Zero heroes

If sales figures are anything to go by, mini excavators have never been so popular, with an incredible 142,818 such machines sold around the world last year, according to Off–Highway Research. This was a 21% increase on 2005's sales figure of 114,065 machines, and ahead of the 14%growth seen in the equipment market as a whole.

The total equipment market was 664,525 units last year, so another way of looking at things is that one in every five construction machines sold last year was a mini excavator.

There are many factors that have contributed to these increased sales. There is a general prevalence of small–scale utilities construction and general road repair and maintenance–work that mini excavators are well suited to. In addition, the fast maturingEuropean equipment rental sector has driven sales up, with renewal policies that are seeing machine worked harder and replaced quicker than they were in contractor–ownedfleets.

Getting shorter

Another strong trend over the last ten years has been the emergence of short– and zero tail swing mini excavators. From being unheard of in the mid–1990s, zero tail swing machines are generally estimated to account for some 40% of today's compact excavator market.

The advantage of such machines is that they are designed so that the rear counterweight does not extend beyond the footprint of the tracks when slewing, or, if it does, the overhang is minimal. This means it is impossible for the back of the machine to hit people or objects when rotating.

The downside to such machines is that for any given digging performance they generally need to be wider and heavier than their conventional counterparts to ensure stability. Kevin Zimmer, business director of Bobcat's European excavators business said, “Certain sizes have a bigger reward or bigger benefit–particularly above 3 tonnes. You see certain applications favouring minimum or zero swing machines, such as working close to buildings. You also see things the other way–machines that tend to work in open spaces are often conventionally designed.

“As you go smaller–under 2.5 tonnes–the reward for zero tail swing becomes less because of the footprint and weight of the machine. We also believe there will always be a market for conventional machines above 2.5 tonnes there are benefits in terms of performance and so on.”

Andrew Knight, vice president for global marketing of Volvo Construction Equipment's compact equipment business echoed these sentiments, “The general view is the smaller the machines, the less necessary a short radius design is. The 8 to 9 tonne machines are very popular as short radius excavators and the compromises are much less. By volume I would say it's about 60% standard and 40% short radius, but that's an average across the 1 to 11 tonnes sector,” he said.

“There are other things such as width and weight, which are very important for customers when it comes to transport. If something like transport weight is a key criteria, a conventional machine might be better. People understand that you can get the same performance from a shot radius machine but of course it's going to be a bit heavier,” added Mr Knight.

According to David Phillips, managing director of Off–Highway Research, price is also an important consideration. “A 5 tonne machine's price is such that the additional cost of a zero tail swing version is not that much. However, in the largest sector–around 2 tonnes, which is about 30 to 40% of the total market–the additional cost would make a tremendous difference, and there's a question about whether it is needed,” he said.

According to the manufacturers however, in weight classes where there is a choice between conventional and short radius machines, the price differential is not as great as it once was. “I don't fell there s a big price differentiation now, especially as we've got better at building them. I see a continuing narrowing of the price gap for that reason,” said Mr Knight.

Mr Zimmer had similar sentiments. “You're seeing the price gap between traditional and zero tail swing models come closer together, partly because a lot of manufacturers have gone towards zero tail swing machines,” he said.

Looking at the new machines that have come onto the market in the last year–many of which were launched at the Bauma exhibition in Munich, the preference for reduced and zero tail swing machines could not be clearer.

Bobcat, which introduced its first zero tail swing excavator, the 3.6 tonne 430 ZHS, as recently as late 2003 has since added to its range this year with the 4.7 tonne 435 ZHS. Bauma saw the launch of two complementary smaller machines, the 2.6 tonne 425 ZTS and 2.9 tonne 428 ZTS.

The company has also launched new machines in the sub 2 tonne class in the shape of an enhanced version of the 1.5 tonne 323 mini excavator as well as an all–new 1,476 kg (3,248 lb) 321 machine.

All four feature load–sensing hydraulics, while an interesting addition is Bobcat's FastTrack option. This replaces the conventional track drive with a hydrostatic drive that increases the travel speed from the normal 4.2 km/h–around walking speed–to 8 km/h or more.

Volvo also has a four–model range of short tail swing excavators, and it is interesting to note that this is one of the companies that classifies machines as big as its 8.5 tonne ECR 88 model as ‘compact’. Bauma saw it introduce upgraded versions of two of these, the ECR 58 Plus and ECR 88 Plus, which weigh in at 5.8 and 8.5 tonnes respectively, and now feature heavier counterweights for improved lifting capacities.

Volvo's 5.5 tonne EC55B Pro is the most popular of its compact machines. It is available in a demolition specification with ROPS/FOPS protection, 380 mm wide steel tracks and additional undercarriage protection. When carrying a new Volvo HB300 low noise breaker (see equipment pages this issue), the machine complies with European noise directive 2000/14/CE, allowing it to be used inside buildings.

According to Olivier Cuisnier, global marketing manager for Volvo compact excavators: “We have seen increased demand for the EC 55B Pro as a specialist small demolition unit. It offers the advantage of compact size, enabling it to be easily transported and operated in restricted sites.”

Like the larger of Volvo's two new machines, Komatsu's PC88MR–6 underlines the popularity of larger compact machines with a zero tail swing design. The new 8.3 tonne machine features closed circuit load sensing hydraulics, and a quiet, spacious cab with a suspension seat and air conditioning.

