Iron Tower Research Articles

The Iron Tower

The Iron Tower Hugh Coyle (bio) Paris, France March 1889 Every morning for well over a year, burly laborers in blue serge work clothes had trundled along Rue Malakoff past Alfred’s house toward the Champs de Mars, soon to be the fairgrounds of France’s Exposition Universelle. The clatter of wooden clogs on cobblestones punctuated their conversations like so many misplaced commas, while the clip-clop of horses pulling delivery wagons laden with pig iron added its own percussion to the chaos of human chatter. Then, soon after they had reached the end of the avenue and crossed the Seine, the distant pounding of the blacksmiths’ and riveters’ hammers would ricochet among the buildings and disrupt Alfred’s concentration even more, triggering migraines that persisted no matter how much waxed cotton he stuffed in his ears. As if the constant racket weren’t enough, Alfred was distracted further by the controversial centerpiece of the exposition: Gustave Eiffel’s Tour en Fer de Trois Cents Mètres. Not to be outdone by the Americans and their Washington Monument, the exposition’s planning committee had approved Eiffel’s plans for a thousand-foot-high iron tower to serve as a physical gateway to the fairgrounds and a symbol of French ingenuity and achievement. After spending most days in his laboratory in the Parisian suburbs, Alfred would return home for dinner with Sofie, his Viennese mistress, and then enjoy a short walk alone to the Seine to look over at the exposition grounds and measure the tower’s upward climb. At first, the inward slant of its four legs had seemed a mistake, an affront to the perpendicular lines and right angles of classical architecture. The twisted iron and blocks of concrete suggested only the skeleton of a structure. Where was the muscle? Where was the skin? What sort of architect would only sketch a crude building against the same French blue sky that had inspired so many sumptuous paintings? No wonder hundreds of artists had published articles in the city’s newspapers protesting the tower’s construction, deriding it as useless and monstrous, giddy and ridiculous, a ghastly and nightmarish smokestack whose hateful shadow would seep like a blot of ink across the many beautiful new parks and gardens created throughout the city. Alfred felt a spiteful glee on reading these letters and editorials aloud to Sofie over meals, translating from French to her native German as he went along. Eiffel’s dream of building the tallest and most ostentatious structure in the [End Page 74] world, complete with mechanical lifts and revolving beacons at its apex, seemed a desperate attempt to displace the pyramids as one of the Seven Wonders of the World. It was one thing for critics to have mistakenly cast Alfred, the pragmatic inventor of dynamite, as some wicked Prometheus bringing fire back to the world. It was far more accurate for them to describe a pompous architect like Eiffel as Narcissus, climbing high into the Parisian sky with the sole intent of admiring his own reflection in the Seine down below. Despite Alfred’s denouncements, Sofie’s interest in the tower and the exposition grew day by day. Such was the way of it. What pleased her irked him. What made her laugh made him cringe. The gentle touches that she mistook for sexual intimacy made him feel, now more than ever, ashamed of and repulsed by his own desires for human contact. The colder and darker workdays of winter had led to inevitable slowdowns on the tower’s completion. Recent rains and heavy fogs often obscured the workers’ progress, bolstering Alfred’s suspicion, verging on hope, that construction might not be finished in time for the exposition’s grand opening in May. When news of strikes and walk outs had appeared in recent papers, Eiffel responded by placating his workers with higher wages and hot wine served whenever hoarfrost laced the ironwork. Alfred pounded the table after translating the article for Sofie. “Imagine my workers, drunk and distractable when they should be closely monitoring subtle shifts in the color and temperature of volatile solutions!” There was no need to imagine it. There had been...

Construction Process of Continuous Unreeling and Setting of Leading String Based on Trajectory Theory

The increasing construction of power transmission line promotes the development of construction technology of overhead power transmission line in our country into a brand-new era; while the paving of leading string of traditional overhead power transmission line is still to be completed by climbing the iron tower and manual operation of construction personnel. Therefore, it has been extremely urgent to implement research on the construction process of the power transmission line’s leading string threading into pulley, thus reducing the frequency of operation at height of construction personnel. This paper aims to introduce the ejection construction technology of UAV based on trajectory theory to reconstruct the line tackle device, states the construction process flow of multi-rotor UAV utilizing ejection technology to conduct continuous unreeling and setting of leading string with ejection technology in detail, summarizes the full process of construction, conducts contrastive analysis with traditional construction process, and summarizes the social benefit and economic benefit of new type of construction process.

