The Ranger III, the National Park Service ship that brings visitors to Isle Royale National Park, has been outfitted with a water ballast treatment system that is designed to prevent invasive species from hitching a ride.
The system was installed in May, and after some trial runs, by late June the Ranger III was back at work hauling visitors across Lake Superior between the park and Houghton, Michigan.
The crew of Ranger III minimizes the amount of ballast released through careful ballast management, but ballast water intake and discharges are required at times for safe ship operations and therefore treatment is critical. Currently there are invasive species found at the island that are not found in Houghton and vice versa, so choosing a system to prevent transfers was critical.
There are many ballast treatment systems available on the market. Thanks to Great Lakes Restoration Initiative funding to the Park Service, the park was able to hire an engineering firm to identify and review the potential treatment systems available for small ships with design and operating characteristics similar to Ranger III.
“The analysis that supported our selection and installation of this system can help inform the freshwater fleet of International Maritime Organization approved systems for small ships,” Phyllis Green, the park’s superintendent, said in a release. “We would love to see industry take a leadership role in protecting the Great Lakes by installing treatment systems on ships. If ship owners and treatment system developers and vendors work together they can create more freshwater treatment options.”
Isle Royale selected the Hyde Guardian HG60 system. The Hyde Guardian treatment system utilizes a combination of mechanical filtration and UV sterilization to remove or inactivate organisms in the ballast stream.
Ballast water is treated during both uptake and discharge. During uptake, the ballast water is pumped through a 50 micron disc filter manifold. Organisms and particulates separated by the filter are back-flushed and returned overboard at the uptake source.
Following filtration, the ballast water passes through a UV treatment chamber, where the water is exposed to UV radiation emitted by a series of high intensity lamps. During discharge, the ballast water bypasses the disc filter manifold and passes through the UV treatment chamber only before being discharged overboard.
The NPS installation addressed many of the questions raised by industry about increased costs if the ship has to be dry docked or how installation will impact ship operations. Thanks to excellent installation planning by Fraser Shipyard in Superior, Wisconsin, who worked through regulatory issues and helped adapt the system to Ranger III, the park was able to install the system at Isle Royale’s dock in Houghton between trips to the island.
Great Lakes equipment installation experts from Schwartz Boiler Shop from Cheboygan, Michigan, and Northern Machining and Repair Inc. from Escanaba, Michigan, completed the install.
Ranger III traverses a 76 statute miles route, a distance covered in approximately six and a half hours. The vessel was built in 1958 and is 165 feet long. For stability and handling, the ship carries ballast on each crossing of the lake.