Cat roll-out

25 April 2008

Caterpillar's new 20 to 37.5 tonne D Series excavators (324D shown) all feature a full firewall, rub

Caterpillar's new 20 to 37.5 tonne D Series excavators (324D shown) all feature a full firewall, rubber bumpers and a double plate on the hydraulic tank for added protection and extended service life.

Of the 26 new machines IC saw at Caterpillar's Malaga testing ground just over half use Cat's new Tier 3/Stage IIIA compliant ACERT engines. This is of course in response to the US Tier 3 and European Stage IIIA diesel engine emission laws that came into effect on 1 January this year for the 130 to 560 kW powerband. However, Cat's new mini-excavators and backhoe loaders use Mitsubishi engines when previously they used power units from Cat's Perkins subsidiary.

Mike Birks, mini hydraulic excavator product manager, told IC, “Caterpillar has a joint venture with Mitsubishi in Japan. The technology is proven and we wanted to eliminate the development risks. However, when it comes to Tier 3/Stage IIIA for the lower powerbands we'll look again at Perkins' engines.”

Compact machines

Cat's range of compact mini excavators has been expanded and updated. The range now includes the 301.6C (1.7 tonnes), 301.8C (1.8 tonnes), 302.5C (2.8 tonnes) and the 303C CR – compact radius (3.3 tonnes), 304C CR (4.7 tonnes) and 305C CR (5.1 tonnes) replace the 301.5, 301.8, 302.5, 303C CR, 304CR and 305CR respectively, while the 303.5C CR (3.7 tonnes) is a new machine.

According to Mr Birks the main drivers behind the new range were customer demands for more comfort, safety, convenience and performance.

“The new machines all meet these requirements head-on. The rear of the machine is thick steel plate (5 mm) to cope with the knocks on site, which means rental companies won't have the machine out of action for a long time.

“Serviceability has also been improved. A large door gives easy access to all components so it's easy to do routine maintenance, another boon to contractors and rental companies alike, where having a machine sitting in the yard means a loss of revenue.

“All the machines also feature increased power and a level of comfort that could only have been dreamed of when mini excavators first came on the market,” said Mr Birks.

Indeed, the new C-series cab is spacious with a larger flat floor is larger and wider door. For ventilation, the cab's front window, with a gas-strut assisted linkage, is retractable and can be stowed in the roof space.

A suspension seat, console-mounted controls, low effort pilot control joysticks and adjustable wrist supports help “keep the operator focused throughout the day”. In addition, switches incorporated in the joystick provide easy control of boom swing and auxiliary hydraulic functions.

The C Series is also available with a dozer blade fitted to the front of the undercarriage and two travel speeds. The travel control is fitted to the top of the dozer control lever.

“Imagine the operator is using the dozer blade to finish an area of ground, he can doze forwards in the slower speed then lift the blade, flick to the fast speed, and reverse quickly back the starting point,” said Sam Mottram, mini hydraulic excavator marketing consultant.

The new compact radius CR models also offer two travel speeds, but these are engaged automatically.

“The track system senses the amount of drag on the track due to gradient or uneven surfaces and engages the faster speed only if the machine is travelling on a flat, smooth surface with no obstacles. We also fit a lock out switch to allow only the slower travel speed for truck loading operations,” said Mr Mottram.

Another difference in the CR machines is in their digging strength. Stick digging forces have been improved by up to +5% and bucket digging forces by up to +22%. Both the boom and stick cylinders incorporate end damping to reduce shock loading and load spillage.

“In addition, all compact radius machines come with an auto idle function, which was previously only found on larger machines. This not only reduces engine revolutions and fuel consumption when the controls are not operated for a few seconds but, also makes communicating with workers outside the machine a lot easier,” added Mr Mottram.


Besides mini excavators Cat has also launched eight next generation excavators from 20 to 37.5 tonnes. The new D Series machines – 320D (21.5 tonnes), 320D RR (23.5 tonnes), 321D CR (24.0 tonnes), 323D (23.5 tonnes), 324D (25.5 tonnes), 325D (28 tonnes), 328D CR (37 tonnes), 330D (37.5 tonnes) – replace the seven model C Series. As the product designations indicate, the D-series includes compact radius (CR) and reduced radius (RR) variants.

These new excavators use Cat's Tier 3/Stage IIIA ACERT engines and ADEM 4 electronic controllers, which manage all engine processes to increase fuel efficiency and reduce emissions.

Göran Hjerpe, hydraulic excavators product specialist, told IC, “The ADEM A4 controller is the brains behind engine responsiveness, self-diagnosis, emissions control and fuel economy. The system provides constant net horsepower through the operating range, which maintains a constant level of productivity regardless of parasitic loads, such as air conditioning.”