Analysis on Corrosion Fracture of Guyed Rod of Cable Stayed Iron Tower in 110 kV Transmission Line

The guyed rod is of great importance for supporting tower and resisting wind pressure, and its reliability is an effective guarantee for safe and stable operation of power grid. In this paper, the fractured guyed rod used for cable stayed iron tower in a 110kV transmission line was investigated by means of macro-morphology inspection, chemical composition analysis, microstructure analysis, scanning electron microscope, mechanical properties test, soil physicochemical properties inspection and energy spectrum analysis. The result showed that electrode potentials difference existed between different parts on the surface of the guyed rod caused by the uneven distribution of oxygen concentration was the major reason for electrochemical corrosion. Under the action of oxygen concentration cell, the effective cross-sectional area of the guyed rod decreased below the critical value, leading to the final fracture of the guyed rod.

Design and Experimental Research of Rope Missle

The UAV (unmanned aerial vehicle) unfolding guide rope is the construction process adopted in the tension stringing of overhead power transmission line. At present, due to the limit of UAV control precision, the function of threading the guide rope into the paying-off sheave groove directly cannot be realized, and we can only unfold the guide rope of UAV to the cross arm of iron tower, and then, make the operation personnel at height transfer the guide rope into the steel wire groove of paying-off sheave. Therefore, the construction efficiency of this process is relatively, and there is operation at height, with a certain safety risk. In this project, it is planned to develop a launching device carried by UAV, and this device uses the compressed carbon dioxide (CO2) which is relatively safe as power source, which realizes the instantaneous release of compressed air through electromechanical servo control, and then generate the power which promotes the “rope missle” to fly. The tail of “rope missle” is connected with guide rope, and when it flies forward, the traction guide rope will move forward synchronously. After the “rope missle” threads into the sheave, the compressed air will be released completely, and then, the “rope missle” will transfer into the motion of a free falling body, thus further driving the falling of guide rope, so as to realize the function of “rope missle” tracts the guide rope to realize threading into the paying-off sheave.

Maritime targets classification based on CNN using Gaofen‐3 SAR images

The classification and detection of maritime targets are widely used in shipping navigation and military fields. With the development of spaceborne synthetic aperture radar (SAR) technology, more and more very high-resolution SAR images can be acquired for maritime targets recognition. However, due to the different imaging mechanisms between SAR images and optical images, it is difficult and laborious to interpret SAR images manually. This study uses a modified Alexnet structure to realise maritime targets classification on the Gaofen-3 spaceborne SAR images. The maritime targets dataset (MTD), including boats, cargo ships, container ships, windmills, oil tankers, and iron towers, is conducted. Moreover, the proposed convolution neural networks (CNNs) structure is trained and tested on the MTD. Experimental results show that the model can get an accuracy of 92.10% in classifying the six kinds of targets, and the performance is superior compared with other CNNs and traditional supportive vector machine algorithms.

C band transhorizon signal characterisations in evaporation duct propagation environment over Bohai Sea of China

Evaporation duct is an anomalous mechanism of transhorizon propagation in marine and coastal regions. In order to better understand the characteristics of signal fading, a C band signal transhorizon propagation experiment was carried out with a 107km path length over the Bohai Sea of China. Using an iron tower with meteorological and oceanographic (METOC) sensors at multiple altitudes, a direct diagnostic method of evaporation duct is presented. The dependence of signal strength on evaporation duct height, antenna height, and METOC parameters is analysed. The experimental results indicate that the signal strength tends to be linearly dependent on the evaporation duct height when the transmitter and receiver antennas are submerged within the duct layer. Normally, the signal strength is stronger when the relative humidity is lower. Stronger signal strength tends to occur under near-neutral or stable atmospheric conditions or when the air-sea temperature difference is higher. The results indicate that the signal strength distribution of fast fading is close to Rayleigh distribution, and the probability density of fade slope is symmetric at 0dB/s. These results have important implications for the design of ducting communications system.

