Whangarei’s second harbour bridge between Pohe Island and Port Road provides an alternative option for traffic travelling from Onerahi to the south of the city and eases queues at Victoria Bridge and the Dent Street intersection.
The bridge and associated walkways and cycleways will complete a circuit from the Town Basin, along Riverside Drive, over to Port Road and back to the Town Basin.
While many boats will be able to pass under the bridge without requiring the lifting platform to be raised, skippers of boats over 6.5 metres in height will need to phone or radio a request to see if the bridge needs to be raised.
McKay’s objective was to build an integrated, safe, robust, distributed control system with an intuitive (remote) user interface.
Scope of Work Performed:
- Integrated System: One control system taking care of multiple aspects of the controls such as hydraulic control, traffic management, lighting control, CCTV, PA, Intercom.
- Safety System: Safety functions comply with SIL3 / CAT3/4 safety.
- Robust Nature: Each day 8000 cars on average as well as many pedestrians and vessels have interactions with the bridge. McKay or the council could not afford to suffer the consequences of any potential breakdowns. If something goes wrong with the bascule, costs would be vast.
- Distributed System: To reduce the number of cables, the control system is distributed over the entire bridge. IO racks and other interfaces have been installed on the east abutment, in all four totems, the switchboard room and the control room.
- Intuitive User interface: Operators need to be able to concentrate on the bridge operations as opposed to the control itself. Also new operators need to be up and running as fast as possible.
With a project as complex as Te Matau a Pohe, there were many successes. The major achievements are as below:
- McKay delivered what was promised and in many circumstances went over and above the requirements. The design and build of this project was as complex as it could get. We found immense success in thinking laterally.
- McKay was able to positively contribute to the aesthetics of the bridge by designing the cable chain and totems.
- The project and our involvement were completed on time, an important objective outlayed in the initial plans of the project. Moreover we pride ourselves in the fact that we completed the work inside of the eight-month building period.
- McKay was low maintenance for the main contractor. In other words, we tried to deal with design changes; specifications code, design clashes between civil and electrical engineers and were able make internal decisions. Again this highlights how McKay can always offer electrical end-to-end solutions, a point of difference that our clients highly value.
- The commissioning went very smoothly taking into consideration that a bridge like this had never built before.
- Regarding the quality, the customer and main contractor were particularly impressed with the control desk including the user interfaces, the architectural lighting and the main switchboard.
- During the build we went through a value engineering process. By excluding aspects of a separate security system, the traffic management system and the cable reel, we managed to cut significant cost.