FABRICATION PLANT FOR LATTICE TOWERS AND TUBULAR STEEL POLES

Towers or masts are built in order to fulfil the need for placing objects or persons at a certain level above the ground. Typical examples are:

Single towers for antennae, floodlight projectors or platforms for inspection, supervision or tourist purposes.

Systems of towers and wires serving transport purposes, such as ski lifts, ropeways, or power transmission lines.

For all kinds of towers the designer should thoroughly study the user’s functional requirements in order to reach the best possible design for the particular structure. For example, it is extremely important to keep the flexural and torsional rotations of an antenna tower within narrow limits in order to ensure the proper functioning of the equipment.

The characteristic dimension of a tower is its height. It is usually several times larger than the horizontal dimensions. Frequently the area which may be occupied at ground level is very limited and, thus, rather slender structures are commonly used.

Another characteristic feature is that a major part of the tower design load comes from the wind force on the tower itself and its equipment, including wires suspended by the tower. To provide the necessary flexural rigidity and, at the same time, keeping the area exposed to the wind as small as possible, lattice structures are frequently preferred to more compact ‘solid’ structures.

Bearing in mind these circumstances, it is not surprising to find that the design problems are almost the same irrespective of the purpose to be served by the tower. Typical design problems are:

• Establishment of load requirements.
• Consistency between loads and tower design.
• Establishment of overall design, including choice of number of tower legs.
• Consistency between overall design and detailing.
• Detailing with or without node eccentricities.
• Sectioning of structure for transport and erection.

A lattice tower, also called angle steel tower or electrical tower, is one kind of freestanding framework tower for power transmission line of all voltages, often designed as a space frame or a hyperboloid structure. They are widely used as an electricity transmission towers especially for voltages above 100 kilovolts, being as a self-radiating tower or a carrier of aerials, even an observation tower.

Lattice steel towers comprise of several different metal structural elements linked as well as products or welded. A variety of types of lattice steel towers exist. These towers may also be called self supporting transmission towers or free-standing systems, due to their power to help themselves. These systems are not always made from steel; they can also be made from aluminum or galvanized steel.

Lattice steel towers are made up of many different steel structural components connected together with bolts or welded. Many different types of lattice steel towers exist. These towers are also called self-supporting transmission towers or free-standing towers, due to their ability to support themselves.

Lattice towers provide the advantage of a smaller cost investment compared to others, since they use about half as much material as tubular towers. Yet the lattice tower still provides similar stiffness and reliability as tubular towers. Lattice towers allow wind to pass through the base and tower sections, decreasing the pressure and resistance on the structure. One disadvantage according to some people is the appearance of lattice towers.

Lattice structure Lattice steel towers are made up of many different steel structural components connected together with bolts or welded. Many different types of lattice steel towers exist. These towers are also called self-supporting transmission towers or free-standing towers, due to their ability to support themselves. These towers are not always made of steel; they can also be made of aluminum or galvanized steel. Self- supporting lattice structure are used for electricity transmission line tower. The lattice structure can be erected easily in very inaccessible location as the tower member can be easily transported. Lattice structures are light and cost effective.

A lattice tower is a framework construction made of steel sections. Lattice towers are used for power lines of all voltages, and are the most common type for high-voltage transmission lines. Lattice towers are usually made of galvanized steel. A lattice tower is usually assembled at the location where it is to be erected. This makes very tall towers possible (up to 100 meters – in special cases even higher). Assembly of lattice steel towers can be done using a crane. Lattice steel towers are generally made of angle-profiled steel beams (L- or T- beams). For very tall towers, trusses are often used.