Computer implementation of piecewise cable element based on the absolute nodal coordinate formulation and its application in wire modeling

A new high-voltage electricity wire model is proposed to simulate the dynamic behavior of the wire after tension failure and the nonlinear sliding joints between the wire and the iron tower. A previously developed piecewise cable element based on the absolute nodal coordinate formulation is used with its computer implementation given in this paper. In order to describe the initial tension in the wire, a static solving approach is used to achieve equilibrium between the element elastic force and the external force including the tension. The obtained configuration of the wire is then used as the initial configuration of analysis in case of unloaded external tension force. Thereby, the dynamic behavior of the wire can be modeled. The sliding joint constraint is used to describe the motion of the wire going through the iron tower after tension failure. A new static solution approach is developed to avoid the sliding joint constraint violation in the resulting equilibrium configuration. The convergence of the piecewise cable element based on the absolute nodal coordinate formulation is tested. A set of comparative results is presented to demonstrate the feasibility of the method proposed in this investigation.

Simulation calculation of electric field protection for live working on Ultra‐high voltage transmission line

The current standards related to live working provide no determined path for equal potential working, in which only safety distance is referred, so that the works are often executed relying on the line maintenance experience. As high-voltage and strong space electrical field intensity exist in 1000 kV ultra-high voltage transmission lines, the real-time safe distance measurement is difficult to be conducted and the exhaustive full-scale experiments are difficult to accomplish due to the varied true tower models and lines. Simulation calculation is aroused for improving the efficiency of safety distance calculation and safety path planning during the process of importing and exporting the potential according to the different kind of tower and the actual line situation. Here, with the cup type iron tower and hanging basket mode, the electrical field intensity in and outside of screening clothes at different part of body while climbing tower and during equal-potential process are calculated, and then the safety distance, the combination gap, and the optimal path planning are carried out. The simulation results demonstrate that electrical field intensity meet safety requirements using the proposed planning path, which enriches the theoretical basis for the safety operation of ultra-high voltage live working.

Safety Analysis of Self-climbing Rod on High-voltage Tower

In-situ electrification lifting of transmission towers is a safe, reliable and economical construction method developed in recent years. In this paper the self-climbing mandrel transfer mechanism was described in detail and the live in-situ lifting of a 110kV dual-circuit iron tower was used as an example to describe in detail the lifting process and force analysis of the self-climbing bar in the in-situ live charging technology, which shows the reliability of climbing rod in the lifting process.

Design and Implementation of a New Climbing Robot for High Voltage Transmission Tower

A new type of high voltage transmission tower climbing tower robot is designed. Firstly, the structure of the transmission tower is analyzed to determine that the robot manipulator is a five-degree-of-freedom structure. Secondly, a manipulator capable of automatically positioning and tightening the angle steel surface was designed according to the L-shaped angle steel of the tower. The manipulator adopts electromagnetic absorption and grasping and tightening the angle steel. Thirdly, the theoretical calculation of climbing steps is carried out to determine the maximum step of the torsional climbing gait. Then STM32 SCM is used as a carrier to carry out various functional modules to achieve effective control of the robot’s rotation, movement and positioning. Finally, the finite element simulation of the robot model was performed to analyze the deformation and stress of each component during the climbing process, and the rationality of the structure was verified. In addition, the experiment of tower climbing was carried out with the experiment iron tower in the outdoor. The results show that the robot manipulator is tightened and reliable, the weight bearing is large, the degree of freedom is not redundant, the climbing speed is fast, and the movement of obstacle crossing can be realized smoothly.

Detection of Bird’s Nest in High Power Lines in the Vicinity of Remote Campus Based on Combination Features and Cascade Classifier

High-voltage transmission towers are built to supply electricity for campuses and local residents. In order to guarantee the power supply and safety for remote campus, the unmanned aerial vehicles (UAVs) are used to take the images of high power lines to alarm potential malfunction. A novel method of bird’s nest images detection based on cascade classifier and combination features is proposed. Different features of the bird’s nest and iron tower are analyzed, and the following four novel features are proposed: proportion of white area (PWA), ratio of white pixels (RWP) in each lap, projection feature (PF), and improved burr feature (IBF). The combined features are used to describe the characteristics of the bird’s nest backbone area and the edges, respectively. Furthermore, the cascade classifier combined with the four proposed features is used for the further classification of bird’s nest region. The proposed detection process mainly consists of three stages. First, the suspected bird’s nest region is obtained by template convolution. Second, PWA and RWP with low dimensionality and high discrimination are used to classify the sample set of suspected nest region. Third, based on the previous classification results with positive and negative samples, PF and IBF are adopted to further conduct the secondary classification in order to reduce the misclassified samples, and the final classification label is determined by the second classification results. Experimental results show that the proposed algorithm can accurately detect the nest and achieve good performance.

