Excavators: Digging deep

When contractors need to dish the dirt they look for a sturdy, reliable vehicle that will get the job done in optimum time at the lowest cost, maximising on fuel efficiency and labour.

Luckily, a new breed of excavator is emerging that is both fuel-efficient and offers greater cab comfort to help contractors get the most out of their personnel. Excavators are being redefined to be clean, lean and resourceful, be they new low exhaust emission models for Europe, Japan and the US, or new models for countries with lower (or no) standards.

And as global construction activity starts to tick up once again, demand is also on the up for these powerful machines, both from contractors and rental companies alike.

Size matters

In the infrastructure segment of course, the scale of projects often dictates that the bigger classes of earthmoving machines are used. And with many of the largest projects taking place in emerging markets, manufacturers are putting more and more emphasis on larger, more powerful and more efficient machines designed specifically for these regions.

Caterpillar’s new 336D2 (Series 2), for example, is a powerful and productive 36 tonne machine that offers an improved fuel system and enhanced hydraulics.

The 336D2 uses the Cat C9 ACERT engine that can meet either US Tier 2 or Tier 3 equivalent emissions standards. The C9 engine provides electronic fuel and air management to ensure optimum performance.

The engine runs at a constant speed of 1700 rpm, which also contributes to fuel economy and reduced noise levels.
Meanwhile, Cat’s improved hydraulic system features a new electric pressure sensor that reduces hydraulic flow from the pump during light-load or no-load situations, which also helps conserve fuel.

The 336D2 is available in standard and long undercarriage and contractors can choose from two booms and five sticks. The excavator offers a maximum dig depth of 8 m and a horizontal outreach of 11.6 m.

Back in more developed regions, JCB has updated its crawler excavator in the same class – the 38.3 tonne JS360 –with a new Tier 4 Interim engine.

The JS360 is now powered by a six-cylinder, 7.8 litre Isuzu engine, which according to JCB, provides operators with fuel savings of up to 8% compared with the Tier 3 machine. This efficient engine produces 281 hp (210 kW) at just 1900 rpm, driving a twin pump, load sensing hydraulic system to deliver strong digging performance. When equipped with a 6.45 m main boom and a 2.21 m dipper, the JS360 delivers 25,300 kgf of dipper tearout and 27,716 kgf of bucket tearout force.

The JS360 is also available in XD demolition specification or with a 21 m long reach boom for waterway maintenance and dredging operations. The JS360LC XD features added protection for both the machine and the operator, including an XD cage for the cab, heavy duty undercarriage and side impact protection.
Also available is the JS360 HRD with a modular three-piece demolition rig, the machine offers 21 m of reach from the ground to the bucket pin.

Meanwhile, New Holland’s E385C crawler excavator, which weighs in at a hefty 38 tonnes, is equipped with a powerful common-rail engine, which maximises on fuel efficiency. The E385C offers an eco working mode, and meets Stage IIIB EU specifications on exhaust emissions, with its integrated cooled exhaust gas recirculation (EGR) system.

Designed for heavy-duty work, the E385C comes with a Bulk Excavator Heavy (BEH) configuration, which includes a shorter monoboom and powered bucket linkage to give greater stability and higher breakout force. A bigger bucket is available for the E385C BEH, which can carry +18% more material than the standard version.

At the lighter end of the excavator spectrum, Komatsu has introduced its 18-tonne PC170LC-10 to the European market. Following on from the PC160LC-8, Komatsu says the dash-10 offers between +5% and +15% more lift capacity.

Driven by an 115 hp (86 kW) engine with a variable-flow turbocharger, the PC170LC-10 is also up to 10% more fuel efficient than its predecessor.

Cab comfort

Tipping the scales at 42.6 tonnes, the new Hyundai R430LC-9A is the latest addition to the manufacturer’s Robex excavator range. The new Stage IIIB machine, which is being rolled-out across Europe, slots in between the existing R380LC-9A and the R480LC-9A. The R430LC-9A’s new economy mode helps operators conserve fuel. According to Hyundai, it offers 5% fuel savings in comparison to previous models.
However, what sets this excavator apart is the focus on operator comfort.

The R430LC-9A features a Hyundai -9A cab, which offers a fully adjustable suspension seat and armrests. The joystick consoles are also adjustable in height to ensure less operator fatigue. A fully automatic air-conditioning system provides a constant ambient temperature.

In-cab technology includes a 7-inch (178 mm) LCD colour touch screen for programming personal machine preferences, including work modes, self-diagnostics, maintenance check lists and start-up machine security codes. The screen also enables the operator to see the rear view camera, providing all round visibility.

Launched at March’s ConExpo-Con/Agg exhibition in the US, Luigong’s 50-tonne 950E excavator follows in the tracks of the Chinese manufacturer’s D series. Again, attention has been paid to operator comfort with the 950E offering one of the largest cabs in the industry.

The cab windows are widened for better visibility, especially the right downward view for steering and excavation. An enlarged skylight with rolling sunshade provides excellent visibility and good ventilation.
The on-board LCD monitor displays machine operational states, warnings, audible alarms and maintenance information in a choice of 10 languages. The LCD monitor also serves as the display for the rear view camera, which improves safety.

A pilot lock handle installed on the handrail box prevents unexpected movement as it interlocks the machine ignition system. Liugong has also designed its operating handles to be soft and flexible to avoid operator fatigue.

Fuel efficiency

For contractors looking to maximise on fuel efficiency, hybrid machines could be the answer with technology that captures and reuses waste energy.

Hybrid excavators first entered the market back in 2008 and today the technology has been refined to offer up to +30% fuel savings compared to standard machines.

