Steel Transmission Towers Research Articles

Automated design of three-legged steel transmission towers

This paper describes the analysis and design of a self-supporting steel transmission tower utilizing a full-size computer in combination with a programmable desk calculator. The tower has only three legs and all its members are composed of angles. A different orientation of the leg angles has been proposed, which avoids the difficulties experienced previously in the fabrication of such three-legged towers while retaining the full benefit of their lesser weight as compared to classical, four-legged towers. A comparison was made by the authors between a high quality existing design of a four-legged tower and a three-legged tower using the same main geometrical and loading parameters. A saving in steel weight of 13.9% resulted when using a three-legged tower as compared with a four-legged type.

溶融亜鉛めっき高力ボルトの遅れ破壊

At present, Hot-dip Galvanized high strength hexagon bolts having high strength levels of above 95kg/mm2 are frequently used for fastening structural members of outdoor structures such as a transmission steel tower in Japan.Though Hot-dip Galvanizing is very superior in corrosion resistance in general, delayed fracture has occurred presumably due to hydrogen embrittlement. Therefore, we thought the following two reasons for the delayed fracture occurance: Hydrogen enters into the steel by acid pickling in the Hot-dip Galvanizing process and stays in. Or the cracks occur in the Galvanized layer under fastening, and then, hydrogen enters into the steel from the environmental atmosphere.To ascertain the above consideration, we performed the static bending test and delayed fracture test etc. on the Cr-steel specimens subjected to the same heat treatment as that for the bolt. As the result, we obtained the following conclusions.(1) Delayed fracture occured even in a short dipping time.(2) The thick Galvanized layer makes transmission of hydrogen atoms difficult, so that it is not possible to remove hydrogen from the steel by the usual baking treatment.(3) Delayed fracture almost never occurs when the acid-dip process is not incorporated.(4) Delayed fracture often occurs because cracks nucleate in the Galvanized layer by adding impact energy on a bolt.

Closure to “Design of Self-Supported Steel Transmission Towers”

Closure to “Design of Self-Supported Steel Transmission Towers”

Discussion of “Design of Self-Supported Steel Transmission Towers”

Discussion of “Design of Self-Supported Steel Transmission Towers”

Design of Self-Supported Steel Transmission Towers

Design practices are reviewed with comments on existing codes; economy of using various materials such as A-7 steel, high strength steel, and aluminum; results of tests; proper design is outlined and savings through careful analysis are indicated.

Impulse Voltage Characteristics of Power Transmission Steel Tower.

Impulse Voltage Characteristics of Power Transmission Steel Tower.

Corrosion and Protection of Galvanized Steel Transmission Tower Footings

Abstract Galvanized steel transmission tower footings in direct contact with most aerated native soils in southeastern Michigan have practically indefinite lives if not connected to electropositive...

Modern steel tower transmission lines

Some important requirements for modern steel tower transmission lines are presented in the following outline prepared by Group II of the A.I.E.E. subcommittee on steel transmission towers and conductors. This material is intended as a general guide to designers and is not a specification. Clearances, mechanical reliability, strength against lightning, and prevention of vibration, are considered.