defined fro
the WPR2000 wheel
Warp of the rail seats relative to each other
• This is a condition not understood in ARTC until relatively
recently
• However was a common problem in the heavy haul and
South Africa
• For twenty years there had been a truth it was caused by
peak and dipped welds
Mould numbers still visible
• Mould numbers are still
visible
• Sleepers that skew have
same mould numbers
Possible mechanism that causes skewing Rail seat Casting tolerances
Skew Sleepers TAR
Skew Sleepers TAR
Special pad to
prevent skewing
Mechanism of sleeper skewing• Identified in overseas railway in Pilbera in Australia
• Cause is warping of rail seats in longitudinal direction
• Moulds tolerance should be 1 in 400 on rail seat but some
moulds are 1 in 100
• Demonstrate with eraser
The longer rail span
• The longer span over skewed sleepers increases the rail
stress even further
• Fatigue life of rail is shorter than we think
Bending stress with skewed sleepers
• The bending stress with skewed sleepers is 60 % higher than
with regular spaced sleepers will have a significant impact
on rail fatigue life
Lesson for turnouts
• Rail seat tolerances must be 1 in 400 for rail seats in the
turnouts
• If this cannot be achieved then special anti skew pads
should be provided for turnouts
Heavy haul• Some examples in the Hunter Valley
• Kinematic Gauge Optimisation
• It’s a development from one of the suppliers, twice as expensive as
a normal turnout but they last at least 3 times as long
• They are shaped with a curve in turnout
Points 203• Hunter has installed 2 x KGO switches, 203a points has lasted 4
years, previous switch life was 12months.
• Also on at 142Pts installed Nov 2009, still OK, previous life 6
months
• The tangential switch assembly is an AS60Kg / AS68Kg ZU1-60 arrangement that has been
• manufactured to improve performance by incorporating Kinematic Gauge Optimisation or KGO
• In simple terms the switch and stock rail have been designed to assist the wheel in traversing the
• entry into the switch by controlling the wheel more effectively in both the straight and curving
• movements. The KGO design achieves this by bending the stockrails outwards by up to 15mm to
• achieve a varying rolling radius difference on the wheel. This widening of the stockrail at the entry
• of the switch also has the added advantage of increasing the thickness of the blade through the first
• 10 metres of the blade
Lubrication of Turnouts
Lubrication of turnouts
Lubricators not working
Lubricators not working
Flushing
QuestionsMoney