Safety devices for the lifting industry
By Laura Hatton03 June 2013
Cranes on site present many potentially hazardous and dangerous situations. An example that can afflict all cranes with a hoist line is known as two-blocking. It occurs during hoisting when the hook assembly comes into contact with the boom point sheave assembly during a lift. Manufacturer Rayco-Wylie is offering a new generation anti-two-block (A2B) system to overcome this potentially fatal scenario. The R147 device works by warning the operator when the hook reaches its maximum safe height, which is measured by electrical sensing devices. The R147 is designed to conform to CE, OSHA and FCC safety regulations.
To help operators on the job site, Italian manufacturer Ravioli has introduced the PME Evolution slip ring model. The unit, a vital component of the crane that electrically links the upper and lower sections of a crane through the centre of the slewing ring, is fitted with an encoder that allows the operator to check the exact position of the crane’s rotation. The slip ring unit also includes a high protection range (IP65 rated) designed so that it can be used in severe environmental conditions.
A common condition on site to be aware of is overloading a crane. UK-based manufacturer Straightpoint has designed a new range of alarmed shackle load cells to help prevent this potentially lethal situation from happening. The re-engineered shackle load cells include an audible overload warning so, if a load being lifted is too heavy for the chosen crane, a warning sound will activate, indicating that the operator should lower the load or reduce the lifting radius and thereby help ensure the safety of operators, other people in the vicinity, equipment and the load being lifted.
To ensure safe and continuous usage, the product works around other wireless equipment and has no external antennae. In addition, the load cells have a long battery life, a company spokesperson says. All Straightpoint products comply with US ASME standard (B30.26-2010) and are CE marked for sale in Europe.
An area of technology that is having an impact on the design and function of operator assistance devices are colour display screens. Although some may consider colour screens to only represent an aesthetic value, manufacturers are quick to point out there is a safety function to them as well.
As a spokesperson from LSI-Robway (LSI), a manufacturer of crane safety instruments, explains, colour screens can provide operators with a visual representation that can be read more easily. This can make certain environments a lot safer to work in.
Rayco-Wylie has also opted for colour screens throughout its new rated capacity indicator (RCI), range, the i4500 series. The i4500 series is designed to monitor operations such as boom sequencing, outrigger monitoring, range limiting and wind speed in the construction and offshore industries. Safety information, engine data and camera images are displayed on a 4.3 or 7 inch (110 or 180 mm) colour screen.
“Other benefits to end users include a load chart, software and calibration files, which are downloadable from a USB key,” adds a company spokesperson. The series is designed to comply with the European safety standard EN ISO 13849-1. It also conforms to the OSHA, the FCC and the US standard J159, according to the manufacturer.
From LSI are the GS820-10 (FCC/IC) and the GS820-11 (CE) displays, which are used to monitor wireless sensors, including load sensors, angle sensors, A2B, wind speed sensors, slew sensors and load charts. Stepping up a notch from colour screens, the product comes as standard with a program allowing operators to set up a 3-D viewing area for restricting slew (work area definition software), boom radius and tip height. The information is presented on a transflective LCD 320 x 240 pixel display and comes with a buzzer output and visual alerts, the company adds.
Jacco Hartkoon, business development manager at Orlaco, a manufacturer of industrial camera systems and other operator assistance devices, explains in further detail why visual aids can be vital to crane operators, “What we have seen in the industry is that crane drivers need bigger screens. This demand is partly because buildings are getting taller, which means that cameras have to have more capacity for zooming in. In the past we designed 7 inch [180 mm] screens to display this information, but now we are providing 12 inch [300 mm] screens and cameras with greater zoom efficiency.”
To meet demand for increased zoom capabilities, Orlaco has introduced a new range of compact cameras built with complementary metal oxide semiconductor (CMOS) type sensors, the Amos and Amos IR LED camera series. Amos IR LED cameras are fitted with an adapted lens and fifteen infrared LEDs, which provide the operator with detailed camera images both day and night, the manufacturer said. When displayed on a 12 inch monitor the operator can view the images through a picture in picture (PIP) feature, which allows two camera images to be viewed on the same screen at the same time.
Another feature that the cameras have is a visual ‘safety ticker’, which shows the operator that the camera is registering information in real-time. As Hartkoon, explains, “These cameras help increase safety by helping the operators see the winches, the rear view and the load view.”
Aside from crane camera systems that allow an operator to monitor hazards visually, devices that monitor invisible factors, for example, weather conditions, can also be of great benefit to crane operators. The wireless GS025 wind speed sensor from LSI is one example. The sensor monitors wind speed (up to a maximum range of 1,400 metres per second) and is suitable for almost any environment, including sites of wind turbines. In case of sensor or output failure, the device indicates any faults to the crane operator on a visual display. The wind speed sensor system GS550 is built to comply with many safety-related standards, including the latest European EN 13000.
Rayco-Wylie has also introduced a wireless wind speed indicator to the lifting industry. The R180 monitors wind speed and uses direct sequence spread spectrum transmission technology, a system which carries signals over the full bandwidth of the device’s transmitting frequency. According to the manufacturer, this system makes the indicator better suited for use over a long range, making it resistant to radio frequency interference (RFI). Data is displayed on a weatherproof screen, and there are audible and visible alarms. Applications for the device include telescopic cranes, lattice boom cranes and dock cranes. The R180 is designed to conform to CE, OSHA and FCC safety regulations.