Traffic Light Pole

Figure 1 shows a traffic light pole.

Traffic light pole.
Traffic light pole with stay cables

The structure consists of a tower crane-like frame with four stay cables, which are marked by the numbers. 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 stay cables are tensioned by turnbuckles, which are connected to the circular hollow profiles by eye bolts. A schematic lateral view of two traffic light poles is shown in figure 3.

Traffic light poles.
Structure 1 Structure 2
Schematic structural drawing of two traffic light poles

Structure 1 represents the above shown light pole with a single front stay cable instead of two; there are a total of three stay cables and three turnbuckles. Structure 2 has a single uninterrupted stay cable with one turnbuckle; the cable passes over two saddles. The red arrows represent forces, assuming that the structures are equal except for the previously mentioned.

  • What are the main structural differences between the two traffic light poles?
  • Figure 4 shows the back sector and an enlarged view of it.

    Back sector.
    Global view Enlarged view 1
    Back sector of a traffic light pole

    Stay cable 4 is connected to an eye anchor rod by a turnbuckle; an offset between the eye anchor rod axis and the stay cable axis is noticeable.

  • How does the offset affect the structural behavior of the traffic light pole?