Ausgrid’s City Zone Substation was reaching the end of its design life and would shortly be retired. Diona was contracted by Ausgrid to construct new underground 11KV cables along a 1.8km route through the city CBD. This involved laying new conduits which would join numerous cable pits throughout the city. With the need to prevent water ingress in the pits Hauff-Technik mechanical press seals were specified in to meet the requirements of the project. Water ingress in pits has huge implications as it cost time, money, and labour to pump out. These are valuable resources which should be greater spent on other areas of the network. Thanks to the collaboration of Ausgrid and Diona over 800 Cable Seals were successfully installed on the Network. If these pits need to be accessed in the future there will be zero maintenance involved and massive cost savings for Ausgrid.