Scotland 03 / 2010 Neil Wylie Innovative Transport Equipment Ltd Tyre Development
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Timber Hauliers Conference Scotland 03 / 2010 Neil Wylie Innovative Transport Equipment Ltd Tyre Development • 1846 – Robert William Thomson invented and patented the pneumatic tire • 1888 – First commercial pneumatic bicycle tire produced by Dunlop • 1889 – John Boyd Dunlop patented the pneumatic tire in the UK • 1890 – Dunlop, and William Harvey Du Cros began production of pneumatic tires in Ireland • 1890 – Bartlett Clincher rim 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 – Michelin introduced pneumatic automobile tires • 1898 – Schrader valve stem patented • 1900 – Cord Tires introduced by Palmer (England) and BFGoodrich (U.S.) • 1903 – Goodyear Tire Company patented the first tubeless tire, 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 radial tire • 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 – Pirelli introduced the wide radial tire • 2005? - Michelin introduces the Tweel 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 Axle @ 6 tonnes 1.5 Single Axle Twin Tyred @ 8 Tonnes EDA 1 Tandem Twin Tyred Axles @ 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 wheel slip and reduced rolling resistance) • 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, Depth, mm -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 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.