Support towers

The main building narrowed to a sharp point that cut into the sky like a dorsal fin throwing up ripples of cloud around four supporting towers. 

Even though aluminum doesn t conduct electricity as well as copper, it costs less to use aluminum than copper for transmission of electricity. Aluminum cables are much lighter than copper cables, so fewer support towers are needed to hold the miles and miles of cable that span the country. Fewer support towers means lower cost for all consumers of electricity. 

Two major considerations are required to design a foundation for a self-supporting tower soil loading and tower stability. The load on the soil below the tower must not exceed the maximum load the soil will support. The foundation must keep the tower in a vertical position so it will not be overturned by the maximum forces acting on it. 

See sections on Stresses in Tower Shell and Foundation Bolts for Self-Supporting Tower. ... 

Support Grid Grating or some other type of support through which vapor or liquid can pass. Used to support tower packing (catalyst, raschig rings, etc.). 

Foundations and structural supports. Tower crane foundations and structural supports (including both the portions of the structure used for support and the means of attachment) must be designed by the manufacturer or a registered professional engineer. 

For large-base, self-supporting towers, the radials should be split among each leg pad, as shown in Fig. 10.237. The radials may be brought up out of the soil (in air) and each attached at spaced locations... 

FIGURE 10.237 Interconnecting a self-supporting tower to the buried ground system. 

Transients generated on the antenna side because of a lightning discharge are no less troublesome. The tower is a conductor, and any conductor is also an inductor. A typical 150-ft self-supporting tower may exhibit as much as 40 /xH inductance. During a fast-rise-time lightning strike, an instantaneous voltage drop of 360 kV between the top of the tower and the base is not unlikely. If the coax shield is bonded to... 

Pattern optimization is another method that can be used to maximize radiation to the intended service area. The characteristics of the transmitting antenna are affected, sometimes greatly, by the presence of the supporting tower, if side-mounted, or by nearby tall obstructions (such as another transmitting tower) if top-mounted. Antenna manufacturers use various methods to reduce pattern distortions. These generally involve changing the orientation of the radiators with respect to the tower and adding parasitic elements. 

Thus the maximum bonding stress due to wind load is 4070 psi in the self-supported tower and only 251 psi in... 

The pressure-tap tubes led to water manometers which were located on the tank supporting tower. They were constructed from 4-in. stainless steel tubing with 3-ft sections of -in. glass tubing inserted where the water levels were... 

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