25 April 2008
Sales of wheeled loaders last year in China, Europe, North America and Japan were expected to top 140000 units, according to market research specialist Off-Highway Research. China is the main markets for wheeled loaders with around 95000 units expected to be sold there during 2005. This volume of means that wheeled loaders are one of the most popular pieces of construction equipment in the world and have earned that position thanks to their versatility.
Introduction of the new European Stage IIIA and US Tier 3 engine emissions laws for the 130 to 560 kW powerband at the beginning of this year has triggered a wave of new machine launches. But with so many manufacturers competing for a share of this important market, the latest models not only have new engines, but also feature the latest technology to further improve versatility and cut fuel consumption.
Additions to wheeled loader specifications in recent years have included auto-dig functions, improved operator comfort and advanced engine management. Another of the key developments over recent years has been the rise in popularity of &tool carrier' wheeled loaders, with an increasing number of manufacturers offering this variant.
These machines replace the traditional Z-bar front linkage with an arrangement that allows the front attachment to be lifted parallel to the ground, allowing pallet forks to be used. Such machines are normally fitted with a hydraulic &quick hitch' to allow attachments to be changed without the operator getting out of the cab.
While this adds to the versatility of the machine, the parallel linkage generally offers less breakout force than a Z-bar, so for quarrying and heavy earthmoving work a traditional wheeled loader is likely to be the best option. This generally means that tool carrier wheeled loaders tend only to be available in the smaller machine classes, where versatility and the need to use different attachments is more important than earthmoving &grunt'.
Case launched its first tool carrier wheeled loader – the 127 kW 14.4 tonne 721D XT – last year at ConExpo in Las Vegas, US. Case has now added the 101 kW 11.5 tonne 621D XT and 82 kW 9.8 tonne 521D XT to the line up. All three models feature a redesigned linkage which provides more bucket roll back for increased material retention, and offer lift capacities of up to 6.3 tonnes.
The range also has low profile routing of the hoses to follow the contour of the loader arm more closely and a redesigned attachment area to remove objects which previously impacted on the view to the bucket and coupler. The XT range is also available with ACS and JRB hydraulic couplers as a factory installed option and these allow the machines to use other supplier's attachments.
“Now the operator has a clear view to the forks for easy pick up of pallets and loading of trucks,” said Case marketing manager David Wolf. “Visibility to the attachment, jobsite and latching pins has been improved, which ensures more productive and comfortable operation.”
New Holland's range has also been updated with the addition of the W50TC, W60TC, W70TC and W80TC tool carrier wheeled loaders, which replace their non tool carrier predecessors. The new loaders have a mono boom front end – a concept first developed in 2000 by Caterpillar for its G-Series tool carriers – with the cylinders located underneath, giving the operator an excellent view of the front attachment.
All four tool carriers feature Deutz engines, rated at 40, 44, 45 and 56 kW respectively. Tipping loads range from 2.95 to 3.75 tonnes at full articulation, with dump heights from 3.25 to 3.45 m. The 4.8 tonne W50TC has a travel speed of 20 km/h, while the other models, which weigh 5.1, 5.6 and 5.9 tonnes, can reach 35 km/h.
New in Komatsu's compact wheeled loader range are the 55 kW and 61.5 kW WA90-5 and WA100M-5 and also follow the trend for tool carriers. The company's &Easy Fork' loader linkage enables parallel movement and high payloads in pallet fork applications, and a hydraulic quick coupler is fitted as standard, allowing rapid switching between the forks, buckets and other attachments. The loaders have a top speed of 30 km/h, allowing them to move quickly between sites, and they also feature a tilt-up cab for easy maintenance access.
Addition of tool carrier systems is not the only way in which manufacturers can boost the versatility of their wheeled loader – Volvo has launched long boom versions of its L60E, L70E, L90E and L110E wheeled loaders. This means that long boom options are now available for models from the 11 tonne L60 E right up to the 50 tonne L330E. As far as the new machines are concerned, this option adds between 0.42 and 0.52 m to the loader's dump height, depending on the model, which is important given the move to high capacity high-sided on-highway trucks in many parts of the world.
