Crane operator assistance devices are a vital part of crane design

Operators benefit from an increasing number of assistance devices. Euan Youdale looks at some of the systems that help and oversee them

Modern technology has ensured that crane operators come under increasing scrutiny from systems built into their machines. Rated capacity limiters, for example, conforming to EN 13000:2010 European Standard have led to well documented concerns, particularly from the USA, that the operator will be prevented from having full control of the crane in an emergency situation. Others, including the European Federation of Materials Handling (FEM), argue the standard will increase overall safety, and assist operators in their jobs. (See the box in this feature of how LSI defines indicators and limiters.)

In addition, new site planning software is controlling the operator's working parameters more than ever before, as well as providing them with advanced information. SMIE, for example, will introduce new combined software to drive anti-collision devices, part of a wider information system for operators and site managers. The Prosite range will ultimately provide operators with information about the entire work site, including the operation of other cranes and when they are shut down for any reason.

Data concerning the work rate of the cranes will be stored and supplied live via wi-fi to site managers who can set new working parameters for the cranes and send these to the operator. Live feeds from the cameras attached to various parts of the crane will also be available through the network. Data from wind monitoring sensors will also be available along with a range of other safety features. The system will be launched later in 2012.

In control

Liebherr introduced its LiDAT data transfer and location system at Intermat 2012. It provides fleet management of all construction equipment on site from one source, with information being delivered about the location and operation of the machines. This means cranes are remotely monitored to ensure they are used at an optimum level, says the manufacturer.

LiDAT incorporates all crane-specific data from its EC-B, EC-H, HC-L, HC, and MK tower crane ranges, as well as from the K series self erecting series. Machine data like lifting capacity tables, load cycles, working hours, wind warnings, or scaling data can be checked at any time.

Positioning, operating and utilisation hours, as well as information about service intervals, and monitoring of equipment usage can be carried out at any time via the LiDAT web portal. Automated reports tailored to tower cranes can be created and adopted and stored in other formats. Large construction sites can be split into specific areas and machine groups. "For hirers of machine fleets, LiDAT offers rapid location of the machines, a clear basis for calculation of hire rates, and notification of the use of the units," adds a company spokesman.

Clear picture

Despite this level of monitoring, indicator systems are now routinely installed in crane cabs to provide the operator with a clear picture of working parameters. RaycoWylie Systems introduced the i4500 all-in-one rated capacity indicator at the Intermat exhibition in Paris, France last month. It was installed on the new UNIC URW-1006 10 tonne capacity spider crane. Graham Riley, Unic Cranes Europe CEO said, "The Rayco Wylie safe load indicator gives the operator the choice of full working area limitation, slew limitation and load moment limitation, as well as data logging facilities and feedback."

Described by Rayco Wylie as a new generation of RCI, the i4500 is designed to accommodate all types of cranes for manufacturers working in the construction or offshore industry. "It offers more complete integration with the crane and the ability to monitor advanced operational parameters, such as boom sequencing, outrigger monitoring, range limiting and wind speed," said a company spokesman. Compliant with European safety standard EN ISO 13849-1, the system can centralise the safety information, engine data and camera images all on one clear, full colour display, adds the spokesman.

Another of example of how technology is shifting comes from Hirschmann with its iVISOR mentor QVGA. The consoles come with integrated SLI controls and digital inputs and outputs, as well as CANopen interfaces. They are designed to be compact and withstand tough environments.

"The console forms a central information system which offers the machine operator all the information he needs, in functional form, at a glance," said a company spokesman.

The contrast of the LCD display is automatically adjusted using the manufacturer's BestVIEW technology, with ambient temperatures and brightness taken into account, adds Hirschmann. A CANopen interface allows networks to be connected.

Winning design

Turning to another area of safety, Terex won the Safety award at the ESTA Awards of Excellence held on 19 April in Paris, France, for its fall protection system.

The ESTA (European Association of Abnormal Road Transport and Mobile Cranes) developed the Safety award to recognise those companies that make a significant impact on safety by promoting safe work practices and equipment that prevent injuries and accidents.

The fall protection system aids in rigging boom sections of lattice boom cranes. The device includes a vest harness with a shock absorber and provides secured, tethered walking and working on the main boom. In the unlikely event of the fall protection being actuated, it stops the fall prior to the worker reaching the ground, lessening the possibility of injury.

Retracted and stowed on the main boom for transport, the fall protection device is quickly installed from ground level, explains Terex.

"Advancing safety standards is a critical part of our product development process," says Klaus Meissner, director of product integrity for Terex Cranes who received the award. "No other manufacturer offers such a fall protection system, and we are excited to be recognised for our work, which benefits safe crane operation for the industry as a whole."

LSI explains the difference between the LMI, RCI and RCL

Load Moment Indicator (LMI):

Hydraulic cranes: pressure transducers are installed on the rod and on the bore side of the lift cylinder and hydraulic control valve

Pressure transducers, as a part of the overall load calculation, take the boom weight into consideration

An LMI system will more accurately show the effects of boom torque, wind, ice, rain, etcetera, on the lifting capacity of the crane

Initial system installation requires that the LMI calculates all empty boom moments

Each boom configuration is installed and calculated twice, once without test weights and once with test weights

Load charts are programmed into the display and the operator can see the load as a percentage of maximum load capacity.

Rated Capacity Indicator (RCI):

Typically measures the hoist rope tension with a load cell, tensiometer or line rider or a load pin

Like the LMI, the RCI incorporates load charts into the display but measures the load by monitoring the hoist rope tension

Pre-calibrated load cells eliminate high installation costs and aftermarket support costs

Designed to warn the operator that rated capacity has been reached.

Rated Capacity Limiter (RCL):

An RCL functions the same as an RCI, but will also engage solenoid lockout valves, if they are installed on the crane.