Heavyweight Bulldozer Models Feature Refined Design, High Fuel Efficiency

Caterpillar has upgraded its popular D11 bulldozer models, first introduced in 1986. The new D11T and D11T CD versions offer design refinements that include Enhanced Auto Shift, Dynamic Inclination Monitor, automatic climate control and available automated ripper control. The D11T and D11T CD's 850-net-hp (634-kW) C32 engine, according to Cat, allows the machines to work fuel-efficiently anywhere in the world, with blades ranging in capacity up to 57 yd3 (43.6 m3) and operating weights up to 248,456 lb (112 698 kg). The engine is configured to meet U.S. EPA Tier 4 Final emissions standards for those geographical areas requiring a high degree of emissions control; for less-regulated areas, it will be configured to meet U.S. EPA Tier 2 equivalent emissions standards.

The Tier 4 Final configuration employs Cat's NOX Reduction System, which captures and cools a small volume of exhaust gas, then returns it to the combustion chambers to lower temperatures and retard formation of nitrogen oxides. In addition, a Diesel Oxidation Catalyst conditions exhaust gases to meet emission standards. A new cooling package uses a two-part radiator with aluminum bar-plate cores that contribute to durability, efficient heat transfer and corrosion resistance. The new oil-to-air hydraulic-oil cooler uses similar construction, and a hydraulic variable-demand fan uses less power, reduces fuel consumption and lowers sound levels.

New for the D11T and D11T CD is the Enhanced Auto Shift (EAS) system, designed to conserve fuel by automatically selecting the optimal reverse gear and engine speed, based on load and desired ground speed. When EAS is not activated, an Auto Downshift feature automatically changes gears to most efficiently handle loads. Inside the cab, a Dynamic Inclination Monitor provides a readout of tractor pitch angle and side-to-side slope angle, and Automated Blade Assist Control uses preset blade-pitch positions to simplify positioning. An optional Autocarry system automatically controls the blade during the carry segment. A new operator-presence system locks out the power train and hydraulic system to avoid unintentional machine movement when the operator is entering or leaving the cab, which can be done via an optional hydraulically actuated access ladder that deploys and stores in seconds.

The D11T and D11T CD feature an "OK-to-Start" system that electronically checks critical fluid levels. Routine maintenance is facilitated by easily accessible filters, an optional automatic lubrication system, high-speed oil change for engine and power train systems, and ecology drains for capturing fluids for proper disposal or recycling. A fast-fill fueling system incorporates a positive shutoff to prevent spills.


As featured in Womp 2011 Vol 08 - www.womp-int.com