Excavating Machines ~ these are one of the major items of
builders plant and are used primarily to excavate and load most
types of soil. Excavating machines come in a wide variety of
designs and sizes but all of them can be placed within one of three
categories:-
- Universal Excavators † this category covers most forms of
excavators all of which have a common factor the power
unit. The universal power unit is a tracked based machine
with a slewing capacity of 360° and by altering the boom
arrangement and bucket type different excavating functions
can be obtained. These machines are selected for high output
requirements and are rope controlled. - Purpose Designed Excavators † these are machines which
have been designed specifically to carry out one mode of
excavation and they usually have smaller bucket capacities
than universal excavators; they are hydraulically controlled
with a shorter cycle time. - Multi-purpose Excavators † these machines can perform
several excavating functions having both front and rear
attachments. They are designed to carry out small excavation
operations of low output quickly and efficiently. Multi-purpose
excavators can be obtained with a wheeled or tracked base
and are ideally suited for a small building firm with low
excavation plant utilisation requirements.
Skimmers ~ these excavators are rigged using a universal power
unit for surface stripping and shallow excavation work up to
300 mm deep where a high degree of accuracy is required. They
usually require attendant haulage vehicles to remove the spoil and
need to be transported between sites on a low-loader. Because of
their limitations and the alternative machines available they are
seldom used today.
Excavators