A bucket chain excavator (BCE) is a piece of

heavy equipment Heavy equipment or heavy machinery refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large construction tasks. ''Heavy equipment'' usually comprises five e ...

used in

surface mining Surface mining, including strip mining, open-pit mining and mountaintop removal mining, is a broad category of mining in which soil and rock overlying the mineral deposit (the overburden) are removed, in contrast to underground mining, in which ...

and

dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing da ...

. BCEs use buckets on a revolving chain to remove large quantities of material. They are similar to

bucket-wheel excavator A bucket-wheel excavator (BWE) is a large heavy equipment machine used in surface mining. The primary function of BWEs is ...

s and trenchers. Bucket chain excavators remove material from below their plane of movement, which is useful if the pit floor is unstable or underwater.Tenova TAKRAF. (2007). Tenova Takraf Mining Equipment. Retrieved from http://www.takraf.com/en/products/miningequipment/main.htm .

History

The first documented use of a bucket chain excavator was in 1859 by Alphonse Couvreux, a French entrepreneur. Several Couvreux BCEs were used in the construction of the

Suez Canal The Suez Canal ( arz, قَنَاةُ ٱلسُّوَيْسِ, ') is an artificial sea-level waterway in Egypt, connecting the Mediterranean Sea to the Red Sea through the Isthmus of Suez and dividing Africa and Asia. The long canal is a popular ...

Overview

A bucket chain excavator works similarly to a bucket wheel excavator, using a series of buckets to dig into the material before dumping it in the bucket chute and depositing it through a discharge boom. The primary difference is that the buckets are mounted on a flexible chain similarly to a

chainsaw A chainsaw (or chain saw) is a portable gasoline-, electric-, or battery-powered saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. It is used in activities such as tree felling, limbing, bucking, pruning, ...

blade rather than on a rigid wheel. BCEs are used primarily to excavate material below the vehicle's superstructure while bucket wheel excavators focus primarily on excavating top soil overburden and/or resources. BCEs vary in range and size, although the majority of them are extremely large, with some capable of excavating 14,500 m³/h. The average BCE from

Tenova Takraf TAKRAF Group (“TAKRAF”), is a global German industrial company. Through its brands, TAKRAF and DELKOR, the Group provides equipment, systems and services to the mining and associated industries. Foundation and History While the official foun ...

for example, weighs around 1,150 tons and has a combined length of 58.5 meters, with a 23.5 meter long bucket ladder. The speed of the bucket chain is 1.22 m/s with a digging force of 1,170 kN/m². BCEs such as the RK 5000 from the

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

weigh up to 5,000 tons. Nevertheless, bucket chain excavators are usually smaller than bucket wheel excavators,

dragline excavator A dragline excavator is a piece of heavy equipment used in civil engineering and surface mining. 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. Mo ...

s or conveyor bridges due to the limitations of excavating materials below the base of the vehicle.

Structure

The

superstructure A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstruct ...

of a bucket chain excavator is similar to that of a bucket wheel excavator. The primary component of bucket chain excavators is the bucket ladder and the bucket-chain. Unlike the buckets on a BWE, the buckets on the chain face downwards, allowing the machine to remove overburden or materials significantly below the bench or travel level. The megaton excavator materials are deposited through the bucket chute. Material can be transferred to a bench conveyor directly or via a discharge boom or mobile conveyor bridge. Like the BWEs, bucket chain excavators also feature a fixed or rotating superstructure with a counterweight boom that allows the cutting boom a certain degree of verticality. Likewise have a substructure equipped with either a rail or crawler-mounted undercarriage for mobility and transportation. Some BCEs have 'hopping' pontoons similar to those found on walking dragline excavators.

Gallery

File:Eimerkettenbagger.JPG, Two BCEs supporting a conveyor bridge. File:Excavator RK 5000 Lom ČSA Czech Republic 2016 2.jpg, RK 5000 BCE with walking mechanism. File:Eimerketten bei der Arbeit.JPG, Open pit mining in Cottbus-Nord File:Eimerkettenbagger_Heimdall_03.jpg, Bucket dredger ''Heimdall'' File:Dredging_technique_schematic.png, Bucket dredging

References

{{DEFAULTSORT:Bucket-Chain Excavator Articles containing video clips Engineering vehicles Excavators Dredgers Mining equipment