Analysis and research on new mechanical characteristics of narrow base steel tube tower for transmission line

Compared with the common angle steel tower, the narrow base steel pipe tower has the advantages of simple structure, beautiful appearance, small floor area and better coordination with the urban environment. In the construction of urban high pressure transmission line, the narrow base tower has its own unique advantages and wide application prospects. It has the advantages of ordinary iron tower processing, transportation, assembly, cost saving, small occupancy of single column steel pipe rod, small line corridor and beautiful beauty. In the optimization design of the narrow tower, how to take the wind vibration coefficient of the tower, how to consider the bending moment of the rod end, the design of the narrow base tower and the structure optimization of the narrow tower tower are all the problems to be solved urgently. In this paper, the modal analysis of a single tower is carried out to determine its vibration mode, and then the wind vibration coefficient of a narrow tower is analyzed. Finally, the influence of x and y direction vibration on the frequency of the tower is obtained.

Electrochemical Anti-corrosion System of Iron Tower Based on Solar Power Supply

Aiming at the serious problem of the corrosion of the transmission tower in the coastal area or in the harsh industrial area, a kind of electro-chemical anti-corrosion system based on solar power is designed. The system consists of a solar power module and an electrochemical anti-corrosion module: The solar power module consists of a solar panel, a photovoltaic controller, a accumulator and a constant potentiometer. The Electrochemical anti-corrosion modules include an anode block and an anode bed and reference electrode. The photovoltaic energy technology and forced current cathodic protection technology are used in the system, to achieve the effective protection of the tower anti-corrosion. Solar power supply to the nearest, solve the long-distance transmission loss and the high installation costs, form a simple structure, stable operation, low cost, clean and environmental protection, long service life of anti-corrosion system, with good economic efficiency and social benefits. It is of great significance to ensure the safe operation of the tower, maintain the normal operation of the power grid, and even promotes the optimization and upgrading of the industrial structure, save energy and reduces emissions, improve the safe and stable operation of the power system and the economic benefits, etc.

基于极限平衡理论和有限元强度折减法的预应力锚索加固边坡稳定性分析研究

本文以贵阳会文变至渔安变220千伏线路铁塔边坡为依托工程，采用极限平衡法和有限元强度折减法对高边坡在预应力锚索加固前后的稳定性进行计算分析，探讨了施加预应力锚索后对边坡位移及稳定性的影响，通过模型计算结果与监测资料的对比得出结论：极限平衡理论与有限元强度折减法得到的安全系数和滑动面基本一致。监测资料与计算结果相吻合，预应力锚索加固后该边坡处于稳定状态，本文研究成果可为类似工程设计提供参考。 The paper uses the Slope of 220 kv Variable Pressure Transmission Iron Tower from Huiwen to Yu’an in Guiyang as an engineering example. It calculates and analyses the high slope stability after reinforcement by prestressed anchor cable based on the theory of limit equilibrium method and finite element strength reduction method. It discusses the influence of prestressed anchor cable on stability and displacement. The calculation results are compared with the collected monitoring data and the conclusions are drawn. The safety factors and sliding surfaces by limit equilibrium method and finite element strength reduction method are almost the same. The monitoring data are consistent with the calculation results, and the slope is stable after reinforcement by prestressed anchor cable. Thus, the result can be used as a reference for engineering design.

Design and Application of Coupling Power Supply Device on Overhead Ground Wire

For limited on-line monitoring application of electric transmission line which is caused by communication in addition to tower power supply stability, and closed space plane composed of two lightning protection ground wire and iron tower in alternating magnetic field cutting of overhead transmission line which will generate a certain inductive power in the plane, ground coupled power is on-line monitoring system power that converts ground wire network loss to sustainable power supply. In this paper, based on the comparison of advantages and disadvantages of several coupling power supply design, efficient power electronics energy solutions to deal with wide induction voltage and typical engineering applications for different load conditions, voltage grade and tower type are emphatically introduced.

