Overhead power lines are the highways for transmission of electric energy from the source to the substations catering to consumers. The power lines, built-in synergy with the environment and local landscape, are designed for efficient transmission of electrical energy at the lowest costs. Overhead power lines usually consist of one or more conductors suspended over signature towers. The insulation provided by air ensures lower operational costs for the transmission of large quantities of electrical energy.
Transmission towers are tall steel structures carrying high voltage transmission lines from generating stations to distribution substations. The principal component responsible for power transmission is a set of two, three, or four conductors, which are made up of several wires twisted together, lending flexibility to the conductor. The bare conductors are cooled by complete exposure to the surrounding air, thereby ensuring higher conductivity.
The transmission towers are designed for supporting the load of the conductors apart from withstanding the effects of vibration, strong winds, and ice accumulation. The tower erection process is initiated with lever hoists supporting and aligning the steel structures while workers attend to bolting the joints. The fine-toothed precision geared LB lever hoists (also known as chain jacks) reduce the pulling force, which gives great efficiency to this job. Free-standing transmission towers are provided added structural stability by tensioned cables, better known as guy wires.
The next step is the stringing of conductor wires on the towers. The conductor wires are pulled through the travelers from tower to tower while the machines carrying the conducting wire rolls are strongly anchored to the ground using at least two lever hoists to prevent any untoward movement. The LB lever hoists with their high-performance mechanical brakes, strong load capacity up to 9 tons, provide a perfect grounding for the heavy machinery.
A successful stringing of wires is followed by the installation of insulators, usually made of porcelain, glass, or composite polymers, that prevent high voltage current from leaking to the towers or the ground. Long transmission lines often require the cables to be joined together, a process technically called splicing. Controlled detonations create an implosive compression resulting in the seamless joining of conductors. For splicing, a slug site is set up to hold conductors at ground level using two LB lever hoists for each conductor on each side of the splice.
The point where the transmission pathway changes to buried cables or a major direction change is affected in the transmission lines dead-end towers are created. A glassinsulator is inserted between the tower and the conductor and the crew usually uses two lever hoists per line to maintain the tension during installation. With guided hook latch, chain lock and robust sheet steel housing, the LB lever hoists are extremely reliable even under tough handling conditions. Adequate care has to be taken to adjust the sagging of conductor wires through alternating releasing and securing wire tension. With the completion of the deployment of conductor wires along the power line, the wires are gradually transferred from the supporting travelers to permanent positions on the tower through a process technically known as clipping. Once dead-ending, tensioning, and sagging has been completed, wheeled carts are mounted on the lines to install spacers.
Spacers prevent the lines from rubbing against each other in strong winds and short-circuiting.
Transmission line construction is a financially lucrative sector on account of Government funding for infrastructure projects. The primary focus for procurement of standard equipment is on efficiency, reliability, durability along with compliance with the best standards of safety and security.
The lever hoists are a critical component in the installation process for overhead transmission lines. Robust and ergonomic designs with strong corrosion resistance provided with nickel-plated load chains make LB lever hoists an attractive proposition for workers in this sector. The LB lever hoists meet standard industry specifications and ensure smooth workflow at every step in the installation of overhead power transmission lines.