The crane operation differs from any other as it exposes crane operators to many hazards and new challenges every day. The cranes are very often associated with serious injuries and even death. In fact, the cranes in Australia are involved in about one of three accidents on construction sites, which is a threatening number. Therefore, the crane operators should be very responsible and aware of all possible crane hazards and should include some safety devices. Today, many different safety devices have been invented which, if properly used, could significantly reduce the number of injuries associated with cranes: anti-current, anti-upset, anti-collision, operator protection and others.
Anti-Current Devices
The main use of anti-current devices is preventing the transmission of the electrical current from energized power lines to crane components in contact with the lines, or personnel in contact with the cranes. For this reason, the number of cranes in Australia with safety devices is increasing. These safety devices include insulated boom cages, insulated barriers and insulated lines or links. The familiar warning devices also fall under this category, as they prevent a contact of a crane with some energized structures. An insulated boom cage is a framework of non-conductive electrical materials which is mounted on the rigged tip of the booms of cranes. It prevents the conductive metal boom framework from a contact with an energized power line. It is important this cage to be properly utilized, because otherwise it can cause a ground fault.
Insulated barriers are also very efficient safety devices. They are not attached to cranes and are used when crane operations take place near energized power lines. The insulated barriers are made of hard rubber and are designed with a purpose to prevent a physical contact with power lines. Where there is a possibility of direct contact, the plastic barriers are ideal to ensure safe crane operation.
Insulated lines or links are mounted between the hook and the lifted load of a crane. They help prevent a current from the hoist line, while at the same time protect the operator who guides the hoisted load. The hoist line and the crane are exposed to various electrical hazards, which can lead to fail of the crane. Many testings have confirmed that the insulated lines and links are very effective, even when they are contaminated with mud.
Many cranes in Australia include these safety devices, although none of them can be used as a substitute for removing or de-energizing power lines in areas where cranes are operating. Crane operators should assume all power lines as energized, until an electric company confirms otherwise. Even though all these anti-current devices are helpful safety devices and many cranes in Australia include them, their reliability has been questioned, which is why they should not be considered as extremely protective.
