Construction of the Self-radiating Mast:
The mast body is assembled of dimensional trihedral prismatic sections 5200 mm long, butted with the aid of bolted flanged joints.
Space between the center lines of the belts is 200 mm; the metal section of the mast body is 255.2 m high. The belt sections and spreaders are designed of pipes, the brace struts – of angle sections.
The mast guys and bracing wires are assumed of steel ropes, made of galvanized wires; the mast guys are sectionalized by insulators lengthwise. Joining of guys to the embedded parts of the anchor foundations is carried out by means of tension shackles, which make it possible to perform adjustment of guy tension in the course of erection and maintenance.
Tightening up of guy ropes and measuring of their stresses is made with the help of tightening devices and dynamometers, supplied in one complement.
All metal constructions of the mast body, mechanical details of the guy ropes and embedded parts projecting out of concrete are designed hot – galvanized, while bolts and nuts cadmium – plated.
To comply with the Contract the self – radiating mast has been rated for the maximum wind velocity of 200 km/h. this value has been assumed as a design one, being constant over the whole mast height, with taking into account overloading and dynamic factors.
When testing the constructions under the conditions of rarely occurring, particularly sever winds, the following safety factors have been obtained:
1.4 – for elements of the mast body,
2.4 – for the guys,
3.4 – for the base insulator, which ensure the structure strength.
Under the conditions of normal operation, the safety factors will be much higher than the mentioned above. The design seismic factor in the region of Rawalpindi is assumed on the basis of the map delivered by the Customer.