New players

The latest manufacturers to enter the zero tail swing sector are the two Koreans, Doosan Infracore and Hyundai. Both entered the market is year with machines in the popular 3.5 nne class–Doosan's is the DX35Z, while yundai's is the R35Z–7. The latter comes with

0.11 m³ bucket as standard and offers a aximum diggingdepth of 3.15 m, while it has dump height of 3.46 m.

Finding the fullest ranges of compact xcavators in general, including short tail swing odels, tends to mean looking at Japan's ading manufacturers–Japan, after all was the region where the concept w established. It is these manufacturers th also seem to be moving towards zero swing machines in the lower (sub–2 ton weight classes.

The three new additions to Hitac compact line–up at Bauma were all s tail machines, the 1.1 tonne ZX10U–2, tonne ZX17U–2 and 2.3 tonne ZX22 Changes to the counterweights imp stability, while the cabs have been imp with more legroom, better visibility an conditioning. w Holland's new 1.6 tonne

E18 SR, developed in conjunction s excavator partner Kobelco, features dercarriage whose width can be ed hydraulically from 0.99 m to 1.3 is allows it to get into tight spaces the undercarriage is reduced, while ng the gauge gives the E18 SR stability when working. her new machines at Bauma ded Amman–Yanmar's 1.68 tonne 7, 4.64 tonne ViO45 and 5.21 tonne 5. According to Ammann–Yanmar, arger machines feature a wealth of gn improvements, such as better hose ng and cylinder protection, gger dozer blade and the on of a quick coupler. er added two 5 tonne class mini excavators to fill gaps in its 12–model range at Bauma. The 50VX and 55VX are both zero tail swing models weighing in at 4.8 and 5.3 tonnes. Similarly, Hanix Europe launched the 5.5 tonne H55DR, which features a larger, more comfortable floating cab to reduce noise and vibration within the cab, and an improved control layout. Fuel consumption has also been reduced, withHanix saying that fuel savings of 5% are possible. The counterweight sits as lo as possible in the swing frame to provide a lo centre of gravity, improved handling, cont and stability.

At the lighter end of the spectrum, Messe has three new mini excavators on the mark covering the 1.3 to 2.8 tonne classes. The 1.3 tonne M–13 is a short (rather than zero) radi machine, and is narrower than its predecess with a 0.99 m undercarriage width.

The M–16U meanwhile is a genuine zero ta swing machine, with a hydraulically adjustab undercarriage. This is 0.99 m wide whe retracted for access through tight spaces, bu it can also be extended to 1.3 m wide fo added stability. Further up the range is the 2 tonne M–28U, another zero tail swing mod that comes in just under the 3 tonne mark

– an important cut–off point for transportation in many countries.

Neuson has added the 2.6 tonne 28Z3 zero ta swing model to its rang this year, giving it fou such machines in its rang from 2.6 to 7.5 tonnes. A interesting feature is the ti up cab, which has bee carrieddown from last year new 38Z3, an innovation th makes it easy to maintain t machine. The addition of conditioning–another feature of the 38–will also be welcome by operators in climates.

JCB's compact excavator range compri 14 models from 0.8 to 8 tonn and incorporates both conventio and zero tail swing models. One the latest additions is the 8035Z a 3.7 tonne zero tail swing model, which sits alongside two other new models, the 2.7 tonne 8025ZTS and 3.2 tonne 8030ZTS.

Whatever your mini excavator needs, you'll ?nd a machine to meet them in the Komatsu range. These highly compact machines deliver outstanding power and stability while working in even the smallest spaces. At their heart, the CLSS hydraulic circuit guarantees unrivalled performance and precision regardless of load and engine revs. Maximizing your overall productivity, the new Komatsu quick coupler lets you change attachments rapidly and easily. Moreover, the convenient positioning of inspection points and major hydraulic components reduces maintenance times. Komatsu covers the mini excavator range up to 5 tons with 9 machines designed to meet any need. Not bad for a digger.

All three have revised boom and stick designs, while a low–mounted one piece counter weight improves stabilitiy. Access to the cab has been improvedwith a larger door, and this can now be locked open. Crucially though, evenwhen left in this position, it does not overhang the tracks' footprint.

Also new at Bauma was the 8020, a traditional machine in the 1.9 to 2.3 tonne class. JCB says this is the largest excavator that can be legally towedbehind crew cab pick–up trucks under European regulations.

In a similar vein, one of the few traditional overhanging counterweight mini excavator launched at Bauma was Terex's 2.5 tonne TC 25–a fact that underlines the diminished popularity of zero tail swing designs in the smaller weight classes. A new boom design and hydraulics improve performance, and as with all Terex minis, the boom cylinder is top–mounted for greater protection. It boasts a dump height of 2.8 m and 15.8 kN ofbreakout force.

Choices, choices

The large number of manufacturers marketing compact excavators in Europe, both traditional and short radius designs, means more choice and hopefully keener prices for rental companies and contracters.

Another factor is the increasing number of Chinese manufacturers that are achieving CE–mark certification to sell their products in Europe. It remains to be seen how good the quality of these machines are and how well they are supported with servicing and spare parts, but again it should mean more competition among suppliers, more variant models and better prices.