Breaking new ground – compact dumpers & mini-excavators
Published: 24 February, 2012
There seems to be no let up in the continued popularity of mini excavators and site dumpers. Used individually or as a matched pair, such equipment has become an essential and practical tool for anyone that would have previously reached for the wheelbarrow and spade.
The ability to move such compact kit quickly and efficiently on a trailer behind a van or pickup is adding to the popularity of what have effectively become motorised versions of the traditional wheelbarrow and shovel.
Opting for mechanisation
UK Cat equipment-distributor Finning sees the market growing as a result of legislation, a shortage of labour and the move away from hand-held equipment in favour of more productive, mechanised methods.
“Given the choice, few would opt to dig a hole by hand,” says Finning’s Michelle Rastall. “It has become mechanisation every inch of the way, particularly as the market has expanded away from the traditional 1.5 to 3-tonne sector to include ultracompact excavators and tracked dumpers too.”
Such market expansion has been fuelled by the introduction of several key innovations, including expanding-width track frames, short radius upper structures and attachment versatility. Here, it’s easy to see how the bigger picture starts to unfold. Smaller machine developments have risen from renovation projects, DIY enthusiasts and local authority maintenance teams looking for mechanised solutions where narrow access and space limitations have dictated that a wheelbarrow and shovel have been the only viable option.
The zero-tailswing sector
Neuson excavator specialist Brian Gardner of NK Lifton agrees. “The mini excavator has evolved into a thoroughbred work tool,” says Gardner. “These machines are now recognised for their abilities and their innovation.”
Gardner believes the market will continue to grow throughout 2004, driven by a desire by operators to step further and further away from annual labour.
“Our new Vario compact models will continue to push the boundaries for those who want a premium product, while our entry into the zero-tailswing sector provides yet further choice for potential purchasers or hire customers,” he comments. Neuson’s 5-tonne and 7.5-tonne zero tailswing machines are said to have wider cabs and better service access than any other similar size excavator as a result of using a side-mounted engine.
It is a design element that also enhances machine stability, says the company.
The firm’s Vario offset slew system can now be found on the compact 3-tonne 3003, 3.5-tonne 3503, and larger 6-tonne 6002 and 8-tonne 8002 models.
“We’re very positive about increasing our sales through the second half of 2004,” says Gardner.
All-hydrostatic drive systems
Filtermech Plant Sales, which imports the IHI mini excavator range, has added two more zero tail-swing machines to an expanding portfolio for 2004. These include the 9NX micro model and the 1.5-tonne 15NX.
Features of the 9NX include an automatic slew brake system that locks the upper structure when slewing is not required - the firm says that it eliminates upper structure drift that can occur when operating on inclined surfaces.
Bobcat’s Keith Hoskins also believes that the market is still increasing, and he reckons the company’s new 430ZTS - Bobcat’s own zero-tailswing machine - will create an opportunity to grow the range, by applying the concept to other models in the Bobcat range.
The firm says the 430 ZTS mini-excavator is the first to feature an all-hydrostatic drive system for its under-carriage, called FastTrack.
The machine’s travel system uses a pair of independent hydrostatic circuits employing piston pumps and high torque axial drive motors to supply power to each track.
As a result, travel speeds of 4.2kph and 8kph are possible, and the firm adds that dedicated hydrostatic track drive offers better torque control when dozing. It also allows smoother turns under load when compared to conventional track drive systems.
Powered by a Kubota direct injection diesel engine rated at 42hp, the 430ZTS offers a maximum dig depth of 3m and a maximum reach at ground level of 5.09m. An offset boom provides 90 degrees of left swing, and 50 degrees to the right.
Operating weight is 3.6 tonnes and ground pressure, on 320mm tracks, is said to be 4.11psi.
At the bottom end of its range, the firm has joined the subone tonne sector with its 316 model - it has an operating weight of 820kg and with an overall width of 750mm, it is narrow enough to pass through a 76cm-wide doorway. Following its move into the micro-excavator sector, JCB has focussed its attention on its traditional mini excavator range, by introducing a series of enhancements.
The 802, 803, 804 and 8052 models now get Tier 2 emission compliant engines, along with a new cab interior and improved controllability. The 8052 also benefits from twospeed, auto-kickdown track motors.
