Last time I wrote for Cranes Today, in the April 1999 issue, it was to highlight some of the key developments of products offered by manufacturers of truck mounted loaders.
Many of the ‘anticipated future requirements’ have now become reality and the headline of the article proved to be very apt – ‘Longer, Stronger, Faster Loaders’.
Due to the vast range of products available and, more so, the key design criteria, it is more important than ever to ensure that the operator is offered the right tool for the job. A number of machines have now been developed with a niche application in mind; others with the intention of providing a ‘multi-purpose solution’ for a broader range of operators.
With regard to a machine being used on a hook-only application, the standard way in which lifting capacities are stated in brochures throughout the industry can often be misleading to the untrained eye. For example, two manufacturers can offer a 25tm-class machine, which in the brochure, will show the main boom at 15° above the horizontal position. In theory, both machines should lift 5t at 5m and this will be clearly identifiable on the brochure. What is much less clear is that one machine may be fitted with power linkages which dramatically enhance the lifting capacity above or below the horizontal line. The operator, therefore, may be under the impression that two machines are the same, because they are both 25tm. The fact is, the machine with linkages is capable of performing tasks at various radii far beyond the abilities of the other. These linkages alone can add noticeably to the price of a machine, yet they can save the operator money, as in some instances he would have to buy a larger (non-link) machine to get the same benefits.
On grabbing cranes, it is far more common to avoid the use of linkages. This is to reduce weight and cost. Not having linkages also improves the operating speed of the loader, which is an important consideration for this type of application.
So what about the grab loader? Whether the grabbing application is muckaway (clamshell bucket), or brick & block (builders merchant), there are striking differences in the requirements of the operator. For example, the muckaway operator will do a perhaps 20 or 30 operations at four or five different sites a day. The builders merchant, on the other hand, is working more on a multi-drop basis, making two or three lifts at a time, but visiting many more sites in a day.
The majority of manufacturers now design their mainstream range loaders to be in the B3 loading group as standard. This means that they are suitable for hook applications and medium-duty grabbing applications, without any de-rating being necessary for when a grab is attached. The B4 loading group is considered to be more for arduous grabbing applications, such as muckaway, scrap handling, and forestry applications. There are a very limited number of genuine B4 loaders on the market.
Taking the mainstream/multi-purpose loaders out of the equation, what are the main differences between a hook crane and a grab crane? As stated earlier, linkages are one consideration. Boom configuration can be another. For example a grabbing crane may have a shorter outer boom/extension configuration than a hook crane. There are reasons for this – a grab crane will normally be travelling in an unfolded position permanently over the vehicle body and it is important that it will ‘fit’ into the back of the vehicle body in a straight line. Also, if the outer boom is shorter than the inner, the angle of hook approach near to the loader column is better, thus improving the chances of evenly distributing the load across the vehicle body.
Can I fit a grab to my hook crane? If the loader is designed to B3 group as standard then the answer is a definite maybe! However, if you are specifying a machine for hook work and may occasionally require it for grab duty, you need to ensure that the correct number of hydraulic functions are available. You also need to consider whether the crane will still fold up for transit and whether the standard control configuration is sufficient for when a grab is fitted. It is now relatively simple (and cost-effective) to buy a grab attachment with a quick release mechanism, which allows you to switch from hook to grab operations in a couple of minutes.
What about cost? In tonne/metre terms, a grab crane is not necessarily more expensive than a hook crane. However, the price of a grab crane is influenced by the number of extra facilities often required for that application. These would definitely include extra valve functions and piping, plus the cost of the grab attachment itself. Additionally, it is not uncommon for a set of stand-up controls to be fitted and other peripherals such as a larger oil tank (or oil cooler), which helps cope with the additional heat generated by the more arduous application.These extra items can easily increase the cost of a standard machine by some 40% or 50% – which brings us back to the circular argument of choosing the right tool for the job.
Sadly, other factors can have an undue influence on an operator’s choice of loader. The loader industry in the UK, for example, has seen instances of a product being specified to meet a target price (or worse, a competitor’s price), rather than the true requirements of the end-user. There have also been a number of occasions where a customer will be offered ‘the next best thing’ because it happens to be either available from stock or on special offer. In defence of our industry, this is not always the fault of the company offering the product. It seems that some customers prefer to feel that they have got a good deal rather than knowing that they have bought the right tool. They go on to learn that the wrong tool is never a bargain. However, most operators are very professional and are becoming increasingly well educated about what they are fitting to their trucks. In summary, and irrespective of all the arguments, it is up to the industry to try and maintain integrity. As we all know, the long term effect of selling the wrong machine means our reputation takes a blow.
Whatever the application, the best advice to any operator specifying a new truck-mounted loader is to satisfy yourself that the machine is right for the job and to do your utmost to ensure you have considered any future demands which might be placed on it during its lifetime. As with cars and trucks, consider the whole-life cost and any product benefits, which will nearly always save you problems (and money) in the longer term.
