How remote monitoring is protecting NSW harbours

Cathodic protection (CP) is an electrochemical technique used to control the corrosion of metal. CP systems are commonly used to protect structures such as pipelines, storage tanks, steel piles, offshore oil platforms and reinforcing steel in concrete.

NSW Ports has existing cathodic protection systems at five of its berths in Port Kembla, but these impressed current CP systems vary in age, with some installed as far back as the 1980s. In order to enhance surveillance and provide more accurate energy monitoring, NSW Ports enlisted cathodic protection and remote monitoring company Omniflex to install remote monitoring at each CP system.

The available space to mount remote monitoring equipment inside each CP system enclosure was different, so Omniflex designed custom configurations for each monitoring system. Further complicating the monitoring requirements was the fact that CP systems on both concrete and steel structures needed to be monitored, with different numbers of transformer/rectifiers (T/R), anodes and reference electrodes.

The measurement data is sent via the 4G mobile phone network to the NSW Ports Data2Desktop web portal, which integrates the CP systems at Port Kembla into NSW Ports’ existing remote berth-monitoring. This portal provides a convenient single point for the monitoring of cathodic protection performance and energy consumption across all of NSW Ports’ CP assets.

Ominflex’s PowerView iRef8 monitoring unit.

“Monitoring of CP systems involves measuring T/R output voltages as high as 60 volts, individual anode currents using existing current shunts which are only millivolts and reference electrodes which require very high input impedances,” explained David Celine, Managing Director of Omniflex. “Our PowerView iRef8 monitoring unit, with its individual channel isolation, high input impedance and multiple measurement ranges, is purpose-designed for these CP monitoring applications.

“Traditionally, checking cathodic protection functionality is done by inspection once every six or 12 months,” Celine added. “Corrosion is silent and any failures such as disconnected anodes or failed power supplies could go unnoticed for up to a year, leaving structural steel unprotected against corrosion.”

Tracking the electricity usage of CP systems has other benefits, such as allowing energy consumption to be quantified for cost allocation purposes, especially if third parties are operating the berths. Further, with businesses increasingly needing to measure their carbon footprint accurately in order to meet sustainability goals, monitoring energy usage of CP systems is key.

Top image caption: Port Kembla. Image courtesy of Omniflex.