Various undercarriage options are available, including long, long and narrow, and for extreme applications the 325D and 330D can be equipped with a “heavy-duty/high and wide” undercarriage for increased stability, lifting capacity and visibility. The 330D can also be fitted with the 345C undercarriage, making it suitable for rock and quarry applications, and for feeding mobile crushers.

Standard lifting capacity across the D Series has improved by +5% compared to the C-series, with a hydraulic pressure increase from 34.3 to 35 Mpa. A new heavy lift mode offers +4% more capacity than the standard mode. In the heavy lift mode, the pressure is increased from 35 to 36 Mpa and the hydraulic flow is reduced due to lower engine speed.

The D Series' bucket digging force has been improved by +6%, while stick digging force has been improved by +7%, due to increased pressure and re-designed bucket linkage geometry. A universal Quick Coupler circuit accepts all hydraulic quick coupler systems and attachments, and includes various pressures from 150 to 350 bar.

Service and maintenance requirements have also improved. The hydraulic oil change is now every 8000 hours (previously 4000 hours). The engine coolant change interval is now 8000 hours (previously 6000), while the hydraulic oil filter change interval is now 2000 hours (previously 1000).

Operator comforts include a heated air suspension seat, adjustable armrests, ergonomically designed joystick controls and a full graphic video monitor, which displays a variety easy-to-read information including machine diagnostics and operation.

Cat's latest “technology attachments” – AccuGrade, which uses GPS technology to compare the blade position to a three-dimensional computerized site plan, Machine Security System, an anti theft immobiliser, and Rototilt, which can rotate the bucket 360°, with up to 40° of tilting as it fills and empties – can also be fitted to the D Series.

Backhoe loaders

Cat's new E Series backhoe loaders – 422E (56 kW), 428E (67 kW), 432E (67 kW), 442E (73 kW), plus the 434E (67 kW) and 444E (73 kW) with equal size tyres – all have an operating weight of 10.7 tonnes and replace the previous four model D Series.

Common to all machines is a new load-sensing, flow sharing hydraulics system, and an improved backhoe design and geometry, which offers greater control. The front bucket's breakout forces have been increased +10% (43 to 60 kN depending on model). The new backhoe slider frame design has the option of a powered side shift, while the new extendable E-stick delivers 5.95 to 6.56 m of reach depending on the model.

Scott Haylock, senior backhoe loader marketing consultant, told IC, “The outer sliding E-stick does not drag material back into the wear pads thereby reducing wear. The wear pads are externally serviceable, which allows for fast and efficient adjustment in the field.

“Furthermore, serrations (a series of notches) on the underside of the stick have been incorporated to protect it when working. This means a tougher and more practical stick that doesn't compromise stability, but reduces maintenance and repair costs and delivers longer life. This is a true excavator stick, with all the power that entails,” added Mr Haylock.

Also common throughout the range is a larger cab with air suspension seat, adjustable pod mounted pilot controls, larger windscreen, narrow console, and adjustable work light.

The top of the range 434E and 444E are armed with a 1.15 and 1.3 m3 bucket and breakout forces of 54 and 60 kN respectively, self-levelling system, extra lift height and a quick coupler option.

Other E-series options include all wheel steering and AccuGrade for accurate trench depth and grade guidance. Every model has an on road speed of 40 km/hour thanks to a new axle and drive train design (two or four wheel drive options available).

Wheeled loaders

Cat's new H Series wheeled loaders – 950H (18.5 tonnes, 147 kW), 962H (19.6 tonnes, 158 kW), the 966H (23.9 tonnes, 211 kW), 972H (25.9 tonnes, 229 kW) and the 980H (30.5 tonnes, 237 kW) -all feature its new 6-cylinder ACERT engines (C7, C11, C13 and C15) with ADEM 4 electronic controllers and mechanically actuated electronic fuel injection (MEUI).

The H Series also offers Cat's new Engine Idle Management System (EIMS), which is designed to maximise fuel efficiency, standard steering wheel or Cat's command control steering wheel, non-metallic hood, one piece counterweight, visible sight gauges for transmission oil, hydraulic oil and engine coolant, grouped grease fittings, a new hydraulic service centre, 500 hour hydraulic filter service interval and 1000 hour transmission filter service interval.

The 980H, which uses Cat's C15 engine, has a maximum bucket capacity of 10.5 m3 and a static tipping load of 19.5 tonnes. Break out force is 212 kN, while the dump clearance at full lift and 45° discharge is 3.27 m.

It includes electronic pressure control (ECPC), for smoother transmission shifts, extended component life and increased operator comfort. The 980H also uses Cat's next generation modular radiator (NGMR).

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