Construction methods · Cable-supported and arch bridges

Suspension bridge erection: cables, hangers and deck

The anchorages and towers are built first, a catwalk is hung, the main cables are formed (spun or prefabricated), then the hangers are installed and the deck is lifted in sections from barges below and joined from midspan outward. Every step changes the cable geometry; the sequence is engineered as carefully as the bridge.

How bridges get built · Cable-supported and arch bridges · Suspension bridge erection: cables, hangers and deck

Also called: main cable erection, deck erection by strand jack, suspension bridge construction

section lifted from a bargedeck erected from midspan toward the towersanchorageSuspension bridge deck erection
Concept diagram (TheBridgeEng)

How it is done

  1. Build the anchorages (gravity blocks or rock tunnels) and the towers; string the pilot ropes and hang the catwalks.
  2. Form the main cables by aerial spinning or PPWS; compact and clamp them; install the cable bands and hangers.
  3. Lift deck sections (steel boxes or truss panels) from barges with strand jacks on lifting gantries, starting at midspan and proceeding toward the towers to keep the cable geometry near its final shape; connect temporarily, then bolt or weld once the profile is right.
  4. Wrap and dehumidify the cables, install the surfacing and finishes.

Where it fits

  • Spans over 800-1,000 m, straits and wide rivers, sites where towers can be founded and anchorages built.

Where it does not

  • Sites without anchorage geology or space; spans that a cable-stayed bridge can do (they are cheaper below about 1,000 m).

Plant, pace and money

PlantCatwalk and spinning or PPWS equipment, cable bands, strand jack lifting gantries (2 x 250-500 t), barges, tugs.
ProductivityCable formation 3-6 months; deck lifting 3-6 months for a long span.
CostUSD 10,000-20,000 per m2 of main span for the deck, cables and towers.

Risks and controls

What goes wrong

  • Aerodynamic instability of the partially erected deck (Tacoma is the reminder), cable strand damage, deck section drop, hanger misfit.

Quality assurance

Wind tunnel tests of erection stages, cable survey and sag adjustment, section-by-section geometry, hanger force checks.

Examples

Akashi Kaikyo (1,991 m), Great Belt, Xihoumen, Yi Sun-sin (1,545 m), 1915 Canakkale (2,023 m).

In the bridge game

What Bridge Master applies when you pick it

Deck types: Suspension, Cable-stayed. Spans 700-2000 m, up to 2100 m.

  • +30: The only way to build one.

Try it in the game →

Related methods

Aerial spinning of main cablesPrefabricated parallel wire strands (PPWS)Strand jack liftingSteel and composite pylonsCable wrapping and dehumidification

Further reading

Gimsing and Georgakis · Honshu-Shikoku Bridge Authority technical reports

← Extradosed bridge constructionAerial spinning of main cables →