Sled Anode  

UCORR^® MARINE UTILITY CAST IRON ANODE

Marine structures requiring corrosion control utilize various types of Cathodic Protection (CP) system designs. Typical marine Impressed Current Cathodic Protection (ICCP) systems utilize conventional anode sleds which are comprised of conventional cylindrical anodes (designed for soil applications) fastened to concrete weights utilizing steel hooks. Considering the type and quantity of anodes utilized, each anode sled has one or more wires which are routed to a rectifier.

• The steel hooks utilized to fasten the anodes to concrete weights are typically made of carbon steel. Since the carbon steel hooks are in direct contact with the anodes and electrolyte, they act themselves as anodes and quickly corrode. As the steel hooks corrode, the anodes will become loose and detach from the sled.
• The corrosion products generated from the steel hooks/rods will cause cracks to form in the concrete weights due to the higher volume of material within the concrete/transition locations and damage the sled.
• When anode wires become disconnected, the anode sled current will decrease and the levels of protection will drop. Locating and repairing disconnected anode wires is extremely difficult and costly.
• Since the anode sit on a concrete platform, they are not in direct contact with the underwater mud. This means the protective current travels mainly across the seawater and protects the portion of the structure that is in direct contact with the seawater. Therefore, the portions of the structure that are buried will not receive sufficient current/protection.
• Increasing the number of cylindrical anodes in close proximity will increase the crowding factor, which increases anode sled resistance, reduces current flow, and ultimately lowers the efficiency of the anode sled. In order to overcome increased anode sled resistance, increases in ICCP system voltage are required. This voltage increase could create stray current interference to nearby structures.
• Due to the limited current capacity of conventional anode sleds, multiple anode sleds may be required to achieve adequate protection. This creates various complications when designing CP systems in marine environments.

The Ucorr^® Marine Utility Cast Iron Anode is designed in a manner that the entire volume of the sled is comprised of anode material (high silicon cast iron), which eliminates the need for concrete weights. Only two wire connections are required, which are designed to increase durability/longevity of wire connections.

Advantages...

This innovative anode sled design eliminates the issues associated with conventional sled anodes, including the need for concrete weights, crowding factor concerns, and utilization of numerous wire connections. Additionally, since the entire surface of the Marine Utility Cast Iron Anode is active and the bottom portion of the anode is designed to become partially buried in the mud by its own weight, the anode current output is much greater with improved current distribution to structure components above and below the mudline. The innovative anode sled offers the following advantages over conventional anode sleds:

• Improves current outputs, up to 120 A in seawater.
• Reduces the quantity of anode sleds required to adequately protect target structures.
• Reduces necessary hardware such as wiring, cable trays, connections, etc.
• Eliminates the need for numerous underwater wire connections and associated issues.
• Improves control of current and voltage gradients in CP systems.
• Lowers circuit resistance, resulting in a lower driving voltage, which delivers the following benefits:
  • Decreases risk of stray current interference with nearby structures.
  • Reduces voltage output requirements for transformer rectifiers.
  • Reduces costs associated with operation, maintenance, and repairs.
• Reduces overall CP system costs by 30% to 45%.