Latest earthmoving machines noticeably quieter

The latest generation earthmovers are noticeably quieter than older machines - Mike Woof reports

One of the most strikingly apparent features of the new Tier 4 Interim/Stage IIIB rated construction machines is the noise, or rather the lack of it. With engines running at usual operating speed, these emissions compliant machines are noticeably quieter. There are benefits: for example, this allows site personnel to talk to an excavator operator while a machine door is open, without the need to raise voices as in the past. These machines also cause far less audible disturbance, which will be an important point when working in urban and built-up areas. Tough restrictions on working noise in some towns and cities will mean that operations running these latest machines may be able to work longer hours than those using older equipment.

Cleaner exhaust emissions have been the main benefit of the new compliant engines, which use technology developed at huge expense by the various manufacturers. The reductions in nitrous oxide and particulates are phenomenal, compared with machines from only a few years ago. However, the technology required is reflected in the purchase price and the various manufacturers have also seen fit to ensure customer loyalty by tackling running costs and performance, with better fuel consumption and torque rise for virtually all of the new machines.

Different firms have used an array of technologies to meet the emissions targets, with a diverse combination of in-cylinder improvements and exhaust after-treatment systems. In general the sophisticated emission control systems mean that engines run hotter and require additional cooling, while also requiring bulky exhaust after-treatment packages. As a result, the manufacturers have had to squeeze a good deal of systems under the engine covers without spoiling sightlines and compromising visibility, as well as ensuring the additional cooling fans could be sufficiently sound attenuated to reduce operating noise.
A wide array of manufacturers introduced new Tier 4 Interim/Stage IIIB compliant earthmoving machines this year including 176 Case, 178 Caterpillar, 695 Doosan, 230 Hidromek, 233 Hitachi, 236 Hyundai, 257 John Deere, 2300 Komatsu, 718 Liebherr, 269 LiuGong, 5895 New Holland and 2394 Volvo Construction Equipment.

From Case Construction Equipment comes the new C Series crawler excavators, with the 25tonne CX250C and 37tonnes CX370C being the first available. These are powered by Tier 4 Interim compliant engines, featuring multiple injection, variable displacement turbo-charging, dual or triple exhaust gas recirculation (EGR) and a diesel particulate diffuser. Both machines provide customers with up to 10% fuel efficiency improvement, as the C Series models are equipped with five energy saving systems that automatically reduce engine speed.

New from Doosan are the 38tonne DX380LC excavator and DL420 wheeled loader, as well as an excavator designed for working in tight space confines. The DX380LC is powered by a six cylinder DL08 turbocharged diesel engine providing 202kW, with an e-EPOS electronic control system providing optimum power at reduced fuel consumption in all working operations. Like all heavy Doosan excavators, the DX380LC has as standard the auto idle feature, which reduces fuel consumption and noise and will reduce engine speed to idle if the functions are not used for a period of about four seconds. The new DL420 wheeled loader replaces the DL400 and has a bucket capacity of 4m3. Power for the 22.3tonne loader comes from a 10.8litre 196 Cummins QSM11 electronically-controlled engine rated at 209kW and featuring a high pressure unit injector system and a state-of-the-art combustion system. Two working modes are offered to optimise fuel consumption and productivity, while there are four forward and three reverse travel speed ranges. In addition, Doosan also launched a narrow width crawler excavator, the DX235NLC which, equipped with mono boom, weighs 22.5tonnes. Just 2.54m wide, the DX235NLC excavator is designed to meet transport width regulations in countries such as Italy, without compromising on performance and productivity. The reduced width DX235NLC excavator also suits duties in confined spaces on urban projects.
Hidromek's new range features an automatic powerboost, which increases digging output by 8%, while the modes available can boost slewing speed for example. The machines weigh up to 37tonnes and feature Hidromek's Smartlink satellite monitoring system. Using the Smartlink website, the owner can see where the machine is located, fuel consumption rates, service times, failure codes and engine hours, while the system also offers theft protection and can be used for geo-fencing of working areas.

Hitachi Construction Machinery said that its new Dash 5 excavators replace the earlier Dash 3 Series. First models available are the ZX870LC-5 and ZX290LC-5, which come with optimised hydraulics, improved arm digging force, bucket digging force, lift capacity, swing speed, swing torque, hydraulic flow, engine horsepower and drawbar pull. Power comes from an 2724 Isuzu engine platform that meets Tier 4 interim regulations using cooled EGR and as such, is said to be less complex to maintain than selective catalytic reduction systems. The company said this combination delivers the productivity, fuel efficiency and reliability that customers have come to expect from Tier 3 models. In the ZX870LC-5, the engine is rated at 397kW and features a combined diesel oxidation catalyst and diesel particulate filter in the exhaust system. The 28.7tonne ZX290LC-5 is powered by a 140kW Isuzu engine.

A major innovation from Komatsu comes in the shape of its second-generation hybrid excavator, the HB215LC-1. The 21.6tonne machine features Komatsu's recently-developed electric swing motor, a generator, an ultra capacitor and a 104kW diesel engine. This allows the machine to achieve an average of 25% fuel savings compared with its conventional equivalent machine. The price of the HB215LC-1 is some 30% higher than the firm's conventional machine in this class (either the PC200 or PC210, depending on market).

LiuGong has rolled out an upgraded range of excavators, with the company taking note to improve hydraulic performance. The company claims that its latest machines can meet all the Tier 4 Interim/Stage IIIB emissions requirements. More advanced systems optimise control, power delivery and productivity, and cycle times have been reduced across the board while productivity has been increased.

359 Volvo CE has an array of new emissions compliant machines, including the L110G, L120G and L250G wheeled loaders as well as the EC250D and EC300D excavators, with engine performance having been improved across the board. A spokesperson for the firm says that in general, "We're managing to save 15% fuel on some of these engines." He explained that Volvo CE's new emissions systems are sophisticated and will regenerate the filter automatically when required, as well as being simple to service, "The only thing the customer will notice is the need to change the filter at 4,500 hours. Full power is always available and you never need to stop to allow for filter regeneration." The L250G wheeled loader is of particular note as it marks something of a departure for Volvo CE. The 35tonne machine is effectively in a size class of its own and features much of the rear chassis components from the existing L220. The L250G has a 6.9m3 bucket as standard, z-bar linkage and a higher breakout and since its launch at CONEXPO-CON/AGG 2011, has attracted considerable interest. The first 37 machines were pre-ordered by customers in the US even before production started at the factory. Suited for face working or truck loading the machine offers increased productivity and the spokesperson said, "With this brand new machine size you can fill up an on-highway truck in two passes." Meanwhile Volvo CE's L110G and L120G loaders weigh in at 20.7 and 21.6tonnes, with emissions compliant engines delivering 191kW and 200kW respectively. And the EC250D and EC300D are the latest addition to the excavator range, weighing from 24.6-28tonnes and 30-33tonnes respectively, depending on specification. Multi-mode controls ensure optimised performance for the job being carried out.