Editing Dragline excavator (section)

==Types==
Draglines fall into two broad categories: those that are based on standard, lifting cranes, and the heavy units which have to be built on-site. Most crawler cranes, with an added winch drum on the front, can act as a dragline. These units (like other cranes) are designed to be temporarily dismantled and transported over the road on flatbed trailers. Draglines used in most [[civil engineering]] are of this smaller, crane type. These are used for [[road construction]], port construction, pond and canal dredging, and as [[deep foundation|pile]] driving rigs. These types are built by crane manufacturers such as [[Link-Belt Construction Equipment|Link-Belt]] and [[Hyster Company|Hyster]].

The much larger type which is erected on site is commonly used in [[strip-mining]] operations to remove [[overburden]] above [[coal]] and more recently for [[oil sands]] mining. The [[Big Muskie|largest heavy draglines]] are among the largest mobile land machines ever built, weighing up to 13,500 tons, while the smallest and most common of the site-erected type weigh around 8,000 tons.

A dragline bucket system consists of a large bucket which is suspended from a large [[truss]]-like [[crane (machine)|boom]] (or mast) with [[wire rope]]s. The bucket is maneuvered by means of a number of ropes and chains. The hoist rope, powered by large [[Diesel engine|diesel]] or [[electric motor]]s, supports the bucket and hoist-coupler assembly from the boom. The dragrope is used to draw the bucket assembly horizontally. By skillful maneuver of the hoist and the dragropes the bucket is controlled for various operations. A schematic of a large dragline bucket system is shown below.