China
Africa
Explore chapters and articles related to this topic
Longwall mine design
Published in Syd S. Peng, Longwall Mining, 2019
Tower 110 is located on the chain pillars between the proposed panel 1 and 2. It is oriented at an angle of about 27° from the panel longitudinal direction. The power transmission tower is a steel lattice structure. Its height is about 100 ft (30.5 m), and its base is about 25 × 25 ft (7.6 × 7.6 m).
Generation, Transmission, and Distribution
Published in Joseph E. Fleckenstein, Three-Phase Electrical Power, 2017
Overland transmission is conducted at high voltage over a set of three, bare conductors. An electrical transmission tower will often hold more than one set of conductors, some of which might be at different voltages. Transmission lines are almost always accompanied with at least one grounding cable positioned at the uppermost levels on the towers. The grounding cables are not part of the three-phase circuits and are intended to capture lightning strikes that would otherwise strike the current-carrying conductors. High-voltage transmission cables are always located at a high elevation above ground, away from trees and human activity. In the past years, the towers that hold the transmission cables were of the lattice type that were fabricated of galvanized and painted angle steel. Millions of these structures have been installed in the United States over the years and most may be seen to this day. Largely because of the need for periodic painting, these towers are considered as high-maintenance assets. New installations of transmission towers tend to be of a tubular steel construction. The newer types of transmission towers are mostly fabricated of a specialty steel that requires no painting and which is protected by a layer of oxidized metal that naturally forms on the metal surfaces. A typical, modern design of a high-voltage, tubular steel transmission tower is shown in Figure 2.5. In Europe, transmission towers are mostly made of concrete or wood.
Electric Power Transmission
Published in Pedro Ponce, Arturo Molina, Omar Mata, Luis Ibarra, Brian MacCleery, Power System Fundamentals, 2017
Pedro Ponce, Arturo Molina, Omar Mata, Luis Ibarra, Brian MacCleery
The transmission tower is the supporting unit for overhead transmission lines carrying the transmission cables at a safe height from the ground. Many designs are implemented according to economic factors, the ambient conditions, and mechanical loads (wind loads, weight of cables, etc.).
Effect of modelling complexities on extreme wind hazard performance of steel lattice transmission towers
Published in Structure and Infrastructure Engineering, 2020
Yousef Mohammadi Darestani, Abdollah Shafieezadeh, Kyunghwa Cha
Overhead electric transmission lines face substantial risk of damage in hurricane-prone regions around the world. Past failures of these systems resulted in considerable economic losses as well as societal and organisational disruptions (Campbell & Lowry, 2012; Hoffman & Bryan, 2013). These events highlight the critical role of transmission systems in supporting power delivery to large geographical areas. High-intensity wind-related hazard events such as hurricanes can result in different failure modes in transmission towers as these structures are composed of a large number of elements and connections with different behaviours. Moreover, uncertainties in the demand and capacity of transmission towers and the complex behaviours of tower elements including post-yielding and post-buckling behaviour of the members, joint slippage, and joint failure, along with imperfections enlarge the space of potential failure modes (De Souza, Miguel, Kaminski, & Lopez, 2019; Kempner et al., 2002).
Mapping of the cost of atmospheric corrosion of zinc and galvanised steel due to the effect of atmospheric pollution in the Mexico City Metropolitan area
Published in Corrosion Engineering, Science and Technology, 2022
J. O. Castillo-Miranda, F. J. Rodríguez-Gómez
The infrastructure to conduct high voltage electrical energy is essential for the development of a country, a failure can mean huge economic and human losses due to the lack of electricity in hospitals, industries, and homes. This is made up of transmission lines supported by transmission towers. Therefore, it was decided to use the electrical transmission towers and substations as an object of study. The transmission towers are designed taking into account the location to resist various climatic elements and meteorological phenomena to which they will be exposed. The loads due to the wind, the mass of the transmission line, and accessories must also be considered; in addition to the laying manoeuvers during construction and maintenance.