Big but quiet
One of the largest new wheeled loaders is Komatsu's WA600-6 which was unveiled at the National Construction Exhibition in Sydney, Australia in November last year (see IC, December 2005). The machine has a maximum operating weight just under 53 tonnes and a 393 kW Tier 3 engine and, despite its size, the noise level in the cab is just 73 dB(A) – the lowest in this machine class according to the company.
Komatsu says the engine and its own design of torque converter give the WA600-6 the best rimpull in its class. A variable displacement piston pump for the closed circuit hydraulic system matches the oil flow to the application, which works with the operator-selected engine modes to cut fuel consumption.
Hyundai's new 30 tonne HL780-7A wheeled loader is powered a Tier 3 compliant 259 kW Cummins engine and features a large, comfortable and quiet cab -7dB(A) quieter than the previous model. It replaces the HL780-3A and completes the &Dash-7' update of Hyundai's 6-model HL wheeled loader range.
According to Hyundai, particular attention has been paid to the insulation to achieve extremely low noise levels. The machine also features a lower engine speed, 2000 rpm, which has helped lower fuel consumption further. Among the other new features are some operator-friendly options such as joystick steering, ride-control and a dual brake-pedal arrangement. The HL780-7A also has an all-wheel wet-brake system.
Operator comfort and machine serviceability have also been given special attention. Wide-opening access panels give easy access to all major components and there is provision for plug-in laptop PC diagnosis of all the hydraulic and operating functions, in addition to the in-cab diagnostic display for the operator. There is also the option of a reversible fan to ease maintenance of the radiator and coolers.
“With a range of heavy-duty buckets up to 5.1 m3 capacity, this new machine is seen very much as a high-output, front-line production unit for the mining, quarrying and construction industries. And with a load-over height of 3.4 m, it is well matched for loading large dump trucks up to 80 tonne capacity, and for direct loading of high-sided crushers,” said a spokesman for the company.
The addition of the HL780-7A extends Hyundai's range of wheel loaders to six basic models, from the 10 tonne HL730-7 up to the new 30 tonne the HL780-7A, with a number of special application models as well, such as the &TM' (Tool Master) parallel-lift materials handlers, and &XTD' machines with extended lift-arms.
Moving slightly lower down the power band and Caterpillar has launched a new four model H Series range of wheeled loaders to replace its G Series. The 18 tonne 950H, 19 tonne 962H, 24 tonne 966H and 25 tonne 972H all feature new Cat Tier 3 compliant ACERT technology engines.
Cat's 214 kW C13 (972H), 195kW C11 (966H) and the C7 (156 kW for the 962H and 145 kW for the 950H) engines are all inline six cylinder engines. The design features a mechanically actuated electronic fuel injection (MEUI) system. This is comprised of four major components: injectors, a low-pressure fuel transfer pump, sensors to monitor speed, temperature and pressure, and an ADEM A4:E4V2 controller.
Another new feature is Cat's new, proprietary Load Sensing Hydraulic Implement System. The closed loop system automatically adjusts to operating conditions to provide only the hydraulic flow required by the attachment.
According to Cat, the load sensing system, coupled with the new load sensing system, mean operators can simultaneously lift and tilt the bucket, resulting in better bucket control and less spillage.
Also common to all four machines is an electronically controlled, hydraulically driven fan, which automatically changes speed to meet the cooling requirements of the machine, saving fuel and reducing noise.
Doosan is also launching two new wheeled loaders which is says are the forerunners to a complete upgrade of its Mega range.
The 162 kW, 18 tonne DL300 and the 204 kW, 23 tonne DL400 both feature Tier 3 engines – Doosan's own DL08 in the DL300 and a Cummins QSL9 in the DL400. Both engines are six cylinder in-line units with four valves per cylinder and offer two operating modes – power or economy. Operation of the engine, and other electronic control systems, can be monitored through an electrical diagnostic port.
