Don't Gamble on Corrosion: Corrpro Protects St. Louis Riverboat From Corrosion

If you have visited the St. Louis waterfront, you probably have seen the Admiral. Moored just downstream of the historic Eads Bridge, the Admiral began life as a railroad car ferry in 1907 and in 1940 was converted to an excursion boat. At that time, the stainless steel superstructure was added and she became a landmark on the riverfront.

In 1986, the Admiral was transformed into a permanently moored entertainment center containing shops, restaurants and theaters.

In 1993, work began to make her into a floating casino. As part of the 1986 renovation, cathodic protection was installed on her hull. The Mississippi and all of its debris, however, proved too much for even this system and it suffered several failures over the next five years.

As work began on the Admiral's conversion to a casino, it was apparent that a new cathodic protection system was needed. It was then that Corrpro's Chicago office was hired to develop a cathodic protection system design that would withstand everything that the Mississippi could hurl against it. With the current that the river presents at that spot, the problem was how to protect a 360-foot long ship subject to 12 mph currents, with a debris field that includes 3-foot diameter logs.

To minimize the potential for damage to the anodes, Corrpro D51T high silicon, cast iron, "button" type anodes were chosen. This project not only required a unique anode design but also consideration of the impact of the system's effect on the Admiral's sophisticated electronic equipment, such as computers, gaming machines and cash registers. Much of this equipment is highly susceptible to electrical interference. Therefore, the alternating current supply to the rectifiers and the direct current supply to the anodes were designed with filters, special grounding, and other devices to prevent interference with the shipboard electronics.

As a final design consideration, Corrpro engineers had to consider that the ship would rise and fall about twelve inches as she loaded and off loaded her visitors. This meant the cathodic protection current requirement varied as the Admiral moved up and down. To maintain a constant level of protective current on the hull, Harco permanent reference electrodes, PermacellT and Good-All automatic potential controlled rectifiers, were incorporated into the design.

The solution Corrpro designed for the Admiral is yet another example of Corrpro's innovative capabilities, which ultimately increase the return on our clients' investments.