1. TYRE MAINTENANCE
IN
OPENCAST MINES
CHANDAN CHAMAN

2. What is a tyre?
 From a person on the street
“A round, black rubber thing that holds my vehicle up!”
 From a tyre expert
“a visco-elastic toroid comprised of, high modulus flexible
filaments, embedded in and bonded to, a low modulus matrix,
which forms an anisotropic shell structure”

3. Function of Tyre
• Carry a load
• Guide or Steer the Vehicle
• Transmit engine or brake torque
• Absorb Shock
• Roll
• Last as long as possible

4. Understanding Tyre!
RADIAL TYRE

5. Understanding Tyre!
BIAS PLY TYRE

6. Radial vs Bias Ply
RADIAL
• More technologically advanced solution
• Offers many performance advantages
• More expensive to purchase but has lower cost per
hour than bias
BIAS PLY
• No steel used in casing or Crown
• Cheaper to purchase
• Generally lower life potential
• Higher cost per hour than steel braced Radial

7. What we expect from a tyre?
• Load carrying capacity
• Speed capability
• Grip (during acceleration, braking and steering)
• Handling (steering response)
• Good ride (shock absorption)
• Durability (long life, damage resistance)
• Good appearance
• At a low cost!

8. Common failures
• Punctures
• Cuts
• Cut Separations
• Turn Up Separations
• Tread/Belt Separations
• Heat Separations
• Impact Breaks
• Over Deflection
Repairable
Non-repairable

9. Factors affecting tyre’s life
TYRE MAINTENANCE
• Air pressure maintenance
• Tyre matching
• Rotation policy and scheduled changes
• Alignment
• Mounting procedures
• Repair procedures
• Workmanship and materials

10. Factors affecting tyre’s life
MACHINE MAINTENANCE
Poor mechanical condition of a machine affects the
service life of the tires it uses.
 faulty brakes can cause excessive heating of the
wheels,
 incorrect alignment of the steering wheels
 poorly adjusted suspension, play in the
spindles, the ball joints and the pivots
 Absence of rock ejector

11. Factors affecting tyre’s life
Fixed factors
• Type of equipment
• Weight distribution
• Site speed
• Haul lengths
• Wheel position
• Ambient temperature
Variable factors
• Underfoot conditions
• Operator habits
• Payload position
• Utilisation of support
equipment
SITE CONDITIONS

12. Factors affecting tyre’s life

13. Tyre maintenance : Inflation
Inflation supports and carries the load. Tires are designed
and built to deflect in service.
Inflation pressures are established to assure tires deflect
properly.
The pressures required vary with the load, speed and
type of service.

14. Tyre maintenance : Inflation

15. Tyre maintenance : Inflation
Over inflation can be as serious as under inflation. Over
inflation over stresses the tire carcass.
• Reduces the tire’s ability to envelope irregular objects
in the travel path.
• Causes a loss of traction.
• Makes tires more vulnerable to spin cuts and shock
load damage.
• Reduces flotation in soft ground.
• Produces a hard ride and vehicle vibration.

16. Tyre maintenance : Inflation
An under inflated tire will deflect too much leading to
excessive sidewall flexing. Under inflation typically results
in:
• Irregular or uneven tread wear
• Sidewall radial cracks
• Ply separation
• Loose or broken cords inside the tire
• Fabric carcass fatigue
• Belt edge separation

17. Tyre maintenance : Inflation

18. Tyre maintenance : Tyre Matching
Tire assemblies operated as a dual pair must:
• Have the same outside diameter
• Be from the same brand and type
• Be of the same construction (both bias or both radials)
• Have comparable inflation pressures( Within 1%)
• tires with the same degree of wear i.e. comparable
tread depths (if used tyre are used)

19. Tyre maintenance : Tyre Matching
Some degree of tolerance is however accepted for
difference in diameter of tires (or with differing levels of
wear) mounted on the same vehicle.
For loaders
• 6% between the front and rear axles;
• 3% between the two tires on the same axle.
For rigid dump trucks
• 3% between the left and right tires;
• 1% between two dual tires.
For articulated dump trucks
• 2% between the front and rear axles;
• 1.5% between the two rear axles;
• 1.5% between the tires on the same axle.

20. 3%
6%
LOADER
Tyre maintenance : Tyre Matching

21. 3%
1%
RIGID DUMPER
Tyre maintenance : Tyre Matching

22. 1.5%
1.5%
2 %
Tyre maintenance : Tyre Matching
ARTICULATED DUMPER

23. Tyre maintenance : Tyre Rotation

24. Machine maintenance : Alignment
Alignment refers to the angle formed by the wheels
on the same axle. Toe-in and toe-out lead to
accelerated, uneven wear of the tire on the shoulders.
The outer shoulder in the case of toe-in and the inner
shoulder with toe-out.

