The computer system provides both the operator interface as well as a monitoring system for the hydraulic power supplies and the control system function. This approach was taken so that a qualified electrician can repair the control system to maintain operation even if the computer-based system fails. The bridge is controlled by a conventional relay-based system with a computer operator interface. The bars are driven and pulled using linear actuators. These lock bars are high strength steel 254 mm wide and 382 mm high (10- x 15-inch). When the two leaves are closed, they are locked together with four “lock bars”.

Each cylinder has a bore of 458 mm (18 inches) and a stroke of 3390 mm (133.5 inches). Three cylinders per leaf are used allowing for redundancy such that, if a cylinder fails, the bridge will remain operational. The alignment requirement for these cylinders is more forgiving than for traditional mechanical gearing. Since the alignment of the leaves and machinery is very critical, a decision was made to use hydraulic cylinders to operate the spans. These piers are supported by thirty 1830 mm (72-inch) diameter drilled shafts. The trunnions are supported on towers within the enclosed bascule piers. The leaves weigh approximately 1600 tonnes each. Each leaf is 44.9 meters (147 feet) long and is supported by 6 trunnion bearings. The leaf design utilizes a three girder system for redundancy. The bascule leaves will be constructed from steel with a concrete roadway surface. For this reason, it was important to simplify the construction as much as possible while maintaining the required functionality. Contractors in Southeast Asia do not have experience with movable bridge construction. The clearance under the bridge when closed is 12 meters (39.4 feet). The movable span provides a 50 meter (164-foot) navigation channel with infinite vertical clearance. Box sections supported by drilled shafts and cast-in-place piers.įor this structure, there is a high degree of consideration for the aesthetic characteristic to provide a modern image, as well as retain local architectural characteristics.

Movable bridge