Operator assistance devices: Captain of the ship

Crane manufacturers and independent suppliers of operator assistance devices are now investing more time and money into providing the market with devices that assist crane operators in executing tasks more safely. The line can become blurred, however, between a device that assists and one that intervenes. When should a device stop being an assistance tool and become an overriding function?

Klaus Meissner, director of product strategy at Terex Cranes, says, “We believe that we should not underestimate the role of the operator as the ‘captain of the ship’ but, unfortunately, sometimes these captains feel forced into some action; I guess that the further development of systems should be complemented by a formal education or training and the accompanying certification to re-enforce the captain’s role.”

The international crane manufacturer provides systems to support working space limitation such as collision avoidance and for slewing angle-related capacities on mobile cranes. Terex also offers a number of camera systems to monitor winches, the vicinity of the vehicle when travelling or the load when moving.

Load measurement equipment company Straightpoint, based in the UK, understands the paramount importance of lifting personnel being as well trained and safe as they possibly can be, and does not see technological development in creating operator assistance devices detracting from this. The company’s most popular product is the Radiolink Plus load cell that is capable of both weighing and dynamic load monitoring, the company says.

David Ayling, Straightpoint director, says, “Despite recent improvements in health and safety – more prevalent in some regions and sectors than others – we still see too many crane accidents. They are not all caused by a lack of understanding about the weight and behaviour of the load but crane operators should always strive to gain a thorough knowledge of the load, especially in dynamic and critical lift situations.”

Although most manufacturers do not set out to create devices that will have an overriding function, there has been an increase in requests for this from buyers, says camera systems manufacturer Orlaco. Paul de Jong, account manager, explains, “We always put the operator’s responsibility first. We do not design products to override current crane operations. There is, however, an increase in requests to deliver such systems.”

As well as vision systems, Orlaco also provides devices for proximity detection on all kinds of tower, harbour and mobile cranes.

Safety first

Marcus Rösth, manager of control systems, loader cranes at Hiab, says, “Some features and assistance devices are driven by legislations and national standards - we do not see these regulations as limitations.”

The company, part of Cargotec, offers several operator assistance devices, including a virtual cage where the crane cannot operate (for example, when operated from a standing platform), an electronic over load protection (OLP) system and vehicle stability functions that give the user optimal outreach without sacrificing the stability of the vehicle.

Electronic systems manufacturer RaycoWylie offers load, angle and anti-two-block (A2B) indicators but also more complex systems showing safe working load, hook height, boom angle and collision avoidance, among others.

Manon Huard, account manager for the OEM distribution network at RaycoWylie, adds, “Our systems are in continuous development using the latest technology with the main goal of increasing safety. Tighter international standards and regulations are constantly monitored by our engineering and R&D departments - we have to keep up with current regulations and prepare ahead for any upcoming changes.”

Maria Kotzurek, product management crawler cranes at Liebherr-Werk Nenzing, explains how the focus has to remain on helping crane operators. “It is always a balancing act between increasing safety and not changing too many aspects in operating the crane, thus limiting the operator to a great extent,” she says. “Liebherr tries to develop devices to help crane operators to avoid dangerous situations.”

Crawler crane models from Liebherr-Werk Nenzing with load capacities up to 300 tonnes have two new control assistance systems: the Vertical Line Finder (VLF) and the Horizontal Load Path (HLP). They are additions to the Litronic control system – a unified operator control system. The VLF provides precise vertical lifting of the load ropes, and the HLP allows loads to be moved more precisely and efficiently to the intended positions, even when the view is obstructed, the company says.

Meissner at Terex speaks about the positive changes that have come from devices created through new safety regulations. “On the systems required by regulation, the LMI system should be mentioned,” he says. “For mobile cranes, according to EN13000: 2010, the systems with the override out of the direct reach of the operator have eliminated a whole category of incidents in Europe.”

Keeping up with upcoming safety regulations, LCM Systems has recently launched a SOLAS compliant container weighing system that enables container ports to meet the requirements of the legislation being implemented on 1 July 2016, the company says.

