Smaller construction equipment offers versatile options, particularly on highway repair and maintenance projects. Patrick Smith reports
Visitors to any highway construction site across the world will see a sizeable amount of utility equipment in action carrying out a variety of tasks.Indeed, because of its smaller, more compact size, such multi-task equipment is essential when repair and maintenance projects are being carried out, particularly in urban areas where space may be limited.
For example, versatile, multi-purpose backhoe loaders can be used as an excavator and as a loader, allowing operators to quickly travel on the road to the jobsite, says
They are available in various configurations, while machines such as skid steer loaders can be used for a vast variety of applications, and can serve as an effective tool carrier.
"The name itself explains the main features of this multi-functional machine. It can load earth into a truck, dig and move landscaping and building materials, clean roads, grind asphalt, clear the road from snow and serve many other purposes," says Komatsu, which also points to compact excavators with tight swing radii as being ideal for working in confined areas.
Indeed, the company is upgrading its MR-3 mini-excavators with new options that boost versatility and operator comfort. The machines now come with optional proportional fingertip controls, auto-idling and adjustable oil flow on the auxiliary circuit. The control improvements are particularly useful for operators working with attachments on a regular basis as the systems reduce operator fatigue.
The auxiliary oil flow rate can be adjusted from the operator's seat and maximum flow is set by pushing two switches on the monitor panel. Also helping to reduce fuel consumption is the new auto-idling system which automatically reduces engine rpm when the control levers are left in neutral position for more than a few seconds.
These options can be retrofitted to the PC30MR-3, PC35MR-3, PC45MR-3 mini-excavators and the PC80MR-3 midi excavator and later this year they will be available as options for the PC26MR-3 mini-excavator and will be factory fitted on the PC80MR-3.
HCME product sales manager Compact Line (EMEA), Joep van den Maagdenberg, said: "The introduction of the ZX29U-3, ZX33U-3 and ZX38U-3 into the European market is an important development for HCME.
"Designed for small construction projects and general groundworks, the machines are ideal for working in urban areas where particular environmental care is required."
The Hitachi ZX29U-3, ZX33U-3 and ZX38U-3 are all equipped with next generation three-cylinder engines, which comply with Environmental Emission Regulations EU Stage III A and are rated at 19.7-21.3kW.
The ZX48U-3 and ZX52U-3 also meet the regulations and are equipped with powerful, yet relatively low-noise, four-cylinder engines rated at 28.4kW.
All the machines use Eco Zone technology, which helps to cut fuel consumption while still maintaining a high level of productivity.
Chinese construction equipment manufacturer,
According to the company, LiuGong engineers have optimised the hydraulic systems to improve precision, promoting a 15% increase in cubic metres of materials handled per hour. In addition, fuel consumption has been reduced by 10%, and a stronger upper frame design increases durability.
In the UK, Powell Plant & Contractors has taken delivery of a new
At the heart of the machine a 4litre Tier III engine operates in conjunction with an advanced mode control system ensuring the maximum possible hydraulic horsepower available is delivered at a constant engine speed under varying load conditions. Each track is powered by an automatic two-speed shift travel motor providing a maximum drawbar pull of 119kN on gradients up to 35º.
Equipped with a 4.6m boom and 3m dipper arm, the maximum reach is 8.8m and lifting capacity across carriage at full reach is 1.69tonnes.
Meanwhile,
Operators can select from two working modes, Eco or low flow, to optimise productivity. In Eco the machine runs all three pumps, while in low flow the third pump is disengaged. The third pump also cuts out as engine revs pass 1,700rpm, so there is little point in an operator revving the machine for more power. A secondary benefit is faster extradig extending dipper performance.
The new B-Series 3 loaders (SSL models 216B3, 226B3, 236B3, 242B3, 252B3 and MTL models 247B3 and 257B3) incorporate design refinements.
In addition, a larger engine and more powerful hydraulics for the 242B3 and 257B3 are said to make these models power-dense machines "that maintain a nimble size and excellent manoeuvrability." Specific design refinements for all B-Series 3 models include a redesigned dead-engine lower valve, single electronic control module (ECM), which is relocated for improved access and reliability, plus new ECM-enabled features.
"The basic redesign of the 242B3 SSL and 257B3 MTL involves adding substantial power, both engine and hydraulic, to allow these small-frame machines to perform as larger machines in confined spaces. "Installing the Cat C3.4 DIT diesel engine, rated at 53kW, gives these two models a 25% increase in net power, compared to their B-Series 2 counterparts, and a 28% boost in peak torque. The C3.4 DIT also runs at a lower, more fuel-efficient speed, 2,500rpm, which is 500rpm less than the B-Series 2 engine," says Caterpillar.
Complementing the more powerful engine in the 242B3 and 257B3 is a more capable hydraulic system. Calculated hydraulic horsepower (the hydraulic power available to do work) is up by nearly 40% for these two new B-Series 3 models.
"This increase significantly improves the capability and efficiency of the 242B3 and 257B3 when handling standard-flow work tools such as brush cutters, power box rakes and trenchers.
"Larger lift and tilt cylinders give the two new models a gain in boom and bucket breakout force, from 13 to 19%, depending on model and circuit. Increased breakout forces provide enhanced performance in all basic functions such as loading, lifting and digging," adds Caterpillar.
A civil engineering contractor is making use of
The
McDermott took delivery of six new Wacker Neuson machines from local dealer Beddoes Machinery Sales, which were specially selected for the 24-week contract. The order comprises four mini-excavators, a 28Z3, 38Z3, 50Z3 and 2404, plus a pair of 9503 wheeled machines with triple booms used for placing stone and backfilling duties. Three minis are equipped with VDS, enabling the operator to tilt the machine's entire superstructure by up to 15°, which is said to be ideal for the M6 project where a lot of the digging has to be carried out on sloping embankments.
Where the embankment is steeper, the machines only have to dig a minimum amount of material away in order to accommodate the uphill track and then deploy the VDS to level the cab. In the even steeper sections, and where access by even a mini is impossible, the company has to resort to a purpose-built trenching attachment.
