Components of a suspension bridge

The main parts of a suspension bridge are:

1. Main cables: two or more parabolic (or catenary) cables of high-tensile steel wire that carry the whole load in tension and pass over the towers to the anchorages.
2. Towers (pylons): steel or reinforced concrete columns that support the cables through saddles at their tops and transfer the vertical load to the foundations.
3. Saddles: castings at the tower tops (and at the splay points) on which the cable rests; they allow the cable to slide or roll and so keep the tower free from bending.
4. Suspenders (hangers): vertical ropes or rods that transfer the load from the deck or stiffening girder to the main cable.
5. Stiffening girder (or truss): a beam or truss along the deck that distributes concentrated loads, reduces local deflection and prevents the cable from changing shape under moving loads (three-hinged, two-hinged or unhinged).
6. Deck (roadway) and floor system: floor beams and slab that carry the traffic.
7. Anchorages (anchor blocks): massive concrete blocks or rock anchors at the ends of the cables that resist the horizontal pull and any uplift.
8. Side spans and back stays: cable portions from the tower to the anchorage.
9. Wind cables, wind ties and bracing: lateral cables and bracing that resist wind forces.
10. Bearings and expansion joints: at the towers and abutments for movement of the deck.

        tower                         tower
         ||        main cable          ||
 anchor  ||  .--------.______.--------.||  anchor
 block<--||-'   |  |  |  |  |  |   | '-||-->block
         ||     hangers (suspenders)    ||
   ======||=== stiffening girder + deck ===||======
         ||                              ||