25. Tapered wear due to faulty alignment
Machine maintenance : Alignment

26. Machine maintenance : Suspension
Incorrect adjustment of the suspension can lead to
the overloading of certain tires. Although the wear
on the tires may seem visually similar to that of an
alignment fault, there is a clear difference when you
touch them: there are no sharp edges.

27. Machine maintenance : Rock Ejector

28. Site Condition: Underfoot Condition
 Maximum grade not to exceed 7%.
 Road width to allow two trucks to pass without
spillage.
 Regular cleaning of loading, dumping & haul roads.
 Road crown or cross fall as flat as possible and still
drain. Typical road crown is 2- 4%
 Curve radii as large as possible. Haul roads should
be super elevated to correspond to vehicle travel
speeds.
 Avoid waterholes/potholes as they could hide
submerged tire hazards.
 Do not overwater haul roads or work areas. Wet
rubber cuts more easily than dry rubber.

29. Site Condition: Operator Habit
The way machines are driven can significantly reduce
the service life of the tires:
 inappropriate driving: sudden acceleration,
repeated heavy braking, cornering at high speed;
 spinning of the drive wheels (scrapers during
loading, loaders at the quarry face).

30. Site Condition: Payload Position
Correct payload position

31. Site Condition: Overload
Effect of the degree of overloading on the service life of
a tire
Overload (%) Reduction in tyre service life (%)
10 15
20 30
30 50

32. For Longer Tyre Life
 Never turn front steering axle tires when the vehicle
is standing.
 Keep off windrows. These are often present when
haul roads are being graded.
 Do not drive on the berm of the road.
 Do not drive over spillage.
 Do not drive or back over rocks at shovel or dump
areas.
 Avoid tire spin.
 Do not overload haulage trucks.
Do’s & Do Not for Dumper Operator

33. For Longer Tyre Life
 Control spillage and maintain a level working pad at
loading areas.
 Do not overload haulage trucks.
 Properly center load in bed of truck.
 Station a cleanup dozer at each loading area.
 Properly match shovel or wheel loader to trucks
being loaded.
Do’s & Do Not for Shovel Operator

34. For Longer Tyre Life
 Patrol haul roads and clean up spillage.
 Fill depressions and dips in the road.
 Main roads where haulage speeds are highest should
get the most attention.
 Two graders should work roads where haulage
vehicles are wider than a single grader blade.
 Create and maintain road crown to provide proper
drainage.
 Don’t leave high windrows. Tandem patrols help to
reduce grader created windrows.
Do’s & Do Not for Grader Operator

35. For Longer Tyre Life
 Do not overwater haul roads or work areas. This can
lead to unnecessary cuts in tire treads and sidewalls.
 Water acts as a lubricant for rubber.
 Wet rubber cuts more easily than dry rubber.
 Some watering benefits grading operations.
 Excessive watering of hard packed, smooth surfaces
is a safety hazard. Vehicle control/safety is reduced
on a slick, wet road surface.
Do’s & Do Not for Water tanker Operator

36. For Longer Tyre Life
 Do not overwater haul roads or work areas. This can
lead to unnecessary cuts in tire treads and sidewalls.
 Water acts as a lubricant for rubber.
 Wet rubber cuts more easily than dry rubber.
 Some watering benefits grading operations.
 Excessive watering of hard packed, smooth surfaces
is a safety hazard. Vehicle control/safety is reduced
on a slick, wet road surface.
Do’s & Do Not for Water tanker Operator

38. Storage of tyre
Tires and tubes deteriorate rapidly if improperly stored.
• Improper storage conditions include:
• Direct sunlight.
• Heat.
• Air in motion.
• Ozone.
• Gasoline and oil.
• Dust or moisture inside tires.

39. Storage of tyre
New Tyres
• Store vertically indoors in a cool, dark, dry, draft free
area. If tires must be stored outdoors, they should be
covered with opaque, waterproof tarpaulin.
• Store away from electrical devices such as motors
and switches. These are a source of ozone.
• Do not store in rooms with or near gasoline or
lubricants
• Provide CO2 fire extinguishers in tire storage areas.

40. Storage of tyre
Mounted Tyres
• If tires are stored on a machine, it should be blocked
up. Air should be released to 10 psi (.7 bar) or less.
• Protect each tire with an opaque, waterproof cover.
• Machines resting on tires should be moved once a
month. This prevents deflection strain on only one
part of the tire.
• Do not use paint to preserve tires.

41. THANK YOU
chandanchaman@gmail.com