Timber Hauliers Conference

Scotland 03 / 2010 Neil Wylie Innovative Transport Equipment Ltd Tyre Development

• 1846 – invented and patented the pneumatic • 1888 – First commercial pneumatic tire produced by • 1889 – patented the pneumatic tire in the UK • 1890 – Dunlop, and William Harvey Du Cros began production of pneumatic in Ireland • 1890 – Bartlett Clincher introduced • 1891 – Dunlop's patent invalidated in favor of Thomson’s patent • 1892 – Beaded edge tires introduced in the U.S. • 1894 – E.J. Pennington invents the first balloon tire • 1895 – introduced pneumatic automobile tires • 1898 – patented • 1900 – Cord Tires introduced by Palmer (England) and BFGoodrich (U.S.) • 1903 – Goodyear Tire Company patented the first , however it was not introduced until 1954 • 1904 – Goodyear and Firestone started producing cord reinforced tires • 1904 – Mountable rims were introduced that allowed drivers to fix their own flats • 1908 – Frank Seiberling invented grooved tires with improved road traction • 1910 – BFGoodrich Company invented longer life tires by adding carbon black to the rubber • 1919 – Goodyear and Dunlop announced pneumatic truck tires[2] • 1938 – Goodyear introduced the rayon cord tire • 1940 – BFGoodrich introduced the first commercial synthetic rubber tire • 1946 – Michelin introduced the • 1947 – Goodyear introduced first nylon tires • 1947 – BFGoodrich introduced the tubeless tire • 1963 – Use of polyester cord introduced by Goodyear • 1965 – BFGoodrich offered the first radial available in North America • 1967 – Poly/glass tires introduced by Firestone and Goodyear • 1968 – United States Department of Transportation (DOT) numbers required on new tires in USA • 1974 – introduced the wide radial tire • 2005? - Michelin introduces the Typical resource road hauling 100 90 UNCONTROLLED TIRES

60

30 CONTROLLED TIRES 0 PRIMARY SECONDARY SECONDARY PRIMARY UNLOADED UNLOADED LOADED LOADED

TIRE PRESSURE (psi) PRESSURE TIRE 100 kph (60 mph) 80 kph (50 mph) 80 kph (50 mph) 100 kph (60 mph)

LOAD & SPEED STATUS

• Uncontrolled tires are over-inflated for 75% of the cycle Manufacturers Deflection Recommendations

• High Speed Operations 10 – 14% Deflection

• Low Speed Operation 17 – 21% Deflection Reducing tire pressure causes fundamental changes to tire-road interaction

Less Stiffness and impact Spring Rate energy

Contact Contact Lighter Area stress footprint, distribution more tread Tire inflation changes footprint size, shape, and contact pressure Tyre Pressure and Effect on Pressure Area of Subgrade Effect Tyre Pressure Has on EDA’s

Effect Tyre Pressure Has On EDA's

2.5

2

Single Tyred @ 6 tonnes 1.5

Single Axle Twin Tyred @ 8 Tonnes EDA

1 Tandem Twin Tyred @ 15.5 Tonnes

0.5

0 50 60 70 80 90 100

Pressure (PSI) Truck benefits of reduced tire pressure • Enhanced traction and gradeability • Improved flotation (fewer delays and assists) • Improved fuel efficiency (less and reduced ) • Reduced shock and vibration (improved ride and less component damage) • Improved tire life and recap-ability (better puncture and cut resistance) • Longer vehicle life Vertical stress distribution in a low standard road

Vertical stress, psi 0 10 20 30 40 50 60 70 80 90 100 110 120 0 AC

BASE -250

-500 Largest stressSUBGRADE reductions occur

-750 in surfacing and base layers

100 psi inflation Depth, mm Depth, -1000 65 psi inflation 35 psi inflation SUBGRADE -1250 2045 kg tire load

-1500 Road benefits of reduced tire pressure • Less road damage Slower rutting, less washboard, less aggregate breakdown, less erosion, healing, less fatigue cracking in A.C. surfaces • Reduced structural requirements Thinner base layer needed • Less environmental impact less dust, less sediment, less metal • Longer haul season 0.4

100 psi 0.3

0.2 Cumulative 60 psi damage at the Mid-winter thaws end of one 0.1 winter/spring Spring thaw 0 season as a function of tire 1.2 pressure

0.8 (from 1993 study for 0.4 USFS by Kestler and

Berg) 0.4 100 psi

60 0 Modeling when to resume hauling on seasonally load restricted roads

Road friendly trucks start when their road consumption rate equals the baseline condition

1.5 mm 1.25 mm 3-4 wk

frozen SLR summer Surface Rebound Surface Time Road consumption rate from least friendly legal truck at end-of-SLR period is the baseline condition

Typical New Zealand Log Truck 44 Tonnne GCM 22m Long