Construction methods · Steel erection

Temporary towers and bents for steel erection

Modular steel towers placed under splices so girders can be set in shop lengths and joined before the span acts alone. They must carry the partial structure plus wind and must come out once the span is complete.

How bridges get built · Steel erection · Temporary towers and bents for steel erection

Also called: temporary support towers, falsework bents, shoring towers

How it is done

Found the towers on spread footings, mats or driven piles; brace them longitudinally and laterally.
Set girder sections on the towers with adjustable heads; complete splices; release the towers by jacking down after the span is continuous and the deck is placed if the design requires.
Remove and reuse.

Where it fits

Steel spans over 40-50 m erected by crane, spliced girders, arch rib assembly.

Where it does not

Deep water, navigation routes, soft ground without piles, positions in the traffic below.

Plant, pace and money

PlantModular tower systems (e.g., heavy-duty shoring), jacks, foundations.

ProductivityDays per tower.

CostUSD 50,000-300,000 per tower depending on height and foundation.

Risks and controls

What goes wrong

Settlement changing the girder geometry, buckling under wind, vehicle impact.

Quality assurance

Temporary works design and check, foundation verification, jack-down sequence.

Examples

The game's spliced girder and steel crane erection assume towers where spans exceed the crane reach.