Ross Laboratories delivered a multi-channel sweep boat to the St. Paul District Corps of Engineers on September 20th. Officially named Launch 21 the 24-foot boat was tested in the Mississippi River at LaCrosse and used to demonstrate a sub-bottom profiler before going into storage for the winter at the district service base at Fountain City Wisconsin. Kevin Ressie will operate and manage the new boat.
The survey system is designed for inland rivers and shallow water surveying.
The boat is a Little Giant series work boat from SeaArk Marine Inc. customized to accommodate the Ross hydrographic survey system. Besides installing cabinets to exactly fit the survey equipment SeaArk added two feet to the length of the cabin.
“The smaller aft deck didn’t matter because they don’t use that area much and the extra space in the cabin with another seat makes a world of difference for the convenience of the boat” said Jim Ross company president.
A 10-foot boom is mounted on each side of the vessel each with two transducers. A hull-mounted transducer makes five transducers which provide an overall 25-foot sweep width. The booms are stored in recessed areas in the hull leaving the deck clear at all times. The booms are deployed by a hydraulic system using controls at the helm station.
Electronics are stowed in two desktop cabinets one containing the depth sounding system and the other a data collection computer and DGPS sub-meter system. Coastal Oceanographics Hypack Max software is installed for data processing.
The St. Paul District is responsible for surveying the Upper Mississippi River from Minneapolis Minnesota to Guttenberg Iowa and in tributaries of the Mississippi including the Minnesota River the St. Croix River and the Black River. There is a total of 38 miles of three and four-foot channels and 284 miles of nine-foot channels. The District does regular surveys of the navigation channels in order to keep the rivers open for commercial and recreational navigation. This new trailerable survey system will help survey crews respond to critical areas quickly with only a two-person crew.
This is the second portable survey boat the District has ordered from Ross who delivered a similar system in early 1999. (See “Survey Launch for St. Paul District Built Around Ross Mini Sweep System” IDR March/April 1999 pp. 20-21.)