It’s taken eight years, but the European Machinery Directive now applies to lorry loaders, in the form of EN 12999. The process has not been easy.
Controversy has courted the subject since before the directive was released, according to HMF export manager Torben Ude Petersen. The industry’s reluctance affected the scope of applicability of the standard, he says. Although the standard was ratified in September 2002, replacement of national standards was delayed until March 2003.
True to form, EN 12999 has raised the bar for loader cranes. According to Hiab: ‘The authorities used to turn a blind eye to minor deviations and imperfections in the different solutions. As there existed no valid interpretation of the Machinery Directive for truck [loader] cranes, different interpretations were accepted. Manufacturers have, for various reasons, failed to keep abreast of developments. An official standard now eliminates any likelihood of misinterpretation. EN 12999 is now the guiding rule.’
The requirements
The standard sets out the minimum requirements for the design and provision of information in instruction manuals. CE-marked lorry loaders sold after March 2003 must comply. Older cranes need not be refitted.
The new standard generally requires more work than before to prevent cranes from tipping. It specifies new technology in the superstructure and in the chassis.
Both a rated capacity indicator and limiter are now required on all new cranes. At the simplest level, a pressure relief valve set to open above 130% of the crane’s rated capacity functions as a limiter for cranes with rated capacity of less than 1,000kg, or a maximum net lifting moment of less than 40,000Nm. For these lighter loaders, a pressure gauge located next to the controls marked with the pressure corresponding to 100% lifting capacity suffices as a rated capacity indicator. Also, crane control positions should be equipped with a red mushroom emergency stop button.
Heavier-duty cranes (rated capacities more than 1,000kg or maximum net lifting moments greater than 40,000 Nm) have more complex requirements. The rated capacity indicator must also warn when the operator has exceeded 90% of capacity, and again when the crane is overloaded. Cranes with outreach greater than 12m should have an audible warning for people near the crane. Exactly when the rated capacity limiter cuts in depends on the outreach, ranging from 108% to 120% of rated capacity.
The rated capacity limiter must also function with manual extensions and winches. Loader cranes of any size must now include valves to prevent the load dropping suddenly.
Because they work in the controlled environment of a stockyard, EN 12999’s stipulations for timber loading cranes are slightly weaker.
EN 12999 also requires greater research into stability of the chassis. Stabilisers need to be locked into the transport position by two independent means, and at least one should be automatic. Their state locked or unlocked should be visible from the drivers’ seat. The stabilisers should now accommodate ground evenness of 10%. And the chassis should now be equipped with levelling bubbles.
The standard does not include language that requires users to deploy stabilisers when lifting, although the UK’s Health & Safety Executive (HSE) is already pushing for an amendment. EN 12999 does not in fact even require stabilisers to be installed at all, so long as the crane will not overturn ‘under foreseen operating conditions.’ It then defines that phrase more clearly with a test situation. Loaders may well be unlikely to pass that test, and so stabilisers will probably be included as a matter of course.
The HSE may soon get its way. In a February statement, it said: ‘Manufacturers have agreed to pursue the development of suitable and reliable interlock systems (or an equivalent engineering solution) to be commercially available by 2006.’ (Timber handling loader cranes are again excepted from this requirement.) The manufacturers claim they have made no such agreement, however. Doug Dyson, past chairman of the (UK) Association of Lorry Loader Manufacturers & Importers, says: ‘Manufacturers said it would take at least four years to come up with [stabiliser interlocks]. The HSE translated that to mean they will be there in four years.’
Whatever happens, the HSE has its own advice, beyond the scope of EN 12999: ‘Employers should ensure that interlocks (or an equivalent engineering solution) are fitted where practicable for their machinery and delivery needs,’ it says. It goes on to say: ‘A policy dealing with the delivery of loads and agreed actions to be taken in the event that a lorry loader cannot deliver its load in safety i.e. if both sets of stabilisers cannot be deployed according to the manufacturers’ instructions, must also be in place.’
The changes
According to Lars Andersson, chairman of the CEN committee that prepared the standard, and Hiab’s chief of product safety and control systems, EN 12999 will ‘help pave the way for innovations in electronics in cranes’.
