THE WHEELS JUST KEEP ON TURNING

Back in 1988 around 1,500 wheeled loaders were sold in the UK. Even in the current straitened times that figure is still likely to be around 850 or almost 60% of the 1988 figure. Not a bad performance considering that, for example, crawler loaders have fallen away to almost nothing. If the UK had decided to embrace small wheeled loaders as enthusiastically as some of our Continental cousins have done then the figure could well be considerably higher. Just take a look at any streetworks contract in Germany for example. Zettelmeyer, Atlas Weyhausen, Kramer-Allrad, O&K and Hanomag are all German-based manufacturers which rely heavily on high domestic sales but which have also failed to achieve much market penetration in the UK. However that doesn't mean that they've stopped trying. Far from it in fact - most are redoubling their UK sales efforts. There can't be so much difference in the way that each respective nation goes about its work. Except that the UK has a huge pool of backhoe loaders!

If you take even a cursory look at the number of wheeled loaders in use today you'd be forgiven for thinking how we ever managed without them. If you couple that thought with another on how unsophisticated wheeled loaders were as recently as the early 1960s, then perhaps you'll realise that a sort of revolution has taken place.

The revolution was powered by hydraulics, of course, and you'd be right to wonder how we ever managed without them too. Ropes, pulleys and levers were all very well but hardly the height of efficiency. Nowadays, hydraulic system design has reached such heights that it sometimes seems that it is capable of anything the user can throw at it. Not totally true, of course, but it is certainly very sophisticated.

Boom suspension, built-in weighing systems, automatic return-to-dig and bucket tip kick-out are all taken for granted. All the operator has to do is avoid hitting the receptacle into which he's loading, be it hopper, screen or merely a tipper lorry. Most of the rest of the work has been taken out of the equation by a combination of hydraulics and electronics. So much so that it isn't uncommon today to find a wheeled loader acting as the primary production tool in a quarry - perfectly possible once the face has been drilled and blasted to fragment the stone. Couple the wheeled loader to a modern movable conveyor head like Nordberg's Lokotrack, for example, and the production layout can be highly efficient as well as flexible.

Currently the largest wheeled loader in production is Caterpillar's 994. It weighs around 190t depending on configuration and from a standing start back in 1991, Cat has racked up more than 70 units sold worldwide. The first machine has yet to be sold in this country, but there is one just over the Channel in Belgium. It belongs to Carrieres D'Antoing and it's the primary production machine in a huge limestone quarry which currently outputs around four million tonnes per year. The big Cat feeds four Dresser Payhaulers, each of 120t capacity. They unload direct into the crusher for the primary aggregates operation which is also the start point for the cement production process. The current hourly output is 1,500t per hour, but since the crusher is capable of 3,000t per hour there is clearly room for improvement. The Nirvana of 3,000t per hour will never be reached because the haul distances vary as different benches of the vast quarry are worked in rotation. The big Cat wears a mighty 18m3 bucket and it's scheduled to work around 30,000 hours over a five/six-year period. Contrast that with a more normal 2,000 hours per year and it can be seen that when Carrieres D'Antoing says PRIMARY PRODUCTION MACHINE that's exactly what it means. And the choice of whatever method (wheeled loader or excavator) was entirely open in an operation where the lowest cost per tonne is the driving factor which underpins the whole process. In a price-sensitive industry it's a great incentive.

Machines don't have to be that big to be successful however. Many a local authority uses a small wheel loader or two just to tackle the day to day tasks in a depot or stockyard. Not that it's entirely the prerogative of an LA of course. Some private organisations have discovered the benefits too. In Shepherds Bush, West London, cable/telecomms contractor McNicholas has a materials supply stockyard. As you'd imagine, space is at a premium yet there's a wide variety of materials to be handled. The answer is a small wheeled loader, in this instance a Kramer 312. The compact dimensions of the 312 coupled with a 3m loadover capability means that it can both move easily within the tight lanes of the yard and load into the six-wheel tippers favoured by the construction gangs. Four-wheel steering and hydrostatic transmission help with the precision operation too, of course.

CJ has carried out many a Field Test on various wheeled loaders in which we compare old with new. Despite the fact that each new model seems to reach a pinnacle of achievement the production gains just go on and on. The latest marque to submit to the CJ Field Test torture was O&K with its L45 versus the latest L45B. Over a three-day period, CJ was able to show that, despite identical power outputs, the L45B outperformed the older unit by between 20% and 30% on a series of set tasks. It's able to achieve this because O&K design engineers configured the gearbox ratios to give a lower first ratio (for high digability in the stockpile) coupled with higher upper gear ratios (for faster acceleration out of the pile and into the truck/hopper). So it isn't brute force that tells, it's all about transmission ratio choices and hydraulic system tuning to ensure the bucket can be raised quickly to tipping height in the time it takes to get the (faster) loader positioned over the truck. In fact O&K builds in extra sophistication. If the operator pushes the first gear instant engage button but then the machine senses little resistance as it hits the stockpile, it won't change down. Clever or what?

There's more evidence of hard thinking from other quarters too. Caterpillar has done much research in the wheeled loader field and produced some interesting results. It discovered that European quarries spend around œ250 millions per year on wheeled loaders. Another fact to emerge from this research is that 60% of all wheel loaders (above 75kW) are used primarily for rehandling. Ten per cent are used as primary production (face) units and the remaining 30% are used on light utility duties. Whilst Cat was confident it had the right machines for most applications it felt that there was some scope for improvement in certain key areas.

