The backacter, also known as the backhoe, has an arm at the end of which is a bucket which faces down and towards the machine.

Backacters may be operated by rope or hydraulically.

Hydraulically operated backacter Rope-operated backacter

Arm

BACKACTERS

Excavation is carried out by

•forcing the bucket into the soil and pulling it towards the machine. •The bucket is then raised in a tucked position by the arm. •The arm is rotated until the raised bucket is over the attending haul truck. •The bucket is then released from its tucked position, so as to empty the spoils through the open front end

*Because of the deep excavations on site, a long reach arm may be required depending upon the excavation techniques used.

Used for excavating below the level of the tracks.

Used for excavating below the level of the tracks.

Excavation force applied to the bucket is dependent upon the combined weight of the bucket and the arm.

Excavation force is directly related to the available hydraulic power.

Can excavate to a depth of about 15m; but the shape of the excavation is fixed for a particular machine.

Can excavate up to a depth of 8 m; and the shape of the excavation may be varied to suit the situation.

Bucket capacity in the range of 0.3 to 3.0 m3 and the output 30 to 60 bucket loads per hour, depending on the confinement of the area.

Bucket capacity in the range of 0.1 to 1.8 m3 and the output about 30 to 50 bucket loads per hour.

Hydraulically operated backacter Rope-operated backacter

List of advantages: •There is a free choice of dimensions. There are no size and weight restrictions deriving from the mining industry any longer.

•The big Backacter 1100 is executed with 2 large diesels, and can run half the speed when one doesnot work; in case one has to operate 1 engine instead of 2, the excavator cycle only takes about 9 seconds more, as only during the lifting moment of the attachement, full power is required.  

MAIN CHARACTERISTICS Length o.a.: 64.85 mBreadth: 18.0 mDraught: 3.36 mDredging depth: 18.0 / 26.0 / 32 mExcavator type: Backacter 1100Bucket capacity: 15 / 25 / 40 m³Total installed diesel power:

3,700 kW

Installed power excavator:3,460 kWPropulsion power: 2 x 500 kWBuilt in: 2007

•Cold temperature starting. A classic excavator needs special measures to protect the engine against extreme cold temperatures. By simply heating the engine compartment of the Backacter these problems are solved.

• The machine comprises of a rigid frame, a loader bucket and arm/backhoe.

• A straight boom

• A big diameter slewing ring to cope with highest loads (we can make a choice for this as our Yard is located at sea and not inland).

• Due to this size of the slewing ring, high capacity boom cylinders can be installed. Due to these high capacity cylinders, the heaviests loads can be lifted. Moreover, it creates that the dredging forces on the max. depth can be much higher (about 2.5 times) than those of a classic excavator. The Backacter 1100 (BA1100) can dredge with a 25 m3 bucket till a depth of about 19 metres.

• This creates the highest production rates of an excavator in the industry; the BA1100 has a production rate in heavy soil of 1000 m3 in 45 minutes ! and this with highest penetration / breakout forces (till max. 205 tons). The BA1100 is the strongest dredger in the industry

• Only the rear wheels are powered, so the front wheels do not have to be of the same size.

• The arm/backhoe can turn through 90° in plan and excavate approximately 5 m below the wheels.

• The machine must be estabilised by jacks in this mode, otherwise too much movement and strain on the axles will be generated from the voluminous rear tyres.

Some features of a "Backacter"