Friday, October 8, 2010

Grade, Rolling Resistance and Haul Speed Optimization


HAUL ROAD GRADE


Is there any grade effect/impact for heavy equipment ???

GRADE IMPACT
Performance & Durability
- Large decrease in drive system components
o Accelerated mechanical component wear
o Exceed thermal capacity ratings
- Changes in engine life
- Changes in productivity
- Changes in Tire Life

GRADE IMPACT
Productivity & Fuel Consumption


FUEL CONSUMPTION OF 90TONNER TRUCK
= 80.61 L TR / HR . CYCLE TIME = 13.34 MINUTES


FUEL CONSUMPTION OF 90 TONNER TRUCK
= 74.55 LTR / HR.CYCLE TIME = 12.5 MINUTES


GRADE IMPACT
Tire Life (1)


Source : Maintenance Off The Road Tires (Bridgestone)

Grade Impact
Tire Life (2)
MAXIMUM EXCESS LOAD


Source : Maintenance Off The Road Tires (Bridgestone)

GRADE IMPACT
Tire Life (3)


Source : Maintenance Off The Road Tires (Bridgestone)

GRADE IMPACT
Tire Life (4)


Source : Maintenance Off The Road Tires (Bridgestone)

GRADE IMPACT
Tire Life (5)


Load Incr. = (1- cos alpha) + 2H sin alpha / L
alpha = 5 -> Load = +12%

EXCESSIVE LOAD IMPACT
Damage Tire


Ply Separation 


Heat Separation


Abnormal Wear


Cut and Shock Impact


Bead Damage

GRADE IMPACT
Estimate Component, Fuel Efficiency



HAUL ROAD GRADE



ROLLING RESISTANCE




ROLLING RESISTANCE IMPACT
Productivity & Fuel Consumption


FUEL CONSUMPTION OF 90 TONNER TRUCK
= 74.55 LTR / HR.CYCLE TIME = 12.5 MINUTES


FUEL CONSUMPTION OF 90 TONNER
TRUCK = 69.72 LTR/ HR.CYCLE TIME = 12.18 MINUTES




ROLLING RESISTANCE IMPACT
Machine Performance


Rolling Resistance can have the similiar impact as Grade Resistance.

GRADE & ROLLING IMPACT
Time Motion Study



GRADE & ROLLING IMPACT
Time Motion Study


HAUL ROAD DESIGN
Others Parameter (1)


• Curve Radius
• Superelevation
• Road signs for speed and gear selection.

HAUL ROAD DESIGN
Super Elevation (2)
– Maximize Speeds
– Minimize Tire Wear
– Minimize Spillage



HAUL ROAD DESIGN
Turning Radius (3)


e + f =V ² / (15 R )

e = superelevation rate, feet per foot
f = side friction factor
V = mph ( vehicle speed )
R = curve radius , feet

Detailed data collected from site is the primary source of information for corrective action, and forms a major information source to take future decisions