So Cat addressed the 60% sector for strict marketing reasons - it's the biggest! The result was a pair of machines designed to work best in loose, free-flowing materials, like sand and gravel for example. The Quantum series of wheel loaders is designed to outperform similar machines by being purpose-configured for the job. So Quantums have better power and torque-ier engines, revised gearbox ratios to get both better 'bite' in the heap and faster backout and acceleration to the unloading point. Faster hydraulics get the bucket up to dump height quicker to match the ground speed boost. Production gains of up to 30% have been recorded but real-life scenarios and operator constraints have levelled this out to cost savings of around 15% per tonne day-in, day-out. And when costs are king as they are in a low margin industry like quarrying, then 15% is a very worthwhile gain. We stress that this kind of gain is not 'pie in the sky'. CJ visited a quarry in Eire recently (CJ, 2 June 1994) and watched a pair of Quantums demonstrate the possible production gains in a real working quarry stocking/loading area.

Quantums are not designed to be production face machines, they are solely for rehandling/truck loading. They are typical of the new generation of machines which are being designed to match exactly the job profile for which they are intended. CJ in fact tested a 970F Quantum (CJ, 7 October, 1993) last year and recorded excellent figures in a strictly controlled series of tests. They bore out Caterpillar's design aims almost exactly.

VME, in the guise of Volvo loading shovels, has had great success with waste handling in transfer stations in various areas of the UK. In particular, London has a high proportion of Volvo wheeled loaders in its waste transfer operations. The combination of an operator-friendly cab environment, low noise levels and high-lift loader arms means that Volvo wheeled loaders are well-suited to the work which is often in enclosed buildings. The Swedish company has done huge amounts of research into making machines as user/operator friendly as possible. Of course, so has just about every other manufacturer worth its salt - no point in being left behind in the race. But the point is that Volvo was doing it first! This is where it has been able to reap the advantage.

Volvo has also done lots of work on loading shovels which don't need a steering wheel! Not as strange as it at first seems, the idea is to give the operators' arms an easier task. Instead of being wrapped around a steering wheel they rest naturally on controls built into the seat armrests. It's had a good take-up in Scandinavia but less so here in the UK. Just to make the operator feel at home, Volvo leaves the conventional steering wheel in place - and connected! Volvo calls it CDC - for Comfort Drive Control.

John Lines is md of TM Rentequip, the specialist hire company which concentrates on long-term contracts for wheeled loaders. He says: 'Although this business sprang from the original Volvo importer Anglo-Swedish Equipment, we have no brief anymore to use Volvo machines. However, over the years we have come to discover that for many of our customers, a Volvo wheeled loader is the ideal solution to a problem. The fact that we get superb back-up from VME and excellent residual values at selling time are both bonus points for us.'

Just to illustrate the almost universal application of wheeled loaders, the tale of two JCBs is interesting. A JCB435 with specially built high lift arms and a two cubic metre bucket spends most of its working hours inside the holds of ships at Bristol Royal Portbury Docks. It works hand-in-hand with a pair of Finnish-built Kone Continuous Ship Unloaders which are used to handle cargoes such as coal and grain/feedstuffs.

The 435 comes into play when the Kone has extracted as much coal as possible from the main area of the hold. The wheeled loader is lowered into the hold where it sweeps the remainder of the cargo into a central stockpile from which the Kone continues to feed. Incidentally, the Kone is capable of feeding the dockside conveyor system at up to 4,000 tonnes per hour! Once that task is accomplished, the JCB switches to picking up coal from the nooks and crannies of the hold and feeds it directly into the grizzly fitted at the side of each unloader. The 435 has no less than 6m of dump height as well as a high tip bucket linkage and a forward dump reach of 1500mm. To help cope with the unusual working environment the 435 also has a high capacity radiator, spark arrestor, automatic engine shutdown facility, auto-lubrication and limited slip differentials.

By contrast, JCB has supplied another special 435 to the British Antarctic Survey for use in building and then maintaining a new runway at Rothera Point Station, Adelaide Island, Antarctica.

The JCB design team worked closely with the BAS engineers to make certain the machine would work reliably in temperatures which can dip to minus 30degC in winter! The machine (and a 180kW independently powered snow blower attachment) is designed to run on kerosene instead of gas oil and special lubricants are needed to cope with the low temperatures met. A quick hitch loader attachment copes with the 2.1m3 bucket, pallet forks and the 3m-wide snow blower which is essential for keeping the runway clear. Tyre chains take care of traction in the treacherous ground conditions commonly encountered. All this apart, it's still recognisably a JCB 435 articulated wheeled loader!

One of the areas where wheeled loaders have yet to take off in the UK is that of very small machines. Although the type is very popular in mainland Europe, it hasn't yet made it in significant numbers here. Both Kubota and Pel-Job offer tiny units well-suited to working in very restricted areas. In fact, Pel-Job has one of its EL451 units working in what must be a one-off situation. It handles all of the fetch and carry in a factory specifically set up to manufacture cat litter from waste paper!

VME owns both Zettelmeyer and Michigan which represent opposite ends of the wheeled loader spectrum. German-based Zettelmeyer specialises in small hydrostatic-drive articulated wheeled loaders while US-based Michigan majors on large non-articulated machines.

In fact VME has recently announced that for the first time in its history a Zettelmeyer unit, the SL602, is to be marketed as a direct replacement for a Volvo unit, the L30. It will be interesting to watch what the take-up is as the typical L30 user tends to be conservative with a small 'c' when it comes to machine specification. Once the average L30 operator experiences the Zettelmeyer, logic should dictate that he'll rapidly become a convert. It's that easy to drive!