High winds

Keeping track of wind speed on a construction site can be difficult, especially when changes can occur rapidly. “We provide anemometers as an optional feature, which is equipped at the head of the boom or jib sensing wind speed and showing a warning on the display,” says a Tadano spokesperson. “When the wind speed exceeds the registered amount, the operator is advised to reduce rated lifting capacity. When the wind speed exceeds 14 metres per second Tadano recommends stopping operation. We think this is very important device to avoid overturning accidents caused by a strong wind.”

As well as operator assistance devices measuring wind speed, Tadano also provides Automatic Speed Reduction and Slow Stop Function on slewing, and the Lift Adjuster – the first of its kind, the company says. It is a control system that allows operators to monitor the potential movement of a heavy load. When activated, the system senses boom deflection and adjusts the hoist cylinder to compensate for any radius changes.

Another company investing in wind speed devices is Liebherr-Werk Ehingen. Wolfgang Beringer, head of sales promotion, says, “Our mobile cranes with 70 tonne capacity and bigger are equipped with anemometer as standard. This is an information tool and displays and gives an acoustic warning if the maximum wind speed is exceeded.”

Making the anemometer a standard feature solidifies its importance as an operator assistance device. The Germany-based crane manufacturer offers many devices, including vision systems to monitor every part of the crane, collision avoidance, automatic levelling and automated erection of the luffing jib.

Unified displays

When asked if the industry is moving towards integrated systems and unified displays, load cell manufacturer LCM Systems disagreed, “We do supply integrated systems but we haven’t really seen an increase in demand for this. However, this really does depend on the application with some having a high requirement for it - ports and container terminals for example – and others not at all.”

The company supplies various types of load cells – shackles, pins, links and cells – to the crane and lifting industry that are used to provide weight and overload warning.

Tadano is also wary of creating unified displays since “there is a risk of having no crane operation if the display were to break, with all devices in an integrated system.”

There are other manufacturers, however, which see integrated systems as the way of the future. Liebherr has the LICCON2 technology that allows all crane movements to be controlled remotely, providing clear lines of vision and proximity to the load, along with greater economy and comfort, explains the company. There is also the Liebherr Litronic “one-system solution” described as “the centrepiece for precise and reliable crane operation.”

Huard at RaycoWylie says, “The OEM industry is demanding and some develop their own in-house integrated rated capacity indicator [RCI]. This trend has a heavy influence on the way we are developing and designing our systems destined for this market, requiring interfacing between our system and the cranes’ increasingly complex electronics.”

Looking ahead

Embracing the latest technologies available, many manufacturers are pushing the boundaries when it comes to operator assistance devices. Hiab, for example, has launched a virtual reality headset for remote operation of cranes from the truck cab. Instead of having a direct view of the load, the operator can use HiVision to view the working area, through cameras on top of the crane, providing safe and comfortable crane operation from inside the truck cabin, the company says. Forestry work is a typical application.

Magnetek provides collision avoidance devices to prevent crane-to-crane and crane-to-end collisions and has three systems to choose from, which can be applied to all types of overhead cranes. The LaserGuard2 collision avoidance product is the most technologically advanced system available, the company claims, using self-monitoring optical lasers to check a crane’s position.

A representative from the company shares how Magnetek views the future of operator assistance devices. “In a perfect world, crane operators would be able to monitor the crane on their mobile phone or tablet from the ground or anywhere in the world. That’s the direction we see the industry going.”

RaycoWylie is developing a hybrid system that will see CANbus enabled displays and control equipment interfacing with wireless sensors. “Technology is evolving rapidly, especially due to the popularity of tablets and mobile applications. We aim to follow the same wave and deliver similar products for the crane industry. Products that are simple and have appealing colour screens with user-friendly menus. Nonetheless, behind the pretty display there needs to be a sophisticated system that meets all of the harsh industry regulations and standards,” Huard concludes.