The requirement that cranes have a rated capacity indicator and limiter raises the amount of on-board electronics. But it appears that the standard is embracing what is the current state of the art of electronics among high-end loader cranes.
Here, for example, is Fassi’s description of its Electronic Control System (FX).
‘A system that manages the various functions of the machine, ensuring “intelligently” that, irrespective of the conditions of use, the crane is never subject to overloading and its stability never compromised.’ FX alerts the operator when approaching 90-100% of the capacity, monitors lifting ram pressures and records the crane’s utilisation time, among other functions.
Another example is Hiab’s automatic duty control system, which automatically de-rates the crane by about 10% for grab operations, depending on the operator’s manipulation of the levers.
Atlas has also launched a computer-controlled crane management system that monitors the crane, automatically analyses errors and lowers the load in an emergency. A computer-actuated cut-off system replaces hydraulic components, according to Andreas Finger, head of R&D at Atlas-Terex. It has also made some lower-tech changes, such as secondary stabiliser locks, installing levelling bubbles, covering hydraulic lines, height warnings, and new stabiliser foot-plates.
Opinion among manufacturers varies about how faithfully the standard follows the machinery directive.
‘Many or all of the guidelines established from EN 12999 in its draft stages were adopted as good ideas or common sense solution before they were even finalised as part of the standard,’ says Petersen at HMF. ‘These include secondary stabiliser locking devices, winch safety systems and understanding levels of protection required in general.’
However, Carlo Molesini, Fratelli Ferrari’s customer and technical service director, argues that the machinery directive did not call for the requirement for two separate stabiliser locks, as contained in EN 12999. He also maintains that the requirements for rated capacity limitation on manual boom extensions, audible alarms on larger loaders and stabiliser use on uneven ground also deviate from the machinery directive.
All the same, F.lli Ferrari has developed compensating systems to cope with the changes. It has designed an audible alarm signal running from the rated capacity limiter to the truck’s klaxon. At SAIE 2002, it showed a load cell placed between the manual extension and the hook block. The indicator, powered by a battery that recharges in the truck’s cigarette lighter, transmits load information to a hand-held readout. The device was developed, in response to EN 12999, in conjunction with Autogru PM.
In adapting its old fleet of cranes with manual boom extensions, Effer took a different approach. It re-worked the load charts so that the crane can lift the maximum load whatever the boom position. Into its non-compliant cranes it has also built a second stabiliser lock, included a load capacity indicator, redesigned hose and pipe runs, and redesigned rear stabilisers to accommodate uneven ground, according to export manager Giancarlo Manzano.
Fassi has also rerouted and encased hoses at risks, and added mechanical blocks to protect the stabilisers.
Palfinger’s new cranes are similarly specced. It has installed several secondary locks on stabilisers and also offers an optional transport position monitoring system, re-routed hoses, box levels on stabilisers, alarms for cranes with outreach of 12m and greater, and overload protection when using onboard controls or remote control units.
Using loader cranes
Although primarily a standard for manufacture, EN 12999 does specify some elements of safe use when it sets out requirements for the lorry loader instruction manual. The manual, it says, should include diagrams and descriptions of the controls, pre-start and post-operational checks, service conditions for intended use, warnings about working near power lines and about unhooking hydraulic hoses, advice on ground support, advice about planning a lift, noise emission and temperature ranges suitable for operation.
EN 12999 is even more specific about what instruction manuals must tell operators to consider when planning a lift. These include evaluation of the load selection of lifting gear, the correct setting of the boom system selector switch, position of crane, load and clearances throughout the lift and site conditions.
For some manufacturers, these guidelines do not go far enough. Says Effer’s Giancarlo Manzano: ‘With the introduction of the machinery directive, product liability has been put for the first time in Europe on the shoulders of the manufacturer exclusively. For those manufacturers that are sincerely concerned about the potential dangers relating to the use of their machine, this means a big headache, as there is a virtually infinite number of dangers. It would have been much more appropriate, for instance, to allow the use of knuckleboom cranes only to licensed drivers through the creation of a “driver’s licence” program.’
Now that the hardware aspect of the loader crane industry has been sorted out, it is the human side that must be next on the agenda with formal operator training and perhaps certification ripe for discussion.