A redesign in the cab department sees a flat floor with new pedals and an all-in-one instrument panel with electrical systems manufactured to IP69 standards - the latter is said to allow the cab to be power-washed with no risk of water penetrating the electrical system.
Upturn in the demand
All this activity among the mini excavator sector has brought about an upturn in the demand for site dumpers that can be matched to such productive compact kit.
Thwaites, for example, has chosen to move into the compact sector with its one-tonne capacity Hi-Tip skip-loading dumper. It joins the likes of Lifton and Benford, who offer narrow, one-tonne four-wheel drive dumpers suitable for use with mini excavators.
Working width of the compact machine is said to be less than 1m, but with high lift ability, the machine can discharge into a skip.
A hydrostatic transmission using Poclain wheel motors and a 24hp Yanmar three-cylinder engine provide the tractive effort for Thwaites’ first ultra-compact four-wheel drive dumper. NK Lifton has revised its site dumper portfolio offering new models from ranging from one to five tonnes capacity.
The entry-level LS850 model has been upgraded to carry a one-tonne payload and in recognition if its load carrying capacity, has been designated the 1001. It can pass through an 1180mm opening, but equipped with narrower wheels and tyres and with a reduced payload, the 1001’s width can be brought down to 990mm.
Hydrostatic drive and power from a Yanmar diesel engine gives the 1001 a useful 16.5hp.
Lifton’s former LS1200 has been rebadged as the 1501 with a 1.5 tonne payload and a high-tip skip, while further up therange, the firm’s mid-range three, four and five tonne machines have also been revamped, benefiting from hydrostatic transmissions using an axial piston pump combined with a hydrostatic motor.
Elsewhere in the range, the instrument console offers wraparound leg protection, while cast iron rear bumpers, integral lighting and a one-piece, hinged engine cover are part of the improved package.
Having a tracked dumper with a payload that matches one of its own wheeled dumpers allows NK Lifton to guide potential purchasers who have very specific requirements.
Against the wheeled Lifton 1501, the firm’s TD15 offers several advantages. These include a flat skip bed for load carrying, the ability to pass through 1000mm openings and a high degree of manoeuvrability - contra-rotating tracks see the TD15 spin within its own 2.79m length, where the pivot-steer 1501 has a 3.3m turning radius. Fine if you’re working in open spaces, less so when three- or even five- point turns are required to reposition the wheeled dumper.
There are further spin-offs from using a rubber-tracked undercarriage, including low ground pressure characteristics for use in soft, wet or boggy conditions and there’s also extreme hill climbing ability that sees the TD15 operate safely on slopes of up to 30 degrees.
But there are disadvantages too.
Despite the use of a two-speed hydrostatic transmission, it is much slower than the 1501 (7.5km/h maximum speed against 14km/h) and there’s no hi-tip capability for those looking to discharge into skips. Though it does offer three-way tipping, achieved by moving retaining pins to determine the point of pivot when the bed is raised. And automatic latching and unlatching of the side- or tailgate is a feature of the TD15 too.
Working in wet conditions
Recognising the demand for compact kit, JCB has introduced three tracked machines in its Dumpster line-up.
Badged TD7, TD10 and TD10SL, the petrol-powered models are said to be suitable for accessing very narrow sites and have travel speeds from 2.1-3.4 kph.
Load capacities are 710kg and 800kg for the TD7 and TD10 respectively, though the TD10SL has a reduced capacity of 750kg as a result of its self-loading shovel attachment.
Designed for use with the firm’s Micro excavators, the TD models measure 755mm in width and offer ground bearing pressures of between 0.17 and 0.19kg/sq cm, which gives them the ability to work in wet ground conditions where wheeled machines could not.
Cautrac, the UK importer for Yamaguchi and Morooka rubber tracked carriers, has added high tip versions of the WB05 and WB07 Yamaguchi machines to its range.
With load capacities of 500kg and 700kg, plus tipping heights of 1.25m and 1.3m respectively, the new models are said to retain the low ground pressure characteristics of the standard tipping machines, but with the ability to unload into a small capacity skip.