Contractors that need to move many loads weighing less than 5t have a difficult choice. There are lots of cheap alternatives to mobile, truck or rough-terrain cranes currently on the market. These machines are not cranes, but could be used for lifting by adding an attachment, or even some chains with a hook on the end.
Excavators can be used for lifting duties in Europe, provided they have extra safety systems. US regulations seem to be more flexible.
In recognition of this, the UK certification scheme for those directing lifting operations is now being revised to include a section on other lifting equipment. “The appointed persons employed by contractors are responsible for their sites and should be involved with planning all types of lifts including those involving excavators, telehandlers and lorry loader cranes,” says John Varcoe, senior manager, technical safety and training at trade group the Construction Plant-hire Association.
Telehandlers are sometimes used as crane substitutes
Many models of telehandlers, essentially big rough-terrain forklifts, have a reach of 10m (33ft) or more. Many have a slewing upper section, and look and work in a similar way to cab-down rough-terrain cranes. UK home builder Noble Homes recently bought a telehandler for its operations. “The Terex Girolift 5022 provides functional adaptability with a range of attachments, including a lifting winch, which allows it to operate as a mobile crane,” it said.
Excavators seem a natural choice for some jobs. Contractors replacing pipe often sling chains to the excavators and bucket loaders that they are already using to dig the hole to install sections of pipe.
“Back in the 1980’s, crane hirers were fearful that excavators could take much of their work away from them when they started to be used for lifting,” says Varcoe. “A similar situation has now developed between cranes and telehandlers.”
US attachment firm Kenco has been making barrier grabs for 25 years for use with cranes and excavators. It has launched a new model (not shown), the 13.5t capacity KL30000.
In the UK, excavators can now be used more widely than before. “The Health and Safety Executive limited excavators to lifting in the immediate vicinity of an excavation,” Varcoe says, but notes that this restriction has been effectively lifted by a more recent regulation (LOLER) and standard (BS EN 474-5). At one time, excavators were also limited to lifting less than one tonne. This was a compromise between the fact that they were never sold as a lifting machine but were frequently used as such, according to Adrian Gartland, principal engineer of Enniskillen, Northern-Ireland based Erne Lifting Services. But this is now no longer the case, he adds.
Contractors working in Europe need to make sure that any equipment that they are planning to use meets three criteria. The Machinery Directive, which governs the sale of European equipment, requires two particular safety features for equipment lifting more than 1,000kg (2,500 lbs), or with an overturning moment of more than 40,000Nm.
Excavators that will be used for hooking loads as well as digging should have check valves installed on the hydraulic cylinders that raise the boom to prevent it dropping in case of a loss of pressure, Gartland says.
Second, the machinery needs to have a load moment indicator (LMI) and a warning device – either a horn or a light – that comes on when the equipment is nearly overloaded, and which needs to stay on as long as the equipment is overloaded (BS EN 474-5), according to Gartland.
Some manufacturers spend more money and fit automatic safe load indicators, which continually measure the overturning moment, warn as operators approach the limits, and actually cut out before an overload. According to Varcoe, these devices are becoming more and more popular in other construction equipment. “Many manufacturers offer to supply the more sophisticated and more expensive automatic safe load indicators since these allow a higher safe working load, especially at the shorter reaches,” he says.
The choice of which control system should be fitted also depends on the outcome of a risk assessment, Gartland says. In an excavator, rated capacity indicators and limiters may be controlled by retrofit RCI kits by the likes of Prolec, or by load mode switches, usually found in the rear console with a decal of a hook inside an arrow, Gartland says. Advanced controls can display the radius, the dig depth, boom height, permissible load and actual load. They can also be configured to restrict movements such as slew and height via dump valves.
As widespread as excavators or telehandlers may be on the job site, and as popular as they are for general site tasks, their lifting operations still need to be planned, experts say.
“Every type of lift needs risk assessment and some kind of planning and this is the job normally carried out by the appointed person when lifting with cranes,” says Varcoe. “For other lifting operations it has been the responsibility of the site supervisor as defined by UK Construction (Design and Management) regulations. Obviously, most lifting done by excavators is straightforward and repetitive and will not require such extensive planning as crane lifting operations.”
In the US, there are fewer requirements by law, according to Bill Smith, a former OSHA official, now vice president of risk management at NBIS Construction & Transport Underwriters. “There’s no anti-two block, no LMI, no particular set up for any heavy equipment used for lifting,” he says.
“I don’t think there are enough statistics to show that that’s a problem with all excavators used as a crane. I think there is a bigger problem with telehandlers turning over,” he added.
Partly, this is because excavators do not do much lifting. “People like the idea of a multifunction machine that has different attachments. They can take the bucket off and put the hook on, but they are not using them all the time for lifting.” Those companies that do use such equipment all the time, such as salvage firms, use magnets or grapples.
The US series of construction safety standards, ANSI A10, does not make any particular requirement for front-end loaders or telehandlers.
“I think I would generally follow the manufacturer’s recommendation,” says Matt Burkart, Aegis Corp owner, and a member of the committee that writes and updates the A10 standards. “If they give it a load rating, and produce capacity charts, then you can use it for lifting. The same thing holds true for excavators. If a third party makes an attachment, they have to get approval from the manufacturer,” he says. “I would not approve something to put on a machine on my site if the manufacturer hadn’t approved it,” he adds.
