Bucket-wheel excavators (BWEs) are huge machines used for surface mining.
They are continuous digging machines in large-scale open cast mining operations. What sets BWEs apart from other large-scale mining equipment is their large wheel with a continuous pattern of buckets to scoop material as the wheel turns.
They are among the largest vehicles ever constructed. The biggest bucket-wheel excavator ever built, Bagger 293, is the largest terrestrial (land) vehicle in human history according to the Guinness Book of World Records.
BWEs built since the 1990s, such as the Bagger 293, have reached sizes as large as 96 metres (314.9 feet) tall, 225 metres (738.2 feet) long, and as heavy as 14,200 metric tons (31.3 million lb). The bucket-wheel itself can be over 70 feet in diameter with as many as 20 buckets, each of which can hold over 15 cubic metres of material. BWEs are now capable of operating in extreme climates. Many BWEs have been designed to operate in climates with temperatures as low as -45°C (-49°F).