The Bagger 288 (Excavator 288), built by the German company Krupp for the energy and mining firm Rheinbraun, is a bucket-wheel excavator or mobile strip mining machine. When its construction was completed in 1978, Bagger 288 superseded NASA’s Crawler-Transporter, used to carry the Space Shuttle and Apollo Saturn V launch vehicle, as the largest land vehicle in the world at 13,500 tons.
The Bagger 288 was built for the job of removing overburden prior to coal mining in Tagebau Hambach (stripmine Hambach), Germany. It can excavate 240,000 tons of coal or 240,000 cubic metres of overburden daily – the equivalent of a football field (soccer) dug to 30 m (98 ft) deep. The coal produced in one day fills 2400 coal wagons. The excavator is up to 220 m (721 ft) long (over 2 football fields!) and approximately 96 m (315 ft) high (over 31 stories high!). The Bagger’s operation requires 16.56 megawatts of externally supplied electricity.
It can travel 2 to 10 m (6.6 to 33 ft) per minute (0.1 to 0.6 km/h). The chassis of the main section is 46 m (151 ft) wide and sits on 3 rows of 4 caterpillar track assemblies, each 3.8 m (12 ft) wide. The large surface area of the tracks means the ground pressure of the Bagger 288 is very small (17.1 N/cm2 or 24.8 psi); this allows the excavator to travel over gravel, earth and even grass without leaving a significant track. It has a minimum turning radius of approximately 100 meters, and can climb a maximum gradient of 1:18.
The excavating head itself is 21.6 m in diameter and has 18 buckets each holding 6.6 cubic meters (7.9 yd³) of overburden.