Bømla Contract Period Bømla Bridge is an element of the Triangle Link project, 1996-2001 which is located South of at the West Coast of . The bridge together with a deep sub-sea rock Completion tunnel provides mainland connection southwards for the 2001 island of Bømlo. The is of a design

Construction cost traditional to Norway, i.e. concrete pylons, a narrow NOK 275 mill aerodynamic steel box girder in the main span with two traffic lanes and one pedestrian lane. Approach Services rendered are partly concrete, partly composite viaducts; thus the • Preliminary Design main cables in these areas are backstays, i.e. without • Complete tender design hangers. The main cables are rock- anchored. The • Complete detailed design bridge is set in unspoiled natural surroundings requiring • Construction follow up and special attention to architectural and environ-mental supervision considerations.

Client Norwegian Public Roads Administration

Splay chamber anchorages

Pylon during construction

Bømla Bridge, cont’d

Materials: Design considerations Concrete pylons: C45/C55 Steel box girder: S355 Tender documents were prepared for two Cable wire: 1570 MPa separate cable alternatives, i.e. a locked coil alter-native and an air spun alternative. Geometry: This meant that it was required to develop Main span: 577 m two sets of concepts in areas such as Total length: 998 m hanger clamps, saddles and anchorage Pylon height: 105 m details. Ship Channel: H x B = 00 x 36 m Bridge girder vertical radius: 5206 m Bridge girder width: 13.0 m Bridge girder height: 2.6 m Main span sag/span ratio: 1:10 Side span gradients: 1:1.175/1:1:175 Cable diameter: 302 mm