Developments in excavators and loaders

In the earthmoving sector, much development is being seen in excavators and wheeled loaders used for digging and loading, Mike Woof reports

The recent 688 Bauma exhibition in Germany provided the construction industry with a key insight into the latest machines now available to the excavator and wheeled loader markets, as well as providing a sneak preview of next year's models. Some of the biggest budgets for research and development in the off-highway equipment field at present are being reserved for low emission engine technologies however rather than muck-shifting itself.

The impact of legislation established to reduce emissions from off-highway machines has been immense, triggering massive research and development programmes for all the major manufacturers. The latest stage in this phased roll-out of regulations mean that after-treatment systems will be required on machines for the European and North American markets from the start of 2011 to meet the Tier 4 interim/Stage IIIB emissions requirements.

The appearance of 178 Caterpillar's new 336 excavator at the Bauma exhibition sets a precedent in the earthmoving sector as it is expressly designed to meet the coming Tier 4 interim emissions regulations. Performance has been optimised over previous generation machines from Caterpillar and the excavator cycles faster, has more digging power and is more economical than the the firm's earlier units in this class. However the key feature of the new 336 is the machine's low emissions performance, much of which is achieved by the sophisticated after-treatment package that minimises NOx and particulates.

To install this emissions package Caterpillar has had to raise the deck at the rear of the cab however, making it easy to identify. In recent years Caterpillar and all of its major rivals have concentrated on maximising visibility from the cab, fitting sloping engine covers and providing as uncluttered sightlines as possible. The added bulk of the extra emissions package has required the higher rear area on the 336 though. The extra cost of the emissions package will increase the price of the 336 in comparison with its precessor also, although Caterpillar says that the machine will offer some reductions in long term running costs that will help pay for the system over its life.

While Caterpillar is first to unveil a Tier 4 interim/Stage IIIB compliant excavator, the other major manufacturers will be following suit shortly. And it seems likely that to incorporate the necessary emissions control equipment, some rearward visibility will have to be sacrificed by other manufacturers on their Tier 4 interim/Stage IIIB compliant machines. These will follow similar lines to Cat's new 336 when compared with its immediate predecessor - there is no avoiding the need for the after-treatment devices nor the space they require. However by installing the latest generation of rear view CCTV equipment, which is considerably more durable while also being cheaper than previous systems, the issue of rearward visibility can be easily tackled.

Other manufacturers are offering improved machines that offer increased performance and economy, with their Tier 4 interim/Stage IIIB versions due next year. 176 Case has developed a version of its CX700B excavator that is configured specially for mass excavation duties. To increase its digging, slewing and truck loading performance this machine features a short boom and dipper and has revised kinematics to boost its speed of response. The special mass excavation boom and dipper arm allow 19% greater digging force than the standard version. The mass excavation boom and arm have been reconfigured to increase penetration and performance, as well as boosting working life. The machine is powered by a Tier 3A compliant diesel that delivers 345kW, as with the standard model and the machine also retains the firm's sophisticated control system that optimises engine output to match hydraulic load. Multiple-mode controls allow the operator to set the machine to suit an application, with a boost mode available for additional breakout. To ensure durability, the machine features the heavy-duty undercarriage of the firm's 80tonne class excavator.

Heavy duty construction is also a focus of 695 Doosan's new 38tonne DX380LC and DX700LC

crawler excavators. The DX380LC has the long undercarriage from the larger DX420LC model, which helps maximise stability and the machine is aimed at heavy construction and excavation applications. Weighing in at 38tonnes, the DX380LC delivers a digging force over the bucket of 21.7tonnes while using the power boost function increases the force by around 5% and it is also said to feature a high swing torque. The DX380LC is powered by a six cylinder, 202kW diesel and is equipped with an economy mode and an auto idle system to minimise fuel consumption. Productivity and precision are claimed due to the efficient load sensing hydraulics and the DX380LC is equipped with a large cab that has ergonomic controls and instrumentation.

The new DX700LC is also designed for heavy-duty applications and features a long and wide undercarriage that expands to a maximum working width of 4m for stability. Three arms of varying lengths are available, while digging force over the bucket is 33.3tonnes, while this can be increased by 9% using a power boost feature. Power for the DX700LC comes from an Isuzu diesel rated at 345kW and this features exhaust gas recirculation and an electronic controls for optimum power to minimise emissions and maximise output. The new control system features standard mode and power mode for heavy-duty digging as well as an economy mode for medium-duty digging.

Turkish construction equipment manufacturer 230 Hidromek has launched three new crawler excavators. The HMK220LC, HMK300LC long reach and HMK370LC machines feature a new control panel and a high visibility, high comfort cabin. Although at present the company's excavators weigh up to 37tonnes, larger-size 45-50tonne models will be offered in the future.

From 236 Hyundai comes the long-awaited introduction of its series 9 excavator line-up to the European market. The first machine available is the 21tonne class R210LC-9 crawler model, which is aimed squarely at the earthmoving sector while 25tonne, 29tonne, 32tonne, 38tonne, 48tonne and 52tonne -9 Series models are due to follow shortly. Power for the R210LC-9 is comes from a 196 Cummins diesel delivering 113kW while advanced features make the new Hyundai machines highly productive and efficient, as well as economical to run and comfortable to operate. Sophisticated hydraulics ensure precision working according to the firm, as well as allowing fast cycle times and high productivity. Fuel saving systems are fitted, such as one-touch and auto-deceleration and a fan clutch system that increases the engine cooling fan speed when required. The machine also has a choice of power modes, work modes and is offered with the sophisticated Hi-Mate GPS technology-based remote management system.

Designed for special earthmoving applications, 2300 Komatsu's PC350LC-8 Long Reach machine is fitted with a 17m excavation boom and arm. The 42tonne machine can be used for light or heavy-duty applications sich as slope stabilisation and road construction and has a maximum bucket capacity of 1.1m3. Power comes from a diesel rated at 194kW while safety features include Komatsu's roll-over cab design with a tubular steel frame to protect the operator. The machines have a large full colour monitor panel, giving access to the five working modes which optimise performance and fuel use for each application. The new model is fitted with Komatsu's Komtrax satellite monitoring system, which allows machine data to be accessed over the internet. Komtrax can also be used to help secure equipment including sending a notification if the machine is activated outside an engine lock period.

From 718 Liebherr come the new R954C SHD and R95100 models. The R954C SHD has a service weight of 62tonnes and develops a crowding force of 435kN and a breakaway force of up to 355kN. The R 954C SHD is driven by a Liebherr in-line six-cylinder engine with a pump-pipe-nozzle fuel injection system rated at 240kW.

The new R9100 excavator is powered by the firm's new V12 diesel, which is rated at 565kW and features cooling through separate radiators and a hydrostatic fan drive that ensures the fan only operates when required, reducing fuel consumption. The machine wields a 6.8m3 bucket as standard that has been optimised for maximum penetration and to ensure high fill factors. High breakout and digging forces are also claimed. At the moment the machine is in field-testing and will be available to the market once this intensive programme is complete.

Meawnhile 2394 Volvo says that increases in engine power and fuel efficiency improvements of 6-7% mark out the improved EC360C and EC460C excavators from their predecessors. will receive their international launch. The EC360C and EC460C have received respective boosts of 11.6% and 4% in engine power, increases in torque of 12% and 6%, and higher oil flow and pressure. As a result of higher performance capabilities, main structures and components have been strengthened.