Risk Evaluation of Qinghai–Tibet Power Grid Interconnection Project for Sustainability

The Qinghai–Tibet power grid interconnection project is the first power transmission project with the highest altitude, longest transmission lines, longest distance running across the plateau frozen ground, and highest iron tower in the world. The risk evaluation on it can identify the overall risk level and key risk factors, which can reduce risk-induced loss and promote sustainable construction. In this paper, the risk of the Qinghai–Tibet power grid interconnection project was evaluated by employing a matter-element extension model under a fuzzy environment. After building the risk evaluation index system, the performances and weights of criteria were qualitatively judged by three groups of experts in different fields, and then the risk of the Qinghai–Tibet power grid interconnection project was rated by employing matter-element extension model. Meanwhile, the sensitivity analysis was performed to identify key risk criteria. The empirical results indicate the risk of the Qinghai–Tibet power grid interconnection project belongs to the “stronger” grade, tending to the “strongest” grade. “Social stability risk”, “altitude sickness seizure risk”, “permafrost-induced risk”, “severe weather-induced risk”, and “ecological destruction risk” are key sub-criteria, which should be paid more attention to when taking risk management measures. Finally, some countermeasures for key risks of the Qinghai–Tibet power grid interconnection project were given. The findings in this paper can provide references for engineering managers and related stakeholders.

Construction and 1st Experiment of the 500-meter and 1000-meter DC Superconducting Power Cable in Ishikari

Ishikari project constructs two lines. The length of the Line 1 is 500 m, and connects the photovoltaic cell to the internet-data center. The other line is 1km length, and it is a test facility and called Line 2. The structures of the cable systems are not same to test their performance. The construction was started from 2014 in the field, the Line 1 was completed in May 2015, and it was cooled down and do the current experiment, and warmed up. The Line 2 is almost complete in October 2015. It will be tested in November and December, 2015. In order to reduce the stress of the cable induced by the thermal expansion and contraction, we adopted the way of the helical deformation of the cable. The force of the cable is reduced to 1/3 of an usual cable test. Because the cryogenic pipes are welded in the field and we cannot use the baking of the vacuum chamber of the cryogenic pipe, a new vacuum pumping method was proposed and tested for the cryogenic pipe. Since the straight pipes are used to compose the cryogenic pipe, the pressure drop of the circulation would be 1/100 of the corrugated pipe in the present condition, and it is suitable for longer cable system. The heat leak of the cryogenic pipe is ∼1.4W/m including the cable pipe's and the return pipe's. The heat leak of the current lead is ∼30W/kA in the test bench. Finally the current of 6kA/3sec and the current of 5kA/15min were achieved in Line 1. The reduction of heat leak will be a major subject of the longer cable system. The cost of the construction will be almost twice higher than that of the copper and aluminum over-head line with the iron tower in the present Japan. The cost construction of the over-head line is an average value, and depends on the newspaper.

Process of Tower Erection in Sections with Internal-Suspended and External-Guyed Holding Pole of Pivot Strut of Iron Tower’s Main Members

This thesis introduces the main process flows of holding pole lifting and supporting pole installation during the tower erection by combining the landform features of “high mountains and highlands in Eastern Tibet and Western Sichuan Province” of power transmission and transformation of grid networking between Changdu of Tibet and Sichuan Province, aiming at the problem that that the line stringing of holding pole is influenced by landforms of cliff, etc. and adopting light combined compound-material holding pole as lifting mechanism, to solve the tower erection at the tower positions like cliff and isolating mountains where traditional holding poles cannot be erected effectively.

Structural Finite Element Analysis of Tower Top of Landing-Type Lifting Pole with Double-Level Arms

The landing-type lifting pole with double-level arms is a kind of construction equipment frequently used in erection of large-sized iron tower during the engineering of power transmission line. This equipment lifts heavy load through bilateral symmetry, thus improving the working efficiency. A finite element structural calculation model of tower top of landing-type lifting pole with double-level arms was established according to the actual situation, and this model involved different working amplitude, lifting capacities and unbalanced loading conditions. In addition, the maximum stresses and structural stability coefficients of tower head, lifting arm, draw-bar and rotary tower body were analyzed, and the safety check results of various parts at tower top were obtained. Finally, the design of connection pin of each part at tower top of lifting pole was also proposed.

Structural Design of Large Size Measuring Machine Base on Electro-Optic Automatic Detection

As a result of the large-scale components' measuring environment complex, the workers measuring operation not reliably and so on factor influences, uses the non-contact electro-optic measuring technique is the main development direction of the large size components measuring. In this paper, iron tower component is taken as measuring object, online automatic detection is aimed to achieve, and the system frame is constructed to carry out electro-optic automatic detection of the iron tower component, then designing of large size examination machine will be accomplished.