Traffic Light Pole

Figure 1 shows a traffic light pole.

Traffic light pole.
Traffic light pole structure with stay cables

The structure consists of a tower crane-like frame with one back and two front stay cables. Figure 2 shows a side view of the intersection region.

Intersection region.
 Intersection region between horizontal and vertical profile of a traffic light pole

The stiffness of the vertical profile S1 is bigger than the horizontal one S2. The stay cables are tensioned by turnbuckles, which are connected to the circular hallow profiles by plates. A schematic lateral view of the above shown traffic light pole and a variant without back sector is shown in figure 3.

Traffic light poles.
With back sector Without back sector
Schematic structural drawing of two traffic light poles

The red arrows represent forces, and the blue arrows indicate the vertical displacement direction of the free-ends, assuming that both structures are equal except for the back sector.

  • Can the back sector have a big influence of the free-end vertical displacement?
    What are some possible reasons for the used stay cables?