Caterpillar’s new 336F H hybrid will soon be available with a Tier 4 Final Cat C9.3 ACERT engine. The machine is one of the most efficient on the market as it offers an automatic engine speed control, which lowers engine rpm during no-load/light-load conditions. It also has an engine idle shutdown system and an eco mode. The engine also runs on fuels containing up to 20% bio diesel (B20).

Increasing efficiency is the Cat Swing Energy Recovery (SER) valve, which captures kinetic energy from the 336F H’s swing deceleration, storing it for reuse in hydraulic accumulators.

Komatsu is an established hybrid manufacturer, having just released its third generation hybrid model to the European market. The new HB215LC-2 hybrid hydraulic excavator has an operating weight of 22.6 tonnes and a bucket capacity of 1.68 m³.

According to Komatsu, the new excavator boasts enhanced hybrid components and a new Stage IIIB engine.

Yoshihiro Kobayashi, product manager for hybrid excavators at Komatsu Europe, said, “The new HB215LC-2 will now provide Komatsu customers with an even higher fuel economy. Actual savings will depend on the application, and fuel efficiency is particularly high when operating the excavator with hydraulic attachments.

He added that the extra investment into a Komatsu hybrid machine is typically recovered in less than two years.

Hitachi has also launched a hybrid excavator into the European market. The ZH210LC-5 hybrid combines a hydraulic motor and an eco-friendly electric motor that Hitachi claims can give the same levels of efficiency and smooth swing motion as all Zaxis-5 hydraulic models. The manufacturer says the new hybrid can reduce fuel and CO2 consumption by up to +31%.

Hitachi has incorporated elements from hydraulic, electric and battery-powered excavators to create the Trias HX system. This combines a hybrid system with an energy-efficient Trias hydraulic system to achieve lower levels of fuel consumption.

Another new development in hybrids is the introduction of Sumitomo’s first ever such machine. The 20 tonne SH200HB-6 was launched in Japan in November, and like the Komatsu and Hitachi models, it captures energy that would otherwise be wasted in the braking of the upper structure’s slewing motions with a generator and capacitors.

Sumitomo says the machine is powerful, smooth, controllable and fuel-efficient. The on-board diesel engine is Tier 4 Interim/Stage IIIB compliant, and the company says the hybrid component saves an average of 15% in fuel consumption, compared to a standard SH200-6.

Purchase orders

With the construction industry witnessing the green shoots of economic recovery, contractors and rental firms are once again in the market for excavators and manufacturers are now working to keep pace with demand.

Doosan has seen increased interest in its range of excavators. The South Korean manufacturer recently supplied a range of excavators to DA Boyd Groundworks in the UK. The company has purchased a new Stage IIIIB compliant Doosan DX140LC-3 14-tonne crawler excavator and a new Doosan DX225LC 22-tonne crawler excavator. A Stage IIIB compliant DX255LC-3 25-tonne model is also on order.

ounder of DA Boyd Groundworks, Duncan Boyd said, “We believe the Doosan excavators offer really good value-for-money, combining excellent performance with a truly durable design and construction that allows them to work much more easily than other machines on the market in the tough conditions we work in, in the forests and elsewhere in our area.”

Liebherr has also just fulfilled an order for three R946 crawler excavators from Sibelco Deutschland GmbH, a supplier of mineral raw materials for the ceramics industry.

The R946 has an operating weight of 40 tonnes and is equipped with a 6-cylinder in-line engine, which meets the requirements of the IIIB emission stage.

The excavators will be used in the clay mining pits in the German Westerwald region.

Hitachi meanwhile has again supplied Swiss earthmoving contractor Paul Werhli with a new ZX130-5 through Hitachi’s dealer in Switzerland, Probst Maveg.

“I am a real fan of Hitachi construction machinery,” said Mr Werhli. “After 22 years of operating excavators, I know that Hitachi has the best hydraulics – and the HIOS III (hydraulic) system is perfect on my new machine. It is very precise and exact, and if I make a mistake, I can correct it quickly – it’s most forgiving.

“The ZX130-5 is delivering a favourable level of fuel consumption and I can load a four-axle truck better with this machine. As an operator, I feel more at ease after a day’s work, as it does exactly what I want it to do. As an owner, it is cost efficient, and I like the aesthetic design and the quality of the manufacturing.”

Also in Switzerland, Hitachi has delivered a new Zaxis-5 to family-owned contractor Koch AG. The company has added a ZX350LC-5 for earthmoving and quarrying projects. One of its first assignments was on a new housing development, where it was used to excavate 15,000m3 of earth to make way for the construction of six detached properties.

European return

Meanwhile, Japanese manufacturer Kobelco is hoping to expand sales in Europe after it introduced three new excavators to market in April.
The new Japanese-built SK260LC-9, SK350LC-9 and SK500LC-9 are the second wave of machines released this year by Kobelco Construction Machinery Europe BV (KCME).

Powered by energy-efficient Hino engines, the three large-capacity machines use the latest engine and engine management technology.

“The introduction of three further machines to an already impressive line-up underlines our commitment to providing Europe with the best technology and expertise in excavator manufacture and operation,” said KCME product marketing manager, Peter Stuijt.

Kobelco introduced its SK210LC-9 and SK210NLC-9 models to Europe in January. Equipped with the Hino JO5E-T5J turbocharged engine, the new models comply with Stage IIIB emission regulations. The new units also have three work modes for greater efficiency: heavy, standard and eco.

The next generation of excavator is here, and contractors are advised to weigh up the investment against the cost savings these new energy-efficient machines can offer.