External engine noise and in cab noise have also been reduced through fitting of a dual walled exhaust silencer and a reduction in the speed of the cooling fan. According to Doosan, these changes have cut the in cab noise level to 71 dB(A).
Other improvements include variable flow hydraulic pumps to provide faster lifting and dumping speeds and addition of a ZF's
Ergo Power transmission. The cabs have also been upgraded with adjustable steering columns and air suspended seats, and provide greater visibility and more space than the previous models.
Hitachi has also launched a new series of wheeled loaders with Tier 3 compliant engines. The ZW series include Hitachi's new Total Torque-control System, which allows the operator to find the right balance between traction force and front speed. Depending on the job, the setting can be manually adjusted to traction priority, general work or light duty. The machines also feature automatic transmission with a load-sensing system to improve load-and-carry performance.
JCB has also added two new wheeled loaders to its range – the 426 and 436 -which have +13% higher payload capacities than their predecessors. Operators will appreciate the large cabs, which are +50% bigger than on previous models, and the fact that all daily maintenance checks can be done from ground level.
Liebherr has launched a new range of &2plus2' wheeled loaders, with the first models now fitted with Tier 3/Stage IIIA compliant engines. The new models are the 23 tonne L 566, 23.7 tonne L 576 and 24.5 tonne L 580, which replace the L 564, L 574 and L 580.
While the machines have been restyled, they retain Liebherr's &2plus2' fuel saving drive technology. However, the machines have a new cooling and electronic system, and operators will appreciate the +28% bigger cab, which has a more powerful air conditioning unit.
New safety features include a single-part laminated front windscreen, larger external mirrors and four floodlights. Collision protection has also been included in the rear ballast, and the rear lights have been directly incorporated into the ballast for more protection.
Terex's 74.5 kW 9.2 tonne SKL160 and 129 kW 14.4 tonne SKL260 wheeled loaders are now available worldwide and further models will be added to the range in 2007.
“The SKL260H has been available in Europe since last year and 158 units have already been delivered but it is now available worldwide,” said Terex product manager Dirk Mysch. “Both the SKL160 and SKL260 are good for the waste and materials handling and are competitively priced.”
Besides a quick hitch system for attachments, the heart of the new loaders is the unique SP (Schaeff-Parallel) front loader arm geometry combines the benefits of parallel design with those of Z type design, so full breakout and tearing forces are maintained throughout the lift range.
According to Mr Mysch, most competitive wheel loaders have a mechanical drive, but the SKL260H outperforms the competition with its hydrostatic drive technology and reduces operating costs by up to -10%. “The hydrostatic drive reduces tire slippage,” he said. “You can be working in the muddiest site on earth and be confident that you're going to load the bucket without spinning the wheels. The result is faster cycle times and less wear and tear on the tires.”
Operator comfort has also been attended to and the models feature a new two door cab which is spacious and creates a relaxed working atmosphere. Filtered air from the climate controlled air conditioning makes for a pleasant working environment at all times, with large glass windows down to the cabin floor providing optimum all round visibility at all times.
Komatsu's new WA150PZ-5 weighs in at 8.7 tonnes and is powered by a 71 kW engine. The machine features Komatsu's new &PZ' boom linkage, a modified Z-bar design that provides high break-out forces with the parallel movement required in pallet fork applications.
John Deere's new 18400 lb (8.3 tonnes) 344J wheeled loader has a hydrostatic drive which helps the machine achieve travel speed of up to 19 mph (30 km/h). The 344J is powered by a 71 kW PowerTech engine and offers a maximum breakout force of 17310 lb (7.8 tonnes).
JCB has also added to its compact wheeled loader range with the addition of the 4.8 tonne 406, which is powered by a 43 kW engine and offers a lifting capacity of 2.5 tonnes. The new machine features a wrap around counterweight for greater stability and has been designed to maximise availability with the major service